Introduction

Acute myeloid leukaemia (AML) is a type of cancer affecting the blood and bone marrow. It is a rapidly progressing disease characterised by the abnormal growth and accumulation of immature blood cells (myeloid blasts) in the bone marrow. AML is one of the most common types of leukaemia in adults, and the likelihood of developing the disease increases with age.¹ This article provides an overview of AML, including its causes, symptoms, diagnosis, treatment options, and prognosis. 

Causes and risk factors

The exact cause of AML is not fully understood, but it is believed to result from genetic mutations in the bone marrow cells that produce blood cells. These mutations alter the normal process of cell growth, leading to the uncontrolled growth of immature myeloid cells.¹

Several factors can increase your risk of developing AML, including:²

1. Genetic Mutations: Certain genetic mutations have been associated with an increased risk of AML. These mutations can arise spontaneously or may be inherited.³
2. Exposure to Radiation: Extended exposure to high levels of radiation, such as radiation therapy for previous cancers or atomic bomb radiation, increases your chance of developing AML.
3. Chemical Exposure: Exposure to certain chemicals found in industrial settings or tobacco smoke can increase your risk of developing AML.
4. Previous Chemotherapy or Radiation Therapy: Some chemotherapy drugs and radiation therapy for other cancers can damage bone marrow and increase your risk of developing AML later.
5. Myelodysplastic Syndromes (MDS): Myelodysplastic syndromes are a group of disorders characterised by abnormal blood cell production in the bone marrow. Having MDS increases your risk of developing AML.
6. Age: AML is more common in older adults, and risk increases with age. However, AML can occur at any age, including both children and young adults.
7. Certain Genetic Syndromes: Certain genetic syndromes, such as Down’s syndrome and Li-Fraumeni syndrome, are associated with an increased risk of AML.³

Having one or more of the factors on this list does not mean that you will develop AML, instead, they only increase the likelihood of developing the disease. Sometimes, some individuals with AML have no identifiable risk factors. 

Symptoms

Symptoms of AML vary depending on age, overall health, and the extent of the disease (2, 3). The signs and symptoms of AML can develop gradually and may resemble those of other illnesses. Common symptoms include: 

Some of the most common symptoms of AML are:³

• Fatigue: Persistent fatigue and weakness that does not improve with rest may be an early sign of AML. This fatigue can interfere with your daily activities.
• Shortness of Breath: Difficulty breathing or shortness of breath, especially after exercise, may occur due to anaemia caused by decreased red blood cells.
• Easy Bruising or Bleeding: AML can cause a decrease in platelet numbers in the blood, leading to easy bruising, bleeding gums, or frequent nosebleeds. There may also be excessive bleeding after a minor cut or injury. 
• Frequent Infections: AML reduces the number of healthy white blood cells in the body, which helps the body to fight off infections. Therefore, individuals with AML may experience frequent infections, such as pneumonia, urinary tract infections, or skin infections.
• Bone Pain: Bone pain, particularly in the hips or ribs, may occur because of the accumulation of leukaemia cells in the bone marrow.
• Swollen Lymph Nodes: Enlarged lymph nodes, especially in the neck, armpits, or groin, may indicate the body's immune response to leukaemia cells.
• Unexplained Weight Loss: Significant and unexplained weight loss may occur without changing your diet or exercise habits.
• Fever: Persistent or recurrent fevers may occur, often accompanied by night sweats.

Many of these symptoms are also caused by other medical conditions. If these symptoms are persistent and unexplained, or if you are concerned, seek medical advice from a healthcare professional for further evaluation and diagnosis.

Diagnosis

Diagnosing AML usually begins with a discussion of your medical history and a physical exam by a healthcare provider (4). If AML is suspected based on symptoms or abnormal findings, further tests are needed to confirm the diagnosis and determine if the disease has spread. Common tests used to diagnose AML include:

Some common tests used to diagnose AML are:⁴

1. Blood Tests: These tests can show if there are abnormal levels of different types of blood cells, which is common in AML.
2. Bone Marrow Aspiration and Biopsy: A small sample of bone marrow is taken from the hip bone or sternum with a needle. The sample is examined under a microscope to look for leukaemia cells and learn more about them.
3. Cytogenetic Analysis: This test studies the chromosomes in leukaemia cells to find any abnormalities or genetic mutations that can help classify the type of AML.
4. Flow Cytometry: This lab test checks the cells' size, shape, and surface proteins. It can identify abnormal cell populations, like leukaemia cells, based on their proteins.
5. Immunophenotyping: This type of flow cytometry focuses on the protein markers on cell surfaces. It helps tell different types of leukaemia apart and determine their cell lineage.
6. Molecular Testing: This test looks for gene mutations linked to leukaemia. 

After confirming the AML diagnosis, more tests may be done to see how far the disease has spread. Imaging tests like chest X-rays, CT scans, or PET scans might be used to see if and where the leukaemia has spread around the body.⁴

Treatment options

Treating AML depends on factors such as age, overall health, and the specific type of AML. The goal of treatment is to remove leukaemia cells from the body until remission (no evidence of the disease) occurs.^4,5 Common treatment options for AML include chemotherapy, targeted therapy, stem cell transplantation, and supportive care measures. 

Chemotherapy

Chemotherapy  involves using powerful drugs to kill leukaemia cells and prevent them from growing and dividing.^5,6 Chemotherapy regimens typically consist of combinations of different drugs administered in cycles over several weeks or months. These drugs are given orally or intravenously and may be used alone or combined with other treatments.

Targeted therapy

Targeted therapy specifically targets certain molecules or pathways involved in the growth and survival of leukaemia cells.^5,6 Drugs such as tyrosine kinase inhibitors or monoclonal antibodies may be used to target specific genetic mutations or protein markers present in AML cells. Targeted therapy can be used alone but is often combined with chemotherapy.

Stem cell transplantation:

Stem cell transplantation(bone marrow transplantation) involves replacing diseased or damaged bone marrow with healthy stem cells from a donor.⁷ This procedure aims to replenish the patient's blood cell supply with healthy cells and restore normal blood cell production. Stem cell transplantation may be considered for younger patients with high-risk AML who are in remission after initial treatment or for those who have relapsed after previous therapy.⁷

Supportive care

Supportive care measures focus on managing symptoms and complications associated with AML and its treatment.⁸ This may include blood transfusions to replace depleted blood cells, antibiotics to prevent or treat infections, and medications to manage side effects such as nausea, vomiting, and fatigue.⁸ Additionally, nutritional support, pain management, and psychosocial support services may be provided.

Prognosis

The prognosis for individuals with AML varies depending on several factors.⁸ One crucial factor is age, as younger patients tend to respond better to treatment and have a higher likelihood of achieving remission. The overall health status of the patient is also important, as individuals with pre-existing health conditions or compromised immune systems often face more challenges in managing AML.

Another important factor is the specific subtype of AML and any genetic mutations present in the leukaemia cells.⁸ Certain genetic mutations may indicate a more aggressive form of the disease, while others may suggest a better response to treatment. For some patients, particularly those who achieve complete remission with initial treatment, the prognosis may be relatively favorable. However, even patients in complete remission may still be at risk of relapse.

Unfortunately, not everyone responds well to standard therapies, and some may experience relapse or refractory disease.⁸ Relapsed AML occurs when leukaemia cells reappear after a period of remission, while refractory AML means that the leukaemia cells continue to grow despite treatment efforts. In such cases, the prognosis may be worse, and treatment options may be limited.

Lifestyle and support

Living with AML can be challenging, but there are steps to help improve quality of life and well-being. Maintaining a healthy lifestyle by eating a balanced diet, staying physically active as much as possible, and getting enough rest can support overall health.⁹ It is important to follow any recommendations from your healthcare provider regarding diet, exercise, and other lifestyle habits.

Seeking emotional and social support can help cope with the challenges of an AML diagnosis.¹⁰ This may involve connecting with family members, friends, or support groups who can offer understanding, encouragement, and practical assistance. Many people find comfort in sharing their experiences with others who are going through similar situations. Support groups, both in-person and online, can provide valuable resources and a sense of community for patients and their loved ones.¹⁰

Summary

Acute myeloid leukaemia (AML) presents significant challenges, but advances in treatment offer hope for the future. Recognizing symptoms early and seeking medical advice helps begin treatment as soon as possible. Treatment options include chemotherapy, targeted therapy, and stem cell transplantation, tailored to individual needs. Long-term outcomes vary, but with proper care and support, there is a good chance for long-term remission and high survival rates.