Incidence, treatment, and outcome of parotid carcinoma, 1996-2011: a population-based study in Thuringia, Germany.

Abstract

The objective of this study was to examine patterns of care and survival in a population-based sample of patients with parotid cancer who were treated in Thuringia, a federal state in Germany, between 1996 and 2011. Data of 295 patients with primary parotid cancer from the Thuringian cancer registry were evaluated for patient's characteristics, tumor stage, incidence, and trends in treatment, cancer-specific survival (CSS), and overall survival (OS). Stages IV tumors and the amount of tumors in all age cohorts ≥45 years of age increased significantly during the observation period (p = 0.002; age all p < 0.05, respectively). The highest increase in crude incidence was observed for salivary duct carcinomas [relative risk per decade (RR) 5.46; 95% confidence interval (CI) 1.14-26.14] and rare carcinoma subtypes (RR 9.99; 95% CI 1.85-53.94). CSS at 5 years and at 10 years for all patients was 82.4 and 82.4%, respectively. OS at 5 years and at 10 years for all patients was 60.1 and 48.2%, respectively. CSS and OS did not improve over the time. Salivary duct carcinoma showed the lowest 5-year OS (35.6%). Acinic cell carcinoma had the highest OS rate (85.3%). Multivariate Cox models revealed that higher grading (G3/G4) was a more powerful independent predictor of decreased OS than TNM stage. CSS and OS did not improve during the study period. Incidence of parotid cancer increased significantly in elderly patients. It seems that grading is next to patient's age the better predictor of OS than TNM stage.