First-Line Treatment with Rituximab Improves Survival of Patients with Post-Transplant Lymphoproliferative Disease (PTLD).

Purpose: to compare the response rate and survival between patients diagnosed of PTLD and treated with front-line rituximab and those not treated with rituximab.

Patients and Methods: 108 patients with PTLD have been studied from January 1996 to January 2004. Survival curves were expressed as Kaplan-Meier plots and were compared by the Log-rank test. A multivariate Cox regression analysis was performed to asses the effect of prognostic factors on survival.

Results: median age was 55 years (limits: 18–73). 70% were males. The transplanted organ was: kidney 46%, liver 28%, heart 16%. Median time between transplant and PTLD was 59 months, 25% were diagnosed during the first year after the transplant. The most frequent histological subtypes were: large B-cell lymphoma 53% and polymorphic SLPT 13%. 70% were EBV +. Clinical characteristics at diagnosis were: disseminated disease: 52%, extra-nodal disease: 81%, ECOG ³ 2: 43%, LDH >N: 60%, IPI ³ 3: 40%. Treatments used were: reduction of immunosuppression 91%, chemotherapy 59%, rituximab 33%, antiviral 13%. Response to treatment was: CR 46%, PR 13% failure 11%, not evaluable (early deceased): 29%. With a median follow-up of 15,2 months, survival was: OS 21% and EFS 15%. Forty-six (43%) patients died. The causes of death were: lymphoma progression 15 (33%), infection 15 (33%), toxicity 16 (34%). Survival of patients treated with rituximab was significantly better than the general group: OS 76% (p=0.007) and EFS 70% (p=0.02). Among patients treated with rituximab, 8 (23%) patients died. The significant bad prognostic factors for EFS in the multivariate analysis were: disseminated disease (RR: 2, 95% IC:1,02–3,8; p=0,04), ECOG ³ 2 (RR: 5, 95% IC:2,6–9,8; p=0,0001), not been treated with rituximab (RR: 3,8, 95% IC: 1,7–10; p=0,001). IPI did not have prognostic impact.

Conclusions: survival of patients with PTLD is low with conventional therapy, and the main causes of death are toxicity and infections. Treatment with Rituximab significantly improves their survival. Patients with disseminated disease and bad performance status have worse prognosis. IPI is not a useful index of prognosis in patients with PTLD.