Abstract
BACKGROUND: The efficacy of adding atezolizumab to the platinum doublet regimen for extensive disease small cell lung cancer (ED-SCLC) remains marginally limited. METHODS: We retrospectively assessed the real-world efficacy and safety of atezolizumab in addition to carboplatin and etoposide (EP + A), versus carboplatin and etoposide (EP) alone in previously untreated ED-SCLC patients. RESULTS: From a total of 99 patients, 46 were assigned to the EP + A group, and 53 to the EP group. No significant difference was observed in progression-free survival between the groups. However, the overall survival (OS) was significantly longer in the EP + A group (20.8 vs 12.1 months; HR: 0.52; p = 0.0127). Patients older than 70 years, male, with performance status 0-1, without liver metastasis, and low levels of C-reactive protein and neutrophil-lymphocyte ratio, experienced longer OS in the EP + A group compared to the EP group. CONCLUSION: The addition of atezolizumab to the platinum doublet regimen significantly extended OS in ED-SCLC patients, particularly among certain subgroups, suggesting its potential value in personalized treatment strategies. Further investigation is warranted to validate these findings.