Cetuximab Therapy for Third Line Rechallenge in Metastatic Colorectal Cancer

This research is intended to check the benefit of treatment with cetuximab in metastatic colorectal cancer patients with wild type RAS as third line treatment. The advantage to the patients is unclear. This study will look if mutations in patients’ blood area predictive marker for progression free time (FPT) in metastatic colorectal cancer patients treated with third line cetuximab. A predictive marker for FPT metastatic colorectal cancer patients treated with third line cetuximab will enable a reduction in the number of treated patients. Treatment only of patients with a positive marker is expected to prevent inefficient treatment which will reduce suffering for the patients and reduce unnecessary medical treatment.