What is Acute Myeloid Leukemia (AML)?

“When a person has a cancer of the bone marrow such as acute myeloid leukemia or myelodysplastic syndromes, that factory gets broken. These are cancers,” he says. “Cancers grow, and they grow in an uncontrollable way.”

Dr. Sekeres points out that the way blood cancer grows is different from the way other cancers grow. With breast cancer, for example, someone may develop a lump or a tumor that grows overtime. With AML, as cancer grows in a confined space in the bone marrow, the normal cells in this space that would making the red blood cells, white blood cells and platelets begin dying off. This leads to the bone marrow being filled with cancer cells.

Understanding Acute Myeloid Leukemia

Acute myeloid leukemia is a fast-growing blood cancer that begins in the bone marrow, the factory that makes white and red blood cells and platelets.

Your blood contains different types of cells:

• White Blood Cells: WBCs are involved in many immune-related processes, but the primary goal of WBCs is to fight infections.
• Red Blood Cells: RBCs are involved in carrying oxygen to the organs of the body.
• Platelets: Platelets are cell fragments that are important for helping blood to clot.

Within the bone marrow are stem cells that eventually develop into WBCs, RBCs and platelets. Stem cells can copy themselves or self renew making progenitor cells or precursor cells.  Myeloid progenitor cells turn into red blood cells, granulocytes (a type of white blood cell) and platelets. AML affects the myeloid progenitor cells during a stage of development when they are called myeloblasts. With AML, myeloblasts fail to turn into fully develop blood cells, thus building up in the bone marrow and blood. Also, because the myeloblasts don’t mature, the body lacks RBCs, WBCs and platelets.

According to the National Comprehensive Cancer Network guidelines on AML, to be diagnosed with AML, 20% or more myeloblasts must be present in the blood or bone marrow. (In certain cases, a diagnosis is possible with less than 20%.)

What Are The Risk Factors for Acute Myeloid Leukemia?

For a majority of patients, AML appears out of the blue. But there are some risk factors.

Dr. Gail Roboz, a noted AML expert and medical oncologist at Weill Cornell Medicine, says patients who have undergone chemotherapy and radiation for other forms of cancer can be at increased risk of AML. However, she notes that AML is a rare disease and a majority of cancer patients will not be diagnosed. Dr. Roboz also points out that exposure to organic solvents, such as benzene, are associated with AML, but the association isn't necessarily clear, and doesn't affect treatment options overall.

"One of the things that's actually emerging that as a very important potential predisposition is familial," Dr. Roboz says. "We didn't really used to think of a familial predisposition as important in acute leukemia and yet it might be that up to 10% of leukemias are associated with some sort of familial predisposition."

With this new discovery, people should expect physicians to ask them questions concerning whether family members have had blood disorders, abnormal blood counts, or a history of leukemia.

"That said, the majority of patients have this sporadically or out of the clear blue sky," Dr. Roboz says.

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