Understanding leukemia

Acute myeloid leukemia (AML)

AML is the most common acute leukemia in adults. It develops quickly and needs prompt treatment, but in recent years genetic testing and new drugs have made treatment more precise and personal than ever before. This topic explains what AML is, how it is diagnosed and the main stages of treatment.

Last updated: ~7 min read
Stained blood smear under the microscope showing myeloid blasts with large nuclei among red blood cells
Figure 1.Blood smear in AML: immature myeloid blasts among red blood cells.

01Short answer

Acute myeloid leukemia (AML) is the uncontrolled growth of immature cells of the myeloid line — myeloblasts — in the bone marrow. The blasts crowd out normal blood cells, causing anemia, infections and bleeding. AML mainly affects older adults: in the US the median age at diagnosis is 70, and about 22,720 new cases are expected in 2026. It is diagnosed with blood and bone marrow tests, flow cytometry and genetic tests. The genetic findings define the risk group (favourable, intermediate or adverse) and guide treatment. Treatment usually has an induction phase (to reach remission) and a consolidation phase (to make it last); some people are offered a stem cell transplant. Targeted drugs and less intensive regimens have opened new options, including for older people.

02Simple explanation

In AML, the problem starts in the myeloid family of the bone marrow — the family that makes red cells, platelets and neutrophils. Genetic changes build up in one cell, which stops maturing and starts multiplying quickly. These immature cells are called myeloblasts.

The blasts do not work, but they take up space. Over a few weeks, the marrow fills with them and healthy cells fall: you feel very tired and pale, get frequent infections with fever, and bruise or bleed easily. Sometimes there is bone pain, gum swelling or skin changes.

AML is not one disease but the umbrella name for many subtypes. To tell them apart, the lab studies the genetic “fingerprint” of the blasts — which chromosome and gene changes they carry. The results can take from several days to weeks, but they are very important for choosing treatment.

Treatment usually happens in two stages. Induction aims to reduce the leukemia cells in the marrow as much as possible and reach remission. Consolidation aims to destroy any hidden cells left behind and lower the risk of relapse. For some people, a stem cell transplant is the best choice at this stage.

Not everyone gets the same treatment. Doctors take into account age, general health and the genetic features of the leukemia. For people who cannot tolerate intensive chemotherapy there are gentler but effective regimens, and targeted drugs exist for some genetic changes. AML is a serious illness, but many people reach remission, and some stay in long-term remission.

03Scientific explanation

Diagnosis usually requires myeloblasts to make up ≥20% of the marrow or blood; however, with defining genetic abnormalities — such as t(15;17) PML::RARA, t(8;21) RUNX1::RUNX1T1 or inv(16)/t(16;16) CBFB::MYH11 — AML is diagnosed at a lower blast percentage. WHO 2022 has removed the blast threshold entirely for many genetically defined AML types, while ICC 2022 usually keeps a 10% threshold. The classification also recognises myelodysplasia-related AML (certain mutations or cytogenetic changes, or prior MDS) and therapy-related AML (after previous chemotherapy or radiation).

The most common mutations include NPM1, FLT3 (ITD and TKD), DNMT3A, IDH1/IDH2, TET2, CEBPA, RUNX1, ASXL1 and TP53. The ELN 2022 risk classification sorts these findings into three groups: favourable (e.g. t(8;21), inv(16), NPM1 mutation without FLT3-ITD, bZIP CEBPA mutation), intermediate (e.g. NPM1 mutation with FLT3-ITD, t(9;11)) and adverse (e.g. complex karyotype, −7, TP53 mutation, mutations in ASXL1, RUNX1 and splicing genes, KMT2A rearrangements). The risk group strongly influences whether a transplant is recommended after remission.

The classic backbone of intensive induction is cytarabine combined with an anthracycline such as daunorubicin (“7+3”); in some subtypes targeted drugs are added: FLT3 inhibitors for FLT3 mutations (e.g. midostaurin, quizartinib), gemtuzumab ozogamicin for CD33-positive favourable-risk AML, and liposomal daunorubicin-cytarabine (CPX-351) for myelodysplasia-related and therapy-related AML. Consolidation uses courses of high-dose cytarabine or an allogeneic stem cell transplant. For people who are not suited to intensive chemotherapy, hypomethylating agents (azacitidine, decitabine) combined with venetoclax are one of the standard options.

In relapsed or refractory (non-responding) AML, the mutation profile is checked again: options can include the FLT3 inhibitor gilteritinib, the IDH1 inhibitor ivosidenib, the IDH2 inhibitor enasidenib and menin inhibitors — in 2025 the FDA approved revumenib and ziftomenib for relapsed/refractory AML with a susceptible NPM1 mutation (revumenib is also approved for acute leukemia with a KMT2A rearrangement). Response is tracked through measurable residual disease (MRD), using flow cytometry or molecular methods (e.g. qPCR for NPM1). In the US, overall 5-year relative survival for AML is 33.4% (SEER, 2016–2022), but results vary greatly by age and genetic subtype, and are considerably higher in younger people and favourable subtypes.

04What happens in the body?

Diagnosis: several tests combined

A complete blood count and blood smear give the first clue. A bone marrow aspirate and biopsy confirm the diagnosis. Flow cytometry shows that the blasts are myeloid, and cytogenetic and molecular tests define the subtype and risk group. In some cases, the spinal fluid is also checked.

Induction and remission

After induction, the marrow is “emptied” for a while and blood counts fall very low — protection from infection, transfusions and close monitoring matter during this time. Usually after a few weeks the marrow is examined again: if blasts are below 5% and blood counts have recovered, that is remission.

Close-up of spongy marrow spaces: a few fading violet blasts on the left, and more and more bright red cells, platelets and teal stem cells towards the right.
Figure 2.Remission: after treatment, the blasts fall away and the marrow fills with healthy cells again.

Consolidation and transplant

Remission is not the same as cure — hidden leukemia cells may remain. Consolidation targets them. Depending on the risk group, MRD result, age and whether a donor is available, doctors may offer chemotherapy courses or an allogeneic stem cell transplant.

Targeted drugs and new options

Targeted drugs for FLT3, IDH1, IDH2 and NPM1/KMT2A changes, venetoclax-based regimens and antibody-drug conjugates have changed AML treatment considerably over the past decade. Clinical trials are also an important option — ask your doctor whether a suitable trial is available for you.

Close-up of a cell surface: a small, teal-glowing drug molecule fits precisely into a pocket of a warm orange protein, whose glow begins to fade.
Figure 3.Targeted treatment: a drug molecule blocks the faulty protein in a leukemia cell, like a key in a lock.

05AML: from diagnosis to treatment plan

The treatment decision in AML takes shape in four steps.

Genetic change — Mutations build up in a myeloid precursor cell.1Genetic changeMutations build up in a myeloid precursor cell.
Blasts multiply — Immature myeloblasts accumulate in the marrow.2Blasts multiplyImmature myeloblasts accumulate in the marrow.
Diagnosis and genetics — Marrow tests, flow cytometry, karyotype, NGS.3Diagnosis and geneticsMarrow tests, flow cytometry, karyotype, NGS.
Risk and plan — ELN risk group, age and health are taken into account.4Risk and planELN risk group, age and health are taken into account.
InductionThe goal is complete remission.
Consolidation / transplantTo lower the risk of relapse.
MRD monitoringThe depth of response is tracked.

06Genetic risk groups in AML (ELN 2022, simplified)

Risk groupExample findingsWhat does it usually mean?
Favourablet(8;21); inv(16) or t(16;16); NPM1 mutation without FLT3-ITD; bZIP CEBPA mutationGood response to chemotherapy; a transplant is usually not needed in first remission (taking MRD into account)
IntermediateNPM1 mutation with FLT3-ITD; FLT3-ITD without NPM1 mutation; t(9;11); other unclassified changesThe transplant decision is individual — it depends on MRD, age and donor availability
AdverseComplex or monosomal karyotype; −5/del(5q), −7, 17p abnormalities; inv(3); t(6;9); KMT2A rearrangements (except t(9;11)); TP53, ASXL1, RUNX1 or splicing-gene mutationsA transplant in remission is often recommended where possible; clinical trials are an important option

* This table is a simplified summary of the ELN 2022 recommendations for adults receiving intensive treatment. The risk group is refined during treatment using MRD results. Discuss your own results with your hematologist.

07Key terms

AML
Acute myeloid leukemia — a leukemia in which myeloid blasts multiply quickly.
Myeloblast
An immature cell of the myeloid line.
Induction
The first intensive treatment, aimed at remission.
Consolidation
Treatment after remission to lower the risk of relapse.
Complete remission
Marrow blasts below 5% with recovered blood counts.
Refractory
Not responding to treatment.
Relapse
The return of leukemia after remission.
ELN
European LeukemiaNet; it produces the AML risk classification.
Allogeneic transplant
A transplant of stem cells from a donor.
MRD
Measurable residual disease — a very small number of leukemia cells left in remission.

08Key points

  • AML is an acute leukemia in which myeloid blasts multiply quickly in the marrow.
  • It mainly affects older adults (median age 70 in the US), but can occur at any age.
  • Symptoms usually develop over weeks: tiredness, infections, bleeding.
  • Diagnosis relies on a bone marrow examination, flow cytometry and genetic tests.
  • Genetic findings define the risk group and the choice of treatment.
  • Treatment: induction → consolidation; sometimes a stem cell transplant.
  • Targeted drugs and less intensive regimens have opened new options.
  • Results vary greatly by age and subtype.

09Frequently asked questions

How soon should treatment start after an AML diagnosis?

Because AML develops quickly, treatment usually starts soon. But for many people who are stable, doctors may wait a few days for the first genetic results so they can choose the most suitable treatment. Suspected APL is the exception — treatment starts immediately. Your hematologist decides on the timing.

How long will I be in hospital during induction?

With intensive induction, people often stay in hospital for several weeks — until the marrow recovers and the risk of infection falls. Some less intensive regimens can be given as an outpatient. This depends on the centre and your condition.

I am older. Is there treatment for me?

Yes. Age alone is not a reason to rule out treatment. Doctors consider your general health, other conditions and personal preferences. Venetoclax-based regimens and targeted drugs offer effective options for people who are not suited to intensive chemotherapy.

Does everyone need a transplant?

No. Many people in the favourable risk group who reach MRD-negative remission stay in long-lasting remission without a transplant. A transplant is more often recommended for high-risk disease, MRD-positive status or after relapse. The decision is made individually, weighing benefits against risks.

Is AML inherited?

In most cases, no. But there are rare forms of inherited predisposition (for example involving RUNX1, CEBPA, DDX41 or GATA2). If several family members have had blood disorders, or relatives are being tested as donors, your doctor may offer genetic counselling.

What should I watch for after remission?

It is important to attend regular follow-up visits, tell your team promptly about new symptoms such as tiredness, fever or bruising, and look after your general health. We cover follow-up schedules and MRD tests in a separate topic.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. What is the genetic risk group of my AML?

  2. Is intensive or gentler treatment planned for me, and why?

  3. Is a transplant being considered for me?

  4. How long will I need to stay in hospital during treatment?

My questions

12Sources

  1. National Cancer Institute (NCI). Adult Acute Myeloid Leukemia Treatment (PDQ®) — Patient Version
  2. National Cancer Institute (NCI). Adult Acute Myeloid Leukemia Treatment (PDQ®) — Health Professional Version
  3. National Cancer Institute (NCI), SEER. Cancer Stat Facts: Acute Myeloid Leukemia (AML)
  4. American Cancer Society. Key Statistics for Acute Myeloid Leukemia (AML)
  5. American Cancer Society. How Is Acute Myeloid Leukemia Classified?
  6. American Cancer Society. Signs and Symptoms of Acute Myeloid Leukemia (AML)
  7. American Cancer Society. Risk Factors for Acute Myeloid Leukemia (AML)
  8. NHS. Acute myeloid leukaemia
  9. Blood (American Society of Hematology), 2022. Diagnosis and management of AML in adults: 2022 recommendations from an international expert panel on behalf of the ELN
  10. National Cancer Institute (NCI). Venetoclax — Cancer Drug Information
  11. U.S. Food and Drug Administration (FDA). FDA approves revumenib for relapsed or refractory AML with a susceptible NPM1 mutation
  12. Leukemia (Nature) — WHO 5th edition. WHO Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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