Blast crisis

Blast crisis refers to the transformation of chronic myeloid leukemia (CML) from the chronic or accelerated phase to blast phase.

Blast phase of CML may be discovered incidentally on complete blood count or when assessing patients with symptoms and signs such as fever, fatigue, malaise, weight loss, anemia, thrombocytopenia, or splenomegaly.

Diagnosis of the blast phase of CML is usually confirmed by the percentage of blast cells (e.g., ≥20% [World Health Organization criteria] or ≥30% [MD Anderson Cancer Center and the International Bone Marrow Transplant Registry criteria]) in the peripheral blood or bone marrow. Diagnosis of CML requires the presence of the Philadelphia chromosome (a genetic mutation that results in the oncogenic BCR-ABL fusion gene).

Tyrosine kinase inhibitors are paramount in treatment. Allogeneic stem cell transplant must follow due to rapid relapse.

Blast crisis refers to the transformation of CML from the chronic or accelerated phase to blast phase.

The blast phase of CML is diagnosed by the percentage of blast cells (≥20% by WHO criteria; ≥30% by MD Anderson Cancer Center and the International Bone Marrow Transplant Registry criteria) in the peripheral blood or bone marrow, or the presence of an extramedullary accumulation of blast cells, or large foci or clusters of blasts in the bone marrow biopsy.[1]Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016 May 19;127(20):2391-405. [Erratum in: Blood. 2016 Jul 21;128(3):462.] http://www.bloodjournal.org/content/127/20/2391.long http://www.ncbi.nlm.nih.gov/pubmed/27069254?tool=bestpractice.com [2]National Comprehensive Cancer Network. Chronic myeloid leukemia [internet publication]. https://www.nccn.org/professionals/physician_gls/default.aspx  

CML is diagnosed by the presence of the Philadelphia chromosome (a genetic mutation that results in the oncogenic BCR-ABL fusion gene).[3]Smith G, Apperley J, Milojkovic D, et al. A British Society for Haematology guideline on the diagnosis and management of chronic myeloid leukaemia. Br J Haematol. 2020 Oct;191(2):171-93. https://onlinelibrary.wiley.com/doi/10.1111/bjh.16971 http://www.ncbi.nlm.nih.gov/pubmed/32734668?tool=bestpractice.com