Definitive radiotherapy for squamous cell carcinoma of the pyriform sinus

Background and purpose: To report the long-term results after definitive radiotherapy (RT) for pyriform sinus squamous cell carcinoma (SCC). Material and methods: The data concerning all patients treated for pyriform sinus SCC with RT with a curative intent between 1990 and 2006 were reviewed. Results: A total of 249 patients were included. The median follow-up is 6.5 years. Overall 123 patients had relapsed. For the entire population, the 5-year local control, regional control, freedom-from-distant metastasis, and overall survival rate were 68%, 69%, 78% and 38%, respectively. The 5-year local control rate for the 107 T1-T2 tumors was 85% (95% confidence interval (CI): 75-91). N stage was the main risk factor for the development of distant metastases, with a hazard ratio of 8.9 (95% CI: 2.1-39) and 15.6 (95% CI: 3.6-67.8) for N2 and N3 patients respectively. For patients with N2-N3 disease, pre-RT neck dissection improved regional control but not overall survival. Moderate to severe late complications occurred in 50 patients (28% of the patients without local relapse). Conclusion: A high local control rate can be achieved when treating T1-T2 hypopharynx cancers with definitive radiotherapy. The high rate of nodal and distant relapses among patients with N2-N3 disease warrants intensification of therapy.