Acute myeloid leukaemia (AML) is a type of blood cancer that starts in the bone marrow. Through the bloodstream, it may spread to other body parts, such as lymph nodes, liver, spleen, central nervous system (brain and spinal cord), and testicles in advanced stages.
Acute myeloid leukaemia, in most cases, develops from immature cells that would form white blood cells (other than lymphocytes). However, AML also develops from other blood-forming cells and gives rise to different subtypes of AML. The subtyping is made based on the morphology of cancer cells. Each subtype has a different presentation and prognosis.
Currently, there are no screening tests to support the early detection of acute myeloid leukaemia. This disease often progresses quickly and aggressively, and the symptoms are also quick to surface. Therefore, it is important to report any symptoms that are possibly associated with AML.
Following are some of the symptoms of AML:
- Flat pinpoint red spots under the skin caused by bleeding
- Easy bruising or bleeding
- Weakness or feeling tired
- Shortness of breath
- Loss of appetite
- Weight loss
- Night sweats
Patients may experience one or more of these symptoms. Also, it is important to note that most of these symptoms are associated with other less severe blood disorders as well. Therefore, those with symptoms should consult an expert for a conclusive diagnosis.
Although the exact causes of AML are unknown, there are a few risk factors that are associated with this disease:
- With age, the risk of AML increases
- History of chemotherapy or radiation therapy
- History of childhood Acute Lymphoblastic Leukaemia (ALL)
- Having myelodysplastic syndrome or a bone marrow failure disease
- Congenital disorders like Down’s Syndrome
- Gender (AML is more common among men)
- Exposure to hazardous radiation
- Exposure to benzene
AML can be diagnosed with a simple blood test wherein the sample drawn is examined under the microscope for any abnormalities. If abnormal cells are found, a bone marrow aspiration or trephine biopsy may follow. This helps in classifying the type of acute leukaemia accurately.
A flow cytometry assessment and cytogenetics assessment using peripheral or bone marrow aspirate helps in identifying the AML’s immunophenotype and determining the prognosis.
A lumbar puncture may be recommended if brain metastasis is suspected.
Chemotherapy is the main line of treatment for acute myeloid leukaemia in most cases. Chemotherapy is administered in three different phases, namely:
Induction: Induction, which is an intensive phase, starts soon after diagnosis. The goal of this phase is to induce remission i.e., to destroy leukaemic blast cells in the bone marrow and blood and restore normal blood cell production.
Consolidation: This phase follows the induction phase, and its role is to destroy the leukaemia cells that would have survived the induction therapy. Consolidation therapy helps in bringing down the risk of a relapse or the disease spreading to the central nervous system.
Maintenance: This is a lengthy phase, and its function is to bring down the risk of relapse and help the patient lead a cancer-free life. Maintenance therapy is often administered to treat acute promyelocytic leukaemia (APL) and is rarely used in the treatment of other AML subtypes.
Further, once the patient is in complete remission after consolidation therapy, the doctor may recommend an allogeneic transplant, especially if the patients have poor cytogenetics and in the case of relapse is predicted.
b. Haematopoietic Stem Cell Transplant
Haematopoietic stem cell transplant or stem cell transplant is a curative treatment approach wherein the stem cells extracted from HLA-matched donors are transferred to the patient’s body after the leukaemic cells are destroyed by chemotherapy.
Stem cell transplantation restores normal blood cell production, and most importantly, confers better survival rates.
c. Radiation Therapy
Radiation therapy is a non-standardised treatment for AML, and it is recommended when the disease has spread to the brain or spinal cord.
During radiation therapy, the cancer cells are precisely targeted with high-dose radiation beams. The radiation destroys the cancer cells while minimising damage to the surrounding healthy tissues.
d. Targeted Therapy
Targeted therapy is a personalised treatment approach where the specific genes, the components released or the tissue environment that supports the growth of leukaemic cells are targeted. This treatment blocks the growth of leukaemic cells and also prevents them from spreading to other organs. Targeted therapy also minimises damage to the healthy tissues.
AML is a relatively aggressive disease that requires continuous monitoring and follow-up. AML cytogenetics or the chromosomal structure of the leukaemic cell is the most important prognostic factor for AML. Certain cytogenetic abnormalities have good survival rates, while some cytogenetic abnormalities may be associated with a high risk of relapse and poor survival rates.
Frequently Asked Questions
1. How quickly can AML progress?
Acute myeloid leukaemia, as the name says, progresses quickly – within days to weeks. Fatigue, anaemia, loss of appetite, bruising, rashes, etc., are some of the common symptoms to keep an eye on.
Since these symptoms also indicate other less severe conditions, it is important to consult an expert for a conclusive diagnosis.
2. Is acute myeloid leukaemia treatable?
Yes, acute myeloid leukaemia is treatable. There are many promising treatment options, such as chemotherapy, stem cell transplant and targeted therapy, which support better quality clinical outcomes and higher survival rates.
Early detection plays a significant role in improving the survival rates for AML patients. Since this is an aggressive disease and progresses quickly, patients must not ignore any symptoms.
3. Is acute myeloid leukaemia hereditary?
There is no sufficient evidence on acute myeloid leukaemia being hereditary.
However, individuals with certain genetic disorders, which could be inherited from the parents, may have an increased risk of developing ALL. Those genetic disorders include:
- Down syndrome
- Klinefelter syndrome
- Bloom syndrome
- Ataxia telangiectasia
- Li-Fraumeni syndrome
- Familial Platelet Disorder syndrome
- Fanconi anaemia
- Wiskott-Aldrich syndrome
4. What are the side effects associated with AML treatment?
The types of side effects and their severity depend on the treatment plan recommended by the expert team. Some may experience milder symptoms, while some may experience moderate to severe side effects.
Some of the common side effects associated with AML treatment include reduced immunity, loss of appetite, nausea and vomiting, bowel changes, fatigue, body pain, hair loss, anaemia, etc.
The side effects of the treatment will be discussed during the treatment planning along with the guidance on managing them. If you have any concerns about your treatments or the side effects that they cause, you can always talk to your doctor.
5. Is stem cell transplant inevitable for AML?
No, not all cases of AML need a stem cell transplant. Some patients respond well to chemotherapy, whereas some patients relapse or their health may not support chemotherapy or any other intensive treatments. In such cases, stem cell transplants are preferred.
If you have any questions about stem cell transplants, and their effectiveness, you can always discuss them with your doctor.