Making a diagnosis of myeloma depends on finding abnormal plasma cells or their products somewhere in the body. Plasma cells are cells of the immune system that make antibodies when they are functioning normally. In myeloma, these cells begin to grow and divide abnormally. They make abnormal amounts of antibody-like proteins.
The growth of these plasma cells in the bone marrow can reduce the normal function of the bone marrow. It can also result in thinned, weakened bones that are likely to break. The abnormal antibody-like protein collects in the blood. It can cause problems with blood flow to the kidney and other parts of the body. Usually, symptoms related to these changes bring a patient to the doctor or raise a question of myeloma.
The diagnosis and prognosis of multiple myeloma include the following:
Diagnosis begins with a visit to the doctor. Sometimes, multiple myeloma is noted when blood tests are ordered for an unrelated reason. A biopsy will be needed to confirm the presence of myeloma cells.
The doctor will ask about your symptoms and medical history. You may be asked how your symptoms have progressed. You may also be asked about anything that may increase your risk of multiple myeloma, such as exposure to radiation or toxic chemicals.
The doctor will perform a complete physical exam. This will focus on uncovering evidence of bone damage,
anemia, or impaired circulation, each of which might be the result of myeloma.
To help with the diagnosis, your doctor may need to order tests.
Your doctor may need pictures of your bones. This can be done with:
- Magnetic resonance imaging (MRI)
- Computed tomography scan (CT scan)
- Positron emission tomography/computed tomography scan (PET/CT scan)
Your doctor may need to test your bodily fluids. This can be done with:
- Urine tests
- Blood tests
Bone marrow aspiration or
Cytology is the study of cells. The cytology of cancer cells differs from normal cells. Doctors use the unique cellular features seen on biopsy samples to diagnose and assess cancer.
To diagnose myeloma, the doctor will look for abnormal plasma cells. A plasma cell labeling index, which measures the percentage of dividing plasma cells, is available in some labs. This test gives an idea of how fast the cancer cells are growing. A higher labeling index is associated with a worse prognosis. It means that there are more, faster reproducing plasma cells than there should be.
Staging is the process used to determine the prognosis of a cancer that has already been diagnosed. Staging is needed to make treatment decisions (such as surgery vs. chemotherapy). Several features of the cancer are used to arrive at a staging classification. The most common features are the size of the original tumor, extent of local invasion, and spread to distant sites (metastasis). Low staging classifications (0-1) imply a favorable prognosis. High staging classifications (4-5) imply an unfavorable prognosis.
The Durie-Salmon staging system is used to stage multiple myeloma. The amount of tumor in the body is estimated based on the following factors:
- Blood or urine level of abnormal antibody-like proteins—These are produced by myeloma cells.
- Blood level of calcium—High levels are linked to bone damage caused by myeloma cells growing in the bone marrow and destroying the surrounding bone as their mass expands.
- Bone damage evident on x-ray—This is also a result of destruction of bone caused by growing myeloma cells. This damage has a characteristic appearance on x-ray. Sometimes an x-ray alone will give good evidence of myeloma.
- Blood hemoglobin level—Hemoglobin is the red pigment in red blood cells that carries oxygen to the cells. Low levels may point to decreased production of red cells due to myeloma cells occupying the bone marrow.
- Blood level of beta-2-microglobulin—This is another protein produced by myeloma cells. Increased levels of this protein suggest a large amount of myeloma in the body.
The more myeloma cells and/or their products present in the body, the higher the stage and the worse the outcome. Patients with higher stage disease also tend to have more symptoms from their disease. Based on the Durie-Salmon system, staging of multiple myeloma is as follows:
- A somewhat small number of myeloma cells are present. (This can be measured by plasma cell index.)
- Hemoglobin levels are slightly low.
- Bone x-rays show no damage or only one area of damage.
- Calcium levels are normal, indicating that there is not much bone damage.
- There is a small amount of abnormal antibody-like protein in the blood or urine.
- A moderate amount of myeloma cells are present.
- Other factors fall in a range between Stage I and Stage III.
- A large amount of myeloma cells are present.
- Hemoglobin levels are very low, indicating that the normal bone marrow cells are being crowded out.
- Calcium levels are high, indicating that there is a large amount of bone destruction.
- X-rays show more than three areas of bone destruction.
- A large amount of abnormal antibody-like protein is in the blood or urine.
Prognosis is a forecast of the probable course and/or outcome of a disease or condition. Prognosis is most often expressed as the percentage of patients who are expected to survive over five or ten years. Cancer prognosis is an inexact process. Predictions are based on the experience of large groups of patients suffering from cancers at various stages. Using this information to predict the future of an individual patient is always imperfect and often flawed. But, it is the only method available. A prognosis may or may not reflect your unique situation.
The five-year survival rates for multiple myeloma based on stage are as follows: