Mucoepidermoid carcinoma of the parotid gland treated by surgery and postoperative radiation therapy: clinicopathologic correlates of outcome.

OBJECTIVES/HYPOTHESIS To determine clinical and pathological correlates of outcome among patients treated by surgery and postoperative radiation therapy for mucoepidermoid carcinoma of the parotid gland. STUDY DESIGN Retrospective review. METHODS The medical records of 61 patients treated by surgery and postoperative radiation therapy for localized mucoepidermoid carcinoma of the parotid gland were retrospectively reviewed in an attempt to identify clinicopathologic correlates of overall survival. Secondary endpoints included local-regional control, distant metastasis-free survival, and complications. RESULTS The 3- and 5-year estimates of overall survival were 85% and 79%, respectively. Multivariate analysis identified high tumor grade (hazard ratio [HR] = 7.92) and T4 disease (HR = 3.35) as independent predictors of decreased survival, with the former also predicting for distant metastasis and the latter predicting for local-regional recurrence. The 5-year estimate of overall survival was 83% for patients with non-high-grade tumors, compared to 52% for those with high-grade histology (P = 0.001). Late complications included trismus (2 patients), osteoradionecrosis (1 patient), and hearing loss (1 patient). CONCLUSION Patients with high-grade tumors and T4 disease are at increased risk for treatment failure after surgery and postoperative radiation therapy for mucoepidermoid carcinoma of the parotid gland. Investigative strategies to improve outcome should be considered for these particular patients in the future.