Why Did My MDS Risk Score Change From IPSS-R to IPSS-M?

A change in your risk score when moving from the older IPSS-R to the newer IPSS-M can be alarming, but it often does not mean that your myelodysplastic syndrome (MDS) has suddenly progressed ^[1]. If both scores were calculated using bone marrow tests from the exact same date, the change simply reflects a difference in how the two scoring systems work ^[1]. The newer IPSS-M incorporates detailed molecular data—information about specific genetic mutations—that the older system did not use ^[2].

Important Note: If your new IPSS-M score was calculated from a recent bone marrow biopsy and your old IPSS-R score was from months or years ago, the change might reflect real biological changes in your disease over time. Always ask your doctor if the scores are based on the same sample.

Comparing the Scoring Systems

Both the Revised International Prognostic Scoring System (IPSS-R) and the Molecular International Prognostic Scoring System (IPSS-M) are statistical tools. They estimate how your disease might behave over time to help guide, but not dictate, treatment decisions.

Instead of just adding up points for different abnormalities, the IPSS-M uses a complex mathematical model to weigh how your age, blood counts, blasts, chromosome changes, and specific molecular mutations interact with one another ^[2]. Because of this, you cannot simply translate an old IPSS-R category into a new IPSS-M category; the new score must be completely recalculated using all the required data ^[2].

The Impact of Molecular Data

The most significant upgrade in the IPSS-M is the inclusion of a 31-gene testing panel ^[2]. However, this is not a simple checklist where every single mutation independently raises or lowers your score. The system looks at specific combinations of mutations.

• High-risk alterations: Certain genetic features can significantly increase your risk score ^[2]. A common example is TP53 “multi-hit” disease. This occurs when there is more than one abnormality in the TP53 gene (such as a mutation combined with the loss of the other TP53 copy) ^[3]. Another example is MLL-PTD, which is a specific structural alteration (a partial tandem duplication) involving the KMT2A/MLL gene ^[2].
• Favorable alterations: A mutation in the SF3B1 gene is generally associated with a more favorable outcome and might lower your score, provided certain high-risk mutations are absent ^[2][4].

Six Risk Categories Instead of Five

The IPSS-M divides patients into six categories, compared to the five used in the IPSS-R ^[5]:

1. Very Low
2. Low
3. Moderate-Low
4. Moderate-High
5. High
6. Very High

In large studies validating the IPSS-M, researchers found that about 42% to 46% of patients were reclassified into a different risk group when switching from IPSS-R to IPSS-M ^[1][6][7]. Among those who changed categories, roughly half moved into a higher risk group (upstaged) and half moved into a lower risk group (downstaged) ^[1].

What This Means for Your Care Plan

Receiving a new risk category can be emotionally difficult, especially if your score moves up. It is crucial to understand that risk scores are prognostic tools—they help predict disease behavior—but they are not automatic treatment prescriptions ^[8][9]. Your score is just one part of your overall assessment.

• If your score moved up: This does not mean you immediately need a stem cell transplant or intensive chemotherapy. However, a higher IPSS-M score often prompts a discussion about referring you for a transplant evaluation, as the IPSS-M generally improves the ability to predict survival and the risk of progression to acute myeloid leukemia (AML) compared to the IPSS-R ^[1][7].
• If your score moved down: A lower risk category does not mean you do not need treatment. You may still require therapies for severe anemia, infections, or bleeding ^[9]. Your team may recommend active monitoring (regularly checking blood counts and symptoms) or specific supportive medications ^[10].

Not an Exact Prediction

While the IPSS-M provides a more personalized estimate of your disease risk, it is still based on population averages. It does not dictate exactly what will happen to you. When deciding on a treatment plan or evaluating if a stem cell transplant is appropriate, your doctor will look far beyond your score. They must consider your overall fitness, other medical conditions (comorbidities), donor availability, daily functioning, and most importantly, your personal goals for care ^[11][12]. A risk score is a guide, not a guarantee.