This study adhered to MOOSE guidelines.Databases were searched for studies comparing KRAS, BRAF, microsatellite instability (MSI), CpG island methylator phenotype (CIMP), p53 and p27 status between patients with mucinous and non-mucinous colorectal adenocarcinoma.
What is not known is whether UAC in its morphologic similarity to CAC could show immunohistochemical features of MSI along with KRAS- and BRAF-activating mutations.
Immunohistochemistry using the BRAFV600E mutation-specific monoclonal antibody VE1 is not a useful surrogate for genotyping in colorectal adenocarcinoma.
EGFR gene copy number gains and KRAS/BRAF mutations have been reported to act as positive and negative predictors, respectively, of therapeutic response to EGFR targeted therapies in colorectal adenocarcinoma, a tumour type claimed to be genetically similar to ITAC.
Limited reports in the literature have shown that the variant of colorectal cancer demonstrated a different pattern of genetic alterations of common growth kinase-related oncogenes (K-ras, BRAF), tumour suppressor genes (p53, p16), gene methylation and cell adhesion-related genes related to the Wingless signalling pathway (E-cadherin and beta-catenin) from conventional colorectal adenocarcinoma.
Sanger sequencing is one of several reliable methods in use to detect KRAS and BRAF mutations to facilitate clinical patient selection for anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy in unresectable metastatic colorectal adenocarcinoma (CRC).