fluorouracil + leucovorin + oxaliplatin + raltitrexed

This is a four-drug chemotherapy combination consisting of fluorouracil, leucovorin, oxaliplatin, and raltitrexed. Each component has a distinct mechanism of action targeting cancer cell proliferation: - **Fluorouracil (5-FU)** is an antimetabolite that inhibits thymidylate synthase, disrupting DNA synthesis and function. - **Leucovorin (folinic acid)** enhances the binding of 5-FU to thymidylate synthase, increasing its cytotoxicity. - **Oxaliplatin** is a platinum-based agent that forms DNA crosslinks and inhibits DNA replication and transcription. - **Raltitrexed** is a direct inhibitor of thymidylate synthase. This combination would be expected to have synergistic antineoplastic effects by targeting nucleotide synthesis and directly damaging DNA. While combinations such as FOLFOX (fluorouracil + leucovorin + oxaliplatin) are standard for colorectal cancer[1][2][3][4], the addition of raltitrexed is less common but may be considered in research or specific clinical scenarios.