A prognostic index predicting survival in transformed Waldenström macroglobulinemia

• Published in: Haematologica (Roma) Vol. 106; no. 11; pp. 2940 - 2946
• Main Authors: Durot, Eric, Kanagaratnam, Lukshe, Zanwar, Saurabh, Kastritis, Efstathios, D’Sa, Shirley, Garcia-Sanz, Ramon, Tomowiak, Cécile, Hivert, Bénédicte, Toussaint, Elise, Protin, Caroline, Abeykoon, Jithma P., Guerrero-Garcia, Thomas, Itchaki, Gilad, Vos, Josephine M., Michallet, Anne-Sophie, Godet, Sophie, Dupuis, Jehan, Leprêtre, Stéphane, Bomsztyk, Joshua, Morel, Pierre, Leblond, Véronique, Treon, Steven P., Dimopoulos, Meletios A., Kapoor, Prashant, Delmer, Alain, Castillo, Jorge J.
• Format: Journal Article
• Language: English
• Published: Ferrata Storti Foundation 01.11.2021; Fondazione Ferrata Storti
• Subjects: Life Sciences
• ISSN: 0390-6078; 1592-8721
• DOI: 10.3324/haematol.2020.262899

Histological transformation into diffuse large B-cell lymphoma is a rare complication in patients with Waldenström macroglobulinemia (WM) and is usually associated with a poor prognosis. The objective of this study was to develop and validate a prognostic index for survival of patients with transformed WM. Through this multicenter, international collaborative effort, we developed a scoring system based on data from 133 patients with transformed WM who were evaluated between 1995 and 2016 (training cohort). Univariate and multivariate analyses were used to propose a prognostic index with 2-year survival after transformation as an endpoint. For external validation, a dataset of 67 patients was used to evaluate the performance of the model (validation cohort). By multivariate analysis, three adverse covariates were identified as independent predictors of 2-year survival after transformation: elevated serum lactate dehydrogenase (2 points), platelet count <100x109/L (1 point) and any previous treatment for WM (1 point). Three risk groups were defined: low-risk (0-1 point, 24% of patients), intermediate-risk (2-3 points, 59%; hazard ratio = 3.4) and high-risk (4 points, 17%; hazard ratio = 7.5). Two-year survival rates were 81%, 47%, and 21%, respectively (P<0.0001). This model appeared to be a better discriminant than either the International Prognostic Index or the revised International Prognostic Index. We validated this model in an independent cohort. This easy-to-compute scoring index is a robust tool that may allow identification of groups of transformed WM patients with different outcomes and could be used for improving the development of risk-adapted treatment strategies.