Acute promyelocytic leukemia: from genetic lesions identification to molecularly targeted therapy

Acute promyelocytic leukemia (APL) differs from other types of acute myeloid leukemia both in terms of the spectrum of clinical symptoms, as well as cytogenetic and molecular background. Fast diagnosis of APL enables highly effective targeted therapy initiation and avoiding of serious organ/tissue damage (including fatal bleeding into the central nervous system). In the initial diagnostic process the most important is the rapid identification of the presence of specific cytogenetic and molecular changes involving the retinoic acid receptor alpha ( RARA ) gene located on the 17q21 chromosome. In patients with APL, alongside the most commonly observed translocation t(15;17)(q24;q21) leading to the formation of the PML-RARA fusion, several dozen variant cases have also been identified as a result of other translocations involving RARA gene with different clinical symptomatology and variable sensitivity to the targeted therapy with all-trans retinoic acid and arsenic trioxide. The paper presents the recent data concerning the epidemiology, symptomatology and accurate diagnostics methods useful for early identification of APL and immediate initiation of the molecularly targeted therapy