Acute Myeloid Leukemia (AML) Subtypes
Acute myeloid leukemia (AML) is the
AML goes by many other names, such as:
- Acute leukemia.
- Acute nonlymphocytic leukemia.
- Acute myelocytic leukemia.
- Acute leukemia.
The doctors divide the cancer into different types. Identifying which subtype you have is very important for predicting your outlook.
The different systems used to classify the different types of AML are explained in the next section.
About leukemia
Leukemia is a group of cancers that develop in blood cells. It’s classified based on how fast it develops and what type of cells are affected.
Acute leukemia is a cancer that is expected to develop quickly and require prompt treatment. Myeloid leukemia is when myeloid stem cells become red blood cells, platelets, and some types of white blood cells.
Doctors divide cancer into stages based on the size of the tumor and how far the cancer has spread. Unlike most cancers, the leukemias are usually not the cause of tumors. Doctors divide the disease into different types to predict the outlook and guide treatment.
Two primary classification systems have been used.
- French-American-British (FAB) system. A group of researchers created the FAB system in the
1970s . This system classifies AML into the subtypes M0 to M7 mostly based on how cancer cells look under a microscope. - World Health Organization (WHO) system. The WHO system is now the main system used to classify AML. It considers more factors known to influence someone’s outlook, such as gene mutations or “abnormalities” in chromosomes.
Diagnosing AML subtypes
A physical exam and review of your medical history are needed to determine if you have leukemia. If your doctor suspects a blood cancer, they will order blood tests to look for signs of leukemia. These often include.
- a complete blood count to identify an atypically high white The count of blood cell count. or low red blood cell and platelet count
- a peripheral blood smear to look for atypical characteristics in the size and shape of your blood cells
To confirm an AML diagnosis, doctors take a small sample of your bone marrow for lab analysis. This sample is usually taken from your hip bone.
Cells in your sample will be analyzed in a lab to distinguish your cancer from other types of leukemia and to look for certain genetic mutations. These tests include:
- Flow cytometry is used for immunophenotyping.
- cytogenetic analysis (karyotyping)
- The reaction of a polymerase chain.
- The person has a genetic makeup
The type of cells the cancer develops in and how mature they are are the factors that the FAB system considers when it comes to classification of the cancer.
The
| Subtype | Cells where cancer starts | Name |
| M0 | immature white blood cells | undifferentiated acute myeloblastic leukemia |
| M1 | immature white blood cells | acute myeloblastic leukemia with minimal maturation |
| M2 | immature white blood cells | acute myeloblastic leukemia with maturation |
| M3 | immature white blood cells | acute promyelocytic leukemia (APL) |
| M4 | immature white blood cells | acute myelomonocytic leukemia |
| M4 eos | immature white blood cells | acute myelomonocytic leukemia with eosinophilia |
| M5 | immature white blood cells | acute monocytic leukemia |
| M6 | very immature red blood cells | acute erythroid leukemia |
| M7 | immature platelets | acute megakaryoblastic leukemia |
The WHO system is now the main system used to classify AML. The WHO International Classification of Diseases 11 (ICD-11), which came into effect in January 2022, lists the following subtypes:
- AML with recurrent genetic abnormalities. These subtypes are associated with certain gene changes and are further
categorized as:- There is a translocation between chromosomes 1 and 22 in the leukemia.
- There is a problem in the 3rd part of the chromosomes.
- There is a There is a translocation between chromosomes 6 and 9..
- There is a There is a translocation between chromosomes 8 and 21..
- There is a translocation between chromosomes 9 and 11.
- There is a translocation or an insufficiencies in the 16th chromosome.
- APL (acute promyelocytic leukemia) with the PML-RARA fusion gene
- AML with the mutated NPM1 gene
- AML with two mutations of the CEBPA gene
- AML with the BCR-ABL1 (BCR-ABL) fusion gene (it’s not clear yet if this is a unique group)
- AML with mutated RUNX1 gene (it’s not clear yet if this is a unique group)
- There are changes to theAML with myelodysplasia.
- Therapy-related myeloid tumors.
- Myelodysplastic syndromes
- Down syndrome has myeloid proliferations.
- The blastic plasmacytoid dendritic cell is a type of cell.
- AML, not otherwise classified. These subtypes of AML do not fall into one of the other categories. They closely follow the
FAB classification and include:- Acute basophilic leukemia.
- panmyelosis with fibrosis is a very acute disease.
- The AML has minimal differentiation.
- There is no maturation for AML without it.
- The AML has a maturation number.
- Acute myelomonocytic leukemia is a type of leukemia.
- Acute monoblastic/monocytic leukemia is a leukemia.
- pure erythroid leukemia
- Acute megakaryoblastic leukemia is a type of leukemia.
A translocation is when part of a chromosome switches with another.
Doctors use AML subtypes to help guide treatment decisions. The main treatment for most types of AML is chemotherapy. Certain types of AML like
Doctors consider other factors when determining the best treatment.
- Your age and health.
- Specific genes that have specific changes.
- There are problems with the chromosomes.
- There are markers on leukemia cells.
- The count of blood cell count.
Knowing your AML type can be very important for your outlook. There are certain subtypes that are linked to different outcomes.
For instance,
Other factors can also play a role in determining your treatment plan. Doctors call these factors prognostic factors.
Chromosome abnormalities
The chromosomes of the cells can have an influence on your outlook. Changes associated with a positive outlook.
- There is a translocation between chromosomes 8 and 21.
- The chromosomes 16 are either translocation or inverted.
- There is a translocation between chromosomes 15 and 17.
An unfavorable outlook has atypical characteristics.
- There is a loss of one of the chromosomes.
- Part of the chromosomes is lost.
- There is an abnormality of the 11th chromosome.
- There is a translocation between chromosomes 6 and 9.
- The chromosomes 3 are either translocation or inversion.
- There is a translocation between chromosomes 9 and 22.
- Changes involving more than one chromosomes.
Other factors that affect outlook
Other factors that affect your outlook are listed below.
| Factor | Notes |
| gene mutations | Some mutations like the |
| age | Younger people tend to have a better outlook than older people. |
| white The count of blood cell count. | A white The count of blood cell count. over |
| prior blood disorder | Having a prior blood disorder is associated with a less favorable outlook. |
| AML after treatment for another cancer | AML that develops after previous cancer treatment is associated with a less favorable outlook. |
| infection | Having a blood infection at the time of diagnosis is associated with a less favorable outlook. |
| involvement of your nervous system | Leukemia cells in your brain or spinal cord are associated with a less favorable outlook. |
A type of cancer that develops in immature blood cells is called Acute Myeloid Leukemia. It is divided into different types based on how the cells look under a microscope and other factors.
Knowing which subtype you have is important for determining the best treatment options. Your doctor can explain to you what subtype you have.
