Tag: Colon Cancer

As we understand the molecular biology of colon cancer, it is becoming clear that tumors with MisMatch Repair Deficiency (MMR-D) and high MicroSatellite Instability (MSI) tend to have a favorable prognosis and do not benefit from chemotherapy and on the contrary, 5-FU based chemotherapy may potentially result in a detrimental effect. The Oncotype DX colon cancer 12 gene assay is a valuable tool that can provide additional information in the decision making process.

Testing for KRAS mutations is presently the standard of care prior to treatment with anti EGFR monoclonal antibodies such as cetuximab and panitumumab, as KRAS mutant colorectal tumors do not respond to anti EGFR monoclonal antibodies. However it is becoming clear that BRAF which is involved in intracellular signaling and cell growth and a principal downstream mediator of KRAS, when mutated resulted in shorter progression free survival and overall survival regardless of KRAS status. Targeted therapy may be taking a turn for the better making treatment more personalized.