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Myelodysplastic Syndrome Prognostic Factors
Doctors group cancers in stages (I through IV) to help predict a patient's outlook for survival (prognosis) and to determine the treatment that best meets each patient's needs. This staging system for most cancers is based on the size of the tumor and how far the cancer has spread from the original site in the body. It is used because many early stage cancers can be effectively treated with local interventions, such as surgery and radiation therapy.
However, we do not stage MDS in this way because the abnormal cells have probably spread throughout the bone marrow and most likely the bloodstream, requiring systemic treatment to control the disease. More importantly, doctors can best assess the outlook for MDS patients by evaluating the number of cell types in their bone marrow and bloodstream, their age, and certain chromosome changes (called prognostic factors).
A system has been developed for staging MDS called the International Prognostic Scoring System (IPSS). The system rates 3 factors: (1) the percentage of blasts in the bone marrow; (2) whether chromosome abnormalities are present and, if so, which ones; and (3) how low the patient's blood counts are. These are given a score; the lowest scores have the best outlook for survival.
For example, if your blast percentage is normal, your chromosomes are normal, and your blood counts are only mildly reduced, your average survival, if you are younger than age 60, would be around 12 years. But age changes survival, so if you are older than 70, for example, your average survival would only be 4 years. If, on the other hand, you had a high blast count, abnormal chromosomes, and low blood counts, you would have a high score and an average survival of less than 1 year.
To summarize the significance of these factors, the IPSS groups people with
MDS into 4 categories of increasingly serious prognosis: low risk (score=0),
intermediate (INT)-1 (score=0.5-1) risk, INT-2 (score=1.5-2) risk, and high risk
(score=2.5 or greater). Below is a table for the classifications and the median
survival:
Median survival (half are alive and half have died) in years
| AGE |
LOW RISK |
INT-1 |
INT-2 |
HIGH RISK |
| Below 60 |
11.8 |
5.2 |
1.8 |
0.3 (fewer than 4 months) |
| Above 60 |
4.8 |
2.7 |
1.1 |
0.5 (6 months) |
Another way of looking at survival was done by German authors who looked at
the median survival within each of the WHO groups. Median survival means that half die before the time listed and half survive after that time. Their results are as follows:
| Type |
Median Survival in Years |
| Refractory anemia |
5.5 |
| Refractory anemia with ringed sideroblasts |
5.5 |
| Refractory cytopenia with multilineage
dysplasia |
3 |
| Refractory cytopenia with multilineage
dysplasia and ringed sideroblasts |
3 |
| Refractory anemia with excess blasts-1
(RAEB-1) |
1.5 |
| Refractory anemia with excess blasts-2
(RAEB-2) |
1.0 |
| Myelodysplastic syndrome, unclassified
(MDS-U) |
3.7 |
| MDS associated with isolated del(5q) |
10 |
Age and other prognostic factors (factors that influence the severity of the cancer) within each of these groups will increase or decrease the survival accordingly. Also, there is a wide range among them because the definitions are not exact and depend on the interpretation of the bone marrow appearance, which can vary widely. Finally, these are results are from patients diagnosed as long ago as 1970 and may underestimate survival because of improved treatment.
Myelodysplastic/Myeloproliferative Disease Prognostic Factors
Myelodysplastic/myeloproliferative diseases are not generally staged at all. The one exception is for chronic myelomonocytic leukemia. Here researchers have looked at blood counts and blast percentages to determine prognosis. They found that people with a high white count, low hemoglobin level, or high numbers of blasts had a shorter survival. Depending on how many of these factors were abnormal, average survival ranged from 5 months to 2 years.
Revised: 12/07/2006
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