Multiple myeloma is a cancer of the plasma cells found in bone marrow. The cancerous cells multiply so much that they crowd out normal healthy blood cells and weaken the bones. Once multiple myeloma is diagnosed, the cancer is then staged, which is a standardized way of describing the spread and extent of the disease. Multiple myeloma has two staging systems: The Durie-Salmon staging system looks at calcium, immunoglobulin and hemoglobin levels and the amount of bone damage, while the International Staging System is based on beta-2-microglobulin and albumin levels. Getting an accurate staging of the cancer helps to guide treatment and prognosis.
Stage I
In the earliest stage of multiple myeloma, a minimal amount of myeloma cells are present. Your hemoglobin levels are slightly low but above 10g/dL, X-rays show normal bones or only one area of damaged bone, calcium levels in blood are normal and only a low amount of monoclonal immunoglobulin is measured. Monoclonal immunoglobulin is a protein that is made in some kinds of cancers; immunoglobulins help your body make antibodies that fight infections, and albumin is a main protein in blood plasma that is essential to health. In the International Staging System, beta-2-microglobulin levels are below 3.5 g/mL and albumin levels are 3.5 g/dL or more. Beta-2-microglobulin is a protein that B-cells make; it is found in large quantities in multiple myeloma. In the early stages of multiple myeloma, you might have no symptoms, or you may have some fatigue or shortness of breath due to the myeloma cells crowding out the healthy red blood cells. In this stage of the disease, only small amounts of abnormal protein are found. For Stage I multiple myeloma, the median survival time is about 62 months.
Stage II
According to the American Cancer Society, Stage II presents a moderate amount of myeloma cells. The beta-2-microglobulin level is less than 3.5 g/mL and albumin levels are less than 3.5 g/dL; or the beta-2-microglobulin level is higher than 3.5 g/dL but less than 5.5 g/dL. In this stage, you might start to have more noticeable symptoms such as anemia, more infections, high blood calcium (due to the breakdown of bones) that can cause dehydration, and frequent bruising or bleeding due to the myeloma cells overcoming blood platelets. Because healthy cells that protect you from infection are being crowded out by the myeloma cells, you are more vulnerable to illness. This stage of multiple myeloma carries a median survival time of 44 months.
Stage III
The last stage of multiple myeloma can be diagnosed when a substantial amount of myeloma cells are found, hemoglobin levels are below 8.5 g/dL, blood calcium is more than 12 mg/dL, cancer has damaged three or more areas of bone as visible on an X-ray and there is a substantial amount of monoclonal immunoglobulin in blood or urine. The beta-2-microglobulin is 5.5 g/dL or more in this stage. During Stage III multiple myeloma, symptoms become more apparent and can include kidney damage and failure due to high blood calcium levels, nervous system problems from the abnormal myeloma proteins acting on the nerves, significant bone softening and risk of fractures, and more infections. The American Cancer Society estimates that multiple myeloma patients are 15 times more likely to have infections than cancer-free individuals, because there are not enough healthy cells to make antibodies to protect you. In the last stage of multiple myeloma, the median survival rate is 29 months.
