Blood cancer begins with a single mutated cell. Located in the bloodstream or the bone marrow, that cell will begin to multiply, creating other mutated cells. These cells, rather than maturing and dying, accumulate in the body until they become one of the three main types of blood cancer: leukemia, lymphoma and multiple myeloma. Beyond this basic process, the causes of blood cancer remain a mystery. Over the past 30 years, however, medical knowledge has increased dramatically, and doctors have offered their conjectures.
Immune System Problems
A weakened immune system allows cancer to spread more freely. The AIDS virus, for example, raises the risk of blood cancer by 50 to 100 times. Sometimes, the body's defenses mistake normal, healthy cells for intruders. When this happens, an autoimmune disease, such as lupus or rheumatoid arthritis, results. Autoimmune disease also raises the risk for blood cancer.
Exposure to Radiation
X-rays, like those in a dentist's office, contain relatively low amounts of radiation. CT scans are also harmless. Radiation therapy, on the other hand, raises the chances of blood cancer considerably. The high-energy beams may cause blood or marrow cells to mutate, but medical advancements, fortunately, have reduced this risk.
Exposure to Chemicals
Herbicides, pesticides, solvents and water contaminated with nitrate chemicals may all cause blood cancer. Benzene, in particular, has attracted researchers' attention. Found in gasoline and cigarette smoke, benzene has been linked with two types of leukemia: acute lymphocytic leukemia and chronic myeloid leukemia.
Then there's chemotherapy. Chemotherapy drugs cannot distinguish between cancer and other fast-growing cells, such as hair and blood. As a result, chemotherapy for breast or liver cancer, for example, might cause blood cancer.
The Epstein-Barr virus in Africa and the HTLV-I viruses in the Caribbean, Japan and the southeastern United States have both been linked to lymphoma. Another virus under investigation is HTLV-I, which appears to cause T-cell leukemia. Doctors stress that, even if there is a viral cause, blood cancer is not contagious.
In some cases, blood cancer may be inherited. However, the cancer usually skips generations, and only rarely will it infect more than one member of a family. Often, this type of blood cancer is chronic, meaning that it develops slowly, over a period of years. Its opposite is acute, meaning that the cancer develops rapidly.