Stage as major long term outcome predictor in minor salivary gland carcinoma

BACKGROUND: The myriad of histologic types and anatomic sites of occurrence make minor salivary gland carcinomas the most heterogeneous group of carcinomas of the upper aerodigestive tract. Many publications addressing this group consider different subsections, making it hard to get a clear picture of long term treatment results and of modifying prognostic factors. METHODS: Overall survival, disease specific survival, and percentage rates for no recurrence in all 55 patients with a minor salivary gland carcinoma, treated at the Netherlands Cancer Institute from 1973 to 1994, were calculated and compared to the results in major salivary gland carcinoma patients. Major prognostic factors were univariately analyzed. The median period of follow-up time for patients alive at the end of follow-up was 134 months. RESULTS: The overall 5- and 10-year survival rates were 66% and 57%, respectively. The 5- and 10-year disease specific survival rates (DSS) were 76% and 74%, respectively; and the 5- and 10-year recurrence-free rates were 63% and 60%, respectively. Prognostic for overall survival were age (P = 0.0005), site of occurrence (P = 0.0001), and the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) Tumor, Node, and Metastases (TNM) classification and stage regrouping system (P = 0.0001). Factors predicting DSS were site of occurrence (P < 0.0001) and the UICC/AJCC TNM classification and stage regrouping (P < 0.0001). In surgical patients, histologic evidence for metastatic lymph nodes (P = 0.0037) and vascular invasion (P = 0.0051) conferred a lower DSS. Tumor recurrence was predicted by the UICC/AJCC TNM classification and stage regrouping (P = 0.0001). In surgical patients, soft tissue invasion (P = 0. 0085) predicted tumor recurrence. CONCLUSIONS: Sixty percent of patients treated for minor salivary gland carcinoma were free of tumor ten years later. This equals the result in major salivary gland carcinoma patients. The recent UICC/AJCC TNM classification and stage regrouping are confirmed as major predictors of outcome.