While little is known about BPDCN and how to treat it, authors of a recent study suggest a low threshold for performing a skin biopsy to evaluate skin lesions in patients with hematological cancers, especially when those lesions that are quickly progressing, large or involve atypical sites.
A skin biopsy of a 65-year-old woman’s rapidly progressing facial and scalp lesions helped doctors treating her to diagnose the rare hematological malignancy blastic plasmacytoid dendritic cell neoplasm, according to a case report published last year in the BMJ.1
While little is known about this cancer and how to treat it, the authors suggest a low threshold for performing a skin biopsy to evaluate skin lesions in patients with hematological cancers, especially when those lesions are quickly progressing, large or involve atypical sites.
Blastic plasmacytoid dendritic cell neoplasm is thought to account for less than 1% of hematological cancers. Concurrent CD4, CD56, BCL-2 and CD123 expression defines the malignancy. More than 90% of patients present (many early in the disease) with indolent skin lesions. Patients might also present initially with leukemic, or system, involvement. There have been rare reports of bone marrow, lymph node, central nervous system, spleen, liver, lung and other areas of involvement, according to the paper.
In 10% to 20% of blastic plasmacytoid dendritic cell neoplasm cases, patients have a history of cancer. Common cancers in their pasts include myelodysplastic syndrome, chronic myelomonocytic leukemia and acute myeloid leukemia. These associations, among other things, suggests blastic plasmacytoid dendritic cell neoplasm is a myeloid-related neoplasm, they wrote.
Patients with the cancer have a poor prognosis. The patient in this particular case died four months after her diagnosis. Allogeneic hematopoietic stem cell transplant is the most effective treatment.
In this case, doctors had diagnosed the patient with myeloproliferative disorder and chronic lymphocytic leukemia in 2002. Providers noted an increasing lymphocyte count consistent with early stage chronic lymphocytic leukemia in 2011, so they monitored her blood counts but didn’t treat her. It was in September 2018, when she developed prominent violaceous patches and nodules on her scalp and upper part of the face that doctors diagnosed widespread blastic plasmacytoid dendritic cell neoplasm.
They treated her with hyper-cyclophosphamide, vincristine, doxorubicin, dexamethasone (CVAD) and intrathecal methotrexate. But she continued to progress, even after doctors tried another treatment option, decitabine and venetoclax.
Providers have no clear guidelines for treating blastic plasmacytoid dendritic cell neoplasm. Among the potentially effective treatment regimens, hyper-CVAD, methotrexate and cytarabine, as well as cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or CHOP plus etoposide. Research suggests these patients are at high risk for central nervous system involvement, especially in relapses. As a result, central nervous system prophylaxis using intrathecal therapy is recommended, according to the paper.
The U.S. Food and Drug Administration (FDA) approved tagraxofusp-erzs (Elzonris, Stemline Therapeutics) in December 2018 for blastic plasmacytoid dendritic cell neoplasm in adults and children ages 2 years and older. FDA approved tagraxofusp-erzs, a CD123-directed cytotoxin, based a multicenter, multicohort, open-label, single-arm clinical trial of patients with untreated or relapsed/refractory blastic plasmacytoid dendritic cell neoplasm.
“In the pivotal cohort, seven (53.8%; 95% CI: 25.1, 80.8) of 13 patients with untreated BPDCN achieved complete response/clinical complete response after a median follow-up of 11.5 months. The median response duration was not reached. In the second cohort, of 15 patients with relapsed or refractory BPDCN, one patient achieved a complete response (duration 111 days) and one patient achieved a clinical complete response (duration 424 days),” according to an FDA release on the approval.2
In the case documented in the BMJ, doctors offered the patient tagraxofusp-erzs before it was approved as an experimental agent. But because of logistic issues she didn’t receive the drug. She wasn’t a candidate for the drug after its approval due to performance status, according to the authors.
Researchers have shown a greater overall survival after allogeneic hematopoietic stem cell transplant than with chemotherapy alone. Allogeneic hematopoietic stem cell transplant is preferred over autologous stem cell transplant, according to the paper.
“Stem cell transplantation beyond first complete remission … might have an adverse impact on the survival. However, many patients are elderly and frail, or have rapidly progressive disease that never achieves remission. Thus, they are very poor candidates of stem cell transplant. In such groups, venetoclax with hypomethylating agents like decitabine or azacitidine has shown some benefit,” they wrote.
The authors report no relevant disclosures.
Khan AM, Munir A, Raval M, et al Blastic plasmacytoid dendritic cell neoplasm in the background of myeloproliferative disorder and chronic lymphocytic leukaemia BMJ Case Reports CP 2019;12:e230332.
FDA approves tagraxofusp-erzs for blastic plasmacytoid dendritic cell neoplasm. U.S. Food and Drug Administration. https://www.fda.gov/drugs/fda-approves-tagraxofusp-erzs-blastic-plasmacytoid-dendritic-cell-neoplasm. Published December 21, 2018.