Impact of occult bone marrow involvement on the outcome of rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone therapy for diffuse large B-cell lymphoma.

We assessed the prognostic impact of occult bone marrow involvement, determined by flow cytometry and/or polymerase chain reaction, in a population of 117 consecutive patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP). Twenty-four (20.5%) had morphologically diagnosed and 16 (13.