such as occurs with multiple myeloma reduces
EPO production, resulting in moderate to signifi-
cant ANEMIA. M-proteins can bind with erythro-
cytes in the blood, further reducing their ability to
transport oxygen. M-proteins can also bind with
other substances in the blood including hormones
and cells such as platelets. M-protein binding with
platelets results in COAGULATION(clotting) abnor-
malities including excessive bleeding or thrombo-
sis (clot formation within the blood vessels).
In the late 1990s researchers achieved a signifi-
cant breakthrough in identifying the possible
causes of multiple myeloma with the discovery of
a connection between multiple myeloma and cer-
tain infections, notably herpesvirus type 8 (which
causes another cancer, KAPOSI’S SARCOMA) and HEP-
ATITISC. As well, doctors have long noted connec-
tions between multiple myeloma and occupational
exposure to pesticides (notably DDT) and petro-
leum products, and to radiation exposure such as
RADIATION THERAPY. Multiple myeloma is more
common in people over age 55 and accounts for 1
percent of all cancers doctors diagnose in the
United States each year. It is more common in
men than women and affects twice as many
African Americans, though researchers are unsure
of the reasons.
Symptoms and Diagnostic Path
About half of people diagnosed with multiple
myeloma have no symptoms at the time of diag-
nosis, when blood tests performed for other rea-
sons reveal the abnormalities consistent with
multiple myeloma. Blood tests early in the course
of the cancer may produce inconsistent and non-
specific findings that become relevant with subse-
quent diagnostic procedures. When symptoms are
present they may include
- fatigue, especially with exertion
- frequent nosebleeds (EPISTAXIS) or easy bruising
- GASTROINTESTINAL BLEEDING
- PAIN, often in the back or that feels as though it
originates in the bones - excessive thirst
- HEADACHE
- a haze over the field of vision
Diagnostic blood tests typically show elevated
blood calcium levels, altered blood cell counts,
increased blood proteins, increased blood volume,
the presence of M-proteins, and the presence of
myelocytes (PLASMAcells) in the blood circulation.
NEUTROPENIAand anemia are often present. Diag-
nostic imaging such as X-rays, COMPUTED TOMOGRA-
PHY(CT) SCAN, POSITRON EMISSION TOMOGRAPHY(PET)
SCAN, and MAGNETIC RESONANCE IMAGING(MRI) allow
the oncologist to assess the extent of bone
involvement and damage. Bone marrow biopsy
reveals high plasma cell counts and abnormal
bone marrow structure.Treatment Options and Outlook
CHEMOTHERAPYis the treatment of choice for multi-
ple myeloma. The first chemotherapy agent devel-
oped to treat multiple myeloma in 1958,
melphalan, remains the first line DRUGof choice
today, commonly given in combination with pred-
nisone, a corticosteroid medication. Oncologists
use other chemotherapy agents, usually in combi-
nations with each other and with CORTICOSTEROID
MEDICATIONS, to tailor treatment regimens to an
individual’s age and the cancer’s presentation,
other health considerations, and preferences. Ini-
tial treatment typically produces REMISSION, though
RECURRENCEwithin two years is common. Some
people benefit from radiation therapy that targets
myeloma lesions within the bones. New treat-
ments continue to emerge as researchers gain
understanding of the mechanisms of multiple
myeloma.DRUGS USED TO TREAT MULTIPLE MYELOMA
bortezomib busulfan
carmusine cisplatin
cyclophosphamide dexamethasone
doxorubicin etoposide
melphalan prednisone
thalidomide vincristineThalidomide and thalidomide analogs Thalido-
mide, which debuted in the 1950s as a treatment
for MORNING SICKNESSand insomnia in PREGNANCY
and quickly gained notoriety for causing BIRTH
DEFECTS, emerged in the late 1990s as a successful
treatment in some people for multiple myeloma
that resists other therapies. Thalidomide sup-158 The Blood and Lymph