The International Staging System for Multiple Myeloma (ISS) is a prognostic tool used specifically for patients diagnosed with multiple myeloma, a type of blood cancer. The ISS is designed to predict the survival outcome of these patients based on two laboratory values: serum beta-2 microglobulin and serum albumin levels. The ISS stratifies patients into three stages, with higher stages indicating a poorer prognosis. This calculator is crucial in guiding treatment decisions and informing discussions about prognosis with patients. There are no specific exclusion criteria for its use, but it may be less accurate in patients with renal impairment as beta-2 microglobulin levels can be elevated in this condition.

International Staging System for multiple myeloma (ISS)

# Criteria
 ## Serum β2 microglobulin
A. < 3.5 mg/L
B. 3.5-5.4 mg/L
C. > 5.4 mg/L
## Serum albumin
D. < 3.5 g/dL
E. >= 3.5 g/dL

# Conditions
- A and E
- (A and D) or (B and D) or (B and E)
- (C and D) or (C and E)
- true