Conducting Extended RAS Testing in CRC

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Extended RAS testing should be conducted on tissue collected from the primary tumor prior to the initiation of treatment with an EGFR inhibitor in patients with metastatic colorectal cancer (mCRC). Tissue collected following treatment with an EGFR-targeted monoclonal antibody could provide inaccurate readings, due to the emergence of KRAS mutant clones, notes Axel Grothey, MD.

Extended RAS testing is currently accessible at Universities, Cancer Centers, and commercial laboratories. Enacting extended testing in the community setting requires the discovery of a testing center and overcoming reimbursement hurdles, notes Grothey.

The importance of molecular testing has grown substantially in recent years, warranting more collaboration between oncologists and pathologists, notes Al B. Benson III, MD. Communication with pathology should be streamlined to help expedite molecular testing. This conversation should include a discussion about which molecular findings directly impact treatment. This awareness could enhance the importance of high-quality laboratory assessment, states Tanios Bekaii-Saab, MD.

In addition to examining RAS status, multiple other follow-up analyses will be conducted on the data from the 80405 trial. One of the striking findings from the study was the high rate of patients who went on to be treated with potentially curative surgery (10%). In the study, a surgical consult was required prior to initiating the treatment, says lead investigator Alan P. Venook, MD. This aspect of the trial may have raised awareness concerning this treatment option. In many situations, surgery is overlooked in patients with mCRC and should be considered more frequently, believes Charles D. Blanke, MD.