Clinicopathological characteristics, treatment and prognosis of head & neck small cell carcinoma: a SEER population-based study.

Background: To investigate the clinicopathological characteristics of head and neck small cell carcinoma (H&NSmCC) and identify prognostic factors on the basis of the Surveillance, Epidemiology and End Results (SEER) database.

Methods: Total of 789 primary cases from 1973 to 2016 were included. Univariate and multivariate analyses were performed to identify independent prognostic indicators. An H&NSmCC-specific nomogram was constructed and compared with the AJCC staging system by calculating the time-dependent area under the curve (AUC) of the receiver operating characteristic (ROC) curves.

Results: The incidence of H&NSmCC peaked during the period of 50 to 70 years old, and the most frequent location was the salivary gland. The 5-year disease specific survival (DSS) was 27%. In the multivariate survival analysis, AJCC III + IV stage [HR = 2.5, P = 0.03, I + II stage as Ref], positive N stage [HR = 1.67, P = 0.05, negative N stage as Ref], positive M stage [HR = 4.12, P = 0.000, negative M stage as Ref] and without chemotherapy [HR = 0.56, P = 0.023, received chemotherapy as Ref] were independently associated with DSS. The H&NSmCC-specific nomogram was built based on the independent prognostic indicators. The nomogram demonstrated better predictive capacity than the AJCC staging system for 5-year DSS [(AUC: 0.75 vs 0.634; Harrell's C-index (95% CI): 0.7(0.66-0.74) vs 0.59(0.55-0.62), P < 0.05].

Conclusion: N stage, M stage, AJCC stage and chemotherapy were independent prognostic indicators included in the prognostic nomogram model, which can better predict the survival of H&NSmCC than the AJCC staging system.