Haema 2017; 8(2): 147-167
by Eleftheria Hatzimichael1, Konstantina Papathanasiou2, Theodoros Marinakis3
1Haematology Unit, General Hospital of Ioannina «G. Hatzikosta»,
2Department of Hematology, University Hospital of Ioannina,
3Department of Hematology, General Hospital of Athens «G. Gennimatas», Athens, Greece
Abstract
Acute myeloid leukemia (AML) is a clonal disorder of myeloid cells characterized by rapid growth of immature cells that infiltrate the bone marrow and inhibit hematopoiesis. The FAB Classification (French-American-British Classification, 1976) was the first attempt to classify AML on the basis of morphological and cytochemical characteristics. Given the great heterogeneity of AML patients, the classification into categories with different prognosis and response to treatment was later considered necessary. The classification according to the World Health Organization (WHO) in 2001 and 2008 was a contemporary attempt to classify hematological malignancies based on morphological, cytogenetic, immunophenotypic, molecular and clinical characteristics. The recent WHO classification 2016 is a revision of the previous version with the incorporation of new features. The determination of prognosis is particularly important for the management of AML patients. The risk stratification of AML patients based on prognostic factors is a valuable tool to guide the clinician to take decisions such as the choice of a specific treatment versus another, the decision for allogeneic stem cell transplantation and the choice of standard or research treatment protocols. Response to treatment and overall survival of AML patients is very heterogeneous as well. Age, performance status, karyotype and gene mutations are the most important predictors. The European Leukemia Net (ELN) in 2010 integrated cytogenetic and molecular characteristics (eg, FLT3-ITD, CEBPA and NPM1) to classify patients into four risk groups. The development of new techniques in the genetic landscape of the disease and new antileukemic agents gave rise to new recommendations from the ELN for the diagnosis and management of AML patients (ELN AML Recommendations 2017) that include a revised version of the previous genetic categories and stratify patients into three risk groups (favorable, intermediate and high risk) and include specific differences from the previous recommendations.