Heterogeneity of response and survival in diffuse histiocytic lymphoma after BACOP therapy (bleomycin, doxorubicin, cyclophosphamide, vincristine, prednisone)

Diffuse 'histiocytic' lymphoma (DHL) is heterogeneous pathologically, consisting of four subtypes within Lukes-Collins; large-cleaved (LC), large non-cleaved (LNC), immunoblastic sarcoma of B cells (B-IBS), and immunoblastic sarcoma of T-cells (T-IBS). This heterogeneity is also recognized in the Cooperative Working Formulation on non-Hodgkin's lymphoma. Prior studies have suggested clinical heterogeneity of DHL as well, although conclusions were hampered by small numbers, and lack of therapeutic uniformity. We treated 57 patients with advanced DHL, using BACOP: 22 LNC, 16 T-IBS, 13 B-IBS, six LC. Complete remission rate for LNC was 64 per cent (14/22); B-IBS was 54 per cent (7/13); LC was 33 per cent (2/6); T-IBS was 25 per cent (4/16). (p = 0.10). Median survival for LNC was 27.8 months, B-IBS was 25.9, LC was 14, T-IBS was 12.0. The survival was significantly shorter for T-IBS patients when compared to the others (p = 0.01). By multi-variate analysis, histologic subtype (p = 0.02), age (p = 0.03), and stage (p = 0.06) were significant and independent prognostic variables in predicting survival. We conclude that LNC may respond the most favourably to BACOP, whereas alternative regimens appear necessary for patients with T-IBS.