Survival benefit of postoperative chemotherapy in stage III lung squamous cell carcinoma based on SEER database...

Lung squamous cell carcinoma (LUSC) is a prevalent subtype of lung cancer. This retrospective cohort study aims to explore the effect of postoperative chemotherapy on survival in patients with Stage III LUSC and to assess its heterogeneity across different patient subgroups. Patients diagnosed with postoperative Stage III LUSC between 2010 and 2015 were identified in the Surveillance, Epidemiology, and End Results (SEER) database, and cases with missing information were excluded. The primary outcome measure was overall survival (OS). Propensity score matching (PSM) was employed to balance confounders. Kaplan-Meier (KM) curve was used to assess the OS of patients in different groups. The prognostic risk factors of patients with OS were screened and analyzed through Cox regression analysis. The cohort consisted of 1,784 patients (65.3% receiving chemotherapy), and postoperative chemotherapy was associated with a modest survival benefit: the adjusted hazard ratio (HR) was 0.62 (95%CI: 0.55-0.69, P < 0.001), corresponding to an absolute 5-year OS improvement from 28% (Non-chemotherapy) to 42% (Chemotherapy). Overall, no significant difference was observed in OS between the PSM group and the non-PSM group, except for the variable tumor size, which became significant for OS after matching. Subgroup analyses revealed that chemotherapy improved survival for patients across nearly all characteristics. Univariate and multivariate Cox regression analyses identified marital status, race, gender, and age as significant prognostic factors influencing OS. In conclusion, postoperative chemotherapy significantly ameliorates the survival in most patients with Stage III LUSC, with the most pronounced effects observed in those with N1-2 stage disease and undergoing resection of the lobe, bilobectomy, or pneumonectomy. Our findings provide valuable insights for clinical decision-making and related studies on the application of chemotherapy in patients with Stage III LUSC resection.