Revised International Staging System (R-ISS) for multiple myeloma
ISS stage combined with high-risk cytogenetics and LDH in newly diagnosed myeloma.
Switch how results are explained
R-ISS stage I: ISS I with standard-risk cytogenetics and normal LDH. Five-year overall survival was 82% in the IMWG cohort.
- Evidence grade
- A
What it is and when to use it
The R-ISS combines the ISS stage with chromosomal abnormalities detected by interphase FISH and serum LDH. Stage I: ISS I, no high-risk cytogenetics [del(17p), t(4;14) or t(14;16)] and normal LDH. Stage III: ISS III with high-risk cytogenetics or high LDH. Stage II: all other combinations.
How to interpret it
In the IMWG cohort of newly diagnosed patients, five-year overall survival was 82% in stage I, 62% in stage II and 40% in stage III; five-year progression-free survival was 55%, 36% and 24%.
Limitations and when not to use it
Validated in newly diagnosed myeloma, assessed before treatment. iFISH should be performed on purified (CD138-selected) plasma cells. Most patients fall into stage II, which is heterogeneous; the R2-ISS (2022) adds 1q gain to split it further.
Formulas and cut-offs are from the original authors of each score; see the references.
Last reviewed: June 2026
References
- Palumbo A, Avet-Loiseau H, Oliva S, et al. Revised International Staging System for Multiple Myeloma: a report from International Myeloma Working Group. J Clin Oncol. 2015;33(26):2863-2869. PMID:26240224
- Greipp PR, San Miguel J, Durie BGM, et al. International staging system for multiple myeloma. J Clin Oncol. 2005;23(15):3412-3420. PMID:15809451