The role of high-dose therapy in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) represent a heterogeneous group of non-Hodgkin's lymphomas. With few exceptions (eg, anaplastic large-cell lymphoma expressing the anaplastic lymphoma kinase), PTCLs have generally been reported to have a worse prognosis compared with B-cell lymphomas. Despite the poor outcome after conventional therapy, the impact of high-dose therapy with autologous or allogeneic stem cell transplantation (SCT) in these rare diseases is poorly defined mainly because of the lack of prospective PTCL-restricted studies. Most data exist for high-dose therapy with autologous SCT in relapsing or refractory disease. Because most studies showed similar results for PTCL compared with aggressive B-cell lymphomas in which high-dose therapy with autologous SCT is accepted as standard therapy, this approach seems appropriate in relapsing or refractory PTCL. Results for high-dose therapy with autologous SCT as first-line therapy mainly rely on studies on aggressive lymphomas that also included lymphomas of the T-cell phenotype. Our own recently published PTCL-restricted prospective study confirmed the feasibility with only moderate toxicity and a good response rate. Overall, patients with a good remission status after induction therapy exhibited a high complete response rate after transplantation, and at least a subgroup of patients remained in long-term remission. The greatest uncertainty exists for the impact of allogeneic SCT after high-dose therapy. In refractory or relapsing PTCL, this approach might improve the outcome for eligible patients, especially when using reduced-intensity conditioning. Overall, because data on high-dose therapy for PTCL are limited, larger and randomized studies are necessary to definitely confirm the preliminary results.