Clinical Characteristics and Management of External Auditory Canal Squamous Cell Carcinoma in Post-Irradiated Nasopharyngeal Carcinoma Patients.

Abstract

To describe the clinical characteristics and management of patients with external auditory canal (EAC) squamous cell carcinoma (SCC) that arose after they received radiotherapy for nasopharyngeal carcinoma (NPC) and to compare them with primary EAC SCC patients. Retrospective clinical analysis. Hospital. Nine irradiated NPC patients who subsequently developed secondary EAC SCC and 41 primary EAC SCC patients at a single hospital. Clinical characteristics and management outcomes of patients were reviewed. Clinical manifestations, regions of tumor involvement, the pathological staging, cumulative overall survival rates, Kaplan-Meier method, log rank test, and Mann-Whitney U test. The most common symptoms of both groups were otorrhea, otalgia, and hearing loss. The region most involved in both groups was the EAC. The proportions of early stage (T1,T2) tumors in the post-irradiated and primary EAC SCC group were 56 and 22%, respectively. The 6-month, 1-year, 2-year, and 3-year cumulative overall survival rates of the post-irradiated EAC SCC group were 100, 100, 89, and 89%, respectively. The incidence of radionecrosis was higher in the post-irradiation EAC SCC group than in the primary EAC SCC group. Post-irradiation EAC SCC has similar symptoms and invades similar regions as primary EAC SCC. The proportion of early stage tumors in the post-irradiated EAC SCC group was higher than that in the primary EAC SCC group. High incidence of radionecrosis was observed after the second course of radiotherapy. Aggressive surgical treatment is strongly recommended, but adjuvant radiotherapy for early stage EAC SCC should be provided cautiously.