CML End Phase and Blast Crisis: Implications and Management

Abstract

Treatment of blast crisis (BC) is one of the remaining challenges in the management of CML. Tyrosine kinase inhibitors (TKI) have moderately improved survival in BC, but a median survival of less than 1 year is still unsatisfactory. Earlier recognition of end-phase CML and early treatment intensification might improve outcome. High-risk additional chromosomal abnormalities and somatic mutations have been proposed for risk assessment and better recognition of patients at risk for progression to end-phase CML. In this article we review features of BC, tests required for diagnosis of BC, options of prevention, and the various treatment modalities of BC (intensive chemotherapy alone or in combination with TKI, allo-SCT, investigational agents). The best prognosis is observed in patients that achieve a second chronic phase (CP2). Allo-SCT probably further improves prognosis in CP2. The choice of TKI should be directed by the mutation profile of the patient. Also, a better pathophysiologic understanding of BC is addressed. Current treatment options are combined in a concluding strategy for the management of CML end phase and BC.