Immune checkpoint inhibitor therapy achieved complete response for drug-sensitive egfr/alk mutation-negative metastatic pulmonary large-cell neuroendocrine carcinoma with high tumor mutation burden: A case report

Abstract

Large-cell neuroendocrine lung carcinoma (LCNELC) is classified into lung neuroendocrine tumors according to WHO 2015 classification guidelines and represents approximately 3% of all lung cancer. Because of the rarity of LCNELC, there is a lack of prospective studies guiding treatment. Here, we report a case of a patient with pT2aN2M0 stage IIIA LCNELC (drug-sensitive EGFR/ALK mutation-negative, PD-L1-negative but tumor mutation burden (TMB) high), who progressed rapidly after surgery but achieved a complete response to subsequent immune checkpoint inhibitor (ICI) therapy. The concen-tration of circulating tumor DNA (ctDNA) following the treatment course strongly reflects the response to ICI therapy. This report highlights the efficacy of ICI treatment in metastatic LCNELC patients with a high TMB and suggests that ctDNA analysis in detecting molecular residual disease may facilitate the personalization of ICI therapy.