Purpose: To determine the important clinical/pathologic prognostic factors and optimal treatment of malignant parotid tumors.
Methods and materials: This study was a retrospective chart review of 163 patients treated for malignant parotid tumors at two institutions. Of the 163 patients, 91 were treated with surgical resection and radiotherapy (RT), 56 were treated with surgery alone, and 13 were treated with RT alone. The median follow-up was 5.1 years (range, 0-37 years).
Results: Locoregional recurrence occurred in 37% of surgery-only, 11% of surgery plus RT, and 15% of RT-only patients (p = 0.001, Pearson's chi-square test). Cox proportional hazard multivariate analysis revealed that increasing age and higher stage were each statistically significantly (p < 0.05) associated with a poorer overall 5-year survival and cause-specific survival. Only increasing age and the absence of adjuvant RT were shown in Cox proportional hazard multivariate analysis to impact negatively on local failure-free survival.
Conclusion: In Cox proportional hazards multivariate analysis, only increasing age and stage were statistically significant prognostic factors for survival. The addition of RT to surgery did not improve overall survival but did reduce locoregional recurrence and improve local failure-free survival.