Prognosis for multiple myeloma

Staging indicates the spread of myeloma and the degree of possible complications, which helps determine how the disease will progress in each patient.

The most traditional classification is the Durie-Salmon system which categorises myelomas into three stages.

• Stage I. Includes patients with a haemoglobin level of at least 10 g/dL or normal values, a normal bone survey and a high level of monoclonal protein.
• Stage II. Covers patients who do not meet the criteria for either stage I or stage III multiple myeloma; i.e., they may have bone lesions but they are not advanced.
• Stage III. In this case patients also present anaemia, hypercalcaemia, advanced bone lesions (osteolytic lesions, pathological fractures, etc.) and an even higher level of monoclonal protein.

Each of the three stages is subdivided into A or B, depending on whether or not kidney function is affected.

However, the international staging system (ISS) is currently the most used prognostic system. It only considers the blood levels of just two substances: beta-2 microglobulin (produced by malignant myeloma cells) and albumin (a protein normally found in the blood). Patients with normal albumin levels and low beta-2 microglobulin (B2m) production are classified as stage I; if B2m levels are greater than 5.5 mg/dL then they are stage III (regardless of albumin levels). These results are associated with a better or worse prognosis.

Other prognostic indicators include genetic findings in bone marrow plasma cells and abnormal blood levels of other substances, e.g. lactate dehydrogenase (LDH)