WCLC 2025 - Posters & ePosters-P3.13.04 Consolidation Thoracic Radiotherapy After Chemoimmunotherapy in ES-SCLC: A Multicentric Retrospective Analysis

Pdf Summary

This multicentric retrospective study evaluated the impact of consolidative thoracic radiotherapy (TRT) in patients with extensive-stage small-cell lung cancer (ES-SCLC) treated with first-line chemo-immunotherapy across four European centers between 2020 and 2024. Of 396 screened patients, 336 met inclusion criteria, with 111 (33%) receiving TRT after chemo-immunotherapy and 225 not receiving TRT.<br /><br />The primary endpoint was intrathoracic control rate. Results demonstrated that while overall disease progression rates did not significantly differ between TRT and non-TRT groups (78.4% vs 82.8%, p=0.329), intrathoracic recurrence was significantly lower in the TRT group (40.5% vs 57.8%, p=0.003). Secondary endpoints revealed that TRT was associated with significantly longer progression-free survival (PFS) (8.1 vs 6.1 months, p=0.010) and overall survival (OS) (13.5 vs 11.0 months, p=0.004). The 1-year OS rate was 55% with TRT versus 41% without; at 2 years, 21% vs 12%. Higher-dose TRT further improved outcomes: median PFS of 9.6 vs 8.0 months (p=0.016) and median OS of 20.2 vs 13.1 months (p=0.013).<br /><br />Subgroup analysis highlighted that patients without baseline liver metastases and those exhibiting good response to initial therapy derived the greatest benefit, with median OS of 15.7 months versus 8.4 months in those with liver metastases.<br /><br />This represents the largest retrospective cohort assessing consolidative TRT in ES-SCLC within the immunotherapy era. Findings suggest that consolidative TRT after chemo-immunotherapy reduces intrathoracic recurrence and improves survival outcomes, particularly in selected patient subsets. The study underlines the need for prospective trials to define optimal TRT dosing and better characterize toxicity profiles in this setting, given that pivotal immunotherapy trials did not incorporate TRT.<br /><br />In summary, consolidative TRT appears a promising strategy to enhance intrathoracic disease control and survival in ES-SCLC patients undergoing first-line chemo-immunotherapy.

Asset Subtitle

Federico Monaca

Meta Tag

Speaker Federico Monaca

Topic Small Cell Lung Cancer and Neuroendocrine Tumors

Keywords

consolidative thoracic radiotherapy

extensive-stage small-cell lung cancer

first-line chemo-immunotherapy

intrathoracic control rate

progression-free survival

overall survival

higher-dose TRT

liver metastases

retrospective multicentric study

immunotherapy era