Real-world effectiveness of first-line chemoimmunotherapy versus chemotherapy in older adults with extensive-stage small cell lung cancer: an inverse probability treatment weighted analysis

Aims First-line chemoimmunotherapy (ICI-chemo) has become the standard of care for extensive-stage small cell lung cancer (ES-SCLC). However, older adults are underrepresented in pivotal trials due to strict inclusion criteria that limit participation to highly selected, fit patients. Given the limited real-world comparative data, this study aimed to determine whether older adults with ES-SCLC derive greater benefit from ICI-chemo compared with chemotherapy (chemo) alone.Patients and methods We conducted a single-center retrospective cohort study including ES-SCLC patients aged 65 years or older who started first-line ICI-chemo or chemo between January 2020 and July 2024. Inverse probability of treatment weighting (IPTW) was used to adjust for baseline confounding. The main outcome was overall survival (OS) in the IPTW population.Results In the IPTW population, median OS was significantly longer in the ICI-chemo group (14.95 months; 95% CI, 12.94–19.91) compared with chemo (10.28 months; 95% CI, 8.11–13.17; HR, 0.66; 95% CI, 0.48–0.91; p = 0.011). Multivariable analysis confirmed that ICI-chemo exposure was independently associated with improved OS (HR, 0.608; 95% CI, 0.440–0.841; p = 0.003).Conclusions Our findings provide comparative evidence of improved survival in association with ICI-chemo compared with chemo in older adults with ES-SCLC.