Mucoepidermoid carcinoma of the parotid gland: A National Cancer Database study.

OBJECTIVE: To describe the demographics, tumor characteristics, and prognostic features of mucoepidermoid carcinoma of the parotid gland.

MATERIALS AND METHODS: A retrospective study of the National Cancer Database was reviewed for all mucoepidermoid carcinomas of the parotid gland between 2004 and 2012). Patient demographics and tumor characteristics were abstracted and analyzed. Univariate and multivariate Cox multivariate regression models were used to identify predictors of survival.

RESULTS: A total of 4431 patients met inclusion criteria. Average age at diagnosis was 57 years (median 62, SD 19), with no overall sex preference (52% female), and majority white (78%). The 1-year overall survival was 92.9% (95% CI [92.1-93.6]) and 5-year overall survival was 75.2% (95% CI [73.8-76.7%]). Median overall survival was not reached at 5 years. Factors associated with decreased survival were increasing age, comorbidities, high tumor grade, advanced pathologic group stage, and positive surgical margins. Female sex was the only factor associated with improved survival. Controlling for either histopathologic grade or pathologic stage to determine how patient demographics and tumor characteristics affected overall survival yielded similar results. Of note, intermediate grade tumors, although not independently associated with worse survival, when seen in conjunction with tumors ≥T2 and/or ≥N2, a negative impact on overall survival was seen.

CONCLUSION: Although mucoepidermoid carcinoma of the parotid gland is the most common parotid gland malignancy, it is still a rare tumor with a lack of large population-based studies. Advanced stage and high-grade tumors are significant predictors of decreased survival. Females have improved survival compared to males.