Outcomes of Patients (pts) with Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) Treated with Hyper-CVAD-Based Chemotherapy Regimens: MD Anderson Case Series
Authors: Pemmaraju Naveen , Thomas Deborah A. , Kantarjian Hagop M. , Pierce Sherry , O’Brien Susan , Cortes Jorge E. , Faderl Stefan 
Published: October 2019

Abstract
Abstract 4263

Background:
BPDCN, formerly known as CD4 + CD56 + hematodermic tumor or blastic NK cell lymphoma, is an exceedingly rare and aggressive hematologic malignancy. Although most pts with BPDCN receive intensive multi-agent chemotherapy and are referred for consideration of SCT, their prognosis remains poor and little is known about how to effectively treat these pts.

Objective:
We therefore reviewed the characteristics and outcome of all pts with BPDCN who were referred to us and treated with various Hyper-CVAD-based regimens to identify patterns of disease and response that might be useful for future pts.

Methods:
We conducted a retrospective chart review of pts meeting the following criteria: pathological diagnosis of BPDCN confirmed by an experienced hematopathologist; age 18 or older; treated at MD Anderson Cancer Center, and at least one documented follow-up visit.

Results:
We identified a total of 5 pts who presented between October 2008 and July 2011. All were male. Median age was 65 yrs (range 20–86). At diagnosis, 4 of the 5 pts had bone marrow involvement; 2 pts had skin involvement, and 1 pt with inguinal lymph node involvement. Immunophenotype by flow cytometry was CD4+(4/5 pts) CD56+(1/5 pt negative), TCL-1+ (4/5 pts, unknown in 1 pt) and partial loss/negative for CD3 and CD8 (5/5 pts). Cytogenetics were complex in 2 pts and diploid in 3. Baseline median WBC was 5.4 (2.2–76.5) and baseline median platelet count was 99 (48–112). Median baseline bone marrow blasts: 21% among 4/5 pts (one not evaluable). No pts had prior history of hematologic malignancy. One pt had a daughter with CLL. All 5 pts received first-line therapy with Hyper-CVAD (1 pt received chemotherapy with cyclophosphamide, adriamycin, vincristine, prednionse (CHOP) x1 cycle and then went on to get Hyper-CVAD × 4 cycles afterwards once diagnosis was confirmed as BPDCN). Hyper-CVAD consists of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and Dexamethasone, alternating with high-dose methotrexate and cytarabine for a total of 8 cycles followed by a 24 to 32 months lasting POMP (prednisone, vincristine, methotrexate, mercaptopurine) maintenance. All pts were referred to stem cell transplantation (SCT) if they had a donor and there were no other contraindications for SCT. All pts received a median number of 4 cycles (range 1–5) of Hyper-CVAD and median number of total lines of chemotherapy regimens was 3 (range 1–4). Three pts went on to receive a stem cell transplant (SCT), (2= allogeneic (allo) SCT, 1= autologous (auto) SCT), their outcomes showed: 1 pt achieved CR2 but died of relapsed disease status post auto SCT, 1 pt alive in CR2 for 2 months status post 1 antigen-mismatched allo SCT, 1 pt alive with bone marrow CR1 for 4 months status post allo SCT. For the other 2 pts not receiving SCT, their outcomes were: 1 pt died during first induction course, 1 pt achieved CR1 for 4 months then relapsed and died. The median duration of CR1 was 4 months (4–18). Only one pt received radiation treatment because of a residual mediastinal mass after 3 cycles of Hyper-CVAD despite bone marrow remission. Three of the 5 patients have died with a median overall survival of 32 months (pt with longest follow-up was the 1 pt with no bone marrow involvement at diagnosis and died at 32 months).

Conclusion:
BPDCN is a rare but aggressive malignancy with dismal prognosis in most pts. Despite intensive multi-agent chemotherapy and SCT, response rates are low and survival is short. A better understanding of the biologic basis of the disease and novel treatment approaches are crucial for improving outcome.

Disclosures:
No relevant conflicts of interest to declare.