Long-term survivor of pulmonary combined large cell neuroendocrine carcinoma treated with nivolumab.

Several authors have previously reported that patients with pulmonary combined large cell neuroendocrine cancer ( LCNEC) have a poor prognosis and there is no consensus on the treatment strategy for combined LCNEC as well as LCNEC. Here, we report the case of a long-term survivor with pulmonary combined LCNEC. The patient was a 60-year-old man who underwent thoracoscopic right lower lobectomy. The final histopathology and staging of the tumor showed LCNEC combined with squamous cell carcinoma and T2aN0M0 stage IB. Multimodality treatments including chemotherapy, radiotherapy and surgery for several recurrences were performed after the pulmonary surgery. After immune checkpoint inhibitor (ICI) therapy with nivolumab, all the metastatic lesions shrunk and a partial response was maintained at five years after the first surgery. In our case, ICI after multimodality therapy combining cytotoxic anticancer drugs and radiotherapy was effective in LCNEC with metachronous multiple metastases. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: Immune checkpoint inhibitor after multimodality therapy combining cytotoxic anticancer drugs and radiotherapy was effective in LCNEC with metachronous multiple metastases. The patient survived over five-years after the first surgery. WHAT THIS STUDY ADDS: Immune checkpoint inhibitor may be effective in some LCNEC patients.