Surgical outcome in malignant parotid tumours

Of 494 parotid gland tumours treated in Copenhagen county (population 600,000 inhabitants) in the period 1986-95, 50 patients (34 males, 16 females) had tumours that were proven to be malignant, making an incidence of 0.62/100,000/year. The patients age ranged from 14 to 87 years, mean 64 years. According to the UICC classification system, 6 tumours (12%) were classified as stage I, 23 (46%) as stage II, 14 (28%) as stage III, and 7 (14%) as stage IV. The material included 41 primary parotid gland tumours, histologically the tumours were verified as mucoepidermoid carcinoma (n = 13), adenocarcinoma (n = 9), squamous cell carcinoma (n = 6), carcinoma ex pleomorph adenoma (n = 3), acinic cell carcinoma (n = 3), adenoid cystic carcinoma (n = 3) and other histological diagnoses (n = 4). Primary malignant lymphoma of the parotid gland was diagnosed in six tumours and the last three tumours were metastatic carcinoma. Four therapeutic modalities were applied: surgery only, surgery + radiation, surgery + chemotherapy, and surgery + chemotherapy + radiation. Surgical radicality was achieved in 76% and radicality was unrelated to tumour histology. Normal or nearly normal facial nerve function (HB1&2) was noted at last follow-up in 60%. Five-year crude survival for all patients was 68%. Survival was not dependent on N-classification. Patients in stage I had a better survival than did patients in stages II, III and IV. No significant difference was observed in 5-year crude survival or in the post-operative facial nerve function between the radically operated patients (n = 38) and patients with residual tumour (p = 0.27, Log-rank test), (p = 0.48, chi 2 test).