APC and colorectal carcinoma: Phosphatidylinositol-4,5-biphosphonate 3-kionase (PIK3CA) mutations have been reported in 10–20% of all CRC.31 However, no detectable PIK3CA mutation was found in SRCC in this study, which is consistent with the findings of Inamura et al. who reported a prevalence of only 6.2% (1/16 cases) in SRCC.15 Adenomatous polyposis coli (APC) mutations are the most commonly acquired mutation in sporadic colon cancer, and are considered the initial genetic alteration in CRC tumorigenesis.32 Interestingly, our study found APCmt in only 3% of SRCC compared to 44% in AC group.