“…Since the revised 2015 World Health Organization classification of lung tumors classified LCNEC as a NEN (Travis, Brambilla, Burke, Marx, & Nicholson, ), debates and investigations of the new classification were ceaseless. LCNEC was grouped with NENs due to its similarities with SCLC in terms of morphology, DNA methylation, protein levels, mutational aspects, and transcriptional levels (Aly et al, ; Karlsson et al, , ; Miyoshi et al, ; Rossi et al, ; Simbolo et al, ), in spite of a certain extent of heterogeneity (Clinical Lung Cancer Genome Project (CLCGP); Network Genomic Medicine (NGM), ; Rossi et al, ; Simbolo et al, ). In addition, despite the differences in histopathological characteristics between SCLC and LCNEC, their clinical characteristics are similar, including a generally poor outcome, greater incidence in men than in women, and advanced stage diagnosis (Asamura et al, ; Cerilli, Ritter, Mills, & Wick, ; Xu et al, ).…”