When doctors treat metastatic colorectal cancer, they often use a class of drugs called EGFR inhibitors. However, not every patient responds the same way. New data from a large review of 1,478 patients shows that two specific genetic markers, known as PIK3CA and BRAF mutations, can change the outlook for those undergoing this first-line therapy.
Patients with these mutations saw significantly worse progression-free survival and overall survival compared to those without them. While the initial response rate—how much the tumor shrinks at first—did not show a significant difference between the groups, the long-term outcomes were notably different. These mutations act as negative prognostic biomarkers, meaning they can signal a tougher road ahead for the patient.
Because these mutations clearly impact how long a patient lives and how long the cancer stays stable, experts suggest that testing for both BRAF and PIK3CA before starting treatment is helpful. While these results are based on a meta-analysis rather than a single new trial, they provide a clearer picture of how genetics shape the journey for patients with RAS wild-type metastatic colorectal cancer.
