Chemoradiotherapy versus radiotherapy in patients with stage T1-2N0M0 small cell lung cancer: a retrospective cohort study.

Purpose: To compare survival outcomes between chemoradiotherapy versus radiotherapy in patients with stage T1-2N0M0 small cell lung cancer (SCLC).

Materials and methods: SCLC patients from the Surveillance, Epidemiology, and End Results databases between 2000 and 2020 were investigated. Kaplan-Meier survival analysis was employed to assess cancer-specific survival (CSS) and overall survival (OS).

Results: Among 525 eligible patients, 371 (70.7%) received chemoradiotherapy, 64 (12.2%) underwent radiotherapy, and 90 (17.1%) received chemotherapy. While 5-year SCLC-specific mortality rates were comparable between chemoradiotherapy and radiotherapy groups (57.1% vs. 51.8%, P = 0.660), non-cancer mortality demonstrated significant reduction with chemoradiotherapy (13.3% vs. 30.2%, P = 0.004). After propensity score matching, median CSS was 27 months with chemoradiotherapy versus 26 months with radiotherapy (hazard ratio [HR] = 0.93, 95% confidence interval [CI]: 0.57-1.52; P = 0.787). Multivariable analysis confirmed radiotherapy was not an independent prognostic factor for CSS (HR = 0.85, 95% CI: 0.52-1.41; P = 0.532). Median OS was 21.5 months for chemoradiotherapy and 20 months for radiotherapy (HR = 1.11, 95% CI: 0.76-1.64; P = 0.586). Multivariable analysis confirmed radiotherapy was not an independent prognostic factor for OS (HR = 1.03, 95% CI: 0.69-1.54; P = 0.888).

Conclusion: Radiotherapy demonstrates comparable survival outcomes to chemoradiotherapy in stage T1-2N0M0 SCLC patients.