MGUS Risk Calculator (Mayo 3-Factor Model)
Use this tool to estimate long-term progression risk for monoclonal gammopathy of undetermined significance (MGUS). Educational use only.
What this MGUS calculator does
This MGUS calculator applies the widely used Mayo Clinic 3-factor risk model. It counts three adverse risk factors and assigns a risk group from low to high. The estimated percentages represent long-term progression risk to plasma-cell disorders (for example, multiple myeloma, AL amyloidosis, or related conditions) in historical cohorts.
Risk factors included in the model
- Non-IgG isotype (IgA, IgM, or other)
- M-protein ≥ 1.5 g/dL
- Abnormal serum free light chain ratio (< 0.26 or > 1.65)
| Number of risk factors | Risk category | Approximate 20-year progression risk |
|---|---|---|
| 0 | Low | ~5% |
| 1 | Low-Intermediate | ~21% |
| 2 | High-Intermediate | ~37% |
| 3 | High | ~58% |
How to use it correctly
Enter the most recent values from your lab report:
- M-protein in g/dL (sometimes called M-spike on SPEP)
- Immunoglobulin isotype (IgG, IgA, IgM, etc.)
- Serum free light chain ratio (kappa/lambda ratio)
The calculator then displays your risk score, category, and an estimated long-term progression percentage.
Important interpretation notes
A calculator is only one piece of the picture. Clinical context matters: age, renal function, blood counts, imaging findings, symptoms, and trends over time can all affect management. Risk estimates are population-based and do not guarantee what will happen for any one person.
Common follow-up themes in clinical practice
Low risk MGUS
Often monitored less frequently after an initial re-check confirms stability. Many patients remain stable for years.
Intermediate or high risk MGUS
Usually monitored more closely, especially in the first year after diagnosis or after any laboratory change. Follow-up intervals vary by clinician and by institution.
FAQ
Does a higher risk score mean I have cancer now?
No. MGUS is a premalignant condition, not active myeloma. The score estimates probability of progression over time, not current diagnosis.
Can risk category change?
Yes. If M-protein level, isotype interpretation, or FLC ratio changes, the score can change.
Should this replace doctor visits?
No. It is a quick educational aid, not a substitute for medical care, professional interpretation, or personalized follow-up planning.