Acute myeloid leukemia (AML)
Acute myeloid leukemia is a life-threatening disease, in which cells that become neutrophils, basophils, eosinophils, and monocytes become cancerous and rapidly replace normal cells in the bone marrow.
- Affected people are tired or pale, are prone to developing infections and fever, and easily bruise and bleed.
- Diagnosis requires blood tests and a bone marrow test.
- Treatment consists of chemotherapy to achieve remission, plus additional chemotherapy to prevent relapse, and sometimes stem cell transplantation
Acute myeloid leukemia (AML) is the most common type of leukemia in adults, although it can appear at any age. It is sometimes caused by chemotherapy or radiation therapy given to treat another type of cancer.
There are several subtypes of AML, which are identified based on the characteristics of the leukemic cells.
The acute promyelocytic leukemia is a subtype of AML important. In this variant, chromosomal abnormalities in promyelocytes (which are cells at an early stage of the maturation process that will transform them into neutrophils) cause an accumulation of these immature cells.
Symptoms
The early symptoms of AML are very similar to those of acute lymphoblastic leukemia . Affected people may develop a fever and excessive sweating, which is indicative of an infection. A high risk of infection results from a very low number of normal white blood cells (leukocytes). Weakness, tiredness, and paleness may be signs of anemia, due to a lack of red blood cells (erythrocytes). The deficit in the number of platelets (thrombocytes) causes a tendency to bruise and bleed, sometimes in the form of nosebleeds, bleeding gums, or brain or abdominal bleeding.
Leukemic cells can invade other organs. Leukemic cells in the bone marrow can cause bone and joint pain. When leukemic cells enlarge the liver and spleen, abdominal fullness and sometimes pain are experienced. Leukemic cells can form small lumps (chloromas) throughout the body, including inside or under the skin (called leukemic skin), the gums, or the eyes.
Acute lymphocytic leukemia (ALL) cells can spread to the layers of tissue that cover the brain and spinal cord (meninges), leading to headaches, vomiting, strokes, and vision, hearing, and muscle disorders. facial (leukemic meningitis). Leukemic meningitis occurs more frequently in acute lymphocytic leukemia. In acute promyelocytic leukemia, bleeding or blood clotting problems often occur.
Diagnosis
- Blood test
- Bone marrow examination
The diagnosis of AML is also similar to that of acute lymphoblastic leukemia . A complete blood count is done , including the number and proportion of the different types of white blood cells or leukocytes. To confirm the diagnosis, and to differentiate AML from other types of leukemia, a bone marrow exam is almost always necessary . Immature white blood cells (blasts) are checked for possible chromosomal abnormalities; This information helps doctors determine the type of leukemia and what medications to use to treat it.
Blood tests (including tests for tumor markers and electrolyte abnormalities ) and urine are also performed to detect other abnormalities related to ALL.
Imaging tests may also be necessary. A computed tomography (CT) scan or magnetic resonance imaging (MRI) is done if the person has symptoms that indicate the presence of leukemic cells in the brain. A chest computed tomography (CT) scan may be done to check for leukemia cells in the area around the lungs. Also, a CT scan, MRI, or ultrasound of the abdomen may be done to determine if the internal organs are enlarged. An echocardiogram (ultrasound of the heart) may be done before chemotherapy starts because chemotherapy drugs sometimes affect the heart.
Forecast
Without treatment, most people with AML die within a few weeks to a few months after diagnosis. With treatment, between 20 and 40% survive at least 5 years, without relapsing. With intensive treatment, 40-50% of the youngest people can survive at least 5 years. Since relapses almost always occur within the first 5 years after initial treatment, most people who remain leukemia-free after 5 years are considered cured.
The strongest predictor of survival is the type of genetic abnormality present in the leukemic cells. People with the worst prognosis are those older than 60 years, those with certain findings in blood tests, those with an elevated white blood cell count, those who develop AML after undergoing chemotherapy or radiation therapy for other cancers, and those with who have previously suffered from a myelodysplastic syndrome .
Acute promyelocytic leukemia was once considered the most malignant form of leukemia, but today it is one of the most curable forms of AML. More than 70% of acute promyelocytic leukemia cases can be cured. Quick diagnosis is essential
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Treatment
- Chemotherapy
- Stem (progenitor) cell transplant
Treatment of ALL is aimed at achieving early remission, with destruction of the vast majority of leukemic cells. However, treatment often worsens the condition of affected people before they start to improve.
Treatment inhibits the activity of the bone marrow, drastically reducing the number of white blood cells (leukocytes), particularly neutrophils . When there are too few neutrophils, the chance of getting infections increases. The treatment also alters the mucous membranes (such as the lining of the mouth), making it easier for bacteria to enter the body. You have to be very meticulous to prevent infections, and if any do occur, it should be treated from the first moment. Red blood cell and platelet transfusions are often necessary.
Induction chemotherapy is the first phase of treatment for ALL. Chemotherapy drugs generally include cytarabine for 7 days, given by continuous intravenous infusion, or daunorubicin (or idarubicin or mitoxantrone) intravenously for 3 days. Other medications that may be given are midostaurin or gemtuzumab oxogamycin, or decitabine, azacitidine, venetoclax, or glasdegib (especially in older people or people with certain subtypes of AML).
Consolidation chemotherapy is given when the AML is in remission. People usually receive several additional cycles of chemotherapy within a few weeks of the initial treatment to ensure that as many leukemia cells are destroyed as possible.
The stem cell transplantation allogeneic ( "allogeneic" means the stem cells are from another person) is performed after induction and consolidation in some people at risk of relapse. However, transplantation can only be done if the stem cells are obtained from a person who has a compatible tissue type (HLA compatibility; human leukocyte antigen). The donor is usually a brother or sister, although compatible cells from unrelated donors, or partially compatible cells from family members or unrelated donors, or umbilical cord stem cells are sometimes used.
Unlike acute lymphocytic leukemia, preventive treatment is generally required to protect the brain in adults, and an improvement in survival rate has not been shown with the use of long-term low-dose chemotherapy (therapy of maintenance).
People with acute promyelocytic leukemia may be treated with a type of vitamin A called all- trans- retinoic acid (tretinoin). Chemotherapy is frequently combined with all- trans- retinoic acid , especially if the person has a high number of white blood cells (leukocytes) at the time of diagnosis or if the number of white blood cells rises sharply. Arsenic trioxide is also especially effective against this subtype of AML.
Relapse
People who do not respond to treatment, as well as young people who are in remission but at high risk of relapse (usually identified by certain chromosomal abnormalities), receive high doses of chemotherapy and then a stem cell transplant .
When a relapse occurs, especially in a person who is not a candidate for stem cell transplantation, additional chemotherapy is less effective and often poorly tolerated. Starting another cycle of chemotherapy is more effective in young people and in those whose initial remission lasted longer than 1 year. Doctors often take into account many factors in recommending additional intensive chemotherapy treatment for people who have a relapse of AML
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