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

OBJECTIVES/HYPOTHESIS: We sought to better characterize patient, tumor, and long-term survival characteristics of parotid small cell carcinoma (SmCC) with the National Cancer Database (NCDB). STUDY DESIGN: Retrospective database review. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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. LEVEL OF EVIDENCE: 4 Laryngoscope, 126:2036-2040, 2016.