How Is Waldenstrom Macroglobulinemia Staged?

For most types of cancer, determining the stage of the cancer is very important. The stage of a cancer is a summary of how far it has spread. This can be helpful in predicting outcomes and in deciding on treatment.

There is no standard staging system for Waldenstrom macroglobulinemia (WM) based on the extent of the disease in the body because this hasn’t been shown to be important when looking at outcomes or deciding on treatment.

Instead, doctors look at other factors, such as age, blood cell counts, the amount of immunoglobulin (IgM) in the blood, and the level of another protein in the blood called beta-2 microglobulin (β2M). People with lower levels of IgM and β2M tend to do better than those with higher levels. People with WM who are older, are anemic (based on a low blood hemoglobin level), or have a low blood platelet count tend to have a poorer outlook.

Experts have used these factors to develop a system that helps predict prognosis (outlook) for patients with WM. It is called the International Prognostic Scoring System for Waldenstrom Macroglobulinemia (ISSWM). This system takes into account the factors that seem to predict a poorer outcome, such as:

• Age more than 65 years old
• Blood hemoglobin level 11.5 g/dL or less
• Platelet count 100,000/mcL or less
• Beta-2 microglobulin more than 3 mg/L
• Monoclonal IgM level more than 7 g/dL

Except for age, each of these factors is worth a single point. The points are added to make a score, which is used to divide patients into 3 risk groups:

• The low-risk group includes patients 65 or younger who have no more than 1 point.
• The intermediate-risk group includes those who are older than 65 with 2 or fewer points, and those younger than 65 who have 2 points.
• The high-risk group includes those of any age who have at least 3 points.

These groups can be used to help predict survival (discussed in more detail in Survival Rates for Waldenstrom Macroglobulinemia).