Predictors of survival in parotid small cell carcinoma: A study of 344 cases.

Abstract

We sought to better characterize patient, tumor, and long-term survival characteristics of parotid small cell carcinoma (SmCC) with the National Cancer Database (NCDB). Retrospective database review. We reviewed the NCDB (1998-2012) for all cases of parotid SmCC. Relevant demographic, tumor, and survival variables were extracted and analyzed. Cox multivariate regression was performed to identify prognosticators. Out of 30,813 parotid gland cancers in the NCDB, we found 344 cases of parotid SmCC (1.11%). Age at diagnosis ranged from 23 to 91 years (mean = 73 years). Most patients (73.0%) were male. Most tumors were 2 to 4 cm in size (51.4%). Regional metastases were common (50.8% cN+ and 65.1% pN+) and distant metastasis (7.3%) was uncommon. Occult nodes were found in 14.4% of cases. Overall survival at 5 and 10 years was 37% and 20%, respectively. Although numerous variables were found to significantly impact survival on univariate regression analysis, age (hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 1.03-1.08, P < .001), tumor size of 2 to 4 cm (HR: 2.51, 95% CI: 1.83-5.11, P = .011), tumors >4 cm (HR: 3.44, 95% CI: 1.63-7.27) and distant metastasis (HR: 2.06, 95% CI: 1.02-4.14, P = .043) remained significant prognosticators in our multivariate model. Nodal disease was not a significant risk factor after adjustment (P = .055). SmCC is a rare parotid malignancy with a poor prognosis. Regional metastases were common, whereas distant metastases were uncommon. Elective neck treatment should be considered due to the incidence of occult nodal disease. 4 Laryngoscope, 126:2036-2040, 2016.