When is the right time to find out my k-ras mutational status?

Discuss. For colorectal cancer patients, kras mutation status predicts for efficacy with cetuximab, a biologic drug. This is applicable only for stage 4 cases or if the cancer has come back- thus testing should be considered for these situations. In lung and other camcers, kras testing is not standard.
For cancer treatment. If you are being treated for colon cancer, having the kras mutation dictates what treatments will or will not work. Testing for the mutation is included prior to prescribing these treatments to determine if they will be effective. Typically, if you have metastatic, stage 4 colorectal cancer (spread outside the bowel, i.e. Liver), the tumor's kras gene status will be determined.