Autologous and allogeneic stem cell transplantation in follicular lymphoma

Follicular non-Hodgkin's lymphomas (NHL) usually present in advanced stage and although frequently are chemotherapy-sensitive remain incurable using conventional approaches. Treatment options are evolving rapidly and now include targeted therapies such as monoclonal antibodies. Recent studies, including the EBMTR-sponsored “CUP Trial” (conventional Chemotherapy, Unpurged autograft, Purged autograft), demonstrate that for patients under age 60 years with recurrent chemotherapy-sensitive disease, autologous stem cell transplantation (ASCT) provides a survival benefit over conventional therapy. Allogeneic stem cell transplantation (alloSCT) has become a more effective option. Although incorporation of TBI into the preparative regimen may increase treatment-related mortality (TRM), relapses appear to be reduced compared to a chemotherapy-alone regimen. Reduced-intensity alloSCT procedures now are being performed at an increasing rate, in part due to a lower risk for TRM. Until more data are available, however, reduced-intensity alloSCT should be considered only in cases where myeloablative conditioninig is contra-indicated. There are no clear means for choosing ASCT versus alloSCT, a decision influenced by amount of residual tumor, disease-responsiveness, degree of marrow involvement and extent of prior chemotherapy. ASCT or alloSCT in first remission remains an investigational procedure. Future considerations include incorporation of novel preparative regimens, in vitro purging techinques, anti-lymphoma vaccines, post-transplant immunotherapy and ex vivo-manipulated donor lymphocyte infusions.