Acute myeloid leukemia - Symptoms, Causes, Treatment & Prevention

```html

Overview

Acute Myeloid Leukemia (AML) is a fast‑growing cancer of the blood and bone marrow that originates from myeloid precursor cells. These abnormal cells proliferate rapidly, crowding out normal blood‑forming cells and leading to a shortage of functional red cells, white cells, and platelets.

AML can affect anyone, but it is most common in adults. In the United States, about 20,000 new cases are diagnosed each year, representing roughly 1% of all cancers and approximately 0.5% of all new cancer diagnoses worldwide (American Cancer Society, 2024). The median age at diagnosis is 68 years, and incidence rises sharply after age 60. Although less common in children, a distinct pediatric form exists, accounting for about 15–20% of childhood leukemia cases.

Symptoms

Because AML replaces normal marrow, symptoms often reflect a deficiency of healthy blood components. They can develop over days to weeks and may include:

General/Constitutional

• Fatigue or weakness – due to anemia (low red blood cells).
• Fever or chills – a sign of infection when neutrophils are low.
• Weight loss and loss of appetite.
• Night sweats.

Hematologic

• Easy bruising or bleeding (including nosebleeds, gum bleeding, or heavy menstrual periods) – caused by low platelets.
• Petechiae – tiny red spots on the skin.
• Frequent infections – especially bacterial or fungal infections.
• Shortness of breath on exertion – result of anemia.

Bone‑Marrow Related

• Bone or joint pain – leukemic cells expand within the marrow cavity.
• Swollen lymph nodes, spleen, or liver – palpable in the abdomen.

Neurologic and Other

• Headache, dizziness, or visual changes – from anemia or leukostasis (very high white‑cell counts).
• Bleeding in the brain or gastrointestinal tract – a medical emergency.

Because these signs overlap with many benign conditions, laboratory testing is essential for confirmation.

Causes and Risk Factors

AML is not usually linked to a single cause. Instead, it results from genetic mutations that disrupt normal blood‑cell development. Known contributors include:

Genetic Mutations

• Acquired mutations in FLT3, NPM1, CEBPA, DNMT3A, IDH1/2 and many others are present in >80% of cases (Leukemia & Lymphoma Society, 2023).
• Inherited predisposition syndromes such as familial AML, Fanconi anemia, Down syndrome, and Li-Fraumeni syndrome increase risk.

Environmental Exposures

• Exposure to high‑dose radiation (e.g., atomic bomb survivors, radiation therapy for other cancers).
• Long‑term benzene exposure (industrial solvents, gasoline fumes).
• Chemotherapy agents—particularly alkylating agents (e.g., cyclophosphamide) and topoisomerase II inhibitors (e.g., etoposide)—can cause therapy‑related AML (t‑AML).

Medical History

• Previous myelodysplastic syndromes (MDS) or myeloproliferative neoplasms.
• Chronic immune suppression or HIV infection.
• History of other cancers treated with radiation or certain chemotherapies.

Demographic Factors

• Age: risk increases sharply after 60 years.
• Sex: slightly more common in males (≈1.4:1).
• Ethnicity: higher incidence in White non‑Hispanic populations in the U.S.

Diagnosis

Early diagnosis relies on a combination of clinical suspicion, blood work, and bone‑marrow evaluation.

Initial Laboratory Tests

• Complete blood count (CBC) with differential: typically shows anemia, thrombocytopenia, and abnormal white‑cell counts (often high with a high proportion of blasts).
• Peripheral blood smear: presence of ≥20% myeloblasts is a diagnostic threshold for AML.

Bone Marrow Examination

• Aspirate and biopsy: the gold standard; confirms ≥20% blasts (or specific genetic abnormalities regardless of blast count).
• Flow cytometry: characterizes cell surface markers (e.g., CD13, CD33, CD117, MPO) to differentiate AML from other leukemias.
• Cytogenetic & molecular testing: karyotyping, fluorescence in‑situ hybridization (FISH), and next‑generation sequencing identify prognostically important mutations (e.g., FLT3‑ITD).

Additional Staging Tests

• Lumbar puncture: for suspected central‑nervous‑system involvement, especially in high‑risk subtypes.
• Imaging (CT, PET, MRI): assesses organ infiltration or extramedullary disease.

Risk stratification (favorable, intermediate, adverse) uses cytogenetic and molecular data, guiding treatment intensity (NCCN Guidelines 2024).

Treatment Options

Treatment is individualized based on age, performance status, genetic risk, and comorbidities. Goals include achieving complete remission (CR), preventing relapse, and preserving quality of life.

Induction Therapy

• “7+3” regimen: cytarabine continuous infusion for 7 days plus an anthracycline (daunorubicin or idarubicin) for 3 days. This is the backbone for most fit adults.
• Alternative combinations (e.g., FLAG‑IDA, CPX‑351) are used for high‑risk or therapy‑related AML.

Consolidation / Post‑Remission Therapy

• High‑dose cytarabine (HiDAC): standard for favorable‑risk patients.
• Allogeneic hematopoietic stem‑cell transplantation (HSCT): recommended for intermediate‑ or adverse‑risk disease when a suitable donor is available.
• Targeted agents:
  • Midostaurin for FLT3‑mutated AML (combined with 7+3).
  • Gilteritinib for relapsed/refractory FLT3‑mutated disease.
  • Enasidenib (IDH2 inhibitor) and Ivosidenib (IDH1 inhibitor) for respective mutations.
  • Venetoclax + hypomethylating agents (azacitidine or decitabine) for older or unfit patients.

Supportive Care

• Transfusion of red cells and platelets as needed.
• Broad‑spectrum antibiotics or antifungals for neutropenic fever.
• Growth factors (e.g., G‑CSF) in selected cases.
• Management of tumor lysis syndrome with aggressive hydration and allopurinol or rasburicase.

Clinical Trials

Participation in trials exploring novel agents (e.g., menin inhibitors, bispecific antibodies) is encouraged, especially for relapsed disease.

Lifestyle & Adjunct Measures

• Balanced nutrition, adequate protein intake, and vitamin supplementation as directed by a dietitian.
• Moderate exercise (walking, yoga) when platelet counts permit.
• Smoking cessation and limiting alcohol to reduce infection risk.

Living with Acute Myeloid Leukemia

Managing AML is a team effort involving oncologists, nurses, pharmacists, social workers, and caregivers. Practical tips for daily life include:

Monitoring & Follow‑Up

• Attend all scheduled blood work and bone‑marrow assessments; early detection of relapse improves outcomes.
• Keep a symptom diary—note fevers, bleeding, new pain, or changes in energy.

Infection Prevention

• Practice rigorous hand hygiene and avoid crowds when neutrophil counts are low.
• Stay up‑to‑date with vaccinations (influenza, pneumococcal, COVID‑19) — discuss timing with your oncologist.
• Use protective masks in high‑risk settings and consider prophylactic antibiotics if recommended.

Bleeding Precautions

• Avoid sharp objects, use a soft toothbrush, and shave with electric razors.
• Limit alcohol intake and avoid NSAIDs that impair platelet function.

Nutrition & Hydration

• Small, frequent meals that are high in protein and calories help counteract treatment‑related nausea and weight loss.
• Stay well‑hydrated; aim for >2 L of fluid daily unless fluid restriction is ordered.

Psychosocial Support

• Seek counseling or support groups (e.g., American Cancer Society’s Cancer Survivors Network).
• Ask about financial counseling; many hospitals have resources for medication assistance.

Return to Work/School

• Discuss a phased return with your employer or school; flexible hours and remote options may be needed during intensive therapy.
• Know your rights under the Americans with Disabilities Act (ADA) or equivalent legislation.

Prevention

Because most AML cases stem from random genetic errors, primary prevention is limited. However, risk reduction strategies include:

• Avoiding occupational benzene exposure: use protective equipment, follow safety guidelines.
• Limiting unnecessary radiation: discuss risks of repeat imaging or therapeutic radiation.
• Prudent use of chemotherapy: when possible, use the lowest effective dose and consider protective agents.
• Healthy lifestyle: smoking cessation, balanced diet, and regular exercise may improve overall bone‑marrow health.

Individuals with known inherited predisposition syndromes should receive genetic counseling and regular hematologic surveillance.

Complications

If AML is untreated or inadequately controlled, several life‑threatening complications can arise:

• Severe infections: neutropenia predisposes to bacterial, fungal, and viral sepsis.
• Hemorrhage: thrombocytopenia can cause intracranial bleeds, gastrointestinal hemorrhage, or fatal mucosal bleeding.
• Leukostasis: hyperviscosity from extremely high blast counts may cause respiratory distress, visual loss, or stroke.
• Organ infiltration: leukemic cells can infiltrate the liver, spleen, or central nervous system, causing dysfunction.
• Tumor lysis syndrome: rapid cell death releases potassium, phosphate, and uric acid, leading to renal failure and cardiac arrhythmias.
• Secondary MDS/AML: prior chemotherapy or radiation can cause therapy‑related AML, which often has a poorer prognosis.

When to Seek Emergency Care

---

Sources: American Cancer Society. Cancer Facts & Figures 2024; National Comprehensive Cancer Network (NCCN) Guidelines AML Version 3.2024; Mayo Clinic. Acute Myeloid Leukemia; CDC. Benzene and Cancer; NIH National Cancer Institute. Adult Acute Myeloid Leukemia Treatment (PDQ®) 2024; World Health Organization. International Classification of Diseases for Oncology, 2022; Leukemia & Lymphoma Society. AML Overview 2023.

```