Role of cetuximab in first-line treatment of metastatic colorectal cancer.

The treatment of metastatic colorectal cancer (mCRC) has evolved considerably in the last decade, currently allowing most mCRC patients to live more than two years. Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor play an important role in the current treatment of these patients. However, only antibodies directed against EGFR have a predictive marker of response, which is the mutation status of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS). Cetuximab has been shown to be effective in patients with KRAS wild-type mCRC. The CRYSTAL study showed that adding cetuximab to FOLFIRI (regimen of irinotecan, infusional fluorouracil and leucovorin) significantly improved results in the first-line treatment of KRAS wild-type mCRC. However, results that evaluate the efficacy of cetuximab in combination with oxaliplatin-based chemotherapy in this setting are contradictory. On the other hand, recent advances in the management of colorectal liver metastases have improved survival in these patients. Adding cetuximab to standard chemotherapy increases the response rate in patients with wild-type KRAS and can thus increase the resectability rate of liver metastases in this group of patients. In this paper we review the different studies assessing the efficacy of cetuximab in the first-line treatment of mCRC.