Acute myeloid leukemia (AML) is a rapidly progressing cancer of the blood and bone marrow. It develops when abnormal immature myeloid cells multiply uncontrollably and interfere with the production of normal red blood cells, white blood cells, and platelets. AML can occur at any age but is more common in older adults. Because the disease can progress quickly, prompt diagnosis and treatment are important. Treatment is increasingly personalized and may include chemotherapy, targeted therapy, stem cell transplantation, and supportive care.
What Is Acute Myeloid Leukemia?
The bone marrow produces blood cells from immature cells called stem and progenitor cells. Myeloid cells normally develop into several types of blood cells, including certain white blood cells, red blood cells, and platelets.
In AML, genetic changes cause immature myeloid cells, called blasts, to grow abnormally and fail to mature normally. These abnormal cells can accumulate in the bone marrow and bloodstream, reducing the production of healthy blood cells.
AML is not a single disease. It includes several subtypes with different genetic and molecular characteristics. These characteristics can influence treatment decisions and prognosis.
Common Symptoms
Many AML symptoms result from reduced production of normal blood cells.
Low red blood cell levels can cause anemia and may lead to:
- Fatigue
- Weakness
- Shortness of breath
- Dizziness
- Pale skin
Low levels of healthy white blood cells can increase susceptibility to infections. Possible symptoms include:
- Fever
- Recurrent infections
- Chills
- Persistent illness
Low platelet levels can contribute to bleeding problems, including:
- Easy bruising
- Frequent nosebleeds
- Bleeding gums
- Small red or purple spots on the skin
- Heavy menstrual bleeding
Some people may also experience bone or joint discomfort, unexplained weight loss, reduced appetite, or abdominal fullness caused by an enlarged spleen or liver.
What Causes AML?
AML develops because of acquired genetic changes in blood-forming cells. In most cases, it is not possible to identify one specific cause.
Certain factors can increase the risk of developing AML, including:
- Increasing age
- Previous chemotherapy
- Previous radiation therapy
- Certain blood disorders
- Exposure to high levels of radiation
- Some chemical exposures
- Certain inherited genetic conditions
Having a risk factor does not mean that AML will definitely develop.
How Is AML Diagnosed?
Diagnosis generally begins with blood testing and is followed by examination of the bone marrow.
Tests may include:
Complete Blood Count
A complete blood count measures red blood cells, white blood cells, and platelets. AML can cause abnormal numbers of these cells.
Peripheral Blood Examination
A blood sample may be examined under a microscope to look for abnormal immature cells.
Bone Marrow Examination
A bone marrow aspiration and biopsy can provide detailed information about abnormal blood-forming cells and help confirm the diagnosis.
Genetic and Molecular Testing
Genetic testing is particularly important in AML. Chromosome and molecular studies can identify changes that help classify the leukemia and determine which treatments may be appropriate.
Examples include testing for mutations involving genes such as FLT3, IDH1, IDH2, NPM1, and other molecular abnormalities.
AML Treatment
Treatment depends on several factors, including age, overall health, AML subtype, genetic findings, and whether the disease has certain favorable or unfavorable characteristics.
Treatment may involve:
- Chemotherapy
- Targeted therapy
- Stem cell transplantation
- Supportive care
- Clinical trials
Treatment is often divided into phases designed to achieve remission and reduce the risk of the leukemia returning.
Induction Therapy
Induction treatment is intended to rapidly reduce the number of leukemia cells and achieve remission.
Traditional intensive chemotherapy may include combinations of medicines such as cytarabine and an anthracycline. However, treatment has become increasingly personalized, and targeted medicines may be incorporated when specific genetic abnormalities are present.
Some older adults or people who cannot tolerate intensive chemotherapy may receive lower-intensity treatment approaches.
Consolidation Therapy
After remission is achieved, additional treatment may be recommended to eliminate remaining leukemia cells that cannot be detected through routine testing.
Consolidation may involve additional chemotherapy or other treatments depending on the individual's risk profile.
Targeted Therapy
Targeted medicines are designed to interfere with specific abnormalities that help leukemia cells survive.
Examples include therapies targeting:
- FLT3 mutations
- IDH1 mutations
- IDH2 mutations
- Certain other molecular abnormalities
Targeted therapy may be combined with chemotherapy or used in other treatment settings depending on the specific AML subtype.
Stem Cell Transplantation
An allogeneic stem cell transplant may be considered for selected patients.
The process involves intensive treatment followed by infusion of blood-forming stem cells from a compatible donor.
A transplant can provide a powerful anti-leukemia effect, but it also carries significant risks. Factors such as age, overall health, disease risk, treatment response, donor availability, and previous treatment are considered when evaluating whether transplantation is appropriate.
Supportive Care
Supportive treatment is an important part of AML care.
Because AML and its treatments can reduce normal blood-cell production, supportive measures may include:
- Blood transfusions
- Platelet transfusions
- Antibiotics
- Antiviral or antifungal medicines when appropriate
- Management of treatment-related complications
- Monitoring for infections
Supportive care helps manage complications while leukemia-directed treatment addresses the underlying disease.
Relapsed or Refractory AML
AML is described as relapsed when it returns after a period of remission. It may be called refractory when it does not respond adequately to initial treatment.
Treatment for relapsed or refractory AML depends on previous therapy, genetic characteristics, overall health, and the duration of the previous remission.
Potential approaches include:
- Targeted therapy
- Salvage chemotherapy
- Combination treatment
- Stem cell transplantation
- Clinical trials
Clinical trials can be particularly important when AML has returned or has not responded to standard treatment.
AML and Genetic Testing
Modern AML treatment increasingly relies on genetic and molecular information.
Testing can help identify changes associated with the leukemia and provide information about treatment sensitivity and disease risk.
Molecular findings can also change over the course of the disease, making additional testing useful in certain situations.
Prognosis
AML prognosis varies considerably from one person to another.
Factors that can influence outcomes include:
- Age
- Overall health
- AML subtype
- Chromosomal abnormalities
- Gene mutations
- Response to initial treatment
- Presence of measurable residual disease
- Whether the leukemia is newly diagnosed or has returned
Advances in molecular testing, targeted medicines, supportive care, and transplantation have expanded treatment approaches for AML.
Living With AML Treatment
AML treatment can involve frequent medical appointments, blood tests, hospital stays, and periods of reduced immunity.
Practical considerations may include:
- Monitoring for fever or infection
- Following medication instructions
- Maintaining adequate nutrition and hydration
- Managing treatment side effects
- Attending scheduled blood tests
- Discussing vaccination and infection precautions with the healthcare team
- Receiving emotional and practical support
Family members and caregivers can also play an important role during treatment.
When to Seek Medical Attention
Because AML can progress rapidly, unexplained symptoms such as persistent fever, unusual bleeding, severe fatigue, recurrent infections, or unexplained bruising should receive medical evaluation.
For someone already diagnosed with AML, fever, significant bleeding, breathing difficulty, confusion, severe weakness, or other sudden changes may require urgent medical attention.
Conclusion
Acute myeloid leukemia is a rapidly progressing blood and bone marrow cancer caused by abnormal growth of immature myeloid cells. Symptoms can result from anemia, low platelet levels, and reduced production of healthy white blood cells. Diagnosis commonly involves blood tests, bone marrow examination, and genetic or molecular testing.