methotrexate + cyclophosphamide + cytarabine + etoposide

This is a combination chemotherapy regimen consisting of four antineoplastic agents—methotrexate, cyclophosphamide, cytarabine, and etoposide. Each drug has a distinct mechanism of action targeting rapidly dividing cancer cells: - **Methotrexate** is an antimetabolite that inhibits dihydrofolate reductase, blocking DNA synthesis and cell replication. - **Cyclophosphamide** is an alkylating agent that crosslinks DNA strands, leading to apoptosis in proliferating cells. - **Cytarabine** (also known as Ara-C) is a nucleoside analog that inhibits DNA polymerase during the S-phase of the cell cycle. - **Etoposide** inhibits topoisomerase II, causing double-stranded DNA breaks and preventing cell division. This combination has been used in various protocols for hematologic malignancies such as acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma (including anaplastic large cell lymphoma), and other aggressive lymphoid cancers. The regimen may be part of induction or salvage therapy depending on disease context[2][3][4].