Criteria
International prognostic scoring system for Waldenström macroglobulinemia (IPSSWM)[46][52]
The IPSSWM uses the following adverse factors to risk stratify patients into three risk groups (low, intermediate, and high):
Age >65 years
Hemoglobin level ≤11.5 g/dL
Platelet count ≤100 × 10⁹/L
Beta-2 microglobulin >3 mg/L
Serum monoclonal IgM >7.0 g/dL
Risk groups are defined as:
Low risk: presence of 0 or 1 adverse factors (except age)
Intermediate risk: age >65 years or presence of 2 adverse factors
High risk: presence of ≥3 adverse factors
Although the IPSSWM is useful for risk-stratifying patients, it has limited clinical use and does not help direct treatment, particularly now that newer targeted therapies are available. Furthermore, it lacks precision for estimating outcomes for individual patients.
A revised (point-based) version of the IPSSWM has been developed to address these limitations.[46] The revised IPSSWM uses the following adverse factors to risk stratify patients into five risk groups (very low, low, intermediate, high, and very high):
Age <65 years (0 points)
Age 66-75 years (1 point)
Age >75 years (2 points)
Beta-2 microglobulin >4 mg/L (1 point)
Lactate dehydrogenase (LDH) level >250 IU/L (1 point)
Serum albumin <3.5 g/dL (1 point)
Risk groups are defined as follows:
Very low risk: 0 points
Low risk: 1 point
Intermediate risk: 2 points
High risk: 3 points
Very high risk: 4 to 5 points
11th International Workshop on Waldenström's macroglobulinemia (IWWM-11) response criteria[53]
Complete response (CR):
Absence of monoclonal IgM protein by serum protein electrophoresis and immunofixation
Serum IgM level within normal range
Normal morphology on bone marrow biopsy; no evidence of lymphoplasmacytic lymphoma (LPL) involvement
Absence of extramedullary disease if present at baseline (as per revised CR criteria for malignant lymphoma)[54]
Very good partial response (VGPR):
≥90% reduction in serum IgM levels or within normal range
Partial response (PR):
≥50% to <90% reduction in serum IgM levels
Minor response (MR):
≥25% to <50% reduction in serum IgM levels
Stable disease:
<25% reduction to <25% increase in serum IgM levels
Progressive disease (PD):
≥25% increase in serum IgM levels with a minimum increase of 500 mg/dL from nadir. Reconfirmation is required by two sequential (back-to-back) measurements if serum IgM is being used to support PD. Demonstration of PD by imaging does not require reconfirmation. In the event of discordant response findings, that is, IgM measurement shows a response but imaging shows PD related to WM, then the assessment should be considered PD. Suspected IgM flare or IgM rebound related to therapy is not considered PD.
Any new lesion (>1.5 cm in any axis) or unequivocal evidence of an increase by >50% in any axis to >1.5 cm in size of previously involved extramedullary disease sites from their nadir measurements. Any new lesion consistent with transformed disease.
Nonevaluable (NE):
Suspected IgM flare or IgM rebound, absence of data, or suspected error in data reporting.
Use of this content is subject to our disclaimer