gemcitabine + cyclophosphamide + doxorubicin + vincristine + prednisone

This is a combination chemotherapy regimen consisting of five drugs: - **Gemcitabine** is a nucleoside analog that inhibits DNA synthesis, leading to cell death. - **Cyclophosphamide** is an alkylating agent that cross-links DNA, preventing cell division and causing apoptosis. - **Doxorubicin** (also known as hydroxydaunorubicin or adriamycin) is an anthracycline antibiotic that intercalates into DNA and inhibits topoisomerase II, resulting in DNA damage and cell death. - **Vincristine** (also called Oncovin) binds to tubulin and inhibits microtubule formation, arresting cells in metaphase during mitosis. - **Prednisone** is a synthetic corticosteroid with anti-inflammatory and immunosuppressive properties; it also induces apoptosis in certain cancer cells. This specific combination does not correspond to a widely recognized named regimen. However, four of these agents—cyclophosphamide, doxorubicin, vincristine, prednisone—form the well-established CHOP regimen for non-Hodgkin lymphoma[5][6]. Gemcitabine has been studied as an additional agent or substitute in various experimental regimens for lymphomas or solid tumors but is not part of standard CHOP-based protocols. The mechanism of action involves multiple pathways targeting rapidly dividing cancer cells through cytotoxicity (chemotherapy) and immune modulation (steroid).