Outcomes after Allogeneic Stem Cell Transplantation for Patients with Non-Hodgkin Lymphoma: Texas Children's Hospital Experience 1999-2013

Despite significant improvement in outcomes for patients with pediatric non-Hodgkin lymphomas (NHL), relapsed disease is associated with poor long term survival. Hematopoietic stem cell transplant (HSCT) is used to improve outcome in this setting but there are limited data in pediatric patients with NHL.  Methods: We now report on 29 pediatric patients who underwent allogeneic HSCT at our institute between 1999-2013. Results: There were 16 male and 13 female patients and the median age was 14 years (range 5-23 years). Histological categories were anaplastic large cell lymphoma (ALCL) (n=9), lymphoblastic lymphoma (LL) (n=8), diffuse large B cell lymphoma (DLBCL) (n=7), other B cell lymphomas (Burkitt’s lymphoma=1, Small cell, non-Burkitt's high grade lymphoma=1,  and T-cell rich, B-cell lymphoma=1), and other T cell lymphoma (Stem cell myeloproliferative/T-cell lymphoma =1, and hepatosplenic T cell lymphoma=1). 9 patients received grafts from matched-related donors, 8 from matched-unrelated donors, 8 from mismatched-unrelated donors and 4 from haploidentical donors. 21/29 received a myeloablative conditioning regimen (MAC) while 8/29 patients received a reduced intensity conditioning regimen (RIC). At the time of transplant, 23/28 patients were in complete remission (CR=10) or partial remission (PR=13), while 5/28 patients had persistent or progressive disease based on standard established criteria. The 3 –year relapse free survival (RFS) was 59% (95%CI: 37%-75%). The overall outcomes varied based on the subtype of lymphoma: patients with ALCL had the best outcomes (9/9 patients are alive and disease free) while those with LL had the worst (1 /8 patients is alive and disease free).  Relapsed/progressive disease was the cause of death for all 7 of the LL patients who died. Patients with other B-cell and T-cell lymphomas also fared well (4 /7 with DLBCL and 2 /3 other B- cell lymphomas and 2/2 other T-cell lymphomas, are alive and disease free). Patients in CR or PR had a better OS (18/23) compared with those patients with persistent or progressive disease at time of transplant (0/5). 11/29 patients died (9 from relapse and 2 from treatment related mortality). Conclusions: HSCT offers the possibility of cure for patients with NHL, especially for patients with ALCL and for those patients that have a good response to re-induction therapy prior to transplant.  Relapsed disease post-transplant remains a major challenge for patients with LL and for patients transplanted with non-responsive disease. Post transplant therapies to target residual disease should be evaluated in these patients.