Acute Myeloid Leukaemia (AML)

Key Features of AML:

• Acute: This indicates the disease develops quickly and progresses rapidly if left untreated.
• Myeloid: Refers to the type of blood cells involved; myeloid cells are precursors to red blood cells, white blood cells (except lymphocytes), and platelets.
• Leukaemia: Refers to cancer of the blood, where abnormal white blood cells proliferate and disrupt normal blood cell production.

How AML Develops:

In a healthy bone marrow, myeloid cells mature into various types of blood cells, including red blood cells, platelets, and different types of white blood cells (like neutrophils and monocytes). In AML, the bone marrow starts producing large numbers of immature myeloid cells, known as blasts, which do not function properly. These blasts take over the bone marrow, making it difficult for normal blood cells to develop.

Types of AML:

AML can be classified based on the type of myeloid cell involved and the genetic mutations present in the leukaemia cells. Some common subtypes of AML include:

• De novo AML: AML that develops without a known prior cause.
• Secondary AML: AML that develops as a result of previous cancer treatment or other blood disorders, such as myelodysplastic syndromes (MDS).
• AML with specific genetic mutations: Genetic abnormalities in certain genes (e.g., FLT3, NPM1, CEBPA) can influence prognosis and treatment options.

Symptoms of AML:

Symptoms of AML develop rapidly because the disease progresses quickly. Common signs and symptoms include:

• Fatigue and weakness (due to anaemia from low red blood cells)
• Pale skin
• Frequent infections (due to a low white blood cell count)
• Easy bruising or bleeding, such as frequent nosebleeds or gum bleeding (due to low platelet count)
• Fever
• Bone or joint pain
• Shortness of breath
• Swollen lymph nodes
• Weight loss

Diagnosis of AML:

AML is typically diagnosed through a combination of tests, including:

• Blood tests: The presence of high numbers of immature white blood cells (blasts) in the blood is a key indicator.
• Bone marrow biopsy: A sample of bone marrow is taken to check for the presence of leukaemia cells.
• Cytogenetic testing: To identify chromosomal abnormalities or mutations in the leukaemia cells, which can guide treatment decisions.
• Flow cytometry: To analyse the characteristics of the leukaemia cells and determine the subtype of AML.
• Molecular genetic testing: To identify specific mutations that may influence prognosis and treatment options.

Treatment of AML:

The treatment for AML typically involves aggressive chemotherapy to induce remission, followed by further treatment to prevent relapse. Common approaches include:

• Induction chemotherapy: This is the first phase of treatment, aiming to destroy the leukaemia cells and induce remission (i.e., reduce the number of leukaemia cells to an undetectable level in the blood and bone marrow). It often involves a combination of drugs.
• Consolidation chemotherapy: After remission, consolidation chemotherapy is given to target any remaining leukaemia cells and reduce the risk of relapse.
• Stem cell transplant (bone marrow transplant): For certain high-risk patients or those with relapsed AML, a stem cell transplant may be used. This involves replacing the patient’s damaged bone marrow with healthy stem cells from a donor.
• Targeted therapies: Some types of AML have specific genetic mutations (e.g., FLT3, IDH1/IDH2) that can be targeted with specific drugs designed to inhibit the growth of leukaemia cells.
• Immunotherapy: In some cases, treatments that help the body’s immune system recognise and attack leukaemia cells may be used, such as monoclonal antibodies or CAR-T cell therapy.
• Supportive care: This includes treatments to help manage the side effects of the disease and its treatments, such as blood transfusions, antibiotics for infections, and medications to help with nausea.

Prognosis:

The prognosis for AML varies widely and depends on factors such as:

• Age: Younger patients tend to have better outcomes.
• Genetic mutations: Specific genetic changes in leukaemia cells can influence both prognosis and treatment options.
• Response to treatment: Patients who achieve remission after the first round of chemotherapy have a better chance of long-term survival.
• Overall health: Patients with fewer other health problems generally have a better prognosis.

AML can be a challenging disease to treat, but with advances in chemotherapy, targeted therapies, and stem cell transplants, survival rates are improving. The overall survival rate for AML has been increasing, especially in younger patients, but it remains lower in older adults and those with more aggressive forms of the disease.