Hematopoietic cell transplantation for diffuse large B-cell and follicular lymphoma: Current controversies and advances.

Non-Hodgkin's lymphoma (NHL) constitutes a collection of lymphoproliferative disorders with diverse biologic, histologic, and clinical features. With a better understanding of the molecular pathogenesis, recently there have been major advances in the treatment of NHLs including addition of novel monoclonal antibodies, targeted therapies, and immune activators to the therapy armamentarium. Despite these remarkable developments, autologous hematopoietic cell transplantation (auto-HCT) remains not only a standard-of-care curative option for aggressive NHL but also an important therapeutic option for indolent NHL. In NHL, for patients with high-risk features, including those heavily pretreated or with refractory disease or those experiencing failure after an auto-HCT, allogeneic HCT (allo-HCT) remains the only curative option. In this review, we briefly discuss the role of transplantation in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). In DLBCL patients, we discuss the role of HCT in clinically and biologically defined ultra-high-risk disease. In FL patients, auto-HCT is best reserved for relapsed chemosensitive patients after two to three lines of prior chemoimmunotherapies, who are not candidates for allo-HCT, either because of donor unavailability, associated comorbidities, or patient preference. Reduced-intensity conditioning allo-HCT offers the curative option for patients with relapsed/refractory FL. Although the emergence of targeted, biologic, and immunological therapies is welcoming, it is currently unclear how these new therapies might enhance or replace allo-HCT. Until we have further definitive data, allo-HCT remains the only curative option.