Evaluating the prognostic contributions of TNM classifications and building novel staging schemes for middle ear squamous cell carcinoma

BACKGROUND: A universally acknowledged cancer staging system considering all aspects of the T‐, N‐, and M‐classifications for middle ear squamous cell carcinoma (MESCC) remains absent, limiting the clinical management of MESCC patients. MATERIALS AND METHODS: A total of 214 MESCC patients were extracted from the SEER (the Surveillance, Epidemiology, and End Results) database between 1973 and 2016. The relationships between patient’s characteristics and prognoses were analyzed by Kaplan–Meier and Cox proportional hazards regression models. Novel staging schemes for MESCC were designed by adjusted hazard ratio (AHR) modeling method according to the combinations of Stell’s T‐classification and the eighth AJCC N‐ and M‐classifications, of which performances were evaluated based on five criteria: hazard consistency, hazard discrimination, explained variation, likelihood difference, and balance. RESULTS: T‐classification was the most significant prognostic factor for MESCC patients in multivariable analysis (p = 0.021). The N‐ and M‐classifications also had obvious prognostic effect but were not statistically significant by multivariate analysis due to the limited metastasis events. Three novel staging schemes (AHR‐Ⅰ–Ⅲ models, different combination of T‐ and N‐classifications) and ST (solely derived from Stell’s T‐classification) were developed, among which the AHR‐Ⅰ staging scheme performed best. CONCLUSIONS: Tumor extension, quantified by Stell’s T‐classification, is the most significant prognostic factor for MESCC patients. However, our AHR‐Ⅰ staging scheme, a comprehensive staging scheme that integrating T‐, N‐, and M‐classifications, might be an optimal option for clinical practitioners to predict MESCC patients’ prognosis and make proper clinical decisions.