Modeling large cell neuroendocrine carcinoma of the lung for molecular, therapeutic and microenvironmental inferences: current knowledge and future perspectives

Introduction: Large cell neuroendocrine carcinoma (LCNEC) of the lung is a high-grade non-small cell carcinoma featuring neuroendocrine morphology and neuroendocrine markers. Despite being credited since decades as an independent tumor entity, it continues to represent a diagnostic and therapeutic challenge probably because makes up a heterogeneous melting pot of genetic and epigenetic alterations closely intertwined with host microenvironment. Areas covered: LCNEC of the lung was untangled according to three converging outlooks: (i) diagnostic criteria and molecular alterations as conveyors of pathogenetic diversification; (ii) microenvironmental changes, including immune system, as culprits behind tumor development; and (iii) available clinical trials, including immune-oncology studies as clinical decision-making drivers. Expert opinion: LCNEC of the lung unveils different developmental trajectories, which may account for troubles in diagnosis and clinical decision-making but, at the same time, offer a rationale for personalized targeted treatments or immunotherapy in patient subsets. Currently, the question is fascinating: are we actually ready for a radical route change in the understanding of LCNEC? The answer is still open, but future studies will need to frame LCNEC in its own overarching context among lung cancers according to a holistic vision, which does not limit us to its perception as being ‘just one tumor.’.