Multiple
Myeloma
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Multiple myeloma is the
second-most common blood cancer, after leukemia. It represents about 1% of
all cancers and 2% of all cancer deaths. The onset of multiple myeloma
typically occurs between 65 and 70 years of age, but it appears that there is
both an increasing incidence and earlier onset of the disease. There are
currently more than 40,000 Americans diagnosed with multiple myeloma and
around 14,000 new cases diagnosed each year in the United States. Multiple myeloma is a cancer
of plasma cells in the bone marrow. Plasma cells produce immunoglobulins
which fight infection. There are 5 classes of immunoglobulins (IgG, IgM, IgA,
IgD, and IgE). In multiple myeloma, the plasma cells which produce one of
these classes grows in a cancerous fashion, producing a large quantity of
that class of protein (most comonly IgG). The protein produced is not an
effective immunoglobulin, and essentially crowds out functional
immunoglobulins. More importantly, the cancerous plasma cells crowd out the
other cells in the bone marrow, resulting in a variety of complications, most
commonly decreased red cells (anemia), decreased white cells (weakened immune
system), decreased platelets (problems with clotting), and tiny bone
fractures due to accumulated plasma cells.
Abnormal
plasma cells in a bone marrow slide The cause of multiple
myeloma is currently unknown. There are possible associations with decline in
the immune system, genetic factors, exposure to certain chemicals, exposure
to radiation, and possibly to a virus. There appears to be a slight increase
risk in children and siblings of those with multiple myeloma. In most cases,
individuals who develop multiple myeloma have no clear risk factors,
suggesting that it is a result of several factors acting together. The following links contain
more information about multiple myeloma: IMF
- International Myeloma Foundation |
