Six FAB subtypes (M1 through to M6) were initially proposed in 1976, although later revisions added M7 in 1985 and M0 in 1987. The morphologic subtypes of AML also include rare types not included in the FAB system, such as acute basophilic leukemia, which was proposed as a ninth subtype, M8, in 1999. Treatment
First-line treatment of AML consists primarily of chemotherapy, and is divided into two phases: induction and consolidation. The goal of induction therapy is to achieve a complete remission by reducing the number of leukemic cells to an undetectable level; the goal of consolidation therapy is to eliminate any residual undetectable disease and achieve a cure. Hematopoietic stem cell transplantation is usually considered if induction chemotherapy fails or after a person relapses, although transplantation is also sometimes used as front-line therapy for people with high-risk disease. Efforts to use tyrosine kinase inhibitors in AML continue. Induction
The goal of the induction phase is to reach a complete remission. Complete remission does not mean the disease has been cured; rather, it signifies no disease can be detected with available diagnostic methods. All subtypes except acute promyelocytic leukemia are usually given induction chemotherapy with cytarabine and an anthracycline such as daunorubicin or idarubicin. This induction chemotherapy regimen is known as "7+3" (or "3+7"), because the cytarabine is given as a continuous IV infusion for seven consecutive days while the anthracycline is given for three consecutive days as an IV push.
Each of the WHO categories contains numerous descriptive subcategories of interest to the hematopathologist and oncologist; however, most of the clinically significant information in the WHO schema is communicated via categorization into one of the subtypes listed below. The revised fourth edition of the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues was released in 2016. This classification, which is based on a combination of genetic and immunophenotypic markers and morphology, defines the subtypes of AML and related neoplasms as: In 2022 a new classification has been published. Acute leukemias of ambiguous lineage (also known as mixed phenotype or biphenotypic acute leukemia) occur when the leukemic cells can not be classified as either myeloid or lymphoid cells, or where both types of cells are present. French-American-British
The French-American-British (FAB) classification system provides terminology that is still sometimes used, and it remains a valuable diagnostic tool in areas without access to genetic testing, this system has largely become obsolete in favor of the WHO classification, which correlates more strongly with treatment outcomes.The FAB system divides AML into eight subtypes, M0 through to M7, based on the type of cell from which the leukemia developed and its degree of maturity. AML of types M0 to M2 may be called acute myeloblastic leukemia. Classification is done by examining the appearance of the malignant cells with light microscopy and/or by using cytogenetics to characterize any underlying chromosomal abnormalities. The subtypes have varying prognoses and responses to therapy.