The role of bone marrow transplantation in the non-Hodgkin's lymphomas

In a significant fraction of patients with NHL, disease develops that is resistant to conventional chemotherapy. Experience using high-dose chemotherapy, with or without TBI, and BMT is expanding. Remissions can be achieved in many patients with refractory NHL in particular those patients with tumors that are still chemosensitive. High-dose chemoradiotherapy regimens are toxic and require extensive supportive care. Relapse frequently occurs in areas of previous disease, suggesting failure of the conditioning regimen rather than that an infusion of occult tumor cells in the autologous bone marrow had occurred. Thus, the role of marrow purging in this therapy needs to be further evaluated and compared with findings involving nonpurged marrow reinfusion. It is also important to evaluate the effects of more vigorous attempts at cytoreduction of bulky disease prior to high-dose therapy and BMT. Potential areas for development include the use of this modality as intensification therapy following conventional therapy in patients with intermediate or high-grade NHL with poor prognostic features. Toxicity can be decreased and efficacy increased only if therapy is administered to patients who have not been heavily pretreated and who have lower tumor burden and a good performance status. The role of high-dose chemotherapy and BMT in the nodular lymphomas is not known at this point and requires further investigation. Finally, high-dose therapy with BMT has a definite role in salvaging patients with malignant lymphomas. Many issues need to be resolved, including (1) the optimal timing of this approach, (2) the optimal conditioning regimen, and (3) the need for purging autologous bone marrow prior to reinfusion. The past 10 years have led to significant gains. During the next 10 years, it may be possible to refine this therapy and find solutions to the above issues.