Clinical characteristics and prognostic factors in diffuse large B-cell lymphoma with bone marrow involvement

7588 Background: Although several studies have been reported about non-Hodgkin’s lymphomas (NHL) with bone marrow (BM) involvement, most of them have not performed immunophenotypic studies and contained heterogeneous NHL histologies. Until now, only a few studies with small sample sizes have been reported about clinical characteristics and prognostic factors in diffuse large B-cell lymphoma (DLBCL) with BM involvement. Methods: Between January 1993 and March 2004, 486 patients were diagnosed with DLBCL. Among 84 DLBCL patients who had BM involvement at initial diagnosis, 9 were not ineligible because of the lack of clinical data or unavailability of BM specimen. So, clinical factors and patterns of BM involvement of 75 patients were analyzed in this study. Results: At initial diagnosis, the median age was 57 years (range: 25∼79). In addition to BM, lymph nodes (76%), spleen (23%), Waldeyer’s ring (19%), gastrointestinal tract (16%), lung/pleura (15%), bone (15%), central nervous system (9%), nasal cavity (8%) and liver (7%) were also involved. Among 75 patients, 67 patients received anthracycline-containing chemotherapy; 4 patients received non-anthracycline-containing chemotherapy and 4 could not receive systemic chemotherapy because of combined medical conditions. The median survival was 32.3 months (5-year overall survival [OS]: 38%). In univariate analysis for prognostic factors, high-intermediate or high international prognostic index (IPI), B-symptoms, leucopenia, anemia, thrombocytopenia, pattern of BM involvement (interstitial or diffuse pattern), > 10% replacement of BM area by lymphoma cells, > 10% of large cell infiltration in BM-involved area by lymphoma at initial diagnosis were associated with poor OS (p < 0.05). Multivariate analysis indicated that > 10% replacement of BM area by lymphoma cells (p < 0.001), peripheral thrombocytopenia (p = 0.001) and high-intermediate or high IPI (p = 0.042) were independent predictors of poor OS. Conclusions: To our knowledge, this is the largest study about DLBCL patients with BM involvement. The BM areas involved by lymphoma cells, peripheral thrombocytopenia and IPI at initial diagnosis are independent prognostic factors in these patients. No significant financial relationships to disclose.