Normal cells are more able than cancer cells to repair damage from chemotherapy drugs. This regimen can also be combined with the
monoclonal antibody rituximab if the lymphoma is of
B cell origin; this combination is called R-CHOP. In 2002, a randomized controlled trial showed a higher complete response rate for R-CHOP vs CHOP in elderly patients with Diffuse Large-B-Cell Lymphoma (76% vs 63%). Typically, courses are administered at an interval of two or three weeks (CHOP-14 and CHOP-21 respectively). A
staging CT scan is generally performed after three cycles to assess whether the disease is responding to treatment. In patients with a history of
cardiovascular disease, doxorubicin (which is
cardiotoxic) is often deemed to be too great a risk and is omitted from the regimen. The combination is then referred to as
COP (cyclophosphamide, Oncovin, and prednisone or prednisolone) or
CVP (cyclophosphamide, vincristine, and prednisone or prednisolone). As elderly patients have a greater risk of toxicity from the drugs, an option is to use an attenuated drug regimen, called
miniCHOP. ==Side-effects and complications==