Small cell carcinoma of the head and neck: Incidence and survival trends based on the Surveillance and Epidemiologic and End Results (SEER) analysis.
e17508 Background: Small cell carcinomas of the head and neck (SmCCHN) are rare neoplasms with an unfavorable prognosis. Population based data describing survival and prognostic factors for this malignancy are limited. Methods: Data was obtained from the US National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) database for the period 1973-2013. Patient and tumor related characteristics for SmCCHN were compared with squamous cell carcinomas (SCC) of the same anatomic sites. Survival for the two groups was compared by constructing Kaplan-Meier curves and Cox proportional hazard models with and without propensity score matching. Cox models results were expressed as hazard ratios (HR) and the corresponding 95% confidence interval (CI). Results: The dataset included 609 SmCCHN and 227943 cases of SCCHN. SCCHN patients with SmCCHN included significantly greater proportions of females and whites. SmCCHN was more likely to originate in the salivary glands and present with more advanced stage and grade. The overall 5 year and 10 year survival estimates were 27% and 18%, respectively. Corresponding values for SCCHN were 46% and 31%. The multivariable analyses adjusting for age, sex, race, marital status, year of diagnosis, stage, grade and receipt of radiation, the HR comparing SmCCHN to SCCHN was 1.53 (95% CI: 1.39-1.68). Elderly, male, black and not married persons had worse prognosis compared to their respective reference groups. Other factors independently associated with lower survival included more advanced stage and tumor grade, and earlier decades of diagnosis. In the propensity score matched analyses the corresponding HR was 1.27 (95% CI: 1.15-1.40). Conclusions: Compared to SCCHN, SmCCHN in addition to carrying a worse survival, is more likely to originate in the salivary glands, present with more advanced stage, and affect females and whites.