cetuximab + irinotecan + oxaliplatin + tegafur-uracil

This is a combination regimen consisting of four agents used in the treatment of metastatic colorectal cancer (mCRC): - **Cetuximab** is a chimeric monoclonal antibody targeting the epidermal growth factor receptor (EGFR), inhibiting downstream signaling pathways involved in cell proliferation and survival. - **Irinotecan** is a topoisomerase I inhibitor that prevents DNA replication in cancer cells, leading to cell death. - **Oxaliplatin** is a platinum-based chemotherapeutic agent that forms DNA crosslinks, inhibiting DNA synthesis and function. - **Tegafur-uracil (UFT)** is an oral fluoropyrimidine; tegafur acts as a prodrug for 5-fluorouracil (5-FU), while uracil inhibits dihydropyrimidine dehydrogenase, increasing 5-FU bioavailability. This combination aims to maximize antitumor efficacy by targeting multiple mechanisms relevant to colorectal cancer. While combinations such as cetuximab with FOLFIRI or FOLFOX are standard first-line regimens for mCRC, substitution of intravenous 5-FU with oral tegafur-uracil has been explored for convenience and tolerability[1][2][3]. The regimen would be considered primarily for patients with EGFR-expressing, RAS wild-type metastatic colorectal cancer.