Progression Risk Stratification of Asymptomatic Waldenström Macroglobulinemia
Menée à partir de données portant sur 439 patients atteints d'une macroglobulinémie de Waldenström asymptomatique diagnostiquée entre 1992 et 2014 (durée médiane de suivi : 7,8 ans), puis validée à partir de données portant sur 95 patients complémentaires, cette étude évalue la performance d'un modèle, basé sur le niveau d'infiltration de la moelle osseuse par les cellules lymphoplasmocytaires ainsi que les niveaux sériques de l'immunoglobuline M, de l'albumine et de la microglobuline bêta 2, pour identifier les patients présentant un risque de développer une forme symptomatique de la maladie
BACKGROUND : Waldenström macroglobulinemia (WM) is preceded by asymptomatic WM (AWM), for which the risk of progression to overt disease is not well defined.
METHODS : We studied 439 patients with AWM, who were diagnosed and observed at Dana-Farber Cancer Institute between 1992 and 2014.
RESULTS : During the 23-year study period, with a median follow-up of 7.8 years, 317 patients progressed to symptomatic WM (72%). Immunoglobulin M 4,500 mg/dL or greater, bone marrow lymphoplasmacytic infiltration 70% or greater,
β2-microglobulin 4.0 mg/dL or greater, and albumin 3.5 g/dL or less were all identified as independent predictors of disease progression. To assess progression risk in patients with AWM, we trained and cross-validated a proportional hazards model using bone marrow infiltration, immunoglobulin M, albumin, and beta-2 microglobulin values as continuous measures. The model divided the cohort into three distinct risk groups: a high-risk group with a median time to progression (TTP) of 1.8 years, an intermediate-risk group with a median TTP of 4.8 years, and a low-risk group with a median TTP of 9.3 years. We validated this model in two external cohorts, demonstrating robustness and generalizability. For clinical applicability, we made the model available as a Web page application (www.awmrisk.com). By combining two cohorts, we were powered to identify wild type MYD88 as an independent predictor of progression (hazard ratio, 2.7).
CONCLUSION
:
This classification system is positioned to inform patient monitoring and care and, for the first time to our knowledge, to identify patients with high-risk AWM who may need closer follow-up or benefit from early intervention.
Journal of Clinical Oncology , résumé, 2018