Leukemia Information

Acute myelogenous leukemia (AML) is a type of cancer of the blood and bone marrow — the spongy tissue inside bones where blood cells are made. It's called acute leukemia because it progresses rapidly and affects immature blood cells, rather than mature ones. It's called myelogenous (MI-uh-loj-uh-nus) leukemia because it affects a group of white blood cells called the myeloid cells, which normally develop into the various types of mature blood cells, such as red blood cells, white blood cells and platelets. This type of leukemia is also known as acute myeloblastic leukemia, acute granulocytic leukemia and acute nonlymphocytic leukemia.

Normally, your bone marrow produces immature cells (stem cells) in a controlled way, and they mature and specialize into the various types of blood cells, as needed. In people with AML, the bone marrow produces immature cells that usually develop into a type of abnormal white blood cell called a myeloblast. These myeloblasts aren't able to mature and perform their usual functions. Even worse, they multiply rapidly and can crowd out healthy cells, leaving a person with AML vulnerable to infection, anemia or easy bleeding. Leukemia cells can also spread outside the blood to other parts of your body.

About 10,500 Americans are diagnosed with acute myelogenous leukemia each year, making it the most common form of leukemia. This form of cancer worsens quickly if not treated, but it initially responds well to treatment. Unfortunately, many people with AML experience a relapse. Much ongoing research is focused on decreasing the risk of relapse and improving the long-term outcomes for people with AML.

Signs and Symptoms

General signs of the early stages of acute myelogenous leukemia may mimic signs and symptoms of the flu or other common diseases. These include:

Fever, Weight loss, Loss of appetite, Lethargy and fatigue

More specific signs and symptoms of acute leukemia are caused by a lack of properly functioning blood cells, resulting from overcrowding by leukemia cells. A range of problems can occur, depending on the type of blood cell affected:

Red blood cells. These cells carry oxygen from your lungs to all parts of your body. A shortage of red blood cells (anemia) can cause shortness of breath, fatigue and pale skin.

White blood cells. These infection fighters help your body ward off germs. A shortage of white blood cells (leukopenia) or of a particular type of white blood cells called neutrophils (neutropenia) can result in frequent infections.

Blood platelets. These cells help prevent and control bleeding by prompting your blood to clot. A shortage of blood platelets (thrombocytopenia) can result in easy bleeding and bruising, including frequent or severe nosebleeds, bleeding from your gums, or tiny red marks caused by bleeding into your skin (petechiae).

AML can also cause swollen and bleeding gums, bone pain or joint pain, and swelling of your spleen or liver. If it involves your lymph nodes, it can cause them to swell. If it spreads outside your blood to your central nervous system or other organs, it can cause headache, weakness, seizures, vomiting, dizziness and blurred vision.

Treatment

Treatment of acute myelogenous leukemia depends on your age and the subtype of the disease. 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. The most common course of therapy involves two chemotherapy drugs — cytarabine (Cytosar-U), given continuously for seven days through an intravenous line, followed by an anthracycline drug such as daunorubicin (Cerubidine) or idarubicin (Idamycin) for three days. It's sometimes known as a "7+3" regimen. If you have AML, you'll probably stay in the hospital during the treatment cycle because the chemotherapy destroys many normal blood cells in the process of killing leukemia cells. This chemotherapy can cause anemia, infection and bleeding. If the first cycle of treatment doesn't cause remission, you may need it repeated one or two more times. Several alternative drug combinations also may be used, depending on your specific situation and any problems with your heart, liver or kidneys. Chemotherapy can also be used for consolidation therapy. This phase may include a combination of different medications that mimic the induction, but usually includes high doses of cytarabine by itself for one to three cycles.

Other drug therapy. Arsenic trioxide 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.

Biological therapy. Also known as immunotherapy, biological therapy uses substances that bolster your immune system's response to cancer. Monoclonal antibodies are one form of biological therapy. These antibodies are produced in a laboratory, but they mimic protein products found in your immune system (antibodies) that attack foreign substances (antigens) on leukemic cells. Gemtuzumab ozogamicin (Mylotarg) is a monoclonal antibody linked to a chemical toxin called calicheamicin that's used to treat older people with AML who don't respond to initial treatment or who relapse after successful initial treatment. Researchers are testing its effectiveness in younger people with AML.

Bone marrow transplant. This is another option for consolidation therapy for people at high risk of relapse or for treating relapse when it occurs. This procedure allows someone with leukemia to re-establish healthy stem cells, by replacing their leukemic bone marrow with leukemia-free marrow. If you choose this treatment, you'll receive very high doses of chemotherapy or radiation therapy to destroy your leukemia-producing bone marrow. This marrow is then replaced by bone marrow from a compatible donor (allogeneic transplant). In some cases, you may also be able to use your own bone marrow for transplant (autologous transplant). This is possible if you go into remission and then save healthy bone marrow for a future transplant.

Stem cell transplant. Stem cell transplant is also used for consolidation therapy. It's similar to bone marrow transplant except the stem cells are collected from circulating blood (peripheral blood), rather than the bone marrow, thanks to a medication that causes larger numbers of stem cells to be released from the bone marrow. The cells used for transplant can be your own healthy cells, or they can be collected from a compatible donor. This procedure is used more frequently than bone marrow transplant because of shortened recovery times and possible decreased risk of infection. Researchers are also experimenting with stem cell transplants using stem cells collected from umbilical cord blood.

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

This information was taken from www.mayoclinic.com.