Real-world outcomes of first-line carboplatin–etoposide–atezolizumab in extensive-stage small-cell lung cancer

Abstract

Aim: The addition of atezolizumab to platinum-etoposide chemotherapy has become the standard first-line treatment for extensive-stage small-cell lung cancer (ES-SCLC). However, real-world data regarding treatment outcomes and prognostic factors remain limited. This study evaluated the effectiveness of first-line carboplatin-etoposide-atezolizumab and investigated clinical and PET/CT-derived prognostic factors in patients with ES-SCLC.Materials and Methods: We retrospectively analyzed 59 consecutive patients with ES-SCLC who received first-line carboplatin, etoposide, and atezolizumab between January 2022 and December 2025. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Prognostic factors for OS were evaluated using univariate and multivariable Cox proportional hazards regression analyses.Results: The median PFS and OS were 6.1 months (95% CI, 5.6–6.6) and 8.9 months (95% CI, 6.9–10.9), respectively. Patients with ECOG performance status (PS) 0–1 had significantly longer PFS (6.3 vs. 4.9 months, p=0.001) and OS (13.9 vs. 6.5 months, p=0.002) than those with ECOG PS 2–3. In multivariable analysis, ECOG PS remained the only independent prognostic factor for OS (HR 2.104, 95% CI 1.183–3.741; p=0.016). Brain, liver, and bone metastases, prophylactic cranial irradiation status, and PET/CT-derived nodal and metastatic SUVmax values were not significantly associated with survival.Conclusions: In this real-world cohort of patients with ES-SCLC treated with first-line carboplatin-etoposide-atezolizumab, ECOG performance status was the only independent prognostic factor for overall survival. PET/CT-derived metabolic parameters did not demonstrate prognostic value, emphasizing the continued importance of simple clinical assessment in the chemoimmunotherapy era.