Predicting therapeutic outcome in patients with diffuse histiocytic lymphoma treated with cyclophosphamide, adriamycin, vincristine and prednisone (CHOP).

Seventy-five patients with diffuse histiocytic lymphoma (DHL) ranging in age from 33 to 94 years were treated with cyclophosphamide, Adriamycin, vincristine and prednisone (CHOP). Thirty-eight patients (51%) achieved complete remission, but nine of these patients relapsed after remission lasting one to 23 months (median time to relapse, four months). We used multivariate analysis to identify those characteristics that significantly affected treatment outcome. The chances for complete remission were adversely affected by DHL appearing after histologic conversion from another lymphoma (P = 0.006), the presence of systemic symptoms (P = 0.24), and not having the large noncleaved (LNC) histologic subtype (P = 0.40). The chance for relapse from complete remission was increased only by the presence of systemic symptoms (P = 0.042). Overall survival was adversely affected by the presence of bone marrow involvement (P = 0.002), having other than LNC histologic subtype (P = .010), and the presence of systemic symptoms (P = 0.043). It appears that patients whose DHL appears de novo and who also are symptom status A (70% long-term disease-free survival) or have the LNC histologic subtype (67% long-term disease-free survival) have an excellent outlook when treated with CHOP at the doses used in this study. However, patients with B symptoms (16% long-term disease-free survival), histologic conversion to DHL (8% long-term disease-free survival), previous chemotherapy (8% long-term disease-free survival), and bone marrow involvement (8% long-term disease-free survival) respond poorly and for these patients other treatments need to be identified. In addition, patients with B symptoms who achieve complete remission with CHOP are at high risk to relapse (59% relapse rate) and should be considered for "intensification" therapy after complete remission is documented.