Upon diagnosis of AML, chemotherapy is usually the treatment of choice. The goal of this treatment is to stop leukemic cells from multiplying and to drastically lower the percentage of existing ones through 'rapid cell kill' with the ultimate goal of long term remission. For an AML patient, multiple drugs will be administered (combination chemotherapy) both intravenously through a vein in the arm and orally in the form of pills. This phase of treatment, referred to as Induction Therapy, will make an AML patient extremely vulnerable to bacterial and fungal infections as the immune system is weakened. Induction therapy usually lasts 1-2 weeks, followed by a rest/recovery period of 1-2 weeks – then consolidation therapy begins.
Doctors will look at all of the patient's risk factors, such as age and subtype of AML, in order to plan treatment – the dosage, the drugs and the length of time to administer them. Targeted Treatment includes Cytogenetic and genetic testing for Chromosomal abnormalities that might effect the prognosis. Genetic testing should include assessment of FLT3 Mutation status. This assessment is recommended for all patients with AML by the National Comprehensive Cancer Network (NCCN) and World Health Organization (WHO) clinical practice guidelines. In fact, FLT3 mutation testing is a designated "Standard of Care" for patients diagnosed with acute myelogenous leukemia (AML).
Antibiotics will usually be administered to treat infection and patients that are anemic will receive transfusions of blood and/or platelets to control clotting. AML patients do not make enough platelets. Platelets are small bodies in the blood that are essential for clotting.
Consolidation Therapy (Postremission Therapy)
Once in the consolidation phase, the goal is to reactivate your immune system. The type of postremission therapy used largely depends on the type of AML. Further chemotherapy or bone marrow transplantation may be used if chemotherapy is found to be ineffective. For children, chemotherapy to the central nervous system is given. CNS includes the brain and spinal cord. This therapy is important because without it, there is a one in five chance of a relapse.
Targeted Therapies for AML
Current treatments for AML may reduce the number of AML cells to undetectable levels, which is referred to as complete remission (CR). However, some stem cells are resistant to chemotherapy, which may be the one of the causes of a relapse. Leukemia Stem Cells referred to as LSCs are identified by distinctive cell-surface markers. Certain LSCs can be therapeutically targeted to lower the chance of a relapse.
The standard AML drug, cytosine arabinoside (Ara-C), works by targeting actively dividing cells, but this drug alone does not kill chemotherapy resistant, LSCs. Researchers have combined cytokines with Ara-C and are seeing a ten-fold increase in survival rates compared to just chemotherapy. Cytokine treatment seems to be relatively safe for patients.
Identifying FLT3 Mutation
Testing positive for FLT3 mutation may require a more aggressive treatment, since having the FLT3 mutation usually portends a worse prognosis. Identification of the FLT3 mutation in AML may indicate a need to reassess and modify standard treatment options.
Studies have shown that screening for FLT3 mutations can improve differentiation of subgroups within AML. Read more about FLT3 and AML.
Drugs currently being used to treat AML during the induction phase include:
Arsenic Trioxide (Trisenox)
Tretinoin (ATRA, All-Trans-Retinoic Acid)
Daunorubicin (DNR, Cerubidine, Daunomycin, Rubidomycin)
Cytarabine (Ara-C, Cytosar-U)