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Doctors often group cancers into different stages based on the
size of the tumor and how far the cancer has spread from the original
site in the body. The stage of a cancer can help predict the outlook
for a cancer. Often, the stage of a cancer is used to decide which
treatment is needed.
However, 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 appearance of their
bone marrow, their age, and certain chromosome changes.
International Prognostic Scoring System
The International Prognostic Scoring System (IPSS) is a system
developed for staging MDS. It was intended for use with the FAB
classification system. It rates 3 factors:
- the percentage of blasts in the bone marrow (scored from
zero to 2)
- chromosome abnormalities (scored from zero to 1)
- the patient's blood counts. (scored as zero or
0.5)
Each factor is given a score; with the lowest scores have the
best outlook. Then the scores for the factors are added together to
make the IPSS score.
The IPSS puts people with MDS into 4 groups:
- low risk,
- intermediate - 1 risk (Int-1) ,
- intermediate - 2 risk (Int-2),
- high risk
Below is a table for the outlook for each group:
| IPSS risk group |
5-year survival* |
Risk of leukemia + |
| Low |
55% |
15% |
| Int-1 |
35% |
30% |
| Int-2 |
7% |
65% |
| High |
0% |
100% |
*The 5-year survival rate refers to the percentage of people
who live at least 5 years after they are diagnosed with MDS. The 5-year
rate is used to produce a standard way of discussing outlook. Of
course, many people live much longer than 5 years.
+The percentage of people who will develop leukemia within 5
years of diagnosis of MDS.
WHO prognostic scoring system (WPSS)
More recently, a scoring system was developed based on 3
factors:
- the type of MDS based on the WHO classification
- chromosome abnormalities
- whether or not the patient requires transfusions
| |
No points |
1 point |
2 points |
3 points |
| WHO type |
RA, RARS,
(del)5q |
RCMD,
RCMD-RS |
RAEB-1 |
RAEB-2 |
| Chromosomes |
Good |
Intermediate |
Poor |
|
| Needs Transfusions |
No |
Yes |
|
|
This system puts patients with MDS into 5 groups
Very low risk (score = 0)
Low risk (score = 1)
Intermediate (score = 2)
High risk (score = 3 or 4)
Very high risk (score = 5 or 6)
| Risk Group |
Median Survival* |
Risk of Leukemia (within 5 years)+ |
| Very low |
12 years |
3% |
| Low |
5.5 years |
14% |
| Intermediate |
4 years |
33% |
| High |
2 years |
54% |
| Very high |
9 months |
84% |
*Median survival is the amount of time for half the patients
in the group to die. This is a middle value -- half the patients live
longer than this, and half do not live this long. Median survival is
another standard way to indicate outlook..
+ The percentage of people who will develop leukemia within 5
years of being put into this risk group.
Last Revised: 12/07/2006
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