Predictive factors for survival and treatment outcomes of patients with minor salivary gland malignancies: a retrospective study.

INTRODUCTION: Aim of this study was to explore the incidence, pathology, clinical behaviour and evaluate factors predictive on survival and treatment outcomes in a cohort of patients with minor salivary gland (MiSG) malignancies treated at a single center over a period of 25 years. MATERIALS AND METHODS: Patients who had received primary treatment for MiSG malignancy during 25 years observation period were identified. Outcomes that were evaluated were overall survival (OS), disease specific survival (DSS), recurrence free survival (RFS), locoregional recurrence free survival (LRFS) and distant metastasis free survival (DFS). RESULTS: A total of 88 patients with MSG malignancies were included in the study. The most common location for MiSG malignancies was the oral cavity (65 tumors; 77%). Cumulative OS for 5 and 10 year follow up period was 82% and 62% respectively. Cumulative DSS for 5 and 10 year follow up period was 85% and 73% respectively. Twenty one (23%) patients developed distant metastases during follow-up. High-grade pathology and tumor stage were significant variables on multivariate analysis for all survival and treatment outcomes. CONCLUSIONS: Minor salivary gland malignancies are minor only by name. Tumor histological grade, AJCC tumor stage and pT stage were the strongest predictive factors for survival and treatment outcomes. The elective neck dissection could be considered therapeutic approach for selected cases of high grade MiSG malignancies. Distant metastases were the main cause of death and treatment failure.