Prognostic factors depicting disease-specific survival in parotid-gland tumors.

Purpose: To identify significant prognostic factors that can be used in clinical decision-making with regard to parotid cancer, which is characterized by a complex and diverse group of tumors with variable outcomes. Methods and Materials: A historical cohort of 184 patients with parotid-gland malignancy, who had been registered in the Province of Manitoba from 1970 to 2003, was examined. Survival analysis was performed using Kaplan-Meier curves and a log-rank test for comparing subgroups. The independent effect of factors that predicted survival at the bivariate level was determined using a Cox proportional hazard model. Results: The mean age at presentation was 62 years. The mean follow-up was 64 months. Absolute and disease-specific survival at 5 years was 41.70% and 57.94%, respectively. Survival for Stages I–IV at 5 years was 85.35%, 76.9%, 56.1%, and 8.4%, respectively ( p p p = 0.0486). Conclusions: Despite the variety of malignant parotid tumors, easily identifiable prognostic indicators such as advanced age, tumor size, local invasion, and tumor differentiation have a significant impact on outcome. Patients with adverse prognostic factors benefit from adjuvant radiotherapy. The threshold for the use of adjuvant radiotherapy in managing parotid malignancy should be low.