Unrelated Cord Blood Transplanation for Malignant Lymphoma: A Retrospective Study from the Japan Cord Blood Bank Network (JCBNW).

Unrelated cord blood transplantation (u-CBT) may provide a treatment option for patients with malignant lymphoma (ML) who have failed other conventional therapies and do not have a compatible donor available. Japan Cord Blood Bank Network (JCBNW) has established a registry for u-CBT as a quality management and promotion of CBT. We have analysed 271 patients with ML (aggressive lymphoma=189, indolent lymphoma=52) transplanted from 1999–2006 and reported to JCBNW. The median follow-up was 19 months (1–85) and the median age was 47 years (1–75). At transplant, 83% of the patients are non-CR and 23% had received previous autologous transplants. The conditioning regimen varied according diasease and centers: reduced intensity conditioning regimens (RIC) were used in 49% and ATG/ALG was added in 5% of the cases. GVHD prophylaxis consisted of CsA alone (23%), CsA/sMTX (28%), TAC alone (18%), TAC/sMTX (11%) and others (20%). The median nucleated cell dose infused was 2.6 × 10^7/kg and the graft was HLA identical (6/6) (HLA A and B low resolution and DRB1 allelic typing) in 37 cases, 5/6 in 110, and 4/6 in 122. Median time to neutrophil recovery (>500/mm3) was 22 days (0–61) and 39 days for platelets recovery (>20.000/mm3). The probability of neutrophil recovery was 80%. Grades II–IV aGVHD was observed in 50%. Treatment-related mortality (TRM) was observed in 107 patients (39%), and 61% of them were related to infection. The overall survival (OS), disease-free survival (DFS), and cumulative incidences of disease progression at 2 years after u-CBT were 28%, 21%, and 11%, respectively. In a multivariate analysis, chemoresistance, bacterial infection, and cGVHD were identified as adverse prognostic factors for overall survival. The development of grades II–IV aGVHD was associated with higher rate of DFS, which suggested the existence of a graft versus lymphoma effect. Althouth u-CBT can be an effective therapeutic option for patients with refractory ML, more work is still needed to decrease TRM.