Autologous stem cell transplantation in aggressive non-Hodgkin's lymphoma

High dose therapy with autologous stem cell transplantation (ASCT) has been widely used in the past decade for treating aggressive non-Hodgkin's lymphoma in situations in which conventional therapy was not likely to cure patients. In patients achieving complete remission, ASCT has been proposed for consolidation in a group of lymphoma patients sharing adverse prognostic factors with a high risk of relapse. Results from pilot studies were encouraging. Analysis of the large randomized LNH87 trial, showed an increased survival and disease free survival advantage for ASCT performed after CR when compared to conventional chemotherapy if patients with 2 or more adverse factors were included. For patients who do not achieve CR after conventional treatment, but who are still sensitive to chemotherapy, ASCT may improve results. Pilot studies as well as randomized studies offer support for this approach. Intensive treatment with ASCT has been reported in thousands of relapsing lymphoma patients. For those remaining sensitive to salvage chemotherapy at 5 years, a 40% probability of disease free survival has been uniformly noted. Moreover, these results were confirmed by the randomized PARMA study testing ASCT vs conventional chemotherapy. ASCT is accepted by most centers as the treatment of choice for relapsing lymphoma. For lymphoblastic lymphoma and Burkitt's lymphoma, the role of ASCT in first CR is not well defined, although results from pilot studies and the analysis of registry data support the use of ASCT in lymphoblastic lymphoma with adverse prognostic factors. In conclusion, data supporting the use of ASCT in lymphoma in different settings has been provided by numerous non randomized trials. Completed randomized studies clearly demonstrate a benefit for ASCT in most relapsing patients as well as a subset of patients with poor prognosis. Socio-economic implications of such results must be evaluated, especially since the development of peripheral hematopoietic stem cells will reduce both toxicity and cost.