Treatment of Refractory Hairy Cell Leukemia with a BRAF-inhibitor: Lessons to be Learnt

• Published in: Pathology oncology research Vol. 20; no. 4; pp. 973 - 980
• Main Authors: Sári, Eszter, Nagy, Zsolt György, Baghy, Kornélia, Rajnai, Hajnalka, Bödör, Csaba, Csomor, Judit, Barna, Gábor, Rudas, Gábor, Kovalszky, Ilona, Demeter, Judit
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.10.2014; Springer Nature B.V
• Subjects: Adult; Aged; Antineoplastic Agents - therapeutic use; Biomedical and Life Sciences; Biomedicine; Cancer Research; Drug Resistance, Neoplasm - genetics; Humans; Immunology; Leukemia, Hairy Cell - drug therapy; Leukemia, Hairy Cell - genetics; Male; Middle Aged; Mutation - genetics; Oncology; Pathology; Proto-Oncogene Proteins B-raf - antagonists & inhibitors; Proto-Oncogene Proteins B-raf - genetics; Treatment Outcome; Refractory; BRAF V600E; Vemurafenib; Hairy cell leukemia
• ISSN: 1219-4956; 1532-2807
• DOI: 10.1007/s12253-014-9783-9

Hairy cell leukemia is a rare chronic lymphoproliferative disorder with indolent but progressive clinical course. Patients require treatment when they have significant cytopenia or recurrent infections. The gold standard treatment are purine nucleoside analogues (cladribine and pentostatine), with these agents the rate of complete remission can approach even 95 %. The differential diagnosis between classical hairy cell leukemia and other, rare splenic lymphomas that can mimic this disease might be really challenging. Splenic lymphoma with villous lymphocytes and other new, provisional WHO entities share some, but not all immunophenotypical features with hairy cell leukemia. The correct diagnosis is of an extreme importance as these entities require different treatment. Thus further investigation in the pathogenesis of hairy cell leukemia is required in order to solve this challenge. Discovery of the BRAF V600E mutation as a disease-defining genetic event in hairy cell leukemia can be helpful in both differential diagnosis and treatment of this disease. We report the case of three hairy cell leukemia patients, whose diagnosis or treatment was based on this newly discovered somatic mutation, but the treatment results and side effects were individual.