1799P - Efficacy and safety of integrating consolidative thoracic radiotherapy with immunochemotherapy in ES-SCLC: A real-world retrospective analysis

Background

ES-SCLC remains a challenging malignancy with a poor prognosis. The integration of immunochemotherapy and cTRT presents a potential paradigm shift in treatment. This study aims to evaluate the real-world efficacy and safety of this approach.

Methods

In a single-center retrospective study conducted at Shandong Cancer Hospital, electronic medical records of 828 ES-SCLC patients treated between January 1, 2022, and December 31, 2023, were reviewed. Patients were divided into three cohorts based on treatment strategies: chemoradiotherapy (cohort A), immunochemotherapy without/with cTRT (cohort B/C). Propensity score matching was utilized to adjust for baseline differences. The primary outcomes were rwPFS and OS. Secondary outcomes included the incidence and severity of specific interested adverse events.

Results

Of the 374 patients analyzed, cohort C showed significant improvements in rwPFS and OS compared to cohort A. The median rwPFS in cohort C (10.9 months) was longer than cohort A (7.6 months) and B (8.0 months). The 12-month rwPFS rate was highest in cohort C (41%), compared to cohort A (19%) and cohort B (34%). Median OS (mOS) was 14.0 months in cohort A, 20.8 months in cohort B, and not reached in cohort C, with the lower limit of the 95% CI for cohort C being 17.80 months. The 18-month OS rate in cohort C (63%) was numerically higher than both cohort A (28%) and B (62%). After propensity score matching, cohort C still showed improvements in rwPFS and OS. The incidence of grade 3 or higher adverse events was comparable across cohorts, with myelosuppression being the most common. However, the incidence of grade 3 or higher pneumonitis was notably higher in cohorts B and C, aligning with previous reports.

Conclusions

The combination of cTRT with immunochemotherapy for ES-SCLC showed improved rwPFS and OS, and the overall safety profile remained manageable. These findings highlight the need for further prospective studies to confirm the optimal integration of cTRT in ES-SCLC treatment strategies.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Q. Zhang.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.