Long-term toxicities in 10-year survivors of radiation treatment for head and neck cancer

Objectives To characterize the recognized but poorly understood long-term toxicities of radiation therapy (RT) for head and neck cancer (HNC). Materials and methods We retrospectively evaluated patients treated with curative-intent RT for HNC between 1990 and 2005 at a single institution with systematic multidisciplinary follow-up ≥10 years. Long-term toxicities of the upper aerodigestive tract were recorded and assigned to two broad categories: pharyngeal-laryngeal and oral cavity toxicity. Kaplan-Meier estimates and Chi-square tests were used for univariable analysis (UVA). Cox model and logistic regression were used for multivariable analysis (MVA). Results We identified 112 patients with follow-up ≥10 years (median 12.2). The primary tumor sites were pharynx (42%), oral cavity (34%), larynx (13%), and other (11%). Forty-four percent received postoperative RT, 24% had post-RT neck dissection, and 47% received chemotherapy. Twenty-eight (25%) patients developed pharyngeal-laryngeal toxicity, including 23 (21%) requiring permanent G-tube placed at median of 5.6 years (0–20.3) post-RT. Fifty-three (47%) developed oral cavity toxicity, including osteoradionecrosis in 25 (22%) at a median of 7.2 years (0.5–15.3) post-RT. On MVA, pharyngeal-laryngeal toxicity was significantly associated with chemotherapy (HR 3.24, CI 1.10–9.49) and age (HR 1.04, CI 1.00–1.08); oral cavity toxicity was significantly associated with chemotherapy (OR 4.40, CI 1.51–12.9), oral cavity primary (OR 5.03, CI 1.57–16.1), and age (OR 0.96, CI 0.92–1.00). Conclusion Among irradiated HNC patients, pharyngeal-laryngeal and oral cavity toxicity commonly occur years after radiation, especially in those treated with chemotherapy. Follow-up for more than five years is essential because these significant problems afflict patients who have been cured.