The Role of KRAS Mutation Testing in the Management of Patients With Metastatic Colorectal Cancer

Abstract Context.—KRAS mutations can be detected in approximately 30% to 40% of all patients with colorectal cancer. Several recent studies have shown that patients with KRAS mutations in codons 12 or 13 in metastatic tumors do not benefit from anti–epidermal growth factor receptor therapy with cetuximab or panitumumab. Objective.—To review the literature on the role of KRAS mutation testing for management of patients with metastatic colorectal cancer and to discuss testing strategies. Data Sources.—This review is based on published, peer-reviewed literature; available information from medical organizations (eg, National Comprehensive Cancer Network, American Society of Clinical Oncology, College of American Pathologists); and information from clinical laboratories conducting KRAS mutation analysis. Conclusions.—Multiple methods for detecting KRAS mutations in colorectal tumors are available, and all methods in current clinical use appear to have adequate clinical sensitivity for predicting a lack of response to cetuximab and panitumumab. Pathologist expertise is essential to quality KRAS testing and to determining effective treatment for patients with metastatic colorectal cancer.