Clinical trial NCT00376987: Zinc Supplements in Lowering Cadmium Levels in Smokers
Official title: Do Dietary Supplements of Zinc Reduce Serum Cadmium Levels in Smokers?
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Bladder Cancer
Cervical Cancer
Esophageal Cancer
Gastric Cancer
Head and Neck Cancer
Kidney Cancer
Leukemia
Liver Cancer
Lung Cancer
Pancreatic Cancer
Tobacco Use Disorder
Keywords: renal cell carcinoma
bladder cancer
cervical cancer
esophageal cancer
gastric cancer
adult acute myeloid leukemia
pancreatic cancer
hypopharyngeal cancer
lip and oral cavity cancer
laryngeal cancer
nasopharyngeal cancer
oropharyngeal cancer
paranasal sinus and nasal cavity cancer
non-small cell lung cancer
small cell lung cancer
adult primary liver cancer
tongue cancer
tobacco use disorder
Lead sponsor: Wake Forest University Health Sciences
Sponsor class: OTHER
Collaborators: name: National Cancer Institute (NCI)
First posted: 2006-09-15
Enrollment: 61
Sex: ALL
Minimum age (years): 21
Maximum age (years): 120
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: SINGLE_GROUP
Primary purpose: PREVENTION

Brief summary: RATIONALE: Zinc supplements may lower cadmium levels in smokers and may help prevent DNA damage.

PURPOSE: This clinical trial is studying how well zinc supplements work in lowering cadmium levels in smokers.

Detailed description: OBJECTIVES:

* Determine whether zinc supplements reduce cadmium levels in smokers.
* Measure serum levels of cotinine (a biomarker of smoking), zinc (a marker of compliance), and cadmium (the dependent variable) at 3 pre-supplementation visits and at 6 supplementation visits.
* Determine whether serum cadmium levels (adjusted for serum levels of cotinine) decrease during supplementation with VisiVite Smoker's Formula.
* Determine if increased cadmium levels in the blood of cigarette smokers can be correlated with decreased mismatch repair.
* Determine if administration of zinc-containing supplements reverses cadmium-induced inhibition of mismatch repair.

OUTLINE: This is an open-label, nonrandomized study.

Patients receive oral zinc supplements once daily for 12 weeks in the absence of unacceptable toxicity.

Blood, serum, and urine are collected once weekly for 3 weeks before beginning treatment and in weeks 5, 6, 9, 12, 15, and 17 for biomarker/laboratory analysis. Samples are examined for cadmium, zinc, and cotinine levels by atomic absorption spectrophotometry, expression of mismatch repair proteins (MSH2, MSH6, MSH3, MLH1, and PMS2), levels of messenger RNA by reverse transcriptase-polymerase chain reaction, and microsatellite instability by gel electrophoresis.

After completion of study therapy, patients are followed for 5 weeks.

Eligibility criteria: DISEASE CHARACTERISTICS:

* Currently smoking ≥ 1 pack (20 cigarettes) per day
* Baseline cadmium level ≥ 0.5 μg/L

PATIENT CHARACTERISTICS:

* Negative pregnancy test
* Fertile patients must use effective contraception
* No known gastrointestinal upset due to zinc vitamins or lozenges

PRIOR CONCURRENT THERAPY:

* At least 2 weeks since prior and no other concurrent vitamins and zinc supplements

Primary outcomes:
measure: Reduction of cadmium levels
timeFrame: 17 weeks
measure: Serum levels of cotinine, zinc, and cadmium at 3 pre-supplementation visits and at 6 supplementation visits
timeFrame: 17 weeks
measure: Correlation of increased cadmium levels with decreased mismatch repair
timeFrame: 17 weeks
measure: Reversal of cadmium-induced inhibition of mismatch repair
timeFrame: 17 weeks
Secondary outcomes:
Other outcomes:
Locations:
city: Winston-Salem
country: United States
facility: Wake Forest University Comprehensive Cancer Center
state: North Carolina
Study officials:
affiliation: Wake Forest University Health Sciences
name: Gary G. Schwartz, MD, PhD, MPH
role: PRINCIPAL_INVESTIGATOR
References: