MUCOEPIDERMOID CARCINOMA OF THE PAROTID GLAND: FACTORS AFFECTING OUTCOME

Background. The purpose of this study was to identify the prognostic factors affecting the outcome in patients with mucoepidermoid carcinoma (MEC) of the parotid gland. Methods. A total of 113 patients with MEC who were treated between 1993 and 2002 were analyzed. Results. At median follow-up of 49 months (range, 1-143 months), disease-free survival (DFS) at 5 and 10 years was 84.6 and 84.6%, 80.7% and 67.3%, and 52.5% and 35.0% for low-grade, intermediate-grade, and high-grade tumors, respectively. Five-year and 10-year overall survival was 96.8% for low-grade tumors; 94.1% and 82.4%, respectively, for intermediate-grade tumors; and 73.3% for high-grade tumors. High-grade tumors and lymph node cancer-positive neck tumors strongly predicted poor locoregional control and DFS, while close or positive cut margins showed a trend toward poorer outcomes. Conclusion. Histologic grade is the most important factor affecting outcome in parotid MEC. Adjuvant radiotherapy is recommended for high-grade tumors and should be tailored according to the expected risk of recurrence for low-grade and intermediate-grade tumors. (C) 2010 Wiley Periodicals, Inc. Head Neck 33: 497-503, 2011