Staging for myelodysplastic syndrome

Doctors often group cancer into stages based on the size of the tumor and how far the cancer has spread. This helps them decide on the best treatment for the patient and predict the person’s outlook (prognosis).

But myelodysplastic syndrome (MDS) is a disease of the bone marrow. It cannot be staged by looking at the size of a tumor like some other cancers. In MDS, other factors are used instead. These factors include the patient’s blood counts, the patient’s age, how the bone marrow looks, and certain gene changes in the bone marrow cells.

International Prognostic Scoring System

One system used for staging MDS is called the IPSS system (International Prognostic Scoring System). The system uses 3 factors to stage the cancer:

• The percentage blasts in the bone marrow
• Abnormal chromosomes (genes)
• The patient’s blood counts

On the basis of these factors, the IPSS groups people with MDS into these 4 groups. The higher the risk group, the more serious the disease.

• Low risk
• Intermediate - 1 risk (Int-1)
• Intermediate - 2 risk (Int-2)
• High risk

WHO Prognostic Scoring System (WPSS)

This newer scoring system is based on 3 factors:

• The type of MDS based on the WHO classification
• Abnormal chromosomes
• Whether or not the patient needs blood transfusions

This system puts patients with MDS into 5 groups

• Very low risk
• Low risk
• Intermediate
• High risk
• Very high risk

These risk groups can also be used to predict outlook (see the next section)