Myelodysplastic Syndromes (MDS) are cancers where the bone marrow fails to produce enough healthy blood cells. While many people have no early symptoms, the condition can progress to cause fatigue, frequent infections, and bleeding. For those newly diagnosed, the prognosis is an immediate concern.
It is important to remember that survival rates are statistical estimates based on large groups of people. They cannot predict an individual’s outcome but serve as a guide for patients and doctors to determine the best approach to treatment.
Understanding MDS Survival Statistics
One common measure is median survival, which is the time after diagnosis at which half of the patients in a specific group are still alive. This means half of the individuals live longer than this time, and half do not. The average survival time following an MDS diagnosis is about 2.5 years, but this figure can be misleading because it includes everyone from very low-risk to very high-risk patients.
The overall 5-year relative survival rate for MDS provides another view by comparing people with MDS to the general population.
Key Factors That Influence Prognosis
Several biological factors are examined to determine an individual’s prognosis, as these markers provide insight into the specific characteristics of the MDS cells. The patient’s age and overall health, including other medical conditions, are also important considerations.
A primary factor is the percentage of “blasts” in the bone marrow. Blasts are immature, abnormal cells that are not functioning properly, and a higher percentage in the bone marrow or blood is associated with a more serious prognosis and a greater likelihood of progression to acute myeloid leukemia (AML).
Another component is cytogenetics, which is the study of chromosomes inside the cells. Specific changes in the chromosomes of the bone marrow cells can influence the prognosis, with some chromosomal changes categorized as “good” risk and others as “poor” risk.
The severity of low blood cell counts (cytopenias) also plays a part. Doctors look at the levels of red blood cells (anemia), white blood cells (neutropenia), and platelets (thrombocytopenia), as having one or more severe cytopenias can impact the prognosis.
How Doctors Determine MDS Risk
To provide a more personalized prognosis, doctors use a scoring system that combines the biological factors of blast percentage, chromosome abnormalities, and blood cell counts. This score helps categorize the disease into risk groups, which are used to estimate survival and guide treatment.
The most widely used system is the Revised International Prognostic Scoring System (IPSS-R). This tool assigns points based on the severity of each factor; for instance, a low blast percentage receives fewer points than a high percentage.
Based on the total score, the IPSS-R classifies MDS into five risk groups, each with a different median survival and risk of transforming into AML.
- Very Low-risk: Median survival is approximately 8.8 years.
- Low-risk: Median survival is about 5.5 years.
- Intermediate-risk: Median survival is around 4 years.
- High-risk: Median survival is about 2 years.
- Very High-risk: Median survival is approximately 0.8 years.
These scores also estimate the likelihood of progression to AML, which increases with each successive risk group.
The Impact of Treatment on Survival
Prognostic scores like the IPSS-R are based on data from patients diagnosed years ago, and medical science is continually advancing. Newer treatments can significantly alter these expected outcomes, so a prognosis should be seen as a starting point for a conversation about treatment.
For some patients, an allogeneic stem cell transplant may offer a potential cure. This procedure involves replacing the patient’s unhealthy bone marrow with healthy blood-forming stem cells from a donor. While it is a risky procedure and not suitable for everyone, particularly older adults, it has survival rates of around 50% at three years for those who can undergo it.
Other treatments can also improve survival and quality of life. Drugs known as hypomethylating agents, such as azacitidine, have been shown to increase survival for patients with higher-risk MDS compared to older standards of care. These therapies, along with chemotherapy and supportive care like blood transfusions, aim to control the disease, manage symptoms, and prevent or delay progression to AML. Discussing all available treatment options with a hematologist helps develop a personalized plan.