Second- and Further-line Treatment in Patients with Metastatic Colorectal Cancer

Metastatic colorectal cancer refers to colorectal cancer that has spread to other sites in the body.

Some cancer cells have proteins on their surface called epidermal growth factor receptors (EGFRs). Anti-EGFR drugs inhibit the function of these proteins, preventing them from promoting growth of cancer cells.

Patients for whom treatment with anti-EGFR drugs are considered should undergo genetic testing to check if they have a genetic change, or mutation, in their KRAS or NRAS genes. KRAS and NRAS are cancer-causing genes.

This is as anti-EGFR drugs should be reserved for patients with the standard gene for KRAS and NRAS, and should not be used when a mutation is found in the KRAS or NRAS genes.