Wilms Tumor Gene 1 Expression as a Predictive Marker for Relapse and Survival after Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndromes

Relapse after allogeneic hematopoietic stem cell transplantation (HSCT) is a major concern in myelodysplastic syndromes (MDS), but the role of Wilms tumor gene 1 (WT1) as a predictive marker for post-HSCT relapse remains to be validated. We measured WT1 transcript levels by real-time quantitative PCR from marrow samples of 82 MDS patients who underwent transplantation between 2009 and 2013. Pre-HSCT WT1 expression weakly correlated with marrow blast counts or International Prognostic Scoring System scores and failed to predict post-transplantation relapse. Regarding post-HSCT WT1, transcript levels of relapsed patients were significantly higher in comparison to those in remission. Further analysis using receiver operating characteristics curves showed that higher (>154 copies/10⁴ABL) 1-month post-HSCT WT1 resulted in a higher 3-year relapse rate (47.2% versus 6.9%, P < .001) with poorer disease-free survival (DFS) and overall survival at 3 years (41.7% versus 79.0% and 54.3% versus 82.1%, P= .003 and P= .033, respectively). Multivariate analysis after adjusting for pre-HSCT karyotype and chronic graft-versus-host disease (GVHD) also revealed that higher 1-month post-HSCT WT1 was an independent predictive marker for subsequent relapse (P= .002) and poorer DFS (P= .010). In the higher 1-month post-HSCT WT1 subgroup, patients with chronic GVHD showed lower relapse rate and favorable survival outcome. One month post-HSCT WT1 expression was a useful marker for minimal residual disease and relapse prediction in association with chronic GVHD in the context of HSCT for MDS.