Mucoepidermoid carcinoma: Evaluating the prognostic impact of primary tumor site

Mucoepidermoid carcinoma (MEC) is one of the most common salivary gland malignancies. Our aim was to evaluate the prognostic impact of primary tumor site in patients with MEC. Material and Methods: This cohort identified 308 patients with MEC who underwent primary surgery between 1985 and 2015. Survival outcomes were determined using the Kaplan-Meier method. Hazard ratios for primary site were determined using the Cox proportional-hazards model. Results: One hundred eighty (58%) patients were diagnosed with minor and 128 (42%) with major salivary gland cancer. Primary site in the minor salivary gland group included 137 (44%) oral cavity, 38 (12%) pharynx, 3 (0.9%) nasal cavity, and 2 (0.6%) trachea and larynx. The major salivary gland group included 118 (38%) parotid, 8 (3%) submandibular, and 2 (0.6%) sublingual. With a median follow-up of 73 months, 5-year overall survival and disease-specific survival were 84% and 91%, respectively. Patients with tumors located in the hard palate and retromolar trigone had the best survival, while patients with tumors located in the paranasal sinuses and submandibular gland had the poorest survival. After controlling for tumor grade and stage, MEC primary site was not predictive of survival or recurrence. On multivariate analysis, worse DSS was associated with stage III-IV tumors (HR: 7,11; 95% CI: 1.19-26.43; p = 0.0034) and high-grade tumors (HR: 19.12; 95% CI: 2.26-162.77; p = 0.0068). Conclusions: While high grade and advanced overall stage were found to be independent predictors of worse survival, primary tumor site was not predictive of poor outcome.