Results of a retrospective study showed allogeneic hematopoietic stem cell transplantation (allo-HSCT) using cord blood-derived stem cells was an effective approach to the treatment of patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). The findings from this study were published in Annals of Hematology.
Although allo-HSCT is considered a potentially curative option for patients with relapsed/refractory DLBCL who experience progressive disease following chemotherapy and autologous HSCT (auto-HSCT), as well as some patients with relapsed/refractory DLBCL who are unable to undergo auto-HSCT, only a limited number of studies have investigated this approach to the treatment of patients with this disease. Furthermore, data are scarce regarding the use of cord blood as the source of stem cells in the setting of DLBCL.
This multicenter study included 68 adult patients with DLBCL treated with first allo-HSCT between 2003 and 2016 at 17 transplantation centers in Japan. The primary end point was overall survival (OS), with relapse-free survival (RFS), relapse rate, and nonrelapse mortality included as secondary end points.
Median patient age was 52 years, 32.4% of patients had undergone prior treatment with high-dose chemotherapy and auto-HSCT, and 45.6% had achieved complete remission (CR) or partial remission (PR) at the time of allo-HSCT.
Notably, the source of stem cells was peripheral blood, bone marrow, and cord blood for 27.4%, 32.8%, and 39.7% of patients, respectively. Approximately two-thirds of patients had received reduced-intensity conditioning prior to allo-HSCT, with the remainder receiving myeloablative conditioning.
At a median follow-up of 3.8 years, the rate of 4-year OS was only 4.3% for patients not in remission at the time of transplantation, whereas nearly half of patients in PR/CR prior to allo-HSCT were alive at 4-year follow-up (46.2%; P <.001). Four-year OS rate by stem cell source was 28.6% for bone marrow, 27.2% for cord blood, and 6.5% for peripheral blood (P =.193).
The difference in 4-year RFS was also highly significant when the rate for the group not in remission (7.2%) was compared with those who had achieved CR/PR prior to transplantation (35.8%; P =.005). An analysis of 4-year RFS by stem cell source showed rates of 28.6%, 27.2%, and 6.5% for patients undergoing transplantation with stem cells from bone marrow, cord blood, and peripheral blood, respectively (P = 0.193).
Other findings included no significant differences in nonrelapse mortality based on stem cell source or previous history of auto-HSCT.
Study limitations included the absence of cytogenetic data and immunohistochemical analyses.
The study authors commented that “our analysis showed that allo-HSCT including cord blood transplantation can be a promising therapeutic option for relapsed or refractory DLBCL patients, especially those who have achieved CR/PR.”
Izumi K, Kanda J, Nishikori M, et al. Outcomes of allogeneic stem cell transplantation for DLBCL: a multi-center study from the Kyoto Stem Cell Transplantation Group. Ann Hematol. 2019;98(12):2815-2823.