Abstract 317P
Background
Compared with chemotherapy alone, the addition of atezolizumab in the first-line treatment of patients with extensive-stage small cell lung cancer (ES-SCLC) improves overall survival, though the benefit remains limited. This study aims to investigate the factors influencing prognosis and to assess the impact of the number of induction chemotherapy cycles on treatment efficacy.
Methods
We retrospectively analyzed the data from patients with ESSCLC treated at five centers between March 2020 and September 2022. All 45 patients received first-line treatment with etoposide plus platinum combined with atezolizumab. The primary endpoints were progression-free survival (PFS) and overall survival (OS) in the overall population and subpopulations based on the number of induction chemotherapy cycles. Lasso regression was applied to identify prognostic variables.
Results
The study enrolled 45 patients. The median PFS for first-line treatment was 7 months, and the median OS was 17.6 months. Ten variables were analyzed using Lasso regression, including gender, age, liver metastases, bone metastases, brain metastases, number of first-line induction chemotherapy cycles, first-line immunotherapy maintenance, receipt of cross-line immunotherapy, chest radiotherapy, and brain radiotherapy. The analysis revealed that receiving ≥6 cycles of induction chemotherapy was the most important and only significant variable affecting prognosis (concordance index [C-index]=0.658), with a hazard ratio (HR) of 0.32 (95% CI, 0.17–0.63). Patients who received ≥6 cycles of induction chemotherapy (n=25) had longer median PFS (8 months vs. 5 months) and median OS (18.5 months vs. 13.1 months) compared to those who received
Conclusions
Receiving ≥6 cycles of induction chemotherapy prolonged the median PFS and median OS, making it a crucial factor influencing the efficacy of first-line atezolizumab combined with chemotherapy in patients with ES-SCLC.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.