Multiple Myeloma is a
plasma cell
cancer that affects the
bone marrow. It causes the bones to develop plasmacytomas (tumors), and a large number of abnormal antibodies to be released into the body, leading to hypercalcemia (too much
calcium) and osteolytic lesions (holes in the bone). It usually occurs in people over 40 years old and is relatively rare, with about 12,500 new cases every year.
This disease has a low cell proliferation rate and is resistant to a large number of chemotherapy drugs. Consequently, in most cases there is no cure, and treatment is aimed at relieving symptoms and neutralizing complications. Left alone, a patient with this disease would survive for an average of 7 months after diagnosis. Chemo- and radiation therapy treatment can extend the prognosis to 36-48 months.
The cancerous plasma cells that cause Multiple Myeloma begin their lives as stem cells, which are found in the bone marrow. These cells have the ability to differentiate into every type of blood cell found in the body, including B lymphocytes, the precursors to plasma cells. As these white blood cells become plasma cells, a mutation occurs and causes them to become cancerous. Untreated malignant cells can spread into all bone cavities in the body.
Symptoms of Multiple Myeloma include anemia (low numbers of red blood cells), heightened susceptibility to bacterial infections, bone pain in the spine or ribs, bones that are easily fractured, and renal failure (failure of kidneys to function properly).
This disease tends to affect men more often than women, and blacks more often than whites. It is the second most prevalent blood cancer, though was once mistaken for a type of bone cancer, because of its direct effect on the skeleton. Scientists have not reached a consensus on the cause of Multiple Myeloma, and attribute it to the combination of many different factors, including genetics, exposure to chemicals or radiation, and normal aging of the immune system.