KRAS and small cell lung carcinoma: In adenocarcinoma, high TROP2 expression was associated with the male gender, larger tumor size, advanced stage, and less tumor differentiation but not with genetic alterations in EGFR, KRAS, or ALK. In HGNET, 34% (14/41) of LCNEC and 9.5% (7/74) of SCLC tumors showed high TROP2 expression.