Recursive partitioning analysis of prognostic factors in post-transplant lymphoproliferative disorders (PTLD): a 120 case single institution series.

The post-transplant lymphoproliferative disorders (PTLD) comprise a heterogeneous group of lymphocytic and plasma cell proliferations occurring in recipients of tissue allografts in the setting of immunosuppression. We describe our experience of 120 patients with PTLD seen between 1990 and 2009, one of the largest series reported by a single institution. Post-transplant lymphoproliferative disorders characteristics were analysed with regard to paediatric and adult patients, and with regard to the decade of diagnosis, 1990-1999 (pre-rituximab era) versus 2000-2009 (the rituximab era). We present a new prognostic score using the recursive partitioning model, consisting of the Eastern Cooperative Oncology Group (ECOG) score (0-1 vs. 2-4), age [paediatrics (<16 years old), adults (16-60 years old) and elderly (>60 years old)] and CD20 status (positive vs negative); separating patients into 4 risk categories based on overall survival. Low-risk included paediatric patients with ECOG score of 0-1; intermediate-low-risk included adults aged 16-60 years with an ECOG score of 0-1; intermediate-high-risk included elderly patients with an ECOG score 0-1 or paediatric patients and adults aged 16-60 years with an ECOG score of 2-4 and CD20 positive; high-risk group included patients of any age with an ECOG score of 2-4 and CD20 negative, and elderly patients with an ECOG score of 2-4 with CD20-positive PTLD.