Squamous Cell Carcinoma : Molecular Genetics
Due to the widespread mutagenic effects of cigarette smoking, squamous cell carcinomas of lung show very high mutation rates. Commonly noted genetic abnormalities include: gain/amplification of 3q (SOX2, TP63), 7p (EGFR), and 8p (FGFR1); deletion of 9p (CDKN2A); mutation of TP53 (most frequent), CDKN2A, PTEN, PIK3CA, KEAP1, MLL2, HLA-A, NFE2L2, NOTCH1, and RB1. Pure squamous cell carcinomas usually do not harbor EGFR and KRAS mutations. The image shows nests of tumor cells underneath bronchial epithelium.