International Staging System (ISS) for Multiple Myeloma

The original ISS and revised R-ISS stratify multiple myeloma patients into 3 stages based on beta-2 microglobulin and albumin (original), plus LDH and FISH (revised).

Warnings:
  • ISS originally developed before novel agents (thalidomide, bortezomib, lenalidomide); prognostic significance may differ with modern therapy
  • R-ISS (2015) adds LDH and FISH for more refined risk stratification in the era of novel agents
  • Normal albumin threshold: >=3.5 g/dL (35 g/L)
  • Beta-2 microglobulin can be affected by renal function; elevated in renal impairment
  • A third revision (R2-ISS) further subdivides stage II patients based on 1q gain
Note: ISS Stage II includes all patients not meeting Stage I or III criteria (i.e., beta-2 between 3.5-5.5, or beta-2 <3.5 with albumin <3.5). R-ISS requires FISH testing for del(17p), t(4;14), or t(14;16).
Serum beta-2 microglobulin level
Serum albumin level
LDH relative to upper limit of normal (optional, for R-ISS)
FISH results for high-risk cytogenetics (optional, for R-ISS)

References

Medical Disclaimer

This calculator is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.