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Chronic myelogenous leukemia classification

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: James Nasr[2]


Overview

Overview

Chronic myelogenous leukemia (CML) may into two phases: CML-chronic phase (CML-CP), CML-blastic phase (CML-BP). A third phase, CML-accelerated phase (CML-AP), is also widely recognised, however removed by the World Health Organisation (WHO) in 2022. Some studies still indicate the importance of this phase due to its distinct prognosis and treatment regiment from CML-CP and CML-BP.

Classification

Classification

Chronic myelogenous leukemia is divided into two phases:[1]


CML-Chronic Phase:[2]

  • Indolent phase.
  • Less than 10% blasts in blood and bone marrow.
  • Less than 20% basophils.
  • Platelet counts of 100 to 1000 x 109/L.
  • Absence of extramedullary evidence of leukemia.
  • 90% of patients have CML-CP at diagnosis.
  • Common findings include: anemia, splenomegaly, fatigue, and malaise.


CML-Blast Phase:[3]

  • Most advanced form of CML.
  • 20% or more blasts, according to WHO.
  • Common findings include: nose and gum bleeding, bruising, fever, and infections.


CML-Accelerated Phase:

  • Removed by WHO in 2022, however still discussed due to its distinct prognosis and treatment from CML-CP and CMP-BP.[4][5]
  • Elevated blasts that do not meet the criteria of 20% or more blasts for CML-BP.[5]
  • Platelet count less than 100 x 109/L.[5]
  • Common findings include: splenomegaly and worsening anemia.
References

References

  1. Daniel A. Arber, Attilio Orazi, Robert Hasserjian, Jürgen Thiele, Michael J. Borowitz, Michelle M. Le Beau, Clara D. Bloomfield, Mario Cazzola, James W. Vardiman; The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood 2016; 127 (20): 2391–2405. doi: https://doi.org/10.1182/blood-2016-03-643544
  2. Dushyant Verma, Hagop M. Kantarjian, Dan Jones, Rajyalakshmi Luthra, Gautam Borthakur, Srdan Verstovsek, Mary Beth Rios, Jorge Cortes; Chronic myeloid leukemia (CML) with P190BCR-ABL: analysis of characteristics, outcomes, and prognostic significance. Blood 2009; 114 (11): 2232–2235. doi: https://doi.org/10.1182/blood-2009-02-204693
  3. Hochhaus, A., Baccarani, M., Silver, R.T. et al. European LeukemiaNet 2020 recommendations for treating chronic myeloid leukemia. Leukemia 34, 966–984 (2020). https://doi.org/10.1038/s41375-020-0776-2
  4. Khoury, J.D., Solary, E., Abla, O. et al. The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms. Leukemia 36, 1703–1719 (2022). https://doi.org/10.1038/s41375-022-01613-1
  5. 5.0 5.1 5.2 Senapati, J., Jabbour, E., Kantarjian, H. et al. Pathogenesis and management of accelerated and blast phases of chronic myeloid leukemia. Leukemia 37, 5–17 (2023). https://doi.org/10.1038/s41375-022-01736-5


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