Two large studies published in the New England Journal of Medicine say that women who are at high risk of recurrence of breast cancer rarely benefit from high dose chemotherapy followed by transplantations of their own stem cells. An accompanying editorial reviewed the differences between the studies, one of which, from the Netherlands Cancer Institute, found a slight benefit for some women.
The experimental regimen of high dose chemotherapy and stem cell rescue became controversial when many women and doctors demanded the treatment before randomised trials had been conducted (BMJ 2002;324: 1088-92).
The Dutch study, which was begun in 1993, included 885 patients aged less than 56 years who had had surgery for breast cancer and who had no sign of distant metastases (New England Journal of Medicine 2003;349: 7-1612840087).
Patients randomised to conventional treatment were given fluorouracil, epirubicin, and cyclophosphamide every three weeks, followed by radiotherapy and treatment with tamoxifen, for five cycles of treatment. Patients in the high dose treatment group received the same treatment regimen for the first four cycles, but the fifth treatment comprised high doses of cyclophosphamide, thiotepa, and carboplatin followed by transplantation of the patients' own peripheral blood haematopoietic stem cells.
Five women died in the high dose treatment group: one during treatment and four within 100 days after stem cell transplantation.
The other study, which was begun in 1991 and was coordinated by the Division of Haematology-Oncology at Northwestern University School of Medicine, Chicago, involved 540 women who had breast cancer and at least 10 positive axillary nodes. They were treated either with six cycles of chemotherapy with cyclophosphamide, doxorubicin, and fluorouracil or with the same chemotherapy followed by a cycle of high dose chemotherapy with cyclophosphamide and thiotepa and autologous haematopoietic stem cell transplantation.
Nine women died in the high dose treatment group. The researchers found that adding stem cell transplantation to conventional chemotherapy did not improve disease free survival or overall survival, but the time to recurrence was longer in women who underwent stem cell transplantation.