Why does Durie-Salmon still appear on reports?

It was the first widely adopted myeloma staging system and it captures tumour burden in a way the ISS does not, because it counts bone lesions and paraprotein level directly. Many registries and older trials report it, so understanding it remains necessary even though the ISS and R-ISS now drive most treatment decisions.

What is the difference between the A and B subclass?

The subclass reflects renal function. A means creatinine is at or below 2 mg/dL and B means it is above. The B subclass carries a substantially worse prognosis because renal impairment in myeloma is both a marker of disease burden and an independent driver of morbidity.

How does Durie-Salmon compare with the ISS?

The ISS uses only beta-2 microglobulin and albumin, so it is simpler and more reproducible, and it has largely replaced Durie-Salmon for prognosis. The R-ISS adds high-risk cytogenetics and LDH on top of the ISS and is now the preferred modern staging scheme.

Durie-Salmon Staging for Multiple Myeloma

Stage multiple myeloma by tumour mass with the original Durie-Salmon system, using haemoglobin, calcium, skeletal survey, and paraprotein levels, then add the A or B renal subclass. Stage III with B carries the worst outlook.

Haemoglobin (g/dL)

Serum calcium (mg/dL)

Creatinine (mg/dL)

Serum IgG (g/dL)

Serum IgA (g/dL)

Urine light chain (g/24 h)

Bone lesion scale

Stage IA

Low tumour mass — favourable prognosis. Substage reflects renal function. Substage A (creatinine < 2.0 mg/dL) indicates preserved renal function.

Clinical Guidance

The Durie-Salmon system (Durie & Salmon, Cancer 1975) stages myeloma by estimated tumour cell mass from haemoglobin, serum calcium, M-protein (serum and urine), and the extent of bone lesions. Stage I requires all favourable criteria; stage III requires at least one high-risk criterion; stage II is everything in between. Substage A/B reflects renal function at a creatinine cut-off of 2.0 mg/dL.

The International Staging System (ISS) and its revised form (R-ISS), which use β2-microglobulin, albumin, LDH, and cytogenetics, are now commonly used alongside Durie-Salmon. Interpret this stage with the full clinical and cytogenetic picture.

How It Works

Each component has a specific meaning:

Haemoglobin — The haemoglobin recorded for the scenario being assessed.
Calcium — The calcium recorded for the scenario being assessed.
Skeletal survey — The skeletal survey recorded for the scenario being assessed.
Paraprotein levels — The paraprotein levels recorded for the scenario being assessed.
Then add the A or B renal subclass — The then add the a or b renal subclass recorded for the scenario being assessed.

Note: Interpret the durie-salmon stage result against the thresholds and context described above.

How to Use

Enter the haemoglobin, calcium, skeletal survey, paraprotein levels, then add the A or B renal subclass for the scenario you are assessing. Stage multiple myeloma by tumour mass with the original Durie-Salmon system, using haemoglobin, calcium, skeletal survey, and paraprotein levels, then add the A or B renal subclass. Stage III with B carries the worst outlook. Use the durie-salmon stage result to inform your calculation.

Formula Sources

Related Calculators

ISS Myeloma Staging

Medical Long-tail

R-ISS Myeloma