The Revised International Staging System (R-ISS) for multiple myeloma evaluates the prognosis of a patient using four specific clinical features: serum beta-2 microglobulin, serum albumin, chromosomal abnormalities by iFISH, and LDH levels. The outcomes are categorized into three distinct stages, each with a defined median progression-free survival time.

Each input is classified as follows: 

1. Serum beta-2 microglobulin:
   - < 3.5 mg/L
   - 3.5-5.4 mg/L
   - >= 5.5 mg/L
   
2. Serum albumin:
   - < 3.5 g/dL
   - >= 3.5 g/dL

3. Chromosomal abnormalities by iFISH:
   - No high-risk abnormality
   - High risk abnormality (e.g., del(17p), t(4;14), t(14;16))

4. LDH:
   - Normal
   - High

The computation process involves checking these conditions:

- If serum beta-2 microglobulin is less than 3.5 mg/L, serum albumin is 3.5 g/dL or higher, no high-risk chromosomal abnormalities are present, and LDH is normal, the median progression-free survival time is 66 months. This indicates the most favorable prognosis.

- If serum beta-2 microglobulin is 5.5 mg/L or higher, regardless of serum albumin levels, but with either high-risk chromosomal abnormalities and/or elevated LDH, the median progression-free survival time is 29 months. This represents the least favorable prognosis.

- If the conditions do not fit either of the above scenarios, the median progression-free survival time is estimated to be 42 months, reflecting an intermediate prognosis.

Each of these scenarios takes into account key biomarkers and genetic factors, aligning them into categories that describe the disease progression outlook. The computation checks these conditions in sequence to determine the median progression-free survival, making it crucial to fill in each field accurately to get a precise result. If any input is missing, the system defaults to requesting a complete set of selections.

The Revised International Staging System for Multiple Myeloma (R-ISS) is a prognostic scoring system used specifically for patients diagnosed with multiple myeloma. This calculator is designed to stratify patients into different risk groups based on various clinical and laboratory parameters, including serum albumin, beta-2 microglobulin, lactate dehydrogenase (LDH), and chromosomal abnormalities. The R-ISS is used to predict overall survival and progression-free survival, aiding clinicians in making informed decisions about treatment strategies and patient management. It is not applicable to patients with other types of cancer or those who lack the necessary laboratory data for calculation.

Revised international staging system for multiple myeloma (R-ISS)