Acute myeloid leukaemia (AML) is an aggressive type of cancer that begins in the blood and the blood-forming tissues of the body. It primarily affects individuals over the age of 65.
Acute myeloid leukaemia targets myeloid stem cells, which are responsible for producing red blood cells, platelets, and a type of white blood cell called granulocytes. The condition develops when a myeloid stem cell becomes cancerous. These cancerous cells produce diseased, abnormal cells that cannot function correctly and multiply at a rapid pace. As the disease advances, this abundance of abnormal cells can overwhelm and crowd out healthy blood cells.
Consequently, AML may cause patients to develop anaemia (a deficiency of red blood cells) or impair their ability to clot blood. It can severely weaken the patient's immune system, leading to frequent infections.
There are several subtypes of AML. Classification often depends on specific chromosome abnormalities found in the cancer cells and the types of molecules these cells produce. These specific subtypes are crucial as they significantly impact a patient's treatment plan and overall outlook.
AML is the most common acute leukaemia in adults, with many people diagnosed in India each year. Although children can develop the disease, approximately 60% of all cases occur in people aged 65 and older. As an acute leukaemia, AML is aggressive and can be particularly challenging to treat, making prompt initiation of treatment essential. AML's five-year survival rate is about 30%, though this figure varies based on the cancer's exact subtype and the patient's age.
The body produces millions of blood cells daily, mostly within the bone marrow, the spongy interior of bones that contains immature stem cells. In a healthy person, these immature stem cells first become either lymphoid stem cells or myeloid stem cells.
Lymphoid stem cells develop into white blood cells, which are part of the immune system. They mature into lymphocytes (B cells and T cells), which are responsible for fighting infection.
Myeloid stem cells develop into white blood cells (monocytes and granulocytes, including neutrophils) that fight disease, as well as red blood cells (which carry oxygen), and platelets (which help the blood clot).
Leukaemia occurs when the DNA of a bone marrow stem cell mutates at some stage of its development. The cell turns cancerous, begins multiplying rapidly, and displaces healthy cells in the blood and bone marrow. These diseased cells can also gather in specific organs, including the liver, lymph nodes, spleen, and skin.
Leukaemia types are mainly classified by the type of stem cell that has turned cancerous (lymphoid or myeloid). They are also categorised as either acute or chronic:
Acute leukaemia involves immature cells, preventing them from developing fully and performing their functions. These cells multiply rapidly, making acute leukaemia the more aggressive form.
Chronic leukaemia involves mature or partially mature cells. These cells multiply more slowly and are generally less aggressive.
A risk factor is anything that increases the chance of developing a disease. Identifying these factors can be an important step towards early detection, though not everyone with these risk factors will develop the disease.
Risk factors for acute myeloid leukaemia (AML) include:
Smoking increases the risk of developing AML.
About 60% of all cases are in patients aged 65 and older.
More males develop AML than females.
Previous treatment with chemotherapy or radiation therapy for a prior cancer. The benefits of these therapies far outweigh their risks, even though they can cause AML.
These are chronic bone marrow and blood cancers. MPNs (especially myelofibrosis) can transform into acute myeloid leukaemia. These conditions are treated by experts.
In MDS, the bone marrow does not produce enough healthy blood cells. MDS evolves into AML in 10-20% of patients.
Individuals with certain genetic disorders, such as Down syndrome, Fanconi anaemia, and hereditary cancer syndromes (like Li-Fraumeni syndrome), are at a higher risk.
Long-term exposure to benzene, a chemical used in the petroleum industry, can cause AML.
People with a parent, sibling, or child who has had AML may be more likely to develop the disease.
While there are many different types of leukaemia, the symptoms among these types can be similar. Many symptoms are a result of the body lacking properly functioning blood cells to carry oxygen, fight infection, and stop bleeding. Some symptoms are also caused by low levels of haemoglobin, a protein vital for oxygen transport.
Leukaemia symptoms may include:
Doctors typically diagnose leukaemia through a bone marrow biopsy, which involves using a long needle to take a sample from the hip. Effective leukaemia treatment begins with an accurate and precise diagnosis. Many patients seen at SSCHRC have unfortunately been misdiagnosed before seeking care here. At SSCHRC, suspected leukaemia cells are examined by pathologists who focus exclusively on diagnosing leukaemia and its many subtypes. This specialisation allows us to offer patients the most effective treatment for their specific disease.
A leukaemia diagnosis usually starts with a simple blood test called a complete blood count (CBC).
If the CBC shows the presence of leukaemia cells or abnormal levels of red blood cells, white blood cells, or platelets, doctors may order the following specialised tests. These tests provide a definitive leukaemia diagnosis, determine the extent of the disease, and are used to monitor the disease's progress:
For leukaemia, patients undergo a bone marrow biopsy, where a sample is taken from the hip to check for cancerous cells.
Further tests determine whether certain chromosomes or gene mutations are present in the diseased cells. This process, known as molecular profiling, helps doctors determine the exact type of leukaemia and the patient's prognosis. Since cancers with different genetic features respond differently to treatments, these tests are critical for creating the most successful treatment plan.
While leukaemia begins in the bone marrow, it may spread to the central nervous system (the brain and spinal cord). A lumbar puncture is performed to examine the spinal fluid for this spread. During this procedure, healthcare professionals remove cerebrospinal fluid from the spine with a needle. A small dose of chemotherapy may also be administered into the spinal fluid to eliminate any leukaemia cells that may be present.
Doctors may order imaging examinations to look for the presence of cancer in different parts of the body.
Cancer staging is the process of learning how far a cancer has spread. There is no standard staging system for AML; instead, the disease is described by the patient's treatment and current disease status.
The disease is newly diagnosed and has not been treated (except for supportive care to relieve signs or symptoms like fever or pain). Criteria include:
The disease has been treated, and the following criteria are met:
Refractory cancer is when newly diagnosed AML does not enter remission after chemotherapy. Relapsed or recurrent AML is when the cancer returns after a period of remission. The AML may return in the blood and bone marrow or as deposits in other tissues (known as "extramedullary disease," or leukaemia outside the bone marrow).
As home to one of the India's leading leukaemia programmes, the SSCHRC bring together internationally renowned physicians and a specialised support team to customise your care. These highly experienced experts communicate and collaborate daily, ensuring you receive comprehensive leukaemia treatment.
The goal of treatment is to put the disease into remission and ultimately achieve a cure. For leukaemia, complete remission usually signifies that the patient's bone marrow shows no detectable microscopic evidence of the disease, and their blood counts have returned to normal. Many patients require ongoing maintenance therapy to stay in remission, and some may undergo a stem cell transplant to maintain it. Patients who remain in continuous complete remission for an extended duration are considered cured, meaning they have an extremely low probability of the disease returning. The time frame for a cure is typically measured in years.
Treatment for newly diagnosed AML patients typically centres on chemotherapy. If intense rounds of chemotherapy are too difficult for the patient due to age or overall health, targeted therapy drugs may be given as an alternative.
Stem cell transplantation is also a treatment option for AML. It is usually recommended for patients with recurrent AML or refractory AML. It can also be an initial treatment for patients with particularly aggressive and hard-to-treat types of AML.
Chemotherapy for AML is usually delivered in stages:
This is an intense phase of treatment designed to destroy leukaemia cells in the blood and bone marrow. It usually requires a hospital stay, and the goal is to bring the cancer into remission.
This phase of chemotherapy aims to eliminate any remaining cancer cells that survived the induction phase.
In many cases, AML patients may undergo a third phase, known as maintenance. Patients in this phase receive a lower dose of chemotherapy over a prolonged period to prevent the cancer from returning. Patients may also receive a small dose of chemotherapy into their central nervous system to prevent the disease from spreading there. Stem cell transplant patients also undergo chemotherapy to prepare their body for the procedure.
Targeted therapy drugs are designed to stop or slow the growth or spread of cancer at a cellular level. These therapies interfere with specific molecules (often proteins) that cancer cells need to survive, multiply, and spread, which are typically produced by cancer-causing genes.
A stem cell transplant (also known as a bone marrow transplant) is a procedure that replaces cancerous bone marrow with new, healthy bone marrow stem cells. Transplants are usually performed after an intense course of chemotherapy that destroys the patient's existing bone marrow cells. Patients typically require a hospital stay for three to four weeks after the procedure. This treatment is physically challenging, so it is usually not given to patients who are elderly or otherwise unhealthy.
Radiation therapy uses powerful beams of energy to destroy cancer cells. Since leukaemia cells circulate in the bloodstream, there is no distinct tumour to target. Radiation may be used when the disease has spread to the central nervous system.
As a top-ranked cancer centre, SSCHRC offers multiple clinical trials for AML, many of which are not available elsewhere. These trials investigate new drug combinations and novel drugs, including targeted therapies and immunotherapies.
Some cases of leukaemia can be inherited. Genetic counselling may be appropriate for you. You can learn more about the risk to you and your family on our genetic testing page.