AML, or acute myeloid leukemia, is a fast-moving blood cancer that starts in the bone marrow. It happens when immature white blood cells called “blasts” multiply out of control, crowding out the healthy cells your body needs to make red blood cells, platelets, and functioning white blood cells. This leads to rapid bone marrow failure. AML is diagnosed most often in older adults, with a median age at diagnosis of 68.
How AML Develops in the Body
Your bone marrow normally produces blood cells in an orderly process: stem cells mature into red blood cells (which carry oxygen), white blood cells (which fight infection), and platelets (which help blood clot). In AML, a genetic change in an early-stage white blood cell causes it to get stuck in an immature form and divide rapidly. These immature cells, the blasts, pile up in the marrow and spill into the bloodstream.
Because blasts take up space but can’t do the work of mature blood cells, the marrow can no longer produce enough of what the body needs. Red blood cell production drops, platelet counts fall, and the immune system weakens. This process happens quickly compared to chronic leukemias, which is why the word “acute” is in the name.
Common Symptoms
AML symptoms stem directly from the shortage of normal blood cells. Low red blood cells cause fatigue, shortness of breath, and pale skin. Low platelets lead to easy bruising, bleeding gums, frequent nosebleeds, or tiny red spots on the skin called petechiae. And because functional white blood cells are crowded out, infections become more frequent and harder to shake.
Other signs can include bone or joint pain (from blasts accumulating in the marrow), unexplained weight loss, fevers, and night sweats. These symptoms often develop over just days to weeks, which distinguishes AML from slower-growing blood cancers that may simmer for months or years before causing problems.
Risk Factors
Most cases of AML arise from genetic changes that aren’t preventable or predictable. Still, several environmental and medical factors raise the risk. Exposure to benzene (found in some industrial settings and cigarette smoke), ionizing radiation, and prior treatment with certain chemotherapy drugs all increase the likelihood of developing AML. One study found that people who had previously used cytotoxic agents had roughly eight times the odds of an AML diagnosis compared to those who hadn’t. A family history of cancer also roughly tripled the risk in that same research.
Age is the single biggest factor. AML can occur in children and young adults, but it becomes far more common with each decade of life.
How AML Is Diagnosed
Diagnosis starts with blood tests showing abnormal cell counts, but confirmation requires a bone marrow biopsy. Doctors examine the marrow sample under a microscope and run genetic tests on the cells. Traditionally, AML has been defined by having 20% or more blasts in the bone marrow or blood. Updated classification systems now allow diagnosis at lower blast counts (10% or even less) when specific genetic mutations are present, because those mutations are enough to confirm the disease is AML regardless of how many blasts have accumulated yet.
Genetic testing of the leukemia cells is a critical step. The specific mutations driving a person’s AML shape both the prognosis and the treatment plan.
Genetic Mutations That Shape Prognosis
Two of the most common and consequential genetic changes in AML involve genes called NPM1 and FLT3. An NPM1 mutation is generally good news: patients with this mutation achieve remission about 94% of the time after initial treatment, and their five-year survival is around 71%. An FLT3 mutation (specifically one called an internal tandem duplication) carries a worse outlook, with lower remission rates around 67% and a much higher chance of relapse.
When both mutations occur together, the NPM1 mutation appears to soften the negative impact of FLT3. The interplay between these mutations is one reason genetic profiling matters so much. It determines whether someone is classified as favorable, intermediate, or high risk, which directly influences treatment decisions.
Treatment: Two Main Phases
AML treatment typically unfolds in two phases. The first, called induction therapy, aims to kill as many leukemia cells as possible and push the disease into remission. This phase involves intensive chemotherapy and usually requires several weeks in the hospital because the treatment temporarily wipes out much of the bone marrow, leaving patients vulnerable to infection and bleeding while healthy cells recover.
The second phase, consolidation therapy, begins once remission is achieved. Its goal is to eliminate any remaining leukemia cells that survived induction but aren’t yet detectable. Without consolidation, the cancer almost always comes back. This phase may involve additional rounds of chemotherapy, targeted drugs, or a stem cell transplant, depending on the person’s risk profile.
Targeted Therapies
Over the past several years, drugs designed to attack specific genetic mutations in AML cells have become an important part of treatment. These targeted therapies work differently from traditional chemotherapy: instead of killing all rapidly dividing cells, they zero in on the molecular machinery driving a particular person’s leukemia. Currently approved options target FLT3 mutations and mutations in genes involved in cell metabolism (IDH1 and IDH2). For patients whose leukemia carries one of these mutations, a targeted drug may be used alongside chemotherapy or, in some cases, as a primary treatment.
Stem Cell Transplant
A stem cell transplant (using donor cells) remains the most powerful tool for preventing relapse in high-risk AML. It works by replacing the patient’s bone marrow with a healthy donor’s marrow, which also provides an immune response against any remaining leukemia cells. Transplant is generally recommended for patients whose genetic profile puts their relapse risk at 50% or higher, and it’s considered essential when the risk exceeds 70 to 90%. For lower-risk patients, particularly those with favorable mutations like NPM1, transplant may not be needed in first remission unless there are signs the leukemia isn’t responding well to chemotherapy.
Transplant carries significant risks of its own, including infection and a condition where the donor’s immune cells attack the recipient’s body. Doctors weigh these risks against the likelihood of relapse when making recommendations.
Survival Rates and Outlook
The overall five-year survival rate for AML is about 32%, but that number masks enormous variation. Younger patients (under 60) have survival rates approaching 50%, while patients over 60 face a much steeper challenge, with five-year survival below 10%. Age matters partly because older patients are less likely to tolerate intensive chemotherapy and transplant, and partly because AML in older adults tends to carry higher-risk genetic profiles.
Within any age group, the specific genetic makeup of the leukemia is the strongest predictor of outcome. A young adult with an NPM1 mutation and no FLT3 duplication has a fundamentally different outlook than someone the same age whose leukemia has a complex set of chromosome abnormalities. This is why AML is increasingly treated not as a single disease but as a collection of related diseases, each defined by its underlying genetics and each requiring a tailored approach.