Conditioning regimens before transplantation in patients with aggressive non-Hodgkin's lymphoma.

Substantial progress has been made in understanding the role of autotransplantation in aggressive non-Hodgkin's lymphoma. At present, the clinical indications for high-dose therapy include patients with relapsed or poor prognosis disease. Hematopoietic reconstitution with peripheral stem cells has rendered transplantation less toxic but the optimal preparative regimen remains to be found. It should combine a high antitumor activity with acceptable toxicity to normal tissues. The literature, on combinations of drugs with or without total body irradiation, was reviewed with regard to this objective. BEAM, CBV and ICE, the most common chemotherapy regimens can be considered safe as they cause low transplant-related morbidity. The combination of fractionated TBI and etoposide or cyclophosphamide was not found to be superior. However, it must be kept in mind that comparisons were made on registry data or retrospectively. In every case, relapse of the residual primary disease argue for the need for more effective strategies such as tandem transplantation or sequential high-dose chemotherapy with stem-cell support. To obtain an objective evaluation, these new preparative regimens need to be tested in controlled trials with treatment groups stratified for known prognostic factors.