Definitive radiation therapy for treatment of laryngeal carcinoma: impact of local relapse on outcome and implications for treatment strategies.

PURPOSE: The purpose of this work was to evaluate outcome after radiotherapy (RT) for laryngeal carcinoma and investigate effects of local relapse on ultimate disease control, including surgical salvage procedures. METHODS AND MATERIALS: In all, 435 patients with laryngeal carcinoma (cT1-cT4a) treated with primary RT were retrospectively analyzed. Uni- and multivariate analyses were performed to identify prognostic factors for local relapse-free survival and overall survival.
RESULTS: Median follow-up was 38 months (range 1-144 months). The cumulative frequency of local recurrence was dependent on T stage: cT1 tumors 10%, cT2 18%, cT3 23%, and cT4 36% (p<0.001). Salvage surgery for local persistent/recurrent disease was performed in 59 of 78 patients (76%). The ultimate local control rates at 5 years (including salvage therapy) were 98, 98, 87, and 68% for cT1, cT2, cT3, and cT4 tumors (p<0.001), respectively. For the patients who developed local recurrence, the 5-year ultimate local control rates were 80, 88, 55, and 26% (p<0.001), respectively. Overall survival at 5 years was 68% for patients without local relapse and 50% for patients experiencing local failure (p<0.001). In univariate analysis, cT stage, cN stage, and tumor volume were statistically significant associated with local relapse-free survival. In multivariate analysis for the cT3-4 tumors, only tumor volume remained statistically significant (HR 1.017, p=0.001) for local relapse-free survival.
CONCLUSION: Local control rates for cT1-2 laryngeal carcinomas are favorable and in concordance with previous reports and most recurrences are salvaged. For cT3-4 tumors treated with RT alone, initial local control rates are moderate, and in 60% of recurring cases salvage surgery is attempted, with ultimate local control being achieved in only a subset. For voluminous, locally advanced laryngeal tumors, more aggressive treatment modalities should be considered, including upfront laryngectomy or radiochemotherapy.