Pathologic responses to neoadjuvant chemoimmunotherapy in primary limited-stage small-cell lung cancer.

Background: Immunotherapy has been proved to have a large effect on extensive-stage small cell lung cancer, but the role of immunotherapy in limited-stage small-cell lung cancer (LS-SCLC) is still unknown.

Methods: A retrospective study of six patients with LS-SCLC who were treated with neoadjuvant chemoimmunotherapy (durvalumab plus etoposide combined with cisplatin) was performed. Patients were evaluated by the safety, feasibility and pathologic responses of neoadjuvant chemoimmunotherapy.

Results: Neoadjuvant durvalumab combined chemotherapy was associated with few immediate adverse events and did not delay planned surgery. All patients achieved partial pathologic response (pPR) instead of major pathologic response, or pathologic complete response. No association was observed between programmed death-ligand 1 expression in tumor specimens and the pathologic response. However, tumors with high expression of immune cells such as CD4+ T cells, CD8+ T cells and FoxP3+ Tregs tended to have better pathologic responses than tumors with low expression of immune cells.

Conclusions: Neoadjuvant durvalumab combined chemotherapy could induce pPR with few side effects in resectable LS-SCLC. The immune cells in the tumor microenvironment might play an important role in neoadjuvant chemoimmunotherapy in resectable LS-SCLC.