Cost-effective use of autologous bone marrow transplantation: few answers, many questions, and suggestions for future assessments.

High dose chemotherapy with the support of autologous bone marrow transplantation (ABMT) or peripheral blood progenitor cells (PBPC) has been increasingly used in a variety of haematological and epithelial cancers over the last decade. The rationale of this approach is to overcome the chemotherapy resistance of tumour cells by increasing the dose of cytotoxic drugs. However, the clinical benefit of dose-intensification has been difficult to prove. Almost all studies of ABMT have been done without randomised comparisons with the standard form of therapy for a specific condition. From an economic perspective, the cost of ABMT has been steadily decreasing with improvements in supportive care primarily. Still, current ABMT cost estimates range from $US70 000 to $US150 000 for each uncomplicated procedure. Despite the lack of compelling evidence in support of dose-intensification, ABMT has become a default standard of care after relapse for many patients with lymphoma or leukaemia. We used a decision analysis model to estimate the cost effectiveness of the timing of ABMT in relapsed Hodgkin's disease. The model illustrates the difficulty of using available clinical trial data when follow-up of promising early reports is not available. The model showed that in most situations the optimal strategy is ABMT in second relapse despite growing consensus that immediate ABMT is the treatment of choice. ABMT for women with high-risk or early metastatic breast cancer is one of the most controversial areas in clinical oncology. In the US, several ongoing major randomised trials are addressing the role of ABMT in breast cancer. Using a Markov process we found that ABMT is the preferred strategy under almost all assumptions. The size of the benefit and cost effectiveness of ABMT varied markedly depending on the assumptions made. The model does not supplant the need for randomised trials that concurrently measure efficacy, quality of life, and resource utilisation. However, such analyses point out the critical areas where costs could be cut substantially without effecting efficacy. Drawing conclusions about the cost effectiveness of ABMT for all conditions is hampered by the lack of randomised comparisons of efficacy. Concurrent economic appraisals of selected phase III comparative trials should be considered since the supportive care costs associated with ABMT appear to be stabilising. However, the most important point is that randomised trials are the only mechanism for estimating the therapeutic effect of high dose chemotherapy.