EVALUATION OF PLATINUM-BASED TREATMENT REGIMENS IN DEFINITIVE CHEMO-RADIOTHERAPY FOR HEAD AND NECK SQUAMOUS CELL CARCINOMA

Introduction: Cisplatin-based chemoradiotherapy is the standard of care for the definitive treatment of locally advanced head and neck squamous cell carcinoma (HNSCC) when anatomic preservation is desired. Nonetheless, the equivalence of distinct administration schedules (weekly or every 21 days) and the use of carboplatin as a therapeutic option lacks evidence in this setting. Objectives: Evaluate response rate, toxicity, and survival of different platinum-based definitive treatment regimens in HNSCC. Methods: In this retrospective study, patients with HNSCC who received definitive treatment from 2015 to 2019, either with concomitant weekly or every 3 weeks with cisplatin (CDDP) or concomitant weekly or every 3 weeks with carboplatin, were included. Response rate, toxicity, event-free survival (EFS) and overall survival (OS) were obtained. Differences between groups were assessed by Fisher’s exact probability or chi-square tests, multiple logistic regression, Kaplan-Meier/log rank, and univariate and multivariate Cox analyses. Results: In a median follow up of 22.5 months, 261 patients were included, with a median age of 59.6 years, 85.1% ECOG 0 or 1 and 77.8% in stage IV (IVa or IVb). Most patients were active or former smokers and alcohol consumers. The tumor was in the oral cavity (28.4%), oropharynx (33.7%), and larynx (37.9%). Treatment groups were radiotherapy and concomitant CDDP (n= 215) and radiotherapy and concomitant carboplatin (n= 46). Response rates (79.0% for CDDP and 84.8% for carboplatin, p = 0.472) and grade 3 or 4 toxicity (54.9% for CDDP and 45.7% for carboplatin, p = 0.25) were similar. It was observed that in the CDDP group, the 2-year EFS was 43.7%, and 39.6% in the carboplatin group (p = 0.557), and in the CDDP group, the 2-year OS was 61.5%, and 54.8% in the carboplatin group (p = 0.344). When comparing drug administration schedules, the median EFS of weekly CDDP was 11 months, while every 3 weeks CDDP was 18 months (p = 0.188). About the influence of smoking, 67.4% who never smoked were alive at 2 years, while 47.4% of active smokers remained alive in this period (p < 0.001). Conclusions: 1) The results of the study indicate that the response, toxicity, and survival rates of patients with HNSCC undergoing definitive treatment at our institution are similar but must be confirmed in prospective and randomized study and, 2) Stop smoking is critical to enabling longer survival for HNSCC patients, who received definitive treatment.