Prognostic Value of Clinical Staging According to TNM in Patients With SCLC: A Real-World Surveillance Epidemiology and End-Results Database Analysis

Introduction: SCLC is one of the most lethal malignancies. Classically, staging has been performed using a dual classification distinguishing limited from the extensive stage. This study aimed to evaluate the prognostic value of TNM staging in a real-world population of patients with SCLC. Methods: Patients were selected from the Surveillance Epidemiology and End Results database. Chi-square bivariate analysis was used for the association of binary qualitative variables. A multivariate Cox regression analysis was performed to determine the impact of these prognostic factors on median overall survival (mOS) and long-term survival. Results: A total of 26,221 patients were included (50.7% men, 55.7% ≥65 y, 82% White). At diagnosis, 18,574 (70.83%) presented metastases, which were more frequent in the liver (n = 11,896, 64%). In the overall population, mOS was 8 (7.86–8.14) months, which decreased according to each increasing category of TNM staging (p < 0.0001). The worse mOS was found among patients with stage IV SCLC (6 mo, 95% confidence interval: 5.83–6.17). Long-term survival decreased according to TNM staging, with patients having stage IV SCLC exhibiting the lowest survival rates at all follow-up time points. Within stage IV, the lowest mOS values were found in patients greater than or equal to 65 years and in those with liver metastases. Among the TNM stages corresponding to the limited stage, stage IB revealed the lowest hazard ratios value for risk of death compared with stage IA (hazard ratio = 1.161, 95% confidence interval: 0.97–1.40, p = 0.114), which increased gradually within the limited-stage SCLC. In the multivariate analysis, TNM staging, male sex, and older age resulted in poor prognostic factors for survival. Conclusions: TNM staging seems to define prognosis in patients with SCLC in the real-world setting, particularly for those patients with earlier disease.