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| |  Study Examines Benefits, Risks of Autologous Stem Cell Transplantation for Advanced Breast Cancer COLOGNE, Germany -- January 15, 2009 -- Compared with conventional chemotherapy, autologous stem cell transplantation (autologous SCT) can extend event-free survival for patients with breast cancer. Clinical trials provide proof of this for breast cancer with and without distant metastases. However, there are indications that this type of stem cell transplantation can more frequently give rise to severe complications affecting almost all organ systems. This is the conclusion of the final report of the Institute for Quality and Efficiency in Health Care (IQWiG). Initially, autologous SCT was hailed with great excitement and widely used in the 1980s, but its benefit for patients with advanced breast cancer has been hotly debated by scientists for some years. The Federal Joint Committee (G-BA) therefore commissioned IQWiG to examine the available literature to find out whether autologous SCT could have advantages for breast cancer patients compared with conventional chemotherapy. High-dose chemotherapy usually damages vital haematopoietic stem cells in addition to tumour cells. Consequently, haematopoietic stem cells are removed from the patient before the treatment and then re-implanted afterwards. These stem cells mostly colonise the bone marrow and stimulate haematopoiesis. If the transferred stem cells originate from the patient, this is known as autologous stem cell transplantation (autologous SCT). Autologous tandem transplantation (tandem autologous SCT) represents extremely intensified therapy: following a recovery phase, the patient receives a second transplant. In accordance with the G-BA’s commission, IQWiG conducted a search for trials that compared autologous SCT versus chemotherapy without stem cell transplantation or compared different types of autologous SCT with each other. A total of 19 randomised controlled trials (RCTs) could be included in the benefit assessment. 13 trials investigated patients with breast cancer without distant metastases, 6 trials investigated patients with metastatic breast cancer. Overall, the quality of data was noticeably better than that of all previous IQWiG reports on stem cell transplantation IQWiG and its external experts have come to the conclusion that autologous stem cell transplantation has an advantage over conventional chemotherapy for patients with breast cancer in that it extends event-free survival. They found proof of this in patients with breast cancer both with and without distant metastases. However, this proof of benefit is countered by an indication of potential harm: severe complications affecting almost all organ systems, in particular the haematopoietic system and gastrointestinal tract, occurred more frequently under autologous SCT than under the control therapies. However, the difference could not be precisely quantified, because there was insufficient reporting of complications in the trials. Indications of relevant differences were found in both metastatic and non-metastatic tumours. The comparison of tandem autologous SCT with intensified chemotherapy was the only one where patients with non-metastatic breast cancer not only survived longer without recurrence of breast cancer, but also lived longer. However, these indications are only found in 1 trial and only apply to a specific therapy regimen (WSG AM-01Trial), so that they cannot be generalised. In general, IQWiG is concerned that some of the available trials are quite old. Nowadays, other chemotherapy regimens are normally used, particularly for patients with advanced non-metastatic breast cancer. High-dose chemotherapy in combination with autologous SCT appeared in the 1980s as a promising treatment and was introduced into medical care without adequate clinical trialling (in IQWiG’s view an ethically questionable act). When the results of the first reproducible RCTs became available at the end of the 1990s, disillusionment set in and the number of transplants in breast cancer fell dramatically: in 2002 only 316 patients in Europe received transplants whereas in 1997 this figure was 2626. For patients with metastatic breast cancer in particular, for whom there is still no curative treatment, alternatives must be tested. This also applies to therapies combined with autologous SCT. In view of the risks associated with autologous SCT, the authors of the final report believe that this testing should only take place within controlled trials. In order to better assess the benefits and harms, it would be particularly useful to investigate in further clinical trials whether treatment, optionally with autologous SCT, can extend the life of patients with metastatic breast cancer. This would be a trial looking at the primary outcome of overall survival.
SOURCE: Institute for Quality and Efficiency in Health Care
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