kRAS Mutation Testing

Identifying patients with metastasized colorectal cancer, who will not benefit from treatments targetting epidermal growth factor receptor (EGFR) is now possible.

Prognosis for patients with metastasized colorectal cancer has significantly improved due to the introduction of new treatments that target the EGFR. However, not all patients benefit from these treatments. It has recently been found that in patients with metastatic colorectal cancer, EGRF targetting treatment is only effective in those patients that have a normal (or wild-type) kRAS gene within their tumour.

KRAS mutation analysis has become part of the standard care in patients treated with EGFR targetteing therapy. A number of studies have demonstrated that in patients with metastatic colorectal cancer the addition of either cetuximab or panitumumab as monotherapy or in combination with chemotherapy increases the progression free survival. However, only patients without a mutation in the kRAS gene benefit from this treatment.

References:

Amado RG et al (2008) Wild-type kRAS is required for panitumumab efficacy in patients with metastatic colorectal cancer. J Clin Oncol 26: 1626-1634.

DeRoock W et al (2008) kRAS sild-type state predicts survival and is associated to early radiological response in metastatic colorectal cancer treated with cetuximab. Ann Oncol 19: 508-515.