Long-Term Outcomes of Definitive Radiation Therapy for Nasopharyngeal Carcinoma at a North American Institution : Definitive Management of Head-and-Neck Squamous Cell Carcinoma

To report mature results of a large cohort of patients diagnosed with nasopharyngeal carcinoma treated with definitive radiation therapy. Consecutive patients with newly diagnosed, nonmetastatic nasopharyngeal cancer treated with definitive radiation therapy between 1990 and 2011 were identified. Rates of local control, regional control, distant control, overall survival were calculated from the start of RT using the Kaplan-Meier method. 273 patients with histologically confirmed nasopharyngeal carcinoma were identified. The disease was T1 in 41%, T2 in 18%, T3 in 24%, T4 in 16%, N0 in 26%, N1 in 31%, N3 in 29%, and N3 in 14%. Histology was keratinizing in 12%, non-keratinizing in 87%, basaloid in 1%. Platinum-based chemotherapy was administered to 76%, including 58% who received concurrent and adjuvant chemotherapy, 14% who received concurrent chemotherapy alone, and 4% who received neoadjuvant chemo +/- concurrent. Sixty-five percent received intensity-modulated radiation therapy. Median RT dose was 70Gy. Median follow-up among surviving patients was 46.9 months (range, 0.8 - 253.2 months). Among all patients, the 5-year rates of local control for patients with T1, T2, T3, and T4 disease were 82.0%, 97.7%, 78.8%, and 69.8% respectively. The 5-year rates of overall survival for patients with T1, T2, T3, and T4 disease were 74.3%, 66.7%, 61.2%, and 52.5%, respectively. The 5-year rates of regional control for patients with N0, N1, N2, and N3a-b disease were 84.1%, 87.7%, 89.6%, and 92.9%, respectively. The 5-year rates of overall survival for patients with N0, N1, N2, and N3a-b disease were 70.9%, 65.7%, 66.0%, and 61.7%, respectively. We report excellent rates of local and regional among patients with nasopharyngeal carcinoma treated with definitive radiation therapy in the largest North American series to date with mature follow-up.