Age-Stratified Analysis of First-Line Chemoimmunotherapy for Extensive-Stage Small Cell Lung Cancer: Real-World Evidence from a Multicenter Retrospective Study

Chemoimmunotherapy improved overall survival (OS) and progression-free survival (PFS) in patients with extensive-stage small cell lung cancer (ES-SCLC) in two phase III trials. They set the age-stratified subgroup analyses at 65 years; however, over half of the patients with lung cancer were newly diagnosed at ≥75 years in Japan. Therefore, treatment efficacy and safety in elderly patients ≥ 75 years with ES-SCLC should be evaluated through real-world Japanese evidence. Consecutive Japanese patients with untreated ES-SCLC or limited-stage SCLC unfit for chemoradiotherapy between 5 August 2019 and 28 February 2022 were evaluated. Patients treated with chemoimmunotherapy were divided into the non-elderly (