Sandbox/00038

Template:Plasma cell neoplasm Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ammu Susheela, M.D. [2]

Overview

The Durie-Salmon staging system has been widely adopted to stratify patients with multiple myeloma since 1975. It provides a fair estimate on the tumor burden but has limitations in the categorization of bone lesions. The International Staging System overcomes the limitations of Durie-Salmon system by dividing patients based on the serum levels of β2-microglobulin and albumin. Both Durie-Salmon Staging System and International Staging System are useful for assessing the prognosis of a patient with multiple myeloma. However, neither of them are favorable in making therapeutic options.

Staging

Durie-Salmon Staging System

This system is based on 4 factors:

1. The amount of abnormal monoclonal immunoglobulin in the blood or urine. Large amounts of monoclonal immunoglobulin indicate that significant malignant plasma cells are present and are producing that abnormal protein.
2. The amount of calcium in the blood. High blood calcium levels can be related to advanced bone resorption.
3. The severity of bone damage based on X-rays. Multiple areas of bone damage seen on X-rays indicate an advanced stage of multiple myeloma.
4. The amount of hemoglobin in the blood. Low hemoglobin levels indicate that the myeloma cells occupy much of the bone marrow and that not enough space is left for the normal marrow cells to make enough red blood cells.

This system uses these factors to divide myeloma into 3 stages. Stage I indicates the smallest amount of tumor, and stage III indicates the largest amount of tumor. The table below describes the criteria for the Durie-Salmon staging system:

Stage	Criteria	Cell Mass (x1012/m2)
I	All of the following: Hemoglobin value >10 g/dL Serum calcium value normal (≤12 mg/dL) On radiograph, normal bone structure (scale 0) or solitary bone plasmacytoma only Low M-component production rates IgG value <5 g/dL IgA value <3 g/dL Urine light chain M-component on electrophoresis <4 g/24 hours	<0.6 (Low)
II	Fitting neither Stage I nor Stage III	0.6–1.2 (Intermediate)
III	One or more of the following: Hemoglobin value <8.5 g/dL Serum calcium value >12 mg/dL Advacned lytic bone lesions (scale 3) High M-component production rates IgG value >7 g/dL IgA value >5 g/dL Urine light chain M-component on electrophoresis >12 g/24 hours	>1.2 (High)

International Staging System

This system divides myeloma into 3 stages based only on the serum beta-2 microglobulin and serum albumin levels. The table below describes the criteria for the International Staging System:

Stage	Serum β2 Microglobulin	Serum Albumin	Median Survival
I	<3.5 mg/L	≥3.5 g/dL	62 months
II	<3.5 mg/L OR 3.5–5.5 mg/L	<3.5 g/dL Any level	44 months
III	≥5.5 mg/L	Any level	29 months