AML Full Form

AML is a form of haematological cancer that originates from the bone marrow. The bone marrow forms the spongy component of bones and is the blood cell production site. The bone marrow produces blood cells, including red blood cells, white blood cells, and platelets. In AML, the white blood cells formed are abnormal. These are highly proliferative, abnormally differentiated cancer cells known as myeloblasts. If left untreated, AML moves into the peripheral bloodstream and can spread to other body parts. These body parts may include lymph nodes, brain, liver, cerebrospinal fluid, skin, spleen, and testicles. AML is also known as acute nonlymphocytic leukaemia.

AML incidence

AML is the most common type of acute leukaemia in adults. Approximately 1 in 3 adult leukaemia diagnoses is AML. However, AML constitutes about 1% of all cancers. There is increased incidence with age and, as of 2019, the reported median age at diagnosis was 68 years. Children can also get AML, but this is quite rare. AML accounts for the largest number of leukaemia-associated deaths in the United States in terms of mortality. It has the shortest survival rate. However, this survival rate is subject to contention. Scientists argue that the low median survival rate (usually 5 to 10 months) is an outcome solely observed in older patients who cannot receive chemotherapy without facing unacceptable side effects. Therefore, the lack of treatment options contributes to the low survival rate.

AML risk factors

Age is the greatest risk factor of getting AML. A SEER Cancer Statistics Review report detailed that 54% of AML patients were diagnosed at 65 years or older. Further studies have uncovered that men are more likely to get AML than women. Still, some factors were frequently found in AML patients and thus related as risk factors of AML, including:

• Prior exposure to chemotherapy and radiation
• A history of blood disorders such as myelodysplastic syndrome and thrombocythemia
• Excessive exposure to chemicals such as benzene and formaldehyde
• Genetic disorders such as Down syndrome and Fanconi anaemia
• High-dose radiation exposure
• Smoking, especially after the age of 60

AML Classification

The World Health Organization (WHO) Classification of Tumours of Hematopoietic and Lymphoid Tissues system classify AML into major sub-types. The WHO system is widely accepted as it accounts for prognosis factors. The updated WHO classification system (2016) includes categories such as: 

• AML with certain genetic abnormalities
• AML with myelodysplasia-related changes
• AML due to prior chemotherapy and radiation exposure
• AML by causes not otherwise specified
• Myeloid sarcoma or granulocytic sarcoma
• Myeloid proliferations related to Down syndrome
• Mixed phenotype acute leukaemias

AML symptoms

AML causes various signs and symptoms. Some symptoms are also common in other forms of leukaemia and are non-specific symptoms. Other symptoms are caused by the bodily effects of AML, such as reduced blood cell counts and an increased number of cancer cells. AML symptoms such as:

• Non-specific symptoms: weight loss, fatigue, fever, loss of appetite
• Symptoms of low red blood cell count: anaemia, feeling cold, dizziness, pale skin, shortness of breath.
• Symptoms of low blood platelet count: purpura, excess bleeding, frequent nosebleeds, bleeding gums, and heavy periods in women

Other symptoms develop as cancer spreads to other tissues. These include:

• Joint pains
• Swollen abdomen
• Skin rashes
• Swelling, pain, and bleeding of the gums
• Generalised lymphadenopathy
• Seizures
• Vomiting
• Trouble balancing
• Blurred vision

AML diagnosis

According to 2016 WHO classification, a definite AML diagnosis is confirmed by more than 20% of blasts in the bone marrow and peripheral blood. Medical professional conducts physical exams and lab tests. Three main tests are done to get a diagnosis. These include complete blood count (CBC) tests, a bone marrow biopsy, and a spinal tap. The CBC test examines the presence of myeloid cells in the blood. A spinal tap, also known as a lumbar puncture, ascertains the spread of AML into other tissues, particularly the central nervous system (CNS).

AML treatment

The main treatment options in adults with AML include:

1. Chemotherapy: This is the top-recommended treatment for AML. It plays a significant role in slowing the multiplication of cancer cells. Chemotherapy can be administered in both hospital and hospice settings.
2. Radiotherapy: The radiation levels the patient is exposed to are controlled and target cancer cells. A disadvantage of this form of treatment is that there may also be damage to other healthy cells.
3. Targeted treatment: Specific drugs are administered depending on cancer’s mutations to target certain aspects of the cancer cells halting their growth.
4. Monoclonal antibody therapies: These drugs effectively treat AML unaffected by chemotherapy and relapse cancers.
5. Stem cell or bone marrow transplant: This treatment is recommended for patients in complete remission and is preceded by chemotherapy.

Conclusion:

Acute Myeloid Leukaemia (AML) is a malignant hematologic disorder of the bone marrow characterised by excessive proliferation and abnormal differentiation of myeloid progenitor cells. The incidence of AML increases with age. Scientists linked the cause of AML is genetic mutations and damage. However, they are yet to determine which particular gene or group of genes causes AML. Furthermore, AML treatment has improved over time as various therapies have been developed to manage and cure AML. Curative therapies such as intensive chemotherapy and stem cell transplantation are designated for younger patients. Various therapies may have undesirable side effects on older individuals, leading to poor prognoses and low survival.