Learn how multiple myeloma is diagnosed.
Without knowing what causes myeloma, researchers have been unable to identify specific risk factors, only general characteristics such as being older, male and African-American (where disease rates are highest). In a small number of cases, past treatment with radiation can also increase the risk of developing multiple myeloma later in life. While myeloma is sometimes hereditary (someone with a parent or sibling with myeloma is four times more likely to develop the disease), the overwhelming majority of patients have no family history of the disease. Researchers are investigating whether exposure to certain chemicals, infections with viruses or obesity might be contributors to the condition.
To look for leads on the cause of myeloma, researchers are examining the genetics of malignant cells. For example, patients with myeloma show abnormalities in certain chromosomes. (Humans have 46 chromosomes, which are the bundles of genes that contain the operating instructions for every cell in the body.) Scientists have also found abnormalities in individual genes of cancer cells. By studying how these genetic mutations conspire to make cell growth run amok, researchers hope to find better ways to treat the cancer and offer insight into prevention. For now, however, there is no known way to prevent myeloma from occurring.
The odds of developing myeloma increase in those who have a condition known as monoclonal gammopathy of undetermined significance, or MGUS. This is a state in which plasma cells produce the same M protein that is the hallmark of malignant cells but do not cause any of the health problems associated with myeloma. It’s important that people with MGUS get regular checkups so doctors can look for signs that the condition may be advancing into multiple myeloma. About 1 percent of people with MGUS each year will be diagnosed with disease that has progressed to multiple myeloma, lymphoma or amyloidosis.
A Treatable Disease
Although there is no cure for multiple myeloma, it is a treatable disease. Many patients live full, productive lives after diagnosis. About 38 percent of patients with multiple myeloma live at least five years after their diagnosis, and around 19 percent live at least 10 years. Because new therapies have been developed to treat myeloma in recent years, patients who have been recently diagnosed are expected to live even longer.
At the beginning, many symptoms of myeloma can be unspecific and vague—such as bone pain, repeated infections, loss of appetite and fatigue. Often, symptoms don’t appear until the disease has advanced. Some patients have no outward symptoms at all. Because the first clues to the illness can be vague, patients are often treated for recurring symptoms before doctors perform blood tests and discover the true underlying cause.
While not always immediately apparent, one of the more common early signs of myeloma is pain, which usually originates in the bones. This is because the myeloma cells interfere with the normal give-and-take between cells that form new bone and cells that dissolve the old. Once bones weaken, they can fracture more easily. In fact, doctors have often suspected myeloma after examining a broken bone or identifying other signs of bone distress.
Other times, patients complaining of feeling overly tired may actually be anemic. As myeloma cells edge out red blood cells, the body has trouble getting all of the oxygen it needs.
Other vague symptoms that occur with advanced disease include loss of appetite, nausea/vomiting and confusion caused by increased levels of calcium in the blood. This condition, referred to as hypercalcemia, results from the breakdown of bones.
Occasionally, kidney failure is the first sign that something is wrong. The kidneys can become damaged as they try to filter out high levels of abnormal protein and calcium. To evaluate kidney function, doctors will check the blood and urine for creatinine, a normal substance that is produced by breaking down and building up muscle cells and is filtered out of the bloodstream by the kidneys.
Criteria for Diagnosis
Doctors diagnose myeloma in patients with some of the symptoms listed above by using different forms of imaging to examine bones for lesions and by analyzing samples of blood, urine and bone marrow. Laboratory tests are used to find the telltale signs of myeloma cells and evidence of threats to organs and tissue.
An official diagnosis is based on three basic criteria:
A bone marrow aspiration and biopsy showing that at least 10 percent of the cells in the marrow are plasma cells. In normal bone marrow, only about 5 percent or less of the cell population are plasma cells. For the aspiration and biopsy, doctors take a sample of bone marrow, usually from the hip, though they will also check other areas because the condition can affect some bones more than others. Pathologists will then use a microscope to check the tissue for myeloma cells.
The presence of M protein in the blood or urine over a certain level. M protein is a substance manufactured by myeloma cells and is often the source of kidney damage. It can also cause bleeding problems and blood thickening. The lab will check the levels of many proteins in the blood, including M protein.
Evidence of health threats from excessive plasma cells, including kidney dysfunction, increased calcium levels, bone lesions and/or anemia.The lab will conduct a complete blood count, check for high levels of calcium and monitor kidney function by testing for creatinine.
From "A Patient's Guide to Multiple Myeloma," published in the Winter 2011 issue of CURE. Download the full guide here.