Treatment guidelines for metastatic colorectal cancer patients with RAS mutation

In this study, the American Society of Clinical Oncology Provisional Clinical Opinion (PCO) updated recommendations for treating metastatic (spread to other organs) colorectal cancer patients with RAS gene mutation.

RAS mutation (change) is one of the most common in colorectal tumors. This mutation can affect the response to some anti-cancer drugs. Previous studies showed that patients with this mutation were more resistant to anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy (such as cetuximab [Erbitux] and panitumumab [Vectibix]). The PCO reviewed these studies and updated the guidelines for treatment of metastatic colorectal cancer patients with RAS mutation.

This study addressed the need of metastatic colorectal cancer patients to be tested for RAS mutation.

Thirteen articles were reviewed with information about 19453 patients. 6 out of 13 studies reported an improved survival of patients when an anti-EGFR drug was added to the treatment in patients with no RAS mutation.

Twelve out of 13 studies reported an improved progression-free survival (PFS; time from treatment to disease progression or death) for patients with no RAS mutation, treated with anti-EGFR.

Tumor KRAS and NRAS testing is the recommended procedure before initiating treatment, because RAS mutation in exon 2, 3 or 4 are associated with failure in treatment with anti-EGFR drugs.

The recommendations have suggested that all metastatic colorectal patients who are candidates to start treatment with anti-EGFR drugs should have their tumor tested for mutations in both KRAS and NRAS exons 2, 3 and 4. Anti-EGFR therapy should only be considered for treatment of patients with tumors with no RAS mutations.