American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the standard therapy for all patients with diffuse large B-cell lymphoma?

1. Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone

2. Cyclophosphamide and methotrexate

3. Methotrexate and cytarabine

4. Doxorubicin and bleomycin

The correct answer is: Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone

The standard therapy for all patients with diffuse large B-cell lymphoma (DLBCL) is the combination of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone, commonly referred to as R-CHOP. This treatment regimen has been established as the backbone for managing DLBCL, which is the most common type of non-Hodgkin lymphoma. Rituximab is a monoclonal antibody that targets the CD20 antigen present on the surface of B-cells, including malignant B-cells in DLBCL. By binding to this antigen, rituximab helps to mediate destruction of these cancerous cells through various mechanisms, including antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. The chemotherapy agents included in the R-CHOP regimen have distinct roles: cyclophosphamide is an alkylating agent that interferes with DNA synthesis, doxorubicin is an anthracycline that intercalates DNA and inhibits topoisomerase II, vincristine disrupts the formation of microtubules, and prednisone is a corticosteroid that helps reduce inflammation and can induce apoptosis in lymphoid cells. The R-CHOP regimen is preferred