Impact of the Use of Zinc in the Prevention of Oral Mucositis in Pediatric Patients With Lymphoblastic Acute Leukemia.
Phase: NA
Conditions: Oral Mucositis
Sponsor: National Institute of Pediatrics, Mexico

Date October 30th 2019 
 
 
 
 
NATIONAL AUTONOMOUS UNIVERSITY OF MEXICO 
 
MASTER AND DOCTORAL PROGRAM IN MEDICAL, DENTISTRY AND HEALTH 
SCIENCES 
 
MASTER'S IN CLINICAL DENTISTRY SCIENCES 
 
RESEARCH PROTOCOL: 
IMPACT OF THE USE OF ZINC IN THE PREVENTION OF ORAL MUCOSITIS IN 
PATIENTS WITH LYMPHOBLASTIC ACUTE LEUKEMIA 
 
 
 
PRINCIPAL INVESTIGATOR: DRA. MARTA ZAPATA TARRÉS 
 
Pediatric Oncologist Attached to the Oncology Service of the National Institute of 
Pediatrics 
 
 
 
 STUDENT: CRISTINO SICAIROS BIANCA ANAHÍ 
 
 
 
 

Date October 30th 2019 
 
INDEX 
Summary …………………………………………………………………1 
Background……………………………………………………………….2 
      Acute lymphoblastic leukemia………………………………………2 
      Oral complications of chemotherapy……………………………….3 
      Oral Mucositis………………………………………………………...3 
      Zinc…………………………………………………………………….4 
      Zinc and oral mucositis ……………………………………………..7 
Problem Statement ………………………………………………………9 
Justification ……………………………………………………………….9 
Objetive …………………………………………………………………..10 
Specific objectives ………………………………………………………10 
Hypothesis ……………………………………………………………....10 
Material and methods…………………………………………………..10 
      Study population…………………………………………………….10 
     Selection criteria…………………………………………………..…11 
     Variables……………………………………………………………...11 
Study design ……………………………………………………………..13 
    Statistical Analysis Plan …………………………………….……….14 
Methodology ………………………………………………………….….14 
Ethical Considerations…………………………………………………..21 
Biosafety Considerations……………………………………………….22 
Limitations …………………………………………………………….…22 
Budget ………………………………………………………………..….22 
References ………………………………………………………..….…23 
Consent and Informed Anset……………………………………….....26 
 

1 
Date October 30th 2019 
Introduction: Oral mucositis (OM) is a secondary complication of chemo/ radiotherapy, 
which causes pain, dysphagia and predisposition to infections, being a frequent reason for 
hospitalization that can affect the prognosis of cancer patients. Various interventions for 
the prevention of OM have been studied, including the use of zinc, which is a micronutrient 
that participates in various cellular functions and in wound repair, while showing a 
reduction in the incidence and severity of OM, so the purpose of the present study is to 
evaluate the impact of the use of zinc in the prevention of oral mucositis in pediatric 
patients with acute lymphoblastic leukemia in chemotherapy, comparing it with the use of 
placebo. 
Objective: To evaluate the impact of the use of zinc in the prevention, incidence and 
severity of oral mucositis in patients with acute lymphoblastic leukemia in chemotherapy 
(induction and consolidation phase) of the National Institute of Pediatrics during the period 
from 2019 to 2020. 
Methods: Double-blind randomized clinical trial conducted in pediatric patients with newly 
diagnosed or relapsed acute lymphoblastic leukemia. The subjects will be randomized to 
designate them in the control group (Group1 placebo) or intervention group (Group 2 zinc). 
The zinc/placebo intervention will be administered orally in tablets of 50-100 mg/day, from 
day 1 of chemotherapy until the end of the consolidation phase (2 to 2.5 months). For the 
detection of OM will be used the mucositis scale of the World Health Organization and the 
observation times will correspond to day 1, 4, 7, 14 and 21 of each chemotherapy cycle. 
Patients in both groups with OM will receive the same treatment (mouthwash with 
Gelclair®) and will be observed daily until healing to determine the days of recovery. 
Statistical analysis: Independent t-test and Chi-square test for the difference between the 
two study groups, ANOVA to compare the groups with respect to the severity of OM. 
 
 
 
 
 
 
 
 
 
 
 

2 
Date October 30th 2019 
BACKGROUND 
The leukemias are a heterogeneous group of neoproliferative processes that are 
characterized by a clonal expansion of transforming hematopoietic precursors cells, this 
infiltrate a bone marrow and invade a peripheral blood and other organs.1 The leukemias 
has been classified principally by their duration in: acute or chronic and by their cell type 
are affected in: myeloid, lymphoid and monocytic.2 The acute lukemias (AL) are the more 
frequent type of neoplasia in the childhood and are approximated 33% of malignance 
pediatric illness.1  
Acute lymphoblastic leukemia (ALL) represents 75% of all cases, being more frequent 
between 2 and 5 years of age.1 The worldwide incidence of all types of ranges from 2.0 to 
3.5 cases per 100,000 inhabitants per year, while in Mexico 6/100 000 inhabitants are 
estimated per year;3 so that Mexico is considered to be one of the countries with a high 
incidence and mortality rate in LA.4 The ratio of Lymphoid/myeloid leukemia is 6:1.5 In a 
study on the frequency of acute childhood leukemia in Mexico City, it was found that the 
National Institute of Pediatrics presented 27.6% of all cases, followed by the Pediatrics 
Hospital of Mexico “Federico Gomez” with 20.2%.6 
The treatment is based on polychemotherapy, which is the combination of antineoplastic 
drugs that seek to control cell growth and replication as well as destroy neoplastic cells in 
different phases of the cell cycle. In general, chemotherapy in patients with LLA consists of 
three phases: Induction, consolidation and maintenance, during which the prophylaxis of 
the central nervous system is incorporated, with intrathecal chemotherapy or high doses of 
chemotherapy.7 
Induction aims to eradicate more than 99% of leukemic cells, restore normal 
hematopoiesis and the patient's physical condition. This phase of treatment includes the 
administration of glucocorticoids, with dexamethasone being the most used because it has 
better penetration to the central nervous system, associated with vincristine, L-
asparaginase and an anthracyclic. With induction, usually more than 90% of patients 
achieve complete remission. The consolidation phase improves the remission achieved by 
induction; Commonly the regimens include high doses of methotrexate associated with 6-
mercaptopurine. The maintenance phase aims to maintain the remission already achieved. 
Most regimens include the combination of weekly methotrexate with daily 6-
mercaptopurine. The total duration of treatment should be from 2 years to 2 years and six 
months.8 
Chemotherapeutic protocols are the result of the collaboration of different study groups, in 
2015 Pui et al.,9 conducted a review of the literature to analyze the impact of collaborative 
studies on advances in biology and treatment of LAL in children and adolescents, finding a 
5-year overall survival rate of 82 to 93.5%. However, the substantial proportion of survivors 
face long-term complications; Therefore, the development of new protocols is currently 
aimed at optimizing the use of existing antileukemic agents, by evaluating the 
pharmacogenetics of normal host cells to avoid insufficient or excessive treatment.10 
 

3 
Date October 30th 2019 
Oral complications secondary to chemotherapy 
The lack of selectivity of antineoplastic drugs produces toxic effects in normal cells, 
especially in those with high replication rate, such as the cells of the basal layer of the 
epithelia, in which their renewal capacity is altered resulting in to various complications. 
That is why in patients with hematologic malignancies such as LLA, oral lesions may occur 
secondary to direct damage of the lining epithelium by chemotherapy.6 
The most frequent oral complications that have been reported in pediatric patients under 
chemotherapy are oropharyngeal mucositis (OM), xerostomia, caries and gingivitis, 
followed by opportunistic infections, which occur in up to 30% of cases; being more 
frequent those of fungal origin, although they can also be of bacterial or viral origin 
(candidiasis, cold sores, aphthous stomatitis and angular cheilitis). In the Mexican 
population, study by Castellanos et al., On oral lesions in children with acute lymphoblastic 
leukemia of the National Institute of Pediatrics, found that during the first 8 weeks of onset 
of chemotherapy, 71% of children developed some oral lesion the most frequent being OM 
(65%); which in severe grades (III or IV) was associated with neutropenia and 
malnutrition.6 
Oral Mucositis 
Oropharyngeal mucositis (OM) is a lesion of the oral and oropharyngeal mucosa that 
appears as a result of inflammatory changes in epithelial and subepithelial cells caused by 
the cytotoxic effects of chemo or radiotherapy.11 
The OM consists of four phases: 1) initial inflammation, 2) vascular and epithelial rupture 
3) ulcerative / bacteriological and 4) healing. (7) It begins 3 to 10 days after the start of 
chemotherapy and may persist for 3 weeks. It reaches its maximum peak around 7 to 14 
days and subsequently resolves slowly unless it is complicated by an infection; while, 
better resolution has been associated with neutrophil recovery.12-14 
OM occurs at any age; however, it has been observed that the prevalence is higher in 
pediatric patients than in adults, which can be explained by the higher rate of cellular 
replication during childhood. It is estimated that 52 to 80% of children undergoing 
chemotherapy will experience some degree of OM, which varies according to the type of 
cancer and antineoplastic treatment. In general, children with hematologic malignancies 
present more frequently with OM than those with solid tumors.14 
Chemotherapeutic agents are not equally stomatotoxic.15 The extent of damage depends 
on the drug used, the duration of treatment, the dose and the route of administration; 
Therefore, bolus infusion, prolonged or repeated administration, compared with low doses 
of chemotherapy are associated with an increased risk of developing OM. Drugs that affect 
DNA synthesis, such as antimetabolites (methotrexate, 5-fluorouracil) and purine 
analogues (cytarabine), have been shown to cause OM from 40-60%. Etoposide, 
cyclophosphamide, doxorubicin, daunorubicin, docetaxel and paclitaxel have also been 
related.13 

4 
Date October 30th 2019 
In the ulcerative phase of OM there are complications such as pain, difficulty eating, 
swallowing and speaking, which may require the use of analgesics and nutritional 
support.12 The most severe grades are related to complications such as: deterioration in 
quality of life, increase in the duration and cost of hospital stay, decrease in the survival 
rate of patients due to delayed treatment or reduction in the dose of chemotherapy, as well 
as a higher incidence of secondary infections and may even lead to sepsis and death.16 
Dental care in pediatric patients with cancer is essential, preventive measures and specific 
intervention actions are required to improve oral conditions that favor good nutrition and 
reduce the risk of infections.16 
Recent research has found that OM is the result of a complex process that begins in the 
submucosal endothelium and fibroblasts, with the influence of local cytokines and not just 
direct epithelial cell damage. Thus, through a better understanding of the common 
intracellular pathway of the endothelium, cell apoptosis and interactions between apoptotic 
and inflammatory pathways, new treatments have been developed, which although some 
have been used in the pediatric population, none have been accepted as the treatment of 
choice.14 
There are various treatments for OM including medications such as amifostine, palifermin, 
benzydamine, HCl and pentoxifylline, low intensity laser therapy and various organic 
products such as zinc; however, the effects of these interventions have not been fully 
confirmed.12 
Zinc 
Zinc is a natural mineral and a vital micronutrient in humans that is required for the 
function of more than 200 metalloenzymes, including alkaline phosphatase and carbonic 
anhydrase. It also plays a critical role in the regulation of DNA and the synthesis of RNA 
(through interaction with DNA binding proteins), in the interactions of the hormone-receptor 
complex and in the second messenger system of cellular signal transduction.17 
Therapeutic indications of zinc 
Many studies have shown the benefits of zinc supplementation on infections in human 
populations, such as the reduction in the incidence and duration of acute and chronic 
diarrhea, the decrease of lower respiratory tract infections in infants and young children, as 
well as the urinary infections.20 
The use of zinc in children has been studied mainly for the treatment of diarrhea, since it 
has been found that the consumption of 10 to 20 mg of zinc per day, during and 
immediately after an episode of acute diarrhea decreases its duration and severity, as well 
as the incidence of diarrhea in the next two or three months.21 
Daily zinc requirements as well as some therapeutic indications are shown in Table 1. 
 
 

5 
Date October 30th 2019 
 
 
 
 
 
 
Table 1. Recommended doses and administration intervals of elemental 
zinc (18, 19) 
 
Dietary zinc requirements by age 
Age   
mg / day 
<4  
4 - 6  
7 – 10 
Teenage men and adults 
Teenage and adult women 
Pregnant women 
Lactating women 
5- 10 mg 
10 mg 
10 mg 
15 mg 
12 mg 
15 mg 
16 - 19 mg 
 
Zinc dose indicated for the treatment of Wilson's disease 
Age   
Dose / interval 
1 – 6 años 
6 – 16 años 
>16 años / peso > 57 kg 
     Pregnant women 
Adults 
25 mg twice daily 
25 mg 3 times a day 
50 mg 3 times a day 
25 mg 3 times a day 
3 times a day (maximum dose of 
50 mg 5 times a day). 
 
Zinc dose indicated for the treatment of acute diarrhea 
Age   
Dose / interval 
< 6 months 
> 6 months 
10 mg daily for 10 - 14 days 
20 mg daily for 10 - 14 days 
 
Zinc dose indicated for the treatment of respiratory tract infection 
Age 
Dose / interval 
< 6 months  
> 6 months 
10 mg daily for 10 - 14 days 
20 mg daily for 10 - 14 days 
 
Zinc dose indicated for the treatment of sickle cell anemia 
   10 - 15 mg  per day 
 
Zinc dose indicated for the treatment of enterohepatic acrodermatitis 
   1 - 2 mg * kg weight / day 

6 
Date October 30th 2019 
Secondary and adverse reactions 
Adverse reactions are rare.18 Nausea, vomiting and diarrhea may occur.22 If gastric 
irritation occurs, zinc can be consumed with food, but foods high in calcium, phytates and 
phosphorus should be avoided. . Other symptoms that have been reported are: 
Hypotension, jaundice, pulmonary edema, edema of the mucous membranes of the mouth 
and stomach, unusual tiredness or weakness and gastric ulceration followed by 
perforation.18 
Drug and other gender interactions 
The concomitant use of large amounts of fiber, phosphorus or phytates with zinc 
supplementation may reduce the absorption thereof by formation of non-absorbable 
complexes; Foods that contain fiber, phosphorus or phytates should be consumed at least 
2 hours after the zinc supplement. Large amounts of iron can inhibit intestinal absorption of 
zinc, so it should be consumed at least 2 hours after ingesting iron supplements. 
Zinc may decrease the absorption of penicillin, tetracycline and quinolone.18 
Allergic reaction 
Signs of an allergic reaction may include rash, hives, erythema, edema or peeling; fever, 
wheezing, dyspnea, dysphagia, stertor, labial, lingual or airway edema.22 
Manifestations and management of accidental overdosing or intake 
In general, zinc is well tolerated and acute poisoning is rare. Excess zinc in the body 
interacts with free thiol groups in macromolecules, thereby blocking the active sites of 
enzymes, coenzymes and membrane receptors.23 
Acute poisoning of zinc sulfate has only been reported by deliberate ingestion,24, 25 while 
chronic poisoning is the result of the excess oral zinc supplement that causes secondary 
copper deficiency.26 
In case studies, the most common effects associated with prolonged consumption of zinc 
(ranging from 150 mg to 1-2 g / day) include sideroblastic anemia, hypochromatic 
microcytic anemia, leukopenia, lymphadenopathy, neutropenia, hypocupraemia and 
hypoferraemia. Patients often recover to normal blood patterns after zinc suspension with 
or without copper supplements. 
Gastrointestinal toxicity: Gastrointestinal irritation seems to be dose related. Symptoms 
include nausea (20%), xerostomia (12%), gastrointestinal disorders (10%), abdominal 
pain, vomiting and diarrhea.22 Zinc sulfate in amounts of 2 g / day or more can cause 
gastrointestinal irritation and vomiting.27Acute gastrointestinal bleeding was reported in a 
patient, who required a blood transfusion of 8 units after taking 440 mg of zinc sulfate daily 
for a week. 28 
 

7 
Date October 30th 2019 
Neurotoxicity: Zinc concentrations in the human brain remain in a range of less than 600-
800 ng / L. The optimal concentration of free zinc in its ionic form in the cells is around 10 
ng / L and when it drops to levels less than 0.06ng / L, apoptosis can be activated; while 
when levels exceed 60ng / L toxicity can be reached.29The symptom that has been 
reported most frequently is headache.18 
Hematoxicity: Excessive ingestion of zinc sulfate chronically can induce anemia and 
leukopenia.19 
Endocrines: Decreased HDL has been reported in men, while alterations in triglycerides 
have not been reported.22 
Immune: In a study with 11 volunteers it was observed that excess zinc (300 mg per day 
for 6 weeks) was associated with immunodeficiency and inflammatory response.23 
Toxicity management 
Gastric lavage should be avoided, the administration of chelators such as milk, sodium 
and calcium at a dose of 50 to 75mg / kg / day is recommended.22 
The researchers' response to adverse reactions, allergic reactions and accidental intake 
are described in the investigator's manual. 
Zinc and oral mucositis 
The effectiveness of zinc for the prevention of OM was initially studied in patients with 
head and neck cancer receiving radiotherapy. Ertekin et al. 27 established the dose of 150 
mg of zinc sulfate daily in adult patients, finding a reduction in the severity of OM. Lin et 
al.30 administered zinc chelate at a dose of 75 to 100 mg/day in adults with oral and 
nasopharyngeal cancer, finding a reduction in the development of OM in patients with oral 
cancer. 
Other studies have used zinc sulfate mouthwashes in adults with head and neck cancer in 
radiotherapy and in patients with acute myeloid leukemia in the hematopoietic progenitor 
cell transplant protocol, finding that there were no differences between the zinc group and 
the control group.31, 32 Other studies used L-carnosine zinc mouthwashes in adults with 
head and neck cancer receiving chemo / radiotherapy and in patients with leukemia in the 
transplant protocol, obtaining a reduction in the severity of the OM. 33, 34 
To date, only 3 studies have been conducted in patients receiving chemotherapy, (11) one 
of them was conducted in patients with head and neck cancer; another in patients with 
myeloid leukemia and the last in patients with myeloid and lymphoid leukemia; being all in 
adults, who received 150 mg of zinc sulfate daily, resulting in a reduction in the severity of 
the OM.12, 37, 38 (See Table 3). 
 
 

8 
Date October 30th 2019 
Table 2. Studies that have evaluated the effectiveness of zinc for the prevention of oropharyngeal 
mucositis in cancer patients receiving radio / chemotherapy. 
Reference 
Treatment   
Intervention   
Type of cancer 
Design   
Results   
Ertekin 
et 
al.(27) 
(2004) 
Radiotherapy 
Zinc Sulfate 50 mg / 3 times 
daily 
150 mg / day 
VS. Placebo 
Head and neck 
cancer 
18 - 71 years old 
Randomized clinical trial 
n = 30 
6 weeks 
Criteria 
of 
the 
Radiation 
Therapy 
Oncology Group. 
OM severity reduction 
p <0.05 
Lin et al.(30) 
(2006) 
Radiotherapy 
Zinc chelate 25 mg 2- 4 
times / day 
75 - 100 mg / day 
VS. Placebo 
Nasopharyngeal 
carcinoma / oral 
cancer 
> 18 years 
Randomized clinical trial 
n = 100 
3 months follow-up 
Criteria 
of 
the 
Radiation 
Therapy 
Oncology Group. 
Reduction of the development of severe 
degrees of OM in patients with oral cancer 
Grade II p = 0.017 
Grade III p = 0.0003 
Sangthawa
n et al.(31) 
(2013) 
Radiotherapy 
Zinc Sulfate Oral Rinse 
50 mg 
VS. Placebo 
Head and neck 
cancer 
Randomized clinical trial 
n = 104 
Not significant 
Watanabe 
et al.(33) 
(2010) 
Chemotherapy    
Radiotherapy   
Zinc solution L-carnosine 
  VS. Rinses with tile 
Head and neck 
cancer 
35 - 86 years 
 
Randomized clinical trial 
n = 31 
No observation period indicated 
Common terminology criteria for adverse 
events version 3.0 
OM severity reduction 
≥grade 2 
p <0.05 
Hayashi et 
al. (35) 
(2016) 
ADQ 
HPCT 
Zinc solution L-carnosine 
75mg / 20 mL 4 times / day 
VS. 18.75 mg tablets 4 
times 
/ 
day 
VS. 
No 
premedication 
75 mg / day 
Leukemia 
TCPH 
22 - 73 years 
Comparative study 
n = 66 
1 month post transplant 
Common terminology criteria for adverse 
events version 3.0 
Reduction of severity of OM ≥ grade 2 
p <0.01 
and decreased pain 
p <0.01 
Mansouri et 
al. (36) 
(2012) 
HDC 
TCPH 
Capsules 
of 
220 
mg 
equivalent to 50 mg of zinc 
sulfate 2 times / day 
100 mg / day 
  VS. Placebo 
Hematological 
cancers 
> 15 years 
Randomized double blind clinical trial 
n = 60 
3 weeks 
WHO oral mucositis scale 
 
 
Not significant  
Mehdipour 
et al. (32) 
(2011) 
HDC 
 
0.2% 
zinc 
sulfate 
VS. 
Chlorhexidine 
Gluconate 
Rinse 0.2% 
Myeloid 
and 
lymphoid 
leukemia 
> 15 years 
Randomized double blind clinical trial 
n = 30 
2 weeks 
Spijkervet mucositis scale 
Not significant 
Arbabi-
Kalatl 
et 
al.(37)  
(2012) 
Chemotherapy  
220 mg capsules equivalent 
to 50 mg of zinc sulfate 3 
times / day 
150 mg / day 
VS. Placebo 
Head and neck 
cancer 
18-79 years 
Randomized double blind clinical trial 
n = 50 
20 weeks 
WHO oral mucositis scale 
OM severity reduction 
  In week 8, 12, 16 and 20 
p <0.05 
Gholizadeh 
et al. (38)  
(2017)  
Chemotherapy 
220 mg capsules equivalent 
to 50 mg of zinc sulfate 3 
times / day 
150 mg / day 
VS. Placebo 
Myeloid 
and 
lymphoid 
leukemia 
18 - 71 years old 
Randomized clinical trial 
n = 140 
4 weeks follow-up (week 2 and 4) 
Reduction of severity of OM grade 3-4 
p = 0.004 
Rambod et 
al. (12) 
(2018) 
Chemotherapy 
220 mg capsules equivalent 
to 50 mg of zinc sulfate 3 
times / day 
150 mg / day 
VS. Placebo 
Myeloid 
and 
lymphoid 
leukemia 
> 18 years 
Randomized triple blind clinical trial 
n = 86 
14 days 
WHO oral mucositis scale 
Oral Mucositis Index 
OM prevention 
p = 0.01 
OM severity reduction 
p = 0.01 
OM; Oral Mucositis, HDC: High doses of chemotherapy, HPCT: hematopoietic progenitor cell transplantation. 

9 
Date October 30th 2019 
There are currently no studies evaluating the effectiveness of zinc for the prevention of OM 
in pediatric patients receiving chemotherapy, so the purpose of this study is to conduct a 
clinical trial that evaluated the impact of the use of zinc for the prevention of OM in children 
with LAL in chemotherapy. 
 
PROBLEM STATEMENT 
The development of OM in patients with acute leukemia varies between 81.3% and 90% .8 
The available literature recognizes the importance of prevention and treatment of OM, 
since it has an impact on the quality of life and even on the prognosis of disease in 
patients under chemotherapy. The better understanding of the pathophysiology of this 
entity has allowed the development of new therapies, among which the use of zinc, which 
has shown beneficial effects in the prevention of OM in adult patients with leukemia, and 
because they are not counted with studies in pediatric patients with ALL; The following 
research question arises: 
What is the impact of the use of zinc for the prevention, incidence and reduction of the 
severity of oropharyngeal mucositis in patients with acute lymphoblastic leukemia in 
chemotherapy during the period from 2019 to 2020? 
 
JUSTIFICATION 
In the National Institute of Pediatrics, about 100 new cases of ALL enter each year, which 
will require a multidisciplinary approach throughout the course of cancer treatment, which 
includes the participation of the stomatologist, who must continually establish preventive 
and therapeutic measures of complications buccal, among which the OM stands out as a 
reason for frequent consultation. 
Cancer patients will experience pain, limitation and psychological involvement due to oral 
OM; this debilitating condition also significantly affects nutritional intake, oral care and 
quality of life, representing up to 21.9% of the reasons for hospitalization.8 OM, if not 
properly treated or associated with prolonged neutropenia, may end in septic shock and 
even the death of the patient. 
The use of zinc has been studied as a low-cost alternative for OM, so the realization of this 
study will determine the effectiveness of the use of zinc for the prevention and reduction of 
complications due to OM in pediatric patients with ALL of the Institute National Pediatrics. 
 
 
 
 

10 
Date October 30th 2019 
OBJECTIVE 
To assess the impact of the use of zinc in the prevention, incidence and severity of 
oropharyngeal mucositis in patients with acute lymphoblastic leukemia in chemotherapy 
(induction and consolidation phase) of the National Institute of Pediatrics and the 
Children's Hospital of Mexico during the period from 2019 to 2020. 
SPECIFIC OBJECTIVES 
1. Determine the incidence of OM in patients with ALL assigned control    group 
(Group 1: oral care + placebo) versus the intervention group (Group 2: oral care + 
zinc). 
2. Identify if there are differences in OM severity between Group 1 and Group 2. 
3. Identify if there are differences in the recovery time of the OM between Group 1 
and Group 2. 
4. Identify if there is an association between the severity of OM and severe 
neutropenia in both groups. 
HYPOTHESIS 
The use of zinc reduces the incidence and severity of OM in pediatric patients with ALL in 
chemotherapy compared to the control group. 
 
MATERIAL AND METHODS 
Type of study: Randomized, double blind clinical trial. 
Duration of the intervention: Induction and consolidation phase of chemotherapy (2 to 2.5 
months). 
Inclusion Period: from August 2019 to May 2020. 
 
Study population 
Target population: patients of both sexes from 3 to 18 years of age with newly diagnosed 
or relapsed ALL during the period from 2019 to 2020. 
Study population: patients of both sexes from 3 to 18 years of age with recently diagnosed 
or relapsed ALL treated by the Pediatric Oncology service of the National Institute of 
Pediatrics and the Children's Hospital of Mexico during the period from 2019 to 2020. 
 
 

11 
Date October 30th 2019 
Selection criteria 
Inclusion criteria: Patients aged 3 to 18 years with a recent diagnosis of ALL or relapse 
who accept by informed consent to participate in the study. 
Exclusion criteria. Patients with another disease or systemic condition in addition to ALL. 
Presence of oral infections such as candidiasis, herpetic gingivostomatitis, reactive oral 
lesions. Children with Down syndrome, patients allergic to zinc or mannitol. 
Elimination criteria: Patients who present with hypersensitivity to zinc or placebo 
(mannitol), those who develop a systemic condition that modifies their treatment or 
prevents oral care, as well as patients requesting to leave the study. 
 
Definition of the variables 
DEPENDENT VARIABLES 
  
ORAL HYGIENE 
Combination of physical and 
chemical measures to control 
the formation of bacterial plaque, 
which is the most important risk 
factor in the development and 
evolution of caries and 
periodontal disease. 
Oral hygiene registered with 
the O'Leary index (bacterial 
plaque on dental surfaces 
identified by a developer. It is 
obtained from the sum of 
stained dental surfaces / total 
surfaces, multiplied by 100. 
Qualitative 
Ordinal 
  
1. 
Good 
0% 
to 
15%: 
2. 
Regulate 16% to 
49%: 
1. 
3. Poor: 3.50% to 
100%: 
OM RECOVERY 
DAYS 
Days in which some degree of 
OM is clinically observed until 
healing. 
Number of days from the 
clinical diagnosis of OM (Grade 
≥ 1) to recovery of the oral 
epithelium. 
Continuous 
 1,2 ,3 4, 5… 
INTERVENTION VARIABLE  
 
CONCEPTUAL DEFINITION 
OPERATIONAL DEFINITION 
TYPE 
MEASUREMENT 
ZINC 
Trace element found in most of the 
body's cells, having catalytic, structural 
and cellular regulation functions. 
Food supplement based on zinc 
sulfate in doses of 50-100 mg / day 
for 
prevention 
and 
treatment 
of 
oropharyngeal mucositis . 
Qualitative 
Nominal 
1. Apply 
2. No apply 

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Date October 30th 2019 
 
 
 
 
 
 
 
INDEPENDENT VARIABLES 
  
ORAL 
MUCOSITIS 
  
Inflammatory reaction that affects 
the entire gastrointestinal tract 
from the mouth to the anus 
caused by chemo and / or 
radiotherapy. 
Inflammatory reaction of the 
oropharyngeal mucosa to 
chemotherapeutic drugs, 
according to the WHO scale.  
Qualitative 
Ordinal 
  
Grade 0. Healthy 
Grade 1. Erythema 
Grade 2. Ulcers 
Grade 3. Extensive ulcers 
Grade 4. Ulcers and 
necrosis. 
PAIN 
Localized and subjective sensory 
perception that is the result of an 
excitation or stimulation of 
specialized sensory nerve 
endings. 
Visual scale of facial expressions 
Qualitative 
Ordinal 
 
0-2 No pain 
3-4 Mild 
5-6 Moderate 
7-8 Intense 
9-10 Maximum 
SOCIODEMOGRAPHICAL VARIABLES 
 
CONCEPTUAL 
DEFINITION 
OPERATIONAL DEFINITION 
TYPE 
MEASUREMENT 
 
AGE 
Life time elapsed from 
birth to the current date. 
Life time in years recorded in 
the clinical record. 
Quantitative 
Discreet 
Years 
0 a 18 
 
SEX 
Physiological and 
sexual characteristics 
with which men and 
women are born. 
Biological characteristics 
recorded in the clinical file as 
female and male. 
Qualitative 
Nominal 
Dichotomous 
           1. Female 
2. Male 

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Date October 30th 2019 
 
STUDY DESIGN 
Double blind clinical trial 
Sampling: Sequential non-probabilistic until the required number of participants is 
completed. 
Randomization: sealed envelopes for group assignment. 
Sample size calculation 
Formula for the difference of proportions (incidence of OM). 
 
Assumptions: 
α = 0.05 
Power = 0.90 
Rambod study findings: The effect of zinc sulfate on prevention, incidence, and 
severity of OM in leukemia patients undergoing chemotherapy. 
 
 
CONFUSORY VARIABLES 
ACUTE LEUKEMIA 
LYMPHOBLASTICS 
(LAL) 
Neoplastic disease that results 
from a clonal proliferation of 
lymphoid precursors 
(lymphoblasts), which infiltrates 
bone marrow, produces a 
variable degree of pancytopenia 
and can compromise different 
organs and / or systems. 
Type of leukemia recorded in 
the clinical file according to 
the immunophenotype. 
Qualitative 
Nominal 
 
1. Pro B leukemia 
2. Common leukemia 
3. Pre-B leukemia 
4. Mature leukemia B 
5. T leukemia (precursors) 
6. T leukemia (mature) 
 
NEUTROPENIA 
Reduction of peripheral blood 
neutrophil count . 
Absolute neutrophil count 
obtained by laboratory test 
(blood count). 
Qualitative 
Ordinal 
0. Absence of neutropenia 
1. Mild: 1,000-1,500 / ml 
2. Moderate: 500-1,000 / ml 
3. Severe: <500 / ml 
OPPORTUNIST 
INFECTIONS 
Infections in 
immunosuppressed patients, 
whether of bacterial, fungal or 
viral origin. 
Record of suggestive lesions by 
C. albicans and determination by 
means of KOH, suggestive 
lesions of herpes and 
determination by PCR, 
suggestive bacterial lesions and 
detection through cultures. 
Qualitative 
Nominal 
  
0. Absent 
1. Fungal 
2. Bacterial 
3. Viral   

14 
Date October 30th 2019 
 
 
 
 
 
 
 
 
Statistical Analysis Plan 
Descriptive statistics will be used to characterize the population using measures of central 
tendency and dispersion for continuous variables and distributions of relative and absolute 
frequencies for categorical variables. Independent t-test and Chi-square test for the 
difference between the two study groups. Analysis of variance (ANOVA) to compare the 
two groups with respect to the OM in the five time periods. 
 
METHODOLOGY 
Randomization 
The randomization will be taught by Dr. José de Jesús Figueroa Carbajal, assigned to the 
Oncology service, who is unaware of the objective of the study. 
The randomization technique will be carried out through sealed envelopes, which will 
indicate the bottle that will correspond to the patient, identified as treatment “A” and “B”. 
Likewise, to ensure that the groups are balanced, blocks of 6 sealed envelopes 
containing 3 patients will be made for each group. 
Blinding 
The patient and the investigator will be blinded; for this, the 50 mg zinc and placebo tablets 
will be similar in size, color, shape, weight and taste; the bottles will be classified into 
codes A and B, which in turn will have the same shape, size and color. All of the above will 
be done through the Pharmaceuticals GREMAR S.A. de C.V., which is a Mexican 
company that has a line of food supplements located in Mexico City. 
An independent investigator (who will be blinded for the purpose of the study) will be 
requested to receive the medications (zinc / placebo) prepared by the Pharmaceuticals 
GREMAR S.A. of C.V., so that it provides to the principal investigator only the bottles 
coded as "A" and "B". At the end of the intervention, the independent investigator will be 
asked to reveal the coding of the medications to determine which group (Group 1 placebo 
or Group 2 zinc) corresponds to treatment A and B respectively. 
𝑍𝛼= 1.96 
𝑍𝛽= −0.84 
𝑛= 86 
𝝅𝟏= 𝟕𝟓% 
𝝅𝟐= 𝟒𝟕% 
𝝅𝟏−𝝅𝟐= 𝟐𝟖% 
 
[𝟏.𝟗𝟔 √𝟐(𝟎.𝟕𝟓)(𝟎.𝟐𝟓)   −(−𝟎.𝟖𝟒) √(𝟎.𝟕𝟓)(𝟎.𝟐𝟓)+𝟐(𝟎.𝟒𝟕)(𝟎.𝟓𝟑) ]
(𝟎.𝟕𝟓−𝟎.𝟒𝟕)2
2
= 46 
 
41/5000 
15% losses = 53 patients per group 

15 
Date October 30th 2019 
Instruments 
WHO OM scale 
The oral mucositis scale proposed by the World Health Organization (WHO) in 1979 will 
be used. This instrument was designed based on objective signs (erythema or ulcer) and 
subjective signs (mucosal sensitivity, ability to swallow). 
The classification includes 5 degrees as follows: grade 0, no changes in the oral cavity are 
detected; grade I, pain and erythema in mucosa, gums, tongue or palate; grade II, 
erythema and ulcers, still with a solid diet tolerance; grade III, oral ulcers, tolerance to 
pasty foods and liquid diets; and grade IV, ulcers, erythema, pain, inability to swallow 
fluids, impossible oral feeding, and narcotic requirement to relieve pain. The total score of 
this scale ranges from 0 to 4. 
Visual scale of facial expressions 
This scale was developed by Bieri in 1990 for use in children from 3 years. It is made up of 
faces with different expressions that represent a person who is happy because they do not 
feel pain, and it changes to a sad expression as the pain increases. Each face is assigned 
a score, to answer it, the patient is asked to select the face that best describes how he 
feels. 
Standardization 
It will be carried out through a series of clinical cases with clinical photographs of different 
degrees of OM, evaluated using the WHO's OM scale and contrasting the answers with an 
expert researcher in OM (Dr. Rosaura Gutiérrez Vargas). 
The master's student and a social service student will be standardized, the evaluation will 
be in pairs and independently. 
The weighted Kappa coefficient (kp) for the degrees of OM will be calculated, until a 
minimum of 0.61 to 0.80 is obtained. 
Stages of the study and data collection 
The recruitment of patients will be carried out in the Oncology service of the National 
Institute of Pediatrics and the Children's Hospital of Mexico. Every day you will wonder if a 
new patient arrived with suspected leukemia or relapse. We will be aware of the result of 
the bone marrow aspirate confirming the diagnosis of ALL or relapse. 
The master's student will present indicating that the reason for their vision is to inform 
them about the importance of oral health with respect to their current medical treatment 
and will give them information about the oral care that they should perform for the 
prevention of oral complications secondary to their disease and / or the drugs they will 
receive during their treatment. Visual material will be displayed by means of a computer / 
tablet device that includes information on oral care indicating brushing technique and 
making mouthwashes with bicarbonate solution. Likewise, it will explain what consists of 

16 
Date October 30th 2019 
oropharyngeal mucositis, how it relates to chemotherapy and the preventive measures 
they can perform. Finally, the complications that may occur during the OM will be 
explained, such as: difficulty in eating, speaking or swallowing, as well as the measures 
that must be taken to allow adequate recovery. 
Parents will be invited to participate in the protocol explaining the objectives of the study, 
as well as its risks and benefits. In case of accepting to participate, informed consent and 
assent (in children over 12 years old) will be presented in accordance with the 
characteristics that are written in it. 
The intervention will be assigned under the balanced block scheme. Children will be 
randomly assigned to each of the two treatment groups using sealed envelopes. 
Oral examination, staining of dentobacterial plaque will be performed (the characteristics 
of the plaque revealing solution are described in the researcher's manual) for the 
determination of the oral hygiene index and explanation of brushing technique on day 0 of 
chemotherapy. 
Patients who require dental caries treatment will be rehabilitated by the stomatology 
service according to their stomatological diagnosis and their general con A closed bottle 
containing 100 tablets (treatment A or B) will be provided according to the random 
assignment. It will be indicated to administer 1 or 2 tablets daily (according to the age of 
the patient) from day 1 of chemotherapy. 
A written reminder will be provided to parents in which they must check each day if the 
tablet was taken. 
Calls will be made every 3 days to verify that oral hygiene and tablet administration are 
being carried out; In addition, the reminder will be reviewed twice a week and the 
remaining tablets will be counted in the bottles. 
During the course of chemotherapy (induction and consolidation phase) reviews will be 
performed on days 1, 4, 7, 14 and 21 of each cycle. 
Maneuver 
Group 1 (oral care + placebo): gentle tooth brushing with a soft bristle brush 3 times a day 
and mouthwash with baking soda after each meal (1/4 tablespoon of baking soda 
dissolved in water to make a mouthwash for 3 minutes ) plus the consumption of 1 or 2 
oral placebo tablets (mannitol) from day 1 of chemotherapy. 
Group 2 (oral care + zinc): gentle tooth brushing with soft-bristle brush 3 times a day and 
mouthwash with baking soda after each meal (1/4 of tablespoon of baking soda dissolved 
in water to make a mouthwash for 3 minutes ) plus the consumption of 1 or 2 oral zinc 
tablets (50-100 mg / day of zinc sulfate), from day 1 of chemotherapy. (See Flowchart 1). 
 
 

17 
Date October 30th 2019 
Zinc dose determination 
The studies described in Table 2, have used zinc doses of 50 to 150 mg divided into 2 to 4 
daily doses in adult patients, which was determined from the study conducted by Ertekin et 
al. Because our study would be the first to evaluate the effectiveness of zinc for the 
prevention of OM in children, there is no reference dose in previous studies. 
Due to the above, an exhaustive review of the literature on zinc requirements, therapeutic 
doses and toxic doses was made (Table 1), which are summarized below: 
 Diarios Daily zinc requirements in children: 5 - 10 mg / day in children under 4 
years, 10 mg / day in children 5 to 10 years and 15 mg / day from 11 years. 
  Dose used to treat diarrhea: 10 to 40 mg / day in children older than 6 months. 
 Treatment for Wilson's disease or zinc deficiency: 50 mg / day in children under 6 
years, 75 mg / day from 6 to 16 years and in adults up to 150 mg / day. 
 Toxic dose: 1 to 2 g / day 
Considering the above information, as well as the reported doses of the use of zinc for the 
treatment of OM, it was decided to establish for this study the doses of zinc by age as 
follows: 
 
Patients under 10 will receive 50 mg / day (1 tablet daily). 
 
Patients aged 11 to 18 will receive 100 mg / day (2 tablets daily). 
The characteristics of the tablets are described in Annex VIII. Zinc / Placebo features. 
 
OM treatment 
In the case that the patients attend with some degree of OM, the intervention will continue 
as follows: 
For the follow-up of the OM, observations will be made from the beginning of the table until 
the remission (2 to 3 weeks). 
The treatment of the OM will be the same, regardless of the group to which they are 
assigned, and will consist of: 
Mouthwashes with Gelcliar® ® administered 30 minutes prior to food intake until box 
remission. In addition, oral care measures and zinc / placebo administration will continue. 
 
Pilot test 
The pilot test will be carried out once the protocol is approved by the ethics and research 
committee of the National Institute of Pediatrics. 

18 
Date October 30th 2019 
Six randomized patients with a recent diagnosis of childhood cancer who start 
chemotherapy will be selected, data from the clinical record will be obtained to determine if 
it meets the inclusion criteria. The patient identified as eligible will be visited at his place of 
hospitalization or in the outpatient office of the Oncology Service. 
The intervention will be assigned under the balanced block scheme. Children will be 
randomly assigned to each of the two treatment groups using sealed envelopes. 
The sequence of procedures and the complete description of the instruments can be found 
in the Annex "Pilot test applicator manual". 
Information collection method 
A data record sheet will be filled out that includes the patient's identification form (name, 
age, sex), type of ALL, chemotherapy phase and blood count; which will be obtained from 
the clinical file. It will also include the table for the determination of the WHO OM scale, the 
oral hygiene index and the opportunistic infection registry. 
Registration and processing method. 
The data will be recorded in an Epidata database and analyzed using the STATA 14 
statistical program. 
 
 
 
 
 
 
 
 
 

19 
Date October 30th 2019 
FLOWCHART 1
 

20 
Date October 30th 2019 
In the previous study by Rambod et al. (12), a difference in the incidence of OM of 28% 
was obtained and from this, for the present study the estimated sample size was 106 
subjects. 
Complying with one of the principles that govern clinical trials, which is to reduce the risk of 
the operated subjects to the minimum possible, in case of observing adverse reactions the 
suspension of the study will be indicated; while if there are no complications, recruitment 
will continue until a sample size of 53 subjects is met and at this point the intermediate 
analysis will be performed as shown in Flowchart 2.  
 
 

21 
Date October 30th 2019 
ETHICAL CONSIDERATIONS 
In accordance with the principles and guidelines established by good clinical practices 
(BPC), in accordance with the principles set forth in the Helsinki Declaration of 1964 and 
with the support provided in the General Health Law, in the Regulations of the General 
Health Law in the area of provision of Health Care Services, which establishes that the 
individual welfare of the subjects must sometimes prevail in a study, over the interests of 
science and the community. 
This study will be carried out with the strict observation of the recognized scientific 
principles and respect, handling the affected data anonymously and confidentially. 
Consent 
To parents or to those who exercise parental rights of patients, we provide the information 
related to the study, both verbally and in writing. The master's student made an initial 
invitation to the parents or guardians of the minor for their child to participate in the study 
and read the "Informed Consent Letter" to state the purpose of the investigation and make 
a description of the same In the case of patients older than 12 years, also read the 
"Informed Assent Letter". The signature of the parents and the minor is requested freely 
and voluntarily with the "Declaration of Consent / Informed Consent" after the purpose of 
the investigation has been understood and doubts have been clarified. 
Confidentiality 
To verify the confidentiality and privacy of the participants, the data will be stored in 
databases to which only the researchers of the study have access. 
Risk 
The study is classified with greater than minimum risk. The administration of zinc in doses 
of 50-100 mg / day is considered safe, since no adverse effects have been described at 
that dose. 
Benefits 
Patients participating in the study will have greater clinical control for the prevention of 
oropharyngeal mucositis, since they will be collected before the start of chemotherapy and 
notifications will be received to receive care from the Stomatology service in the case of 
treatment. 
Although no difference is found in favor of the intervention and the necessary sea, the 
suspension of the study, measures will be taken to ensure that participants of both groups 
receive benefits by receiving educational oral care talks, identification of signs of OM, as 
well as Oral hygiene attachments and medications for the treatment of OM. 
 
 

22 
Date October 30th 2019 
BIOSECURITY CONSIDERATIONS 
In accordance with current regulations, the following is held: 
• NOM-052-SEMARNAT-2005 
It establishes the characteristics of hazardous waste, also mentions that expired and 
leftover drugs are considered hazardous waste and therefore, must finally be disposed of 
responsibly.41 
• General law for the prevention and integral management of waste. 
Article 31. The following hazardous wastes and products used, expired, withdrawn from 
trade or disposed of and which are classified as such in the corresponding official Mexican 
standard shall be subject to a management plan: 
VIII. In accordance with the above, the remaining or expired doses of the drug (zinc 
sulfate) should be handled as hazardous waste and its disposal will be as follows: 
Leftover zinc tablets will be kept in closed plastic containers and considering that the 
amount will not exceed 20 bottles (100 tablets per bottle) may be deposited in the 
SINGREM safe containers (National System for the Management of Packaging and Drug 
Residues AC.), which are responsible for the final disposition of expired medicines and 
their leftovers from homes and are located in pharmacies registered in different parts of 
the city. 
 
LIMITATIONS 
Because the population considered for the present study comes from two national 
reference centers, it is frequent that they find the cases with major complications (greater 
risk in terms of the presentation characteristics of LAL or late diagnosis) so they would not 
necessarily represent to all children of LAL in Mexico. 
 
FINANCING 
Materials: Registration formats, intraoral mirror for review, computer equipment, printer. 
Economic: Laboratory tests (blood count, KOH, PCR, bacterial cultures) will be performed 
at the National Institute of Pediatrics and the Children's Hospital of Mexico. 
The zinc sulfate drug and placebo as well as oral hygiene products and medications for 
the treatment of mucositis will be obtained through the Field Work Funds of the Master's 
and Doctorate Program in Medical, Dental and Health Sciences, will not be sponsored by 
pharmaceutical companies. 
Humans: Master's student, master's tutor and social service assistant of Oncology. 

23 
Date October 30th 2019 
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24. Hantson P, Lievens M, Mahieu P. Accidental ingestion of a zinc and copper sulfate preparation. 
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27. Ertekin MV, Koc M, Karslioglu I, Sezen O. Zinc sulfate in the prevention of radiation-induced 
oropharyngeal mucositis: a prospective, placebo-controlled, randomized study. Int J Radiat Oncol 
Biol Phys. 2004;58(1):167-74. 
28. Molokhia MM, Portnoy B. Bleeding gastric erosion after oral zinc sulphate. Br Med J. 
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29. Hsieh H, Vignesh KS, Deepe GS, Jr., Choubey D, Shertzer HG, Genter MB. Mechanistic 
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30. Lin LC, Que J, Lin LK, Lin FC. Zinc supplementation to improve mucositis and dermatitis in 
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31. Sangthawan D, Phungrassami T, Sinkitjarurnchai W. A randomized double-blind, placebo-
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32. Mehdipour M, Taghavi Zenoz A, Asvadi Kermani I, Hosseinpour A. A comparison between zinc 
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33. Watanabe T, Ishihara M, Matsuura K, Mizuta K, Itoh Y. Polaprezinc prevents oral mucositis 
associated with radiochemotherapy in patients with head and neck cancer. Int J Cancer. 
2010;127(8):1984-90. 
34. Hayashi H, Kobayashi R, Suzuki A, Yamada Y, Ishida M, Shakui T, et al. Preparation and 
clinical evaluation of a novel lozenge containing polaprezinc, a zinc-L-carnosine, for prevention of 
oral mucositis in patients with hematological cancer who received high-dose chemotherapy. Med 
Oncol. 2016;33(8):91. 
35. Hayashi H, Kobayashi R, Suzuki A, Ishihara M, Nakamura N, Kitagawa J, et al. Polaprezinc 
prevents oral mucositis in patients treated with high-dose chemotherapy followed by hematopoietic 
stem cell transplantation. Anticancer Res. 2014;34(12):7271-7. 
36. Mansouri A, Hadjibabaie M, Iravani M, Shamshiri AR, Hayatshahi A, Javadi MR, et al. The 
effect of zinc sulfate in the prevention of high-dose chemotherapy-induced mucositis: a double-
blind, randomized, placebo-controlled study. Hematol Oncol. 2012;30(1):22-6. 
37. Arbabi-kalati F, Deghatipour M, Ansari Moghadam A. Evaluation of the efficacy of zinc sulfate in 
the prevention of chemotherapy-induced mucositis: a double-blind randomized clinical trial. Arch 
Iran Med. 2012;15(7):413-7. 
38. Gholizadeh N, Mehdipour M, Chavoshi SH, Kahani S, Sadrzadeh-Afshar M-S. The effect of 
orally-administered zinc in the prevention of chemotherapy-induced oral mucositis in patients with 
acute myeloid leukemia. International Journal of Cancer Management. 2017;10(8). 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

26 
Date October 30th 2019 
NATIONAL INSTITUTE OF PEDIATRICS 
LETTER OF INFORMED ASSENT FOR PEDIATRIC PATIENTS 
Informed Assent Document For Children Over 12 Years 
Name of Principal Investigator: Marta Zapata Tarrés. 
 
The following writing is an invitation for you to participate in the project: 
Impact of the use of Zinc in the prevention of oropharyngeal mucositis in patients 
with acute lymphoblastic leukemia of the National Institute of Pediatrics. 
Name of the child who takes the Assent._______________________________________________ 
Dr. Marta Zapata Tarrés, Pediatric Oncologist  of Pediatric Oncology Service and Dr. Bianca Anahí 
Cristino Sicairos, Pediatric Stomatologist and Master's student, we invite you to participate in this 
research protocol, we will clarify your doubts, if you do not understand some words or concepts 
about the procedures, risks and benefits of the investigation, you can ask us and you can take the 
time you want to reflect if you want to participate or not. 
It is necessary that you decide if you want to participate, for this we ask you to read this format and 
ask any doctor of the study if you have doubts. 
Project description: Oropharyngeal mucositis is a complication of chemotherapy that occurs in 
many of the patients with leukemia like you, we can see it as a redness or ulceration (lesion) inside 
the mouth either in the inner part of the lips, cheeks, tongue, gum, palate and throat. This causes 
pain, discomfort when chewing and can even prevent eating by mouth. 
Zinc is a nutrient that is obtained from food which has helped cancer patients who receive 
chemotherapy do not have oropharyngeal mucositis, which is less bothersome or heals faster. 
This protocol is a study in which the children who participate are divided into two groups, one that 
will receive zinc tablets and another that will receive placebo tablets (tablet with no real action). 
Each child when accepting to participate in the study will belong to one of the random groups (as 
well as when throwing a coin to obtain eagle or sun, in this case treatment A or B); Neither doctors 
nor parents or children will know what treatment they will be receiving until the end of the study. 
Therefore, you can receive zinc or placebo and this will only be given by luck, no one will decide 
which group you will belong to. 
The main purpose of the investigation is: 
 
Teach you oral care as a patient with acute lymphoblastic leukemia (ALL) that will start 
chemotherapy. 
 
Study whether zinc prevents the appearance of oropharyngeal mucositis in children with 
ALL. 
 
Identify from the beginning (early) the picture of oropharyngeal mucositis and treat it. 
With this study, useful research data will be obtained and problems that affect your overall health 
can be detected, such as the difficulty of eating due to having oropharyngeal mucositis. 

27 
Date October 30th 2019 
You are invited to participate as you meet the criteria such as: Be a patient with a recent diagnosis 
of ALL between 3 to 18 years of age who will start chemotherapy who accept by consent and/or 
informed consent participate in the study. 
Among the criteria that make participation impossible are: Patients who have another disease in 
addition to ALL, children with Down syndrome, allergy to any of the medications (zinc and/or 
lactose). You do not have any of these criteria, so you are a candidate for this protocol. 
Do you have any risk for participating in the study? 
Research has a higher risk than the minimum, this means that although zinc at the dose we will give 
you (50-100 mg / day) is considered safe; You can also have nausea, vomiting, diarrhea, as well as 
an allergic reaction (redness, swelling or dry skin; fever, swelling of the tongue, lips and even 
difficulty breathing). In the event that any of the above symptoms may be caused by the 
consumption of zinc / placebo, it should be discontinued and immediately tell your parents and them 
to some of the researchers indicated in this document with name and contact telephone number. 
We believe that the expected benefit will be much greater for your health because the objective is to 
prevent complications of chemotherapy such as mucositis and knowing the results of the study will 
improve the comprehensive care of other children with ALL. 
What are your benefits? 
Children participating in the study will have greater clinical control (reviews) for the prevention of 
oropharyngeal mucositis since they will be seen before the start of chemotherapy and in case of 
requiring attention from the dentists of the hospital they will receive faster attention. We will report 
directly to the Stomatology service. 
Medications (zinc / placebo, bicarbonate, melox, benadryl) and what is necessary for your oral 
hygiene (brush, paste) will be provided at the beginning of the study. 
Procedures: The research involves the continuous review of your mouth and the administration of 
50 mg zinc / placebo tablets twice a day from day 1 of chemotherapy. 
First visit: the data obtained through the clinical file (name, age, sex, diagnosis and name of the 
parents) will be confirmed. You and your parents (who are present) will be given a talk about the 
importance of oral hygiene and care for the prevention of oropharyngeal mucositis through an 
information leaflet and a digital presentation through a computer. 
They will be provided with a sealed envelope in which the medicine code A or B will be indicated 
(remember that we will not know if they will be zinc or placebo), as well as written instructions on 
how to take the tablets. 
The oral examination will be done by the Stomatologist (Dr. Bianca) she will see your mouth inside, 
from the inside of the cheeks, lips, tongue, palate, gum to the throat. You will also see the teeth and 
record if they have cavities, in case of detecting that any one needs treatment, your revision will be 
requested from the stomatology service Finally, to see how your oral hygiene is, the dental biofilm 
(bacteria that adhere to the teeth) will be painted by placing 2 or 3 drops of pink dye and then you 
will be given a brush and paste to be able to remove it and teach you how to brush your teeth. 
Oral care to prevent oropharyngeal mucositis involves tooth brushing and the use of sodium 
bicarbonate rinses (1/4 of a tablespoon of bicarbonate dissolved in water to rinse for 3 minutes) 
after each meal, from day 1 of chemotherapy. The procedures will not cause you harm or pain. 

28 
Date October 30th 2019 
Later visits: Visits will be made on day 1, 4, 7 and 21 of each chemotherapy cycle, to identify data 
from oropharyngeal mucositis. During the visits you will be asked if you have had any discomfort or 
difficulty eating, the oral examination will be done as indicated above, the dental biofilm dye 
(bacteria attached to the teeth) will be applied and the tooth brushing technique will be reinforced. 
What is your participation? 
Your participation (parents or guardians) and yours is very important and will consist of: 
1. Go to the hospital for chemotherapy with brush, toothpaste, baking soda and tablets (zinc / 
placebo) which will be provided at the beginning of the study. 
2. Perform gentle tooth brushing 3 times a day and bicarbonate rinses after each meal. 
3. Promptly administer 50mg zinc / placebo tablets 2 times a day. 
4. Report any concerns such as pain, any complications from the consumption of tablets (zinc 
/ placebo) or inability to perform oral care. 
In case of oropharyngeal mucositis: a series of care will be indicated, consisting of: 
1. Gentle tooth brushing. 
2. Continue consumption of 50 mg zinc / placebo tablets 2 times a day. 
3. Mouthwashes with Melox® / Benadryl® solution (3.7g aluminum hydroxide, 4g magnesium 
hydroxide / diphenhydramine hydrochloride 250 mg) prepared at the moment, mixing 5 ml 
of Melox plus 5ml of Benadryl, cold, administered 15 minutes prior to food intake for 14 
days. 
In this case you will be supervised for the next 3 weeks until the picture of the oropharyngeal 
mucositis is completely cured. 
Who will pay the expenses of the study? 
You will not have to pay anything, all we require is your valuable participation. 
The expenses of the study are given by the Master's and Doctorate Program in Dental Sciences of 
the National Autonomous University of Mexico. 
How will my data be used? 
The personal data will only be known by the researchers or the health personnel who are in charge 
of you, such as the resident doctor and the nursing staff, the data will be kept confidential (secret) 
and the publication that is generated will not include your name or that of your parents and family. 
Participation in this research is voluntary. You can refuse to participate from the beginning or retire 
at any time you want, while maintaining the rights you currently have as a patient of the Institute. 
Who can you call if you have questions? 
The procedures will be performed by: Dr. Bianca Anahí Cristino Sicairos (Pediatric stomatologist and master's 
student), cell 5551061233 and Dr. Marta Zapata Tarres, Pediatric Oncologist, attached to the Pediatric 
Oncology service, telephone 10840900 ext. 1339, cell: 5554184099, which will answer your questions will 
clarify your doubts about the procedures, in the same way there is the participation of the President of the 
ethics committee of this Institute for any clarification, Dr. Alberto Olaya Vargas Chairman of the Committee of 
Ethics Tel: 10840900 ext. 1581. This proposal has been reviewed and approved by the Research and Ethics 
Committees of the INP. If you wish to find out more about this committee, contact Dr. Silvestre García De la 
Puente. Telephone 10840900 ext 1581. 

29 
Date October 30th 2019 
DECLARATION OF INFORMED ASSENT FOR PEDIATRIC PATIENTS 
By signing below you agree that: 
1. 
You have read this assent format. 
2. 
You have had the opportunity to ask questions and these have been answered. 
3. 
Your participation in the study is voluntary. 
4. 
You will be part of the study with the indicated procedures. 
5. 
You know you can refuse to participate and withdraw whenever you want. 
6. 
If you do not follow your doctor's instructions, you may be withdrawn from the study, without affecting 
the medical care you receive. 
Name of the participating child______________________________________________________ 
Mother's Name: _________________________________________________________________ 
Date: _______________ 
Firm: __________________________ 
 
Father's Name: ____________________________________________ Date: _______________ 
Firm: _____________________________ 
 
I have witnessed the exact reading of the consent document for the potential participant and the individual has 
had the opportunity to ask questions. I confirm that the individual has freely given consent. 
Name of witness 1: ______________________________________________________________  
Signature of witness: _______________________  
Address: _______________________________________________________________________ 
Relationship with the participant: ____________________________________________________ 
Date: _________________ 
 
Name of witness 2:______________________________________________________________  
Witness Signature: ________________________  
Address: _______________________________________________________________________ 
Relationship with the participant: ____________________________________________________ 
 Date: _________________ 
 
Name of the researcher or who collects the informed consent: _____________________________ Signature: 
_________________ 
Date: ________________ 
 
I received a copy of this consent 
Name and signature: __________________________________________________________________ 
Date: ______________ 
 
 
 
 
 
 

30 
Date October 30th 2019 
LETTER OF INFORMED CONSENT FOR PEDIATRIC PATIENTS 
Name of Principal Investigator: Marta Zapata Tarrés. 
We hereby allow you to invite them to participate in the protocol: 
Impact of the use of Zinc in the prevention of oropharyngeal mucositis in patients with acute 
lymphoblastic leukemia of the National Institute of Pediatrics. 
Dr. Marta Zapata Tarrés, a pediatric oncologist, attached to the Pediatric Oncology service and Dr. 
Bianca Anahí Cristino Sicairos (pediatric stomatologist and master's student), invite your child to 
participate in this research protocol, we will clarify your doubts in case you don't understand some 
words about the investigation procedures, being free to take the time you want to reflect if you want 
to participate or not. 
Project description: Oropharyngeal mucositis is a complication of chemotherapy that occurs with 
high frequency in patients with leukemia, its identification is through direct observation as a redness 
or ulceration of the internal mucous membranes of the cheeks, tongue, gum , palate and 
oropharyngeal (all tissues of the mouth to the throat) which causes pain, difficulty feeding until the 
inability to feed by mouth (mouth) when it is very severe. 
Zinc is a nutrient that is obtained from food which has been seen that if it is provided to patients with 
various types of cancer who receive chemotherapy it helps to prevent oropharyngeal mucositis or if 
it is less severe and have a faster recovery. 
This protocol is a double-blind randomized clinical trial, which means that study participants will be 
divided into two groups, one that will receive zinc tablets (Intervention Group) and another (Control 
Group) that will receive placebo (medication tablets inactive which in this case are lactose 
monohydrate). Each participant when accepting to be included in the study will be randomly 
assigned to one of the groups having a 50% chance of being in one or another group (such as 
throwing a coin to get eagle or sun); Both the study researchers and the participants will not know 
until the end of the study to which group each patient belongs. Therefore, your child may be 
included without distinction in the group receiving zinc or in the group receiving placebo. 
The main purpose of the investigation is: 
 
Instruct on oral care in patients with acute lymphoblastic leukemia (ALL) who will start 
chemotherapy. 
 
Prevent the development of oropharyngeal mucositis with the administration of zinc 
supplement. 
 
Early detection of oropharyngeal mucositis and its treatment. 
This will allow us to obtain useful data and thus intercept problems that affect the integral health of 
your child. 
Your child is invited to participate as it meets the inclusion criteria: Be a patient with a recent 
diagnosis of leukemia (ALL) from 3 to 18 years of age who will start chemotherapy and accept by 
consent and / or informed consent participate in the study. 
Among the criteria that preclude their participation are: Patients who attend with another disease 
besides LAL, children with Down syndrome, known allergy to zinc sulfate and / or lactose. And your 
child does not have any of these criteria, so he is a candidate for this protocol. 

31 
Date October 30th 2019 
Is there any risk? 
The investigation is classified with greater than minimum risk. The administration of zinc (50-100 
mg/day) is considered safe; However, your child may have nausea, vomiting, diarrhea, as well as 
an allergic reaction (redness, swelling or dry skin; fever, swelling of the tongue, lips and even 
difficulty breathing). In case you consider that any of the above symptoms may be caused by 
zinc/placebo consumption, stop immediately and inform some of the researchers listed in this 
document with name and contact telephone number. 
We believe that for the health of your child, the expected benefit will be much greater because the 
objective is to prevent complications of chemotherapy such as mucositis and knowing the results of 
the study will improve the comprehensive care of children with ALL. 
Benefits for your child: 
Patients participating in the study will have greater clinical control (reviews) for the prevention of 
oropharyngeal mucositis since they will be seen before the start of chemotherapy and will be given 
priority to receive care from the Stomatology service in the event that they require treatment. 
Medications (zinc / placebo, bicarbonate, melox, benadryl) and what is necessary for oral hygiene 
(brush, paste) will be provided to your child at the start of the study. 
Procedures: 
The research consists of the continuous revision of the oral cavity and the administration of 50 mg 
zinc / placebo tablets 1 or twice a day from day 1 of chemotherapy. 
First visit: the data obtained through the clinical file (name, age, sex, diagnosis and name of the 
parents) will be confirmed. They will be given a talk about the importance of oral hygiene and care 
for the prevention of oropharyngeal mucositis through an information leaflet and a digital 
presentation through a computing device. 
You will be provided with a sealed envelope in which the medication code A or B (zinc / placebo) 
will be indicated, as well as written instructions on how to provide it to your child. 
The oral examination will consist of the observation of the internal part of the cheeks, lips, tongue, 
palate, gum and oropharynx (throat). The teeth will also be observed and recorded if they have 
cavities, in case of detecting that any require treatment, an interconsultation will be sent to the 
stomatology service to request their attention. Finally, to evaluate oral hygiene, staining of the 
dental biofilm (bacteria that adhere to the teeth) will be performed by placing 2 or 3 drops of pink 
dye and then brush and paste will be provided to remove it and show the brushing technique. 
Oral care to prevent oropharyngeal mucositis involves tooth brushing and the use of sodium 
bicarbonate rinses (1/4 of a tablespoon of bicarbonate dissolved in water to rinse for 3 minutes) 
after each meal, from day 1 of chemotherapy. The procedures will not cause damage to the oral 
mucosa, or symptoms of pain after examination. 
Later visits: Visits will be made on day 1, 4, 7 and 21 of each chemotherapy cycle, to identify data 
from oropharyngeal mucositis. During the visits you will be asked if your child has had any 
discomfort or difficulty feeding, the oral revision will be done as indicated above, the dental biofilm 
dye (bacteria attached to the teeth) will be applied and the technique will be reinforced of tooth 
brushing. 

32 
Date October 30th 2019 
What is your participation? 
Your participation (parents or guardians) and the child is important and consists of: 
1. Go to hospital for chemotherapy with brush, toothpaste, baking soda and zinc / placebo 
tablets which will be provided at the beginning of the study to perform oral care for your 
child. 
2. Perform gentle tooth brushing 3 times a day and bicarbonate rinses after each meal. 
3. Promptly administer 50mg zinc / placebo tablets once a day for children under 10 years and 
2 times a day for children from 11 years of age, from the start of chemotherapy to the next 2 
and a half months after Your suspension is indicated. 
4. Report any concerns such as pain, any complications from the consumption of zinc / 
placebo tablets or the inability to perform oral care. 
In case your child has oropharyngeal mucositis: a series of care will be indicated, consisting of: 
1. Gentle tooth brushing. 
2. Continue with the consumption of 50 mg zinc / placebo tablets 1 or 2 times a day. 
3. Mouthwashes with Melox® / Benadryl® solution (3.7g aluminum hydroxide, 4g magnesium 
hydroxide / diphenhydramine hydrochloride 250 mg) prepared at the time, mixing 5 ml of 
Melox plus 5ml of Benadryl, cold, administered 15 minutes prior to food intake for 14 days. 
Your child will be supervised for the next 3 weeks until the complete remission of the oropharyngeal 
mucositis picture. 
Who will pay the expenses of the study? 
You will not have to pay anything, all we require is your valuable participation. 
The expenses of the study are foreseen by the Master's and Doctorate Program in Dental Sciences 
of the National Autonomous University of Mexico. 
Informed consent 
This document is provided to the parents or guardians of minor patients who do not have legal 
capacity; however, patients from 7 years of age may refuse to participate in the study and in 
children 12 years of age they will also be provided with an “Informed Assent Letter” in which the 
objective is explained in a simple way of the study and their permission to participate is requested 
and in which case they do not accept they will be discharged from the protocol (to respect their 
decision) even if you as parents have agreed to participate. 
Confidentiality 
The personal data will only be known by the researchers or the health personnel who are in charge 
of the patient, such as the resident doctor and the nursing staff in charge to provide the best care of 
your child, the data will be kept confidential and The publication generated will not include the name 
of the participant or their parents and family members. 
Participation in this research is voluntary. You can refuse to participate from the beginning or 
withdraw at any time, while maintaining the rights your child currently has as a patient of the 
Institute. 
 

33 
Date October 30th 2019 
Who can you call if you have questions? 
The procedures will be performed by: Dr. Bianca Anahí Cristino Sicairos (Pediatric stomatologist 
and master's student), cell 5551061233 and Dr. Marta Zapata Tarres, Pediatric Oncologist, 
attached to the Pediatric Oncology service, telephone 10840900 ext. 1339, cell: 5554184099, which 
will answer your questions will clarify your doubts about the procedures, likewise there is the 
participation of the President of the ethics committee of this Institute for any clarification, Dr. Alberto 
Olaya Vargas Chairman of the Committee of Ethics Tel: 10840900 ext. 1581 
This proposal has been reviewed and approved by the Research and Ethics Committees of the 
INP. If you wish to find out more about this committee, contact Dr. Silvestre García De la Puente. 
Telephone 10840900 ext 1581. 
DECLARATION OF INFORMED CONSENT FOR PEDIATRIC PATIENTS 
I have read the information provided or it has been read to me. I have had the opportunity to ask 
about it and the questions I have asked have been satisfactorily answered. I voluntarily agree to 
participate in this research, I understand that I have the right to withdraw from the research at any 
time without affecting my medical care in any way. 
Rights 
1. You may freely not agree to participate in the protocol. 
2. You have the right to receive an answer to any question, clarification or doubt regarding the 
zinc review and administration procedure. 
3. The review, as well as the necessary elements for oral care are completely free. 
4. In the event that you voluntarily accept, you can withdraw your consent when you wish or 
cannot continue with the follow-up. 
5. If you decide to withdraw your consent, at any time, it will be understood that you no longer 
wish to participate in this study and the attention on the services provided in the INP will NOT 
be affected. 
In order to accept to participate in the project, you must answer the following questions. 
 
Yes 
No  
I have read this consent form. 
 
 
Have you understood the informative letter? 
 
 
Have you had the opportunity to ask and discuss what your participation and your child's 
participation is? 
 
 
Do you agree to comply with the instructions and report any lack thereof in a way you will 
see? 
 
 
Do you agree that the information obtained be used for research purposes and be 
disclosed confidentially? 
 
 
I accept that my child participate in the study. 
 
 
I can choose to have my child participate in the study or to abandon it at any time, 
communicating it to the researchers.  
 
 
If you answer NO to any of the questions, this implies that you reject the invitation to participate in 
the protocol. 

34 
Date October 30th 2019 
Consent 
Yes 
No 
 
If you decide to participate, sign the letter. You consciously agree to participate in the company of 
your child in the protocol. 
Child's Name: ________________________________________________________________ 
Mother's Name: __________________________________________ Date: _______________ 
Signing of consent: _____________________________ 
 
Father's Name: ____________________________________________ Date: _______________ 
Signing of consent: ____________________________________________________________ 
Address:_______________________________________________________________________ 
Phone: _____________________________________ 
 
I have witnessed the exact reading of the consent document for the potential participant and the 
individual has had the opportunity to ask questions. I confirm that the individual has freely given 
consent. 
Name of witness 1: _______________________________________________________________  
Signature of witness: _______________________  
Address: _______________________________________________________________________ 
Relationship with the participant: __________________________________________  
Date: _________________ 
 
Witness Name 2: _________________________________________________________________  
Witness Signature: ________________________  
Address: _______________________________________________________________________ 
Relationship with the participant: ____________________________________________________  
Date: _________________ 
 
Name of the researcher or who collects the informed consent: _____________________________ 
Signature: _________________ 
Date:________________ 
 
I received a copy of this consent 
Name and signature: ______________________________________________________________ 
Date: ______________