Hairy Cell Leukemia Guidelines

Updated: Sep 16, 2018
  • Author: Emmanuel C Besa, MD; Chief Editor: Koyamangalath Krishnan, MD, FRCP, FACP  more...
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Guidelines

Guidelines Summary

The following organizations have released guidelines for the management of hairy cell leukemia (HCL):

  • National Comprehensive Cancer Network (NCCN) [15]
  • European Society for Medical Oncology (ESMO)  [16]
  • Hairy Cell Leukemia Foundation (HCLF) [17]  

Diagnosis

According to NCCN guidelines, immunohistochemistry (IHC) and flow cytometry are essential for establishing a diagnosis of HCL and distinuguishing between HCL and hairy cell variant. The recommended tests include the following [15] :

  • Immunohistochemistry (IHC) panel or flow cytometry: CD19, CD20, CD5, CD10, CD11c, CD22, CD25, CD103, CD123, cyclin D1, and CD200
  • IHC for BRAF V600E mutation 

ESMO and HCLF recommendations concur with the above NCCN recommendations. [16, 17]  

Prognostic Factors

Although no international prognostic system for risk stratification of HCL has been developed, ESMO guidelines consider the following clinical variables to indicate an adverse prognosis [16] :

  • Severe cytopenias (hemoglobin [Hgb] < 10 g/dL, platelets < 100 × 10 9/L, neutrophils < 1 ×10 9/L )
  • Lymphadenopathy
  • Presence of TP53 mutations and lack of somatic mutations in the IGVH genes

In addition, the ESMO guidelines note that patients who achieve a complete response (CR) have a significantly longer disease-free survival than those who achieve a partial response. [16]

Treatment

NCCN guidelines recommend observation in the absence of the following clinical signs [15] :

  • Systematic symptoms
  • Splenic discomfort
  • Recurrent infection
  • Hgb < 12g/dL
  • Platelets < 100,000/μL
  • Absolute neutrophil count (ANC) < 1000/μL

If clinical indications are present, intial first-line treatments are the purine analogues cladribine or pentostatin. [15]

ESMO concurs with the NCCN recommendations, but includes an additional recommendation of interferon alfa for pregnant patients or those with very severe neutropenia. [16]

NCCN defines CR to treatment as the following [15] :

  • Near normalization of peripheral blood counts
  • Absence of HCL cells on bone marrow biopsy or peripheral blood samples
  • Regression of splenomegaly by physical exam
  • Hgb >11g/dL (without transfusion)
  • Platelets >100,000/μL
  • ANC >1500/μL

For patients who do not acheive CR or who relapse less than 24 months after achieving CR, NCCN recommends the following treatment options [15] :

  • Enrollment in appropriate clinical trial
  • Alternate purine analogue with or without rituximab
  • Rituximab monotherapy, if the patient is unable to receive purine analogues
  • Interferon alfa

For patients who relapse more than 24 months after achieving CR, NCCN recommends the following treatment options [15] :

  • Re-treat with the initial purine analogue with or without rituximab
  • Alternate purine analogue with or without rituximab
  • Rituximab monotherapy, if the patient is unable to receive purine analogues

For progressing disease thta is not responsive to purine analogue therapy, NCCN recommends enrollment in ca linical trial or vemurafenib with or without rituximab. [15]

Overall, ESMO guidelines are in agreement with NCCN, but include the following additional recommendations for treatment of refractory disease [16] :

  • Splenectomy may be indicated in patients with symptomatic splenomegaly (>10 cm below the costal margin) and low-level bone marrow infiltration
  • Allogeneic hematopoietic stem cell transplantation
  • Moxetumomab pasudotox
  • Fludarabine with rituximab
  • Bendamustine with rituximab