Primary parotid carcinoma: analysis of risk factors and validation of a prognostic index.

OBJECTIVES: Primary cancer of the parotid gland (PG) is a rare disease characterized by a wide variety of histologies and subtypes. The aim of the study was to identify factors influencing survival and validate the prognostic scores (PS1 and PS2) by Vander Poorten et al. STUDY DESIGN: Retrospective cohort study.

METHODS: All patients with previously untreated PG epithelial malignancies who underwent surgery with curative intent from 2002 to 2015 at a single center were retrospectively reviewed.

RESULTS: 104 patients were included. Mean age was 60.2 years (range 14-88). Definitive pT staging was: 26 (25%) pT1, 19 (18.3%) pT2, 15 (14.4%) pT3, 41 (39.4%) pT4a, and 3 (2.9%) pT4b. Lateral neck nodal metastases were diagnosed in 27 (26%) patients. Five- and 10-year overall survival was 74.7% and 69.4%, respectively. Disease-specific survival at 5 and 10 years was 80.4% and 76.5%, respectively. Recurrence-free survival at 5 and 10 years was 66.9%. PS-1 and PS-2 scores correlated with prognosis. The most critical prognostic variables were grading, nodal metastases, perineural infiltration, lympho-vascular invasion, and skin infiltration.

CONCLUSIONS: Major risk factors in primary PG carcinomas can effectively identify high-risk patients. The prognostic score by Vander Poorten et al. is a highly reliable tool to predict the prognostic profile.