Survival Analysis of Postoperative Adjuvant Chemotherapy for Stage IB Non-Small Cell Lung Cancer Based on Racial Stratification.

Background: The survival benefits of adjuvant chemotherapy for stage IB non-small cell lung cancer (NSCLC) remain controversial. The existing evidence is mostly based on the Caucasian population, especially the differences in efficacy among different races are not yet clear.

Method: Based on the data of patients with stage T2N0M0 NSCLC in the SEER database from 2010 to 2018 (n = 7458), they were divided into white people (6076 cases) and non-white people (1382 cases). The baseline characteristics of the adjuvant chemotherapy group and the non-adjuvant chemotherapy group were balanced by propensity score matching (PSM). The overall survival (OS) was assessed using Kaplan-Meier methodology with log-rank testing, while multivariable Cox regression analysis was employed to identify independent prognostic factors.

Result: Among white people, the OS of the adjuvant chemotherapy group was significantly better than that of the observation group (p < 0.001 before and after PSM), and the benefits were consistent regardless of tumor diameter (≤ 4 or > 4 cm), VPI, or grade of differentiation. There was no statistically significant difference in OS among non-white people (p > 0.05 before and after PSM), and only the poorly differentiated subgroup showed limited benefits (p = 0.008). Multivariate Cox analysis confirmed that adjuvant chemotherapy was an independent predictor of OS in white people (p < 0.001), but not associated with non-white people (p = 0.184).

Conclusion: There are significant racial differences in the efficacy of adjuvant chemotherapy for stage IB NSCLC, suggesting that treatment decisions need to be optimized in combination with racial background.