mitomycin C + Oncovin + semustine + thiotepa

**Mitomycin C + Oncovin + semustine + thiotepa** is a combination chemotherapy regimen consisting of four cytotoxic agents: mitomycin C (an antibiotic that inhibits DNA synthesis by cross-linking DNA strands), Oncovin (vincristine, a vinca alkaloid that disrupts microtubule formation and mitosis), semustine (a nitrosourea alkylating agent that methylates DNA causing strand breaks), and thiotepa (an alkylating agent that cross-links DNA to prevent replication). This multi-agent approach leverages complementary mechanisms to enhance antitumor efficacy against rapidly dividing cancer cells, primarily used historically in gastrointestinal cancers such as colorectal or gastric tumors, though specific trial data for this exact quartet is limited.