Minor salivary gland tumors of the oral cavity: a case series with review of literature.

BACKGROUND: Minor salivary gland tumors (MSGTs) are unusual, accounting for only 15-20% of all salivary gland tumors. The commonest site of MSGTs of the head and neck is oral cavity.

AIMS: To describe our experience with MSGTs of oral cavity seen over a period of one decade and elucidate their prognostic factors.

MATERIALS AND METHODS: Over a period of 10 years, from 1991 to 2000, all MSGTs of oral cavity were analyzed. All demographic, treatment and survival data were recorded. Kaplan-Meier curves were used to find the survival. Multivariate analysis was performed using Cox regression.

RESULTS: We treated 104 patients with curative intent. The commonest site was hard palate, accounting for 54.8% of all sites. The commonest histology was adenoid cystic carcinoma (45.2%). There were 17 (16.34%) pleomorphic adenoma cases, while the remaining 87 (83.66%) were minor salivary gland malignancies. Treatment was surgical in 91.3% of patients. Adjuvant radiotherapy was administered in 38.5% of patients. The median follow-up was 50 months. Recurrences were seen in 22 (25.3%) of the 87 malignant cases. Using Kaplan-Meier analysis, the expected 10-year overall and disease-free survivals were 75.2 and 65.8%, respectively. Survivals were better in non-adenoid cystic tumors (non-ACC). On multivariate analysis, T status, tumor grade and adjuvant therapy were independent prognostic factors for disease-free survival.

CONCLUSIONS: MSGTs of oral cavity have good overall survival despite recurrences. T stage, adjuvant radiotherapy and grade are independent prognostic factors for disease-free survival. Adenoid cystic tumors have worse outlook than non-ACC.