Leukemia is a cancer of the bone marrow, and leads to the production of abnormal blood cells. Eventually, these abnormal cells take over the normal cells such as red blood cells and platelets.
Leukemias are classified by the type of cell they developed from, either myelogenous or lymphocytic, as well as how fast the leukemia grows and progresses. If it is a rapidly progressing leukemia it is called acute, chronic is slower to progress but over time can develop into acute leukemia. Although these diseases have a common origin, they are all different in their signs and symptoms, how they progress and how they are treated.
There are four main types of leukemia:
All of these begin the a cell in the bone marrow but they present differently and have different treatments.
The American Cancer Society estimates that in 2012 we will see more than 47,000 new cases of leukemia in the United States. CLL accounts for over 16,000 of those cases and AML accounts for more than 13,000.
Lymphocytic vs. Myelogenous Leukemi
Lymphocytic or Lymphoblastic leukemia is when the cancerous change begins in a type of marrow cell that forms lymphocytes, which is a type of white cell.
Myelogenous or Myeloid leukemia happens when the cancerous change begins in a type of bone marrow cell that, when healthy, forms red blood cells, platelets and some kinds of white blood cells.
Acute leukemias arise from young immature "blast" cells, myeloblasts or lymphoblasts, these cells do not work like normal cells. They crowd out the normal cells in the bone marrow, which causes a decrease in the number of new normal cells made in the marrow. Without treatment, acute leukemia will progress rapidly.
Chronic leukemias have little or no immature “blast” cells and usually progress more slowly than acute leukemias. The chronic myelogenous leukemia (CML) cell makes blood cells that function almost normally, but the counts become so high that they crowd out the production of other cells such as red blood cells.
In chronic lymphocytic leukemia (CLL), too many lymphocytes that do not function are produced. These abnormal cells replace and interfere with the work of normal lymphocytes in the marrow and lymph nodes and weaken the body’s immune system. Over time, both CML and CLL have the potential to transform into aggressive acute leukemias.
The exact cause of leukemia is not known. Many people who have risk factors will never develop the disease, and some people who develop leukemia have no known risks.
For AML, some risk factors have been identified and include:
Symptoms of Leukemia
The signs and symptoms that a person with acute leukemia displays are the result of the low numbers of red blood cells, platelets, and white blood cells the diseased marrow is able to produce.
Signs and symptoms of acute leukemia may include:
Chronic leukemia patients generally have no signs or symptoms and often the disease is discovered after blood work from a routine visit to their physician. However if the disease is more advanced they may experience symptoms similar to acute leukemia patients.
These symptoms are vague and can be confused for many other illnesses. If you are experiencing any of these symptoms, discuss them with your healthcare provider.