Acute Myeloid Leukemia (AML) Causes, Symptoms, Diagnosis, Treatment, Prevention

Acute Myeloid Leukemia (AML) Causes, Symptoms, Diagnosis, Treatment, Prevention


What Is Acute Myeloid Leukemia?


Acute myeloid leukemia (AML) is a type of blood cancer. AML usually develops from cells that would turn into white blood cells (other than lymphocytes). Sometimes, though, it can develop from other types of blood-forming cells.

Acute Myeloid Leukemia (AML) Causes, Symptoms, Diagnosis, Treatment, Prevention
Acute Myeloid Leukemia (AML)

Acute myeloid leukaemia is a type of cancer that affects the blood and bone marrow. AML is characterised by an overproduction of immature white blood cells, called myeloblasts or leukaemic blasts. These cells crowd the bone marrow, preventing it from making normal blood cells. They can also spill out into the blood stream and circulate around the body. Due to their immaturity, they are unable to function properly to prevent or fight infection. Inadequate numbers of red cells and platelets being made by the marrow cause anaemia, and easy bleeding and/or bruising.

Acute myeloid leukaemia is sometimes called acute myelocytic, myelogenous or granulocytic leukaemia.

Which type of Acute Myeloid Leukemia (AML) do I have ?


AML is not a single disease. It is the name given to a group of leukaemias that develop in the myeloid cell line in the bone marrow. Some years ago doctors from America, France and Britain decided to classify AML into eight different sub-types based on the appearance of the leukaemic cells under the microscope. Each sub-type provides information on the type of blood cell involved and the point at which it stopped maturing properly in the bone marrow. This is known as the French-American-British (FAB) classification system.

The current World Health Organisation’s classification system for AML uses additional information, obtained from more specialised laboratory techniques, like genetic studies, to classify AML more precisely. This information also provides more reliable information regarding the likely course (prognosis), of a particular subtype of AML, and the best way to treat it.

The most important factor in predicting prognosis in AML is the genetic make-up of the leukaemic cells. Certain cytogenetic changes are associated with a more favourable prognosis than others. This means that they are more likely to respond well to treatment, and may even be cured. Favourable cytogenetic changes include: a translocation between chromosome 8 and 21 t(8;21), inversion of chromosome 16; inv(16) and a translocation between chromosome 15 and 17; t(15;17). This final change is found in a subtype of AML called acute promyelocytic leukaemia (APML or M3). APML is treated differently to other types of AML, and usually has the best overall prognosis.

Other cytogenetic changes are associated with an average or intermediate prognosis, while others still are associated with a poor, or unfavourable prognosis. It is important to note that in most cases of AML, neither ‘good’ or ‘bad-risk’ cytogenetic changes are found. People with ‘normal’ cytogenetics are also regarded as having an average prognosis.

Some subtypes of AML are associated with specific symptoms. For example, in some subtypes of AML, leukaemic cells can spread from the blood stream into other parts of the body such as the gums, causing swelling and discomfort. Acute promyelocytic leukaemia (APML or M3) is associated with bleeding and abnormalities in blood clotting.

Causes and Risk Factors for Acute Myeloid Leukemia


If something increases your risk of getting a disease, it's called a risk factor. Risk factors don't tell the whole story. For example, you can have few risk factors and still get a disease or have several and not get it.

Acute myeloid leukemia risk factors include:

  • Exposure to certain chemicals such as benzene (a solvent used in oil refineries and other industries and present in cigarette smoke), certain cleaning products, detergents, and paint strippers
  • Treatment with certain chemotherapy drugs used to treat other cancers, such as mechlorethamine, procarbazine, and chlorambucil -- especially when combined with radiation therapy
  • Exposure to high doses of radiation
  • Certain blood disorders, such as myeloproliferative disorders (for example, chronic myelogenous leukemia)
  • Being male
For most people, the cause of AML is unknown. There is not a way to prevent it, but you may reduce your risk by quitting smoking and avoiding exposure to chemicals.

Symptoms of Acute Myeloid Leukemia (AML)


General signs and symptoms of the early stages of acute myelogenous leukemia may mimic those of the flu or other common diseases. Signs and symptoms may vary based on the type of blood cell affected. Signs and symptoms of acute myelogenous leukemia include:

Acute Myeloid Leukemia (AML) Causes, Symptoms, Diagnosis, Treatment, Prevention
Acute Myeloid Leukemia (AML)

  • Bleeding from the nose
  • Bleeding gums
  • Bruising
  • Bone pain or tenderness
  • Fatigue
  • Fever
  • Heavy menstrual periods
  • Pallor
  • Shortness of breath (gets worse with exercise)
  • Skin rash or lesion
  • Swollen gums (rare)
  • Weight loss
Many symptoms of acute myeloid leukemia are the result of a shortage of normal blood cells. That's because leukemia cells crowd out normal cells in the bone marrow.

Diagnosis and Tests for Acute Myeloid Leukemia (AML)


The doctor will perform a physical exam. There may be signs of a swollen spleen, liver, or lymph nodes.

A complete blood count (CBC) shows anemia and a low number of platelets. A white blood cell count (WBC) is usually high but can be low or normal.

Bone marrow aspiration will show if there are any leukemia cells.

If your doctor learns you do have this type of leukemia, further tests will be done to determine the specific type of AML. Subtypes are based on specific genetic changes or mutations and how the leukemia cells appear under the microscope.

Treatments and drugs for Acute Myeloid Leukemia (AML)


Treatment of acute myelogenous leukemia depends on several factors, including the subtype of the disease, your age, your overall health and your preferences. In general, treatment falls into two phases:

Remission induction therapy


The purpose of the first phase of treatment is to kill the leukemia cells in your blood and bone marrow. However, remission induction usually doesn't wipe out all of the leukemia cells, so you need further treatment to prevent the disease from returning.

Consolidation therapy


Also called post-remission therapy, maintenance therapy or intensification, this phase of treatment is aimed at destroying the remaining leukemia cells. It's considered crucial to decreasing the risk of relapse.

Therapies used in these phases include:

Chemotherapy


Chemotherapy is the major form of remission induction therapy, though it can also be used for consolidation therapy. Chemotherapy uses chemicals to kill cancer cells in your body. People with AML generally stay in the hospital during chemotherapy treatments because the drugs destroy many normal blood cells in the process of killing leukemia cells. If the first cycle of chemotherapy doesn't cause remission, it can be repeated.

Other drug therapy


Arsenic trioxide (Trisenox) and all-trans retinoic acid (ATRA) are anti-cancer drugs that can be used alone or in combination with chemotherapy for remission induction of a certain subtype of AML called promyelocytic leukemia. These drugs cause leukemia cells with a specific gene mutation to mature and die, or to stop dividing.

Stem cell transplant


Stem cell transplant, also called bone marrow transplant, may be used for consolidation therapy. Stem cell transplant helps re-establish healthy stem cells by replacing unhealthy bone marrow with leukemia-free stem cells that will regenerate healthy bone marrow. Prior to a stem cell transplant, you receive very high doses of chemotherapy or radiation therapy to destroy your leukemia-producing bone marrow. Then you receive infusions of stem cells from a compatible donor (allogeneic transplant). You can also receive your own stem cells (autologous transplant) if you were previously in remission and had your healthy stem cells removed and stored for a future transplant.

Clinical trials


Some people with leukemia choose to enroll in clinical trials to try experimental treatments or new combinations of known therapies.

What are the side-effects of treatment for Acute Myeloid Leukemia (AML)?


All treatments can cause side-effects. The type and severity of side effects will vary between individuals, depending on the type of treatment used and how each individual responds to it. In general, more intensive treatment is associated with more severe side-effects. It is important that symptoms are reported immediately to your doctor or nurse, as in most cases they can be treated and are reversible.

AML affects the ability of the bone marrow to produce adequate numbers of blood cells and platelets, and chemotherapy reduces this ability even further. Blood counts generally fall within a week of treatment and may take some time to recover, depending on the type and doses of drugs used. During this time, you are likely to need antibiotics and other drugs to treat, or prevent infection. You are also likely to need blood transfusions to treat severe anaemia, and platelet transfusions to reduce the risk of bleeding.

Other possible side-effects of chemotherapy include:

  • feeling sick - nausea and/or vomiting
  • feeling tired and weak
  • hair loss and thinning
  • mouth problems such as mucositis or ulcers
  • diarrhoea or constipation
  • skin problems sych as dryness, rash or sensitivity to sunlight
  • fertility problems
Your doctor and nurse will discuss with you the possible side-effects of your treatment and how they can be managed.

How to Prevent Acute Myelogenous Leukemia


Many people who develop AML have no risk factors. There is no way to prevent the condition in most people. However, 20% of cases are related to smoking tobacco. Not smoking is the best known way to prevent AML.

Treating some other cancers with chemotherapy and radiation may cause secondary (post-treatment) leukemias. Doctors are trying to figure out how to treat these cancers without raising the risk of developing secondary leukemia. But for now, the obvious benefits of treating life-threatening cancers with chemotherapy and radiation therapy must be balanced against the small chance of getting leukemia years later.

Avoiding known cancer-causing chemicals, such as benzene, can lower the risk of getting AML. But most experts agree that exposure to workplace and environmental chemicals accounts for only a small portion of leukemia cases.

Treatment Options for Adult Acute Myeloid Leukemia


Untreated Adult Acute Myeloid Leukemia


Standard treatment of untreated adult acute myeloid leukemia (AML) during the remission induction phase depends on the subtype of AML and may include the following:

  • Combination chemotherapy
  • High-dose combination chemotherapy
  • Low- dose chemotherapy
  • Intrathecal chemotherapy
All-trans retinoic acid (ATRA) plus chemotherapy for the treatment of acute promyelocytic leukemia (APL)

Adult Acute Myeloid Leukemia in Remission


Standard treatment of adult AML during the remission phase depends on the subtype of AML and may include the following:

  • Combination chemotherapy
  • High-dose chemotherapy, with or without radiation therapy, and stem cell transplant using the patient's stem cells
  • High-dose chemotherapy and stem cell transplant using donor stem cells
One of the treatments being studied in clinical trials for adult AML in remission is arsenic trioxide.

Recurrent Adult Acute Myeloid Leukemia


There is no standard treatment for recurrent adult AML. Treatment depends on the subtype of AML and may include the following:

  • Combination chemotherapy
  • Targeted therapy with monoclonal antibodies
  • Stem cell transplant
  • Arsenic trioxide therapy
Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with adult acute myeloid leukemia. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug.

Outlook (Prognosis) of Acute Myeloid Leukemia (AML)


When a bone marrow biopsy shows no evidence of AML , you are said to be in remission. Complete remission occurs in most patients.How well you do depends on other your overall health and the genetic subtype of the AML cells.

Remission is not the same as a cure. More therapy is usually needed, either in the form of more chemotherapy or a bone marrow transplant.

With treatment, younger patients with AML tend to do better than those who develop the disease at an older age. The 5-year survival rate is much lower in older adults than younger persons. Experts say this is partly due to the fact that younger people are better able to tolerate strong chemotherapy medicines.

If the cancer does not come back (relapse) within 5 years of the diagnosis, you are likely cured.