A study of postoperative pathologic complete response (pCR) following neoadjuvant chemoimmunotherapy in limited-stage small cell lung cancer (LS-SCLC).

This retrospective study evaluated the efficacy and safety of neoadjuvant chemotherapy-immunotherapy combined with radical resection in 7 patients with limited-stage small cell lung cancer (LS-SCLC). Patients received a median of 3 cycles of neoadjuvant therapy with PD-1/PD-L1 inhibitor-based regimens (etoposide combined with cisplatin/carboplatin), followed by surgical resection and adjuvant chemoimmunotherapy. Imaging and biomarker assessments demonstrated significant tumor regression: 3 patients achieved partial response (PR) and 3 achieved complete response (CR) per RECIST criteria. Pathological examination confirmed complete pathological response (pCR) in all 7 patients. All patients successfully underwent R0 resection with low perioperative complication rates and no perioperative mortality. At median follow-up of 42 months, 6 patients maintained durable disease-free survival, while one patient developed left supraclavicular lymph node and cerebral metastases 16 months post-surgery, resulting in death 3 months after diagnosis. Treatment-related adverse events were manageable, predominantly mild to moderate in severity, with no treatment-related deaths. The findings suggest that neoadjuvant chemoimmunotherapy significantly induces tumor regression, enhances resectability, and improves long-term survival in LS-SCLC patients, though larger-scale clinical trials are needed to validate these results and optimize therapeutic strategies for this aggressive malignancy.