What is the role of transplantation for indolent lymphoma?

Despite advances in chemoimmunotherapy, indolent B-cell non-Hodgkin lymphomas (B-NHLs) are generally not considered curable with this approach. Much attention has been paid to the prospect of hematopoietic cell transplantation (HCT) as a way to improve long-term outcomes for this group of diseases. Autologous (auto) HCT provides intensive conditioning therapy followed by rescue of hematopoiesis, and this has been shown in randomized studies to prolong survival compared with more standard chemotherapy, albeit with increased short-term toxicity and the potential for higher rates of secondary malignancies. Allogeneic (allo) HCT can provide anticancer effects beyond the conditioning therapy through the immune-mediated graft-versus-lymphoma (GVL) effect. It can be administered following myeloablative (MA) conditioning or reduced-intensity (RI) regimens aimed at sufficiently suppressing the patient's immune system to allow engraftment of donor hematopoiesis. However, this same potentially curative alloreactivity of the engrafted immune system can lead to graft-versus-host disease (GVHD), a significant cause of morbidity and mortality following allo HCT. This article will discuss the current role of both auto HCT and allo HCT in the management of indolent lymphoma as well as the relative risks and benefits of each approach such that the reader can place this in context of the multitude of options available for patients with indolent B-NHL.