当科における耳下腺癌の治療成績―24年間の検討―

Abstract

Data of a total 254 patients with parotid cancer were analyzed. Mucoepidermoid carcinoma (MEC) was the most common histologic type, followed by carcinoma ex pleomorphic adenoma (CEPA). High-grade malignancy accounted for 110 cases, and low-/intermediate-grade malignancy in 144. The 5-year disease-specific survival and disease-free survival rates in the stage IV cases were 56.2% and 30.8%, respectively. The prognosis was much worse in the T4 and N+ cases than in the early-T stage and N0 cases. The grade of malignancy was identified as an independent prognostic factor; the 5-year disease-free survival rates in the patient groups with high-grade and low-/intermediate-grade malignancy were 34.4% and 91.5%, respectively. High-grade parotid carcinoma comprises 4 major histological types, including salivary duct carcinoma, MEC, CEPA, and adenoid cystic carcinoma; the 10-year disease-free survival rates in patients with the aforementioned types of cancer were 16.4%, 34.9%, 46.1%, and 47.4%, respectively; thus, all of these types carry a poor prognosis. Each histological type was found to have its own characteristic pathological and clinical features, so that the diagnosis, treatment, and follow-up methods also vary accordingly.