Survival Outcomes for Patients With T3N0M0 Glottic Cancer of the Larynx Treated With Radiation Alone vs. Chemoradiation.

PURPOSE/OBJECTIVE(S) Laryngeal preservation with definitive chemoradiation (CRT) in patients with advanced laryngeal cancer has been established through various prospective randomized trials. However, it is unclear what the optimal treatment approach for patients with T3N0M0 glottic cancer is and whether chemotherapy is needed in conjunction with radiation. We sought to evaluate survival differences in patients with T3N0M0 glottic cancer treated with radiation alone (RT) versus chemoradiation. MATERIALS/METHODS Patients with T3N0M0 glottic cancer diagnosed from 2004 through 2017 were identified from the National Cancer Database. Patients treated definitively with RT or CRT were selected. Patients receiving adjuvant RT or CRT were excluded. Baseline differences among treatment groups were identified. Overall survival was estimated with the Kaplan-Meier method and reported as median survival (MS). A multivariable cox proportional hazards model was constructed to identify variables associated with survival. RESULTS A total of 3785 patients were included in the cohort, with 942 (25%) patients who received RT alone and 2843 (75%) who received CRT. With a median follow up of 75.2 months, median survival was significantly longer in patients treated with CRT than in patients treated with RT alone (82 months [m], 95% CI 76-87m vs 29m, 95% CI 25-33m). On multivariable cox model, patient factors associated with decreased overall survival (OS) included omission of chemo (hazard ratio [HR] 1.69, 95% CI 1.52-1.87), age > 70 (HR 1.66, 95% CI 1.15-2.42), comorbidities (HR 1.66, 95% CI 1.15-2.42, and treatment at non-tertiary academic cancer centers (HR 1.24, 95% CI 1.04-1.48). Patients age > 70 and those with multiple comorbidities were significantly less likely to receive chemotherapy (odds ratio [OR] 0.30, 95% CI 0.25-0.37 and OR 0.48 95% CI 0.31-0.76, respectively). When limiting analysis to patients under 70 with no comorbidities, the survival benefit persisted in favor of CRT (MS 113m, 95% CI 102-124m vs. MS 65, 95% CI 47-85m). CONCLUSION Optimal treatment for T3N0M0 glottic cancer has not fully been established in prospective clinical trials. This is the first study to evaluate survival outcomes in this group of patients comparing RT to CRT. Median survival appears to be significantly increased with the use of CRT, and this benefit persists when controlling for age and performance status. This study supports the use of definitive CRT for appropriately selected patients with T3N0M0 glottic cancer.