How is Multiple Myeloma Staged?

Learn how multiple myeloma is staged.

Staging is the process of identifying how far a disease has progressed, and it is important both to prognosis (predicting the course of the disease) and treatment decisions. Although there are different staging systems for myeloma (which are sometimes used in combination), the disease is generally divided into stages that signify the severity of illness. However, predicting the course of the disease will also depend on other factors, such as age and other underlying health problems in addition to cancer. (Because myeloma usually strikes at an older age, patients often have other health issues, including heart problems or diabetes.) Generally speaking, the “stage” in myeloma reflects the number of cancerous plasma cells in the blood.

Smoldering or indolent myeloma means that the disease is at a very early stage and has not caused any symptoms or damage to tissues in the body. About 15 percent of myeloma cases diagnosed each year are at this stage.

Stage 1 disease is more advanced than smoldering myeloma, but it still means that few malignant cells are circulating. Patients with stage 1 disease often have relatively normal levels of red blood cells and calcium. M protein levels are also low, and bone structure is normal or has only a single area of bone damage. Smoldering and stage 1 myeloma can persist for years without progressing or causing any immediate danger.

Stage 2 means that more cancer cells are spreading throughout the body but that the level falls between stage 1 and stage 3.

Stage 3 is the most advanced stage. At stage 3, there are even more plasma cells, and a large amount of M protein is circulating in the blood. Patients with stage 3 disease also have other complications, including extreme anemia and multiple bone lesions.

About one in four patients with myeloma have “high-risk” disease. This type of myeloma is particularly aggressive and may call for more aggressive treatment, such as stem cell transplantation. Doctors determine whether the condition is high risk by looking at genetic abnormalities that signal the disease will advance more aggressively.

While staging myeloma is important to determine a patient’s prognosis and, therefore, decide how aggressively the disease should be treated, the factors used to determine stage are not the only factors that influence prognosis. For instance, it is well known that older patients with myeloma do not live as long as younger patients, even if they both have the same stage of disease. Certain laboratory tests can also help predict how well a patient will do. These include a test called a myeloma cell labeling index, which measures how fast cancer cells are growing (fast growth results in a worse prognosis), and chromosome analysis, which can identify certain chromosomal abnormalities that signal a poorer outlook.

From "A Patient's Guide to Multiple Myeloma," published in the Winter 2011 issue of CURE. Download the full guide here.