Real-world effectiveness of first-line chemo-immunotherapy and chemotherapy on ES-SCLC: A propensity score-matched study.

e20110 Background: This study aims to evaluate whether the combination of chemotherapy and immunotherapy offers superior efficacy and prognosis compared to chemotherapy alone in the real-world first-line treatment of extensive-stage small cell lung cancer (ES-SCLC). The ultimate goal is to provide evidence that can guide clinical practice more effectively. Methods: This study is a single-center retrospective analysis of data collected from 574 patients with ES-SCLC treated at the Fourth Hospital of Hebei Medical University. The data included clinicopathological characteristics, baseline peripheral blood biomarkers, treatment modalities, prognostic outcomes, and efficacy indicators. Propensity score matching was conducted between the chemotherapy group and the chemotherapy combined with immunotherapy group to ensure comparable baseline clinicopathological characteristics.Kaplan-Meier analysis was employed to estimate progression-free survival (PFS) and overall survival (OS) in patients with ES-SCLC. Univariate Cox regression analysis was conducted to evaluate the hazard ratios associated with different baseline characteristics across the two treatment regimens.The results further confirmed that the chemotherapy combined with immunotherapy group demonstrated superior efficacy and prognosis compared to the chemotherapy group.Differences were considered statistically significant at P < 0.05. Results: By the last follow-up on October 15, 2024, the median follow-up duration was 12 months, with a total of 434 deaths (75.6%) recorded. The objective response rates (ORR) were 75.6% for the first-line chemotherapy plus immunotherapy group and 60.4% for the chemotherapy-only group. The 1-year, 2-year, and 3-year overall survival (OS) rates were 35%, 23%, and 23%, respectively, in the combined therapy group, compared to 23%, 14%, and 12% in the chemotherapy-only group. The median progression-free survival (mPFS) was 8 months (95% CI: 7.0–8.9) in the combined therapy group, compared to 6 months (95% CI: 5.5–6.4) in the chemotherapy-only group. The median overall survival (mOS) was 15 months (95% CI: 12.2–17.7) in the combined therapy group and 13 months (95% CI: 11.6–14.3) in the chemotherapy-only group. Univariate analysis revealed that, in the overall population and across baseline characteristics—including gender, age, smoking status, ECOG performance status, and the presence of brain, bone, or liver metastases—the first-line chemotherapy plus immunotherapy group had reduced risks of progression and mortality compared to the chemotherapy-only group. Conclusions: This retrospective study further confirmed that in real-world first-line treatment of ES-SCLC, chemotherapy combined with immunotherapy provides superior efficacy and prognosis compared to chemotherapy alone.