Impact of prophylactic laser therapy on mucositis in patients with head and neck cancer (HNC) undergoing radiotherapy in Brazil.
Authors: Ferrari Renata , Felizardo Ana Carolina , Siqueira Lourenço , Abreu Luana , Araujo Daniele , Araujo Leticia , Fernandes Tauana , Lopes Clara , Peixoto Rafaela , Melo Bianca , Costa Ana Maria , Silva Ruan , Andrade Claudia , Laloni Mariana , Ferrari Bruno Lemos , Ferreira Carlos G. M. , De Marchi Pedro , William Nassib Jr.  , Bergerot Cristiane Decat 
Published: June 2024

12120 Background: Approximately70-90% of patients with HNC undergoing (chemo) radiotherapy experience any grade mucositis. Older age and nutritional status are recognized risk factors. We conducted this single-arm, observational study to test the primary hypothesis that prophylactic laser therapy would reduce the incidence of mucositis among patients with HNC treated in eight cancer centers among the Oncoclinicas Network in Southeast Brazil. Methods: Patients with HNC scheduled for radiotherapy +/- chemotherapy underwent oral health assessments and nutritional risk evaluations using the Patient-Generated Subjective Global Assessment (PG-SGA) before initiating treatment. Prophylactic laser therapy was administered daily throughout all sessions of radiotherapy. Daily follow-up assessments were conducted by a stomatologist to monitor mucositis progression, using the mucositis question from the Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. The study’s primary endpoint was any grade mucositis. With 118 patients, the study would have 80% power with 2-sided alpha of 0.05 to detect a reduction in the cumulative incidence of grade 3+ mucositis from 70% (literature historical control) to 45% with a two-sided alpha of 5% (Chi-square test). Secondary endpoints included incidence of mucositis according to age, sex, stage, primary tumor site, HPV status, concurrent chemotherapy use, treatment setting (adjuvant vs. definitive), and nutritional risk. Results: Of the 118 patients who participated in the study, the median age was 62 years (range, 23-87), 67% were male, with a primary tumor site in the oral cavity (33%), oropharynx (30%, 53% of which were HPV-related), or elsewhere (37%), at stage I/II (30%), III (27%) or IVA/B (43%). Nutritional risk was present in 54% of the patients. Treatment was delivered in the adjuvant (52%) or definitive (48%) settings, with (55%) or without (45%) concurrent chemotherapy. Radiation doses were 60-70 Gy, or ≥ 70 Gy in 91% and 9% of the cases, respectively. Overall, 90% of patients adhered to all prescribed laser therapy sessions. The cumulative incidence of any grade mucositis was 65% (95% confidence interval [CI] 14.6-34.8%), significantly lower than historical controls (P=0.001). The incidence of grade 3/4 mucositis was 28% (95% CI 29.8-52.3%). Analysis of secondary endpoints will be presented at the meeting. The average time from mucositis onset to resolution was 23 days (SD=15.4). Conclusions: The study met its primary endpoint, demonstrating a statistically significant reduction in the cumulative incidence of any grade mucositis with prophylactic laser therapy, as compared to historical controls. The data support further evaluation of this strategy in randomized clinical trials.