Acute Myelogenous Leukemia

Definition

Definition of Acute Myelogenous Leukemia
Acute myelogenous leukemia (AML) is a malignant disease of the bone marrow in which hematopoietic precursors are arrested in an early stage of development. Most AML subtypes are distinguished from other related blood disorders by the presence of more than 20% blasts in the bone marrow.

The underlying pathophysiology in AML consists of a maturational arrest of bone marrow cells in the earliest stages of development. Several factors have been implicated in the causation of AML, including antecedent hematologic disorders, familial syndromes, environmental exposures, and drug exposures. However, most patients who present with de novo AML have no identifiable risk factor.

Symptoms

Symptoms of Acute Myelogenous Leukemia
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:

1. Fever
2. Bone pain
3. Lethargy and fatigue
4. Shortness of breath
5. Pale skin
6. Frequent infections
7. Easy bruising
8. Unusual bleeding, such as frequent nosebleeds and bleeding from the gums

Causes

Causes of Acute Myelogenous Leukemia
Several factors have been implicated in the causation of AML, including antecedent hematologic disorders, familial syndromes, environmental exposures, and drug exposures. However, most patients who present with de novo AML have no identifiable risk factor.

Diagnosis

Diagnosis of Acute Myelogenous Leukemia
If you have signs or symptoms of acute myelogenous leukemia, your doctor may recommend you undergo diagnostic tests, including:

1. Blood Tests: Most people with acute myelogenous leukemia have too many white blood cells, not enough red blood cells and not enough platelets. The presence of blast cells — immature cells normally found in bone marrow but not circulating in the blood — is another indicator of acute myelogenous leukemia.
2. Bone Marrow Test: A blood test can suggest leukemia, but it usually takes a bone marrow test to confirm the diagnosis. During a bone marrow biopsy, a needle is used to remove a sample of your bone marrow. Usually, the sample is taken from your hipbone (posterior iliac crest). The sample is sent to a laboratory for testing.
3. Spinal Tap (lumbar puncture): In some cases, it may be necessary to remove some of the fluid around your spinal cord to check for leukemia cells. Your doctor can collect this fluid by inserting a small needle into the spinal canal in your lower back.

Treatment

Treatment of Acute Myelogenous Leukemia
Current standard chemotherapy regimens cure only a minority of patients with acute myelogenous leukemia (AML). As a result, all patients should be evaluated for entry into well-designed clinical trials. If a clinical trial is not available, the patient can be treated with standard therapy (see below). For consolidation chemotherapy or for the management of toxic effects of chemotherapy, readmission is required.

When receiving chemotherapy, patients should avoid exposure to crowds and people with contagious illnesses, especially children with viral infections. Any patient with neutropenic fever or infection should immediately be treated with broad-spectrum antibiotics.

Appropriate transfusion support must be provided to patients with AML. This includes transfusion of platelets and clotting factors (fresh frozen plasma {FFP}, cryoprecipitate) as guided by the patient’s blood test results and bleeding history. Blood products must be irradiated to prevent transfusion-associated graft versus host disease (GVHD).

Patients with AML are best treated at a center whose staff has significant experience in the treatment of leukemia. Patients should be transferred to an appropriate (generally tertiary care) hospital if they are admitted to hospitals without appropriate blood product support, leukapheresis capabilities, or physicians and nurses familiar with the treatment of leukemia patients.

Prognosis

Prognosis of Acute Myelogenous Leukemia
The prognosis relies on several factors. Increasing age is an adverse factor, because older patients more frequently have a previous antecedent hematologic disorder along with comorbid medical conditions that compromise the ability to give full doses of chemotherapy. A previous antecedent hematologic disorder (most commonly, MDS) is associated with a poor outcome to therapy.

Prevention

Prevention of Acute Myelogenous Leukemia
All patients with AML may want to talk with their doctors about including the possibility of a transplant in their treatment plan. A transplant may be the first choice or it may be a backup plan.