Neoadjuvant chemoimmunotherapy in patients with limited-stage small cell lung cancer: A retrospective study.

e20002 Background: The addition of immune checkpoint inhibitors to chemotherapy significantly improves survival in extensive-stage small cell lung cancer (SCLC) and represents a promising advance in this field. However, the clinical benefit of the implementation of immunotherapy in the first-line setting for limited-stage SCLC (LS-SCLC) remains to be proven. Thus, we conducted a retrospective study to explore the efficacy of neoadjuvant chemoimmunotherapy as a first-line treatment for LS-SCLC. Methods: A retrospective study of patients with LS-SCLC who were treated with neoadjuvant PD-L1/PD-1 inhibitor combined with platinum-based chemotherapy followed by surgery between February 2020 and September 2023 was conducted. Clinical characteristics, R0 resection rate, pathologic complete response (pCR), major pathologic response (MPR), downstaging rate and disease-free survival (DFS) were evaluated. Results: As of September 30, 2023, all 21 patients (stage IIB, n = 4; stage IIIA, n = 9; stage IIIB, n = 8) received 2 to 6 cycles of neoadjuvant chemoimmunotherapy (Table 1). Nine (42.9%) patients achieved pCR and 10 (47.6%) presented an MPR (Table 2). Moreover, the R0 resection rate in total and stage III patients were 95.2% (20/21) and 94.1% (16/17), respectively. After a median follow-up of 11.2 months (range: 2.6-24.2), only two patients relapsed and the median DFS was not reached due to insufficient events. Conclusions: Neoadjuvant immune checkpoint inhibitors combined with chemotherapy demonstrated promising efficacy and feasibility, and are a potential strategy for the management of LS-SCLC. Further prospective clinical trials are necessary to clearly define the benefit of neoadjuvant chemoimmunotherapy and optimize LS-SCLC treatment. [Table: see text][Table: see text]