Anti-PD-L1 plus chemoradiotherapy for limited-stage small-cell lung cancer: a retrospective cohort evaluating efficacy, safety, T-cell subsets and tumor markers

Background Evidence for immune checkpoint blockade with chemoradiotherapy (CRT) in limited-stage small-cell lung cancer (LS-SCLC) remains limited. We evaluated anti-PD-L1 plus CRT versus CRT alone in routine practice. Methods We retrospectively included 42 LS-SCLC patients (June 2020–February 2022). The study group received atezolizumab or durvalumab plus platinum–etoposide CRT; the control group received CRT alone. Primary outcome: progression-free survival (PFS). Secondary outcomes: objective response rate (ORR), disease control rate (DCR), adverse events (AEs), T-cell subsets (CD3+, CD4+, CD8+, CD4+/CD8+) and serum tumor markers (NSE, Pro-GRP, CYFRA21-1, CEA). Responses followed iRECIST; AEs were graded per CTCAE; Kaplan–Meier/log-rank compared PFS. Results Groups were balanced at baseline. Compared with CRT, anti-PD-L1 + CRT yielded numerically higher ORR (90.0% vs 72.7%) and DCR (95.0% vs 90.9%), with significantly longer PFS (p < 0.05). Post-treatment, the combination group showed greater increases in CD3+, CD4+, CD4+/CD8 + and larger reductions in NSE and Pro-GRP (all p < 0.05). Safety was comparable with no new signals. Median follow-up was 15.3 months. Conclusions Adding anti-PD-L1 to CRT for LS-SCLC was associated with improved PFS, favorable immunologic and biomarker changes, and manageable safety in this retrospective cohort, supporting prospective validation.