Abstract
Abstract 4263
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.
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.
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.
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).
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.
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
