Long-term treatment outcome of minor salivary gland carcinoma of the hard palate.

Minor salivary gland carcinoma of the hard palate is rare, and its long-term survival rate is high, making it difficult to evaluate the prognostic factors and the efficacy of treatment. This study was designed to evaluate the treatment outcome of minor salivary gland carcinoma of the hard palate. 103 cases of minor salivary gland carcinoma of the hard palate treated with surgery alone or underwent surgery combined with post-operative radiotherapy hospitalized in Cancer Center, Sun Yet-Sen University, from 1968 to 2008 were reviewed retrospectively. The most common histologic types were adenoid cystic carcinoma in 48 patients(46.6%), mucoepidermoid carcinoma in 37(35.92%), malignant mixed tumor in 15(14.56%), and acinic cell carcinoma in 3(2.91%). The median follow-up time was 74.83 months (range 0.9-356.57 months). Overall outcomes at 5 and 10 years were overall survival (OS), 77.9% and 65.7%; recurrence-free survival (RFS), 64.4% and 53.2%; and disease specific survival (DSS), 77.9% and 67.7%, respectively. There was no significant difference in overall survival (P=0.52), recurrence-free survival (P=0.762) and disease specific survival (P=0.449) between patients who underwent surgery alone and those who underwent surgery plus post-operative radiotherapy. Surgery has been accepted as the primary treatment for minor salivary gland carcinoma of hard palate. Sufficient surgical excision with adequate margins is essential for a favorable outcome. We advocate using radiotherapy in the post-operative context for patients with poorly differentiated, cervical lymph node metastasis, positive or close margins, and large primary lesions.