Blastic plasmacytoid dendritic cell neoplasm with leukemic presentation: an Italian multicenter study

Purpose: To evaluate the clinical features, the prognostic factors, and the efficacy of treatments in patients (pts) with Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) with leukemic presentation. Methods: A retrospective multicenter study was carried out during the period 2005-2011 in 28 Italian hematology divisions among GIMEMA centres. Results: A total of 43 cases were collected (M/F 31/12; median age 68 yo).At diagnosis the median bone-marrow infiltration was 73%; 33 pts (77%) had peculiar skin lesions; lymph nodes and/or spleen involvements were documented in 24 (56%), and extramedullary disease in 9 (21%). In 28 pts (65%) cytogenetic study was performed, revealing an unfavourable karyotype in 12. Forty-one pts received an induction therapy (2 died early), consisting of AML-type regimen in 26 (60%), and ALL/lymphoma-type in 15 (35%); 6 pts (14%) underwent allo-HSCT. Complete remission (CR) was achieved in 17 pts (41%), registering 7 CR after AML-type and 10 after ALL/lymphoma-type regimen, with a significant advantage for ALL/lymphoma-type chemotherapy (p=0.02). The median OS was 8.7 months (range 0.2-32.9):7.1 months (range 0.2-19.5) and 12.3 months (range 1-32.9) in pts received AML-type and ALL/lymphoma-type regimen, respectively (p=0.02). In HSCT-pts the median OS was 22.7 months (range 12-32.9), with a significant advantage with respect to the non-transplanted (median 7.1 months, range 0.2-21.3, p=0.03). Conclusions: BPDCN with bone-marrow involvement is an aggressive subtype of high-risk acute leukemia.With intensive therapy according to ALL/lymphoma-type induction the rate of CR increases. Allo-HSCT performed in first remission may lead to long-term survival in selected cases, but more data are needed.