Acute myeloid leukemia (AML) is a fast-moving blood cancer that starts in the bone marrow, where blood cells are made. Immature white blood cells called blasts multiply out of control and crowd out the healthy cells your body needs to carry oxygen, fight infections, and stop bleeding. It is one of the most common acute leukemias in adults, and because it progresses quickly, it typically requires treatment soon after diagnosis.
How AML Develops in the Bone Marrow
Your bone marrow normally produces a balanced mix of red blood cells, white blood cells, and platelets. In AML, genetic changes in early myeloid cells (the precursors to certain white blood cells) cause them to get stuck in an immature stage. These immature cells, the blasts, keep dividing but never mature into functional blood cells. As blasts accumulate, they physically take up space in the bone marrow, leaving less and less room for normal blood cell production.
The result is a kind of bone marrow failure. Red blood cell production drops, leading to anemia. Platelet production falls, making bleeding and bruising more likely. And despite a surplus of white blood cells, the blasts that fill the bloodstream can’t fight infections the way mature white blood cells do. This triple shortage of functional blood cells drives most of AML’s symptoms.
Recognizing the Symptoms
AML symptoms tend to come on over days to weeks, not months, and they often mimic other common illnesses at first. The most frequently reported signs include:
- Fatigue and pallor from low red blood cell counts
- Frequent or severe infections because functional white blood cells are scarce
- Easy bruising or unusual bleeding, including nosebleeds and bleeding gums, due to low platelets
- Bone or joint pain, particularly in the back and limbs, caused by blast buildup in the marrow
- Fever that may come and go without an obvious infection
- Shortness of breath during activities that didn’t used to be difficult
None of these symptoms alone points to AML, but when several appear together and worsen quickly, blood tests typically reveal the underlying problem.
Known Risk Factors
Most people diagnosed with AML have no single identifiable cause, but several factors raise the risk. Increasing age is the strongest: the median age at diagnosis is in the late 60s. Men are affected slightly more often than women.
Benzene is one of the few well-established environmental risk factors. A population-based study found that people exposed to benzene or related solvents for five or more years had roughly twice the odds of developing AML compared to unexposed individuals. Benzene is present in gasoline, industrial chemicals, and cigarette smoke, which is itself an independent risk factor. Formaldehyde exposure and obesity have also been linked to higher rates.
Previous cancer treatment is another recognized trigger. Certain chemotherapy drugs, particularly a class called alkylating agents, and radiation therapy can damage bone marrow DNA in ways that lead to AML years later. About one-third of people with myelodysplastic syndrome (MDS), a group of conditions in which the bone marrow produces abnormal blood cells, eventually progress to AML.
How AML Is Diagnosed
Diagnosis starts with a complete blood count that shows abnormal numbers of white cells, red cells, or platelets. The definitive step is a bone marrow biopsy: a sample of marrow is examined under a microscope and tested for genetic changes. Under current World Health Organization guidelines, AML is diagnosed when blasts make up 20% or more of the cells in the bone marrow or blood. For certain genetic subtypes, the threshold is lower at 10%.
Genetic testing of the leukemia cells has become just as important as the blast count. Doctors look for specific chromosome rearrangements and gene mutations that determine the exact subtype of AML. This matters because different genetic profiles behave very differently and respond to different treatments.
Why Genetics Shape the Outlook
Two of the most common genetic changes in AML are mutations in the NPM1 and FLT3 genes, and they pull the prognosis in opposite directions. An NPM1 mutation is generally a favorable sign. In one long-term study, patients with this mutation achieved remission about 94% of the time, and their five-year survival was around 64%. The mutation appears to make leukemia cells more vulnerable to treatment.
A FLT3 internal tandem duplication (FLT3-ITD), on the other hand, signals a higher risk of relapse. Patients with an isolated FLT3-ITD mutation who achieved remission had a three-year relapse-free survival of just 24%. When both mutations are present together, the NPM1 mutation partially offsets the negative effect of FLT3-ITD, putting patients in an intermediate risk category. These genetic details directly influence whether someone is recommended for more aggressive treatment, such as a stem cell transplant.
The 2022 WHO classification now defines more than a dozen AML subtypes based on specific genetic abnormalities, each carrying its own expected behavior and treatment approach. Broadly, patients fall into favorable, intermediate, or adverse risk groups, and those categories guide every major treatment decision.
Standard Treatment Approach
For patients healthy enough to tolerate intensive treatment, the first step is induction chemotherapy, aimed at clearing blasts from the bone marrow and achieving remission. The backbone of this treatment has been the same two-drug combination for nearly five decades: a continuous infusion of one drug for seven days paired with a second drug given for the first three days, commonly called the “7+3” regimen. Despite its age, this approach still forms the foundation of AML treatment for most younger, fit patients.
If induction succeeds, which happens in roughly 60 to 80% of younger patients, consolidation therapy follows. The goal is to destroy any remaining leukemia cells that survived the initial round. Consolidation may involve additional cycles of chemotherapy or, for patients with intermediate or high-risk genetics, an allogeneic stem cell transplant.
In a stem cell transplant, a donor’s healthy marrow replaces the patient’s diseased marrow. It is generally recommended during first remission for patients whose predicted relapse risk exceeds 35 to 40% with chemotherapy alone. Patients with favorable genetics, like NPM1 mutations without FLT3-ITD, who show a strong early response typically do not need a transplant in first remission. For patients who relapse, the standard goal is to reach a second remission and then proceed to transplant.
Treatment for Older or Less Fit Patients
Many AML patients are over 65 and may not tolerate intensive chemotherapy. For these patients, lower-intensity regimens have become standard. A combination using a targeted drug called venetoclax alongside a less aggressive chemotherapy backbone received full FDA approval in 2020 for previously untreated AML in adults who cannot undergo intensive treatment. This combination has significantly improved remission rates and survival in this population compared to older low-intensity options.
Acute Promyelocytic Leukemia: A Special Case
One AML subtype stands apart from the rest. Acute promyelocytic leukemia (APL) is driven by a specific genetic rearrangement that fuses two genes called PML and RARA. It can be dangerous at diagnosis because of severe bleeding complications, but it is also the most curable form of AML. Treatment uses two targeted agents, all-trans retinoic acid (ATRA) and arsenic trioxide, which work by forcing the immature leukemia cells to either mature or die. A phase 3 trial found that this chemotherapy-free combination produced a high cure rate with less relapse than traditional chemotherapy-based approaches and lower liver toxicity. For low-risk APL patients, this regimen has largely replaced conventional chemotherapy.
Survival Rates and What Influences Them
Survival in AML varies enormously depending on age, genetics, and overall health. For adolescents and young adults diagnosed between ages 15 and 19, five-year survival is around 66%. That figure drops to roughly 57 to 59% for those diagnosed in their 20s and 30s. For adults over 60, who make up the majority of AML patients, five-year survival is considerably lower, often in the range of 10 to 20%, though newer treatments are gradually improving these numbers.
Genetic risk category is the other major variable. Patients with favorable-risk genetics can expect five-year survival well above 60%, while those with adverse-risk genetics face much steeper odds. Measurable residual disease (MRD) testing, which detects tiny amounts of leukemia remaining after treatment, is increasingly used to fine-tune these predictions. In one study, patients who still had detectable NPM1 mutations in their blood after consolidation therapy had a relapse rate of 59%, compared to 29% in those who tested negative.
AML remains a serious diagnosis, but the landscape is shifting. Genetic profiling now allows treatment to be tailored to the specific biology of each person’s leukemia, and the growing number of targeted therapies means more patients have options beyond traditional chemotherapy alone.