Decision Analysis of Allogeneic Stem Cell Transplantation in Patients with Myelodysplastic Syndrome Stratified According to the Who Classification-Based Prognostic Scoring System (WPSS)

• Published in: Blood 2011-11, Vol.118 (21), p.116-116
• Main Authors: Alessandrino, Emilio Paolo, Porta, Matteo G Della, Malcovati, Luca, Jackson, Christopher H, Pascutto, Cristiana, Bacigalupo, Andrea, van Lint, Maria Teresa, Falda, Michele, Bernardi, Massimo, Onida, Francesco, Guidi, Stefano, Iori, Anna Paola, Cerretti, Raffaella, Marenco, Paola, Pioltelli, Pietro, Angelucci, Emanuele, Oneto, Rosi, Rambaldi, Alessandro, Bosi, Alberto, Cazzola, Mario
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V118.21.116.116

Abstract 116 Myelodysplastic syndromes (MDS) are heterogeneous myeloid neoplasms that range from indolent conditions with a near normal life expectancy to forms very close to acute myeloid leukemia (AML). The WHO classification-based Prognostic Scoring System (WPSS) is able to classify MDS patients into five risk groups (very low, low, intermediate, high, and very high) with different median survival (from more than 10 to about 1 yr). Despite recent progress, the only curative treatment for MDS remains allogeneic stem cell transplantation (allo-SCT), which however involves a non-negligible risk of mortality and morbidity. Allo-SCT is not considered in patients with low WPSS risk, whose median survival is >10 yr. Conversely, eligible patients with high or very high WPSS risk, whose median survival is 1–2 yr, should be offered immediate transplantation. Uncertainty exists about the optimal timing of allo-SCT in the low and intermediate WPSS-risk groups, and to address this issue we performed an ad hoc decision analysis. We analyzed two cohorts of MDS patients: i) 615 patients diagnosed with MDS at the Fondazione IRCCS Policlinico San Matteo, Pavia, Italy, between 1992–2007, who were followed regularly and mostly received best supportive care; ii) 405 patients who received allo-SCT between 1997–2007, reported to the Gruppo Italiano Trapianto di Midollo Osseo (GITMO) registry. In this latter cohort, variables were analyzed at the time of transplantation in patients undergoing allo-SCT upfront, and at the time of remission-induction chemotherapy in those receiving treatment before allo-SCT. We adopted a continuous time multi-state Markov approach to model the natural history of the disease. In this model, each WPSS risk group is represented by a state, and transition is allowed to the next state (to AML from very high risk) or to death. A transition intensity (i.e., instantaneous risk of moving to another state) is then estimated for each possible transition. Allo-SCT is modeled as a time-dependent covariate with 3 levels: i) no allo-SCT; ii) transplantation done no more than 3 months before; iii) transplantation done more than 3 months before. The effect of allo-SCT on survival was estimated by hazard ratios (HR) with respect to the no allo-SCT level. We examined two different policies: policy A) to perform allo-SCT after t months since entering the low-risk state or at the time of progression to intermediate risk; policy B) to perform allo-SCT after t months