[Effectiveness of Nivolumab in Large-Cell Neuroendocrine Carcinoma of the Lung - A Report of Two Cases].

Background: The anti-programmed death-1 antibody nivolumab is an important treatment option for non-small-cell lung carcinoma.However, its effectiveness for large-cell neuroendocrine carcinomas(LCNEC)is still controversial.Here, we report 2 cases of LCNECs that responded to nivolumab.Case 1: A 62-year-old man received chemotherapy and radiotherapy for stage III A lung adenocarcinoma.One year later, another lung lesion was observed and diagnosed as LCNEC using surgical lung biopsy.Although he subsequently received some chemotherapy regimens, the patient developed new brain metastasis, expanded mediastinal lesion, and increased levels of the tumor marker pro-gastrin releasing peptide(ProGRP).We started nivolumab as the sixth-line treatment.In response, ProGRP levels significantly decreased and the mediastinal lesion became smaller.Case 2: A 55-year-old man was diagnosed with stage III A LCNEC and received chemotherapy and radiotherapy.The primary lesion was controlled; however, lung metastases developed and chemotherapy was unable to control them.We provided treatment with nivolumab as the third-line therapy.The tumor marker ProGRP decreased and the lung metastases became smaller.

Conclusion: Nivolumab can be a valuable treatment option for LCNEC.