Diagnostic characterization of acute promyelocytic leukemia and targeted therapy in this leukemia

16^th Global Annual Oncologists Meeting

April 24-25, 2017 Dubai, UAE

S Nasouhi Pur

Tabriz University of Medical Sciences, Iran

Posters & Accepted Abstracts: J Cancer Sci Ther

Abstract :

This type of acute myeloid leukemia is characterized either by abnormal promyelocytes with distinctive large granules and multiple Auer rods (faggots or sultan bodies� cells) or, less commonly, by atypical hypogranular or microgranular cells with bilobed or multilobed nuclei. These cells contain procoagulant material which, when released into the circulation, causes disseminated intravascular coagulation (DIC). Excessive bleeding due to DIC is common. The microgranular variant of APL may be mistaken with Acute Monocytic Leukemia (AMOL). In the microgranular variant M3, only occasional cells have granules visible by light microscopy, so, morphology and immunophenotyping is suggested for diagnosis of this variant M3. The cytogenetic documents of t(15;17), and FISH is required for confirmation of diagnosis. The translocation t(15;17) (q22;q21) or t(15;17) (q22,q11-12) is the genetic hallmark of APL, resulting in the PML-RARa fusion protein. PML-RARa recruits histon deacetylases (HDAC) and represses target genes of wild type RARa leading to a block of myeloid differentiation. The Retinoic Acid Receptor a_ (RARa_) Chimeric Proteins PML-, PLZF-, NPM-, and NuMA-RARa_ have Distinct Intracellular Localization Patterns. NPM-RARa_ is predominantly nuclear whereas NuMA-RARa_ is predominantly cytoplasmic. Typical immunophenotypic findings in APL: CD34. HLA-DR and Tdt usually is negative and CD2 is expression in a minority, CD13++ CD33+++ This leukemia with t(15;17) has a good prognosis, because it is sensitive to retinoid and chemotherapy, whereas PLZF-RARa consistent with this, APL patients bearing the t(11;17) (q23;q21) respond poorly to ATRA treatment and Alltrans retinoic acid (ATRA) as a highly effective therapy in acute promyelocytic leukemia (APL). The patients receiving ATRA followed by chemotherapy did significantly better compared with patients treated with ATRA alone or chemotherapy alone. With this combination the CR rate ranges from 90 to 96 percent. Treatment options for patients with relapsed disease include arsenic trioxide and allogeneic stem cell transplant.

Biography :

Email: snasouhipur1331@gmail.com