But whereas the number of stem cells obtained from a placenta are enough to perform transplantation on a child, they may be too few for an adult. The most common form of marrow transplant done today is an autologous transplant, in which the stem cells come from the patient, having been withdrawn before chemotherapy. But overall, autologous transplant patients have the lowest risk of death from complications. The transplants are, on the other hand, known to be beneficial for treating several cancers involving blood or lymph cells. The data are from the International Bone Marrow Transplant Registry and Autologous Blood and Marrow Transplant Registry-North America at the Medical College of Wisconsin in Milwaukee.
Marrow transplants are standard for a few cancers but available in research studies for many.
To treat some cancers, doctors usually choose to perform the procedure if the patient can tolerate it. For example, the only curative treatment for chronic myeloid leukemia, in which the white blood cells that fight bacteria are diseased, is an allogeneic bone marrow transplant. In North America, most marrow transplants are prescribed for breast cancer. Data from the Autologous Blood and Marrow Transplant Registry of North America show that five years after a marrow transplant, between 15 and 20 percent of the women were still in remission. Physicians are concerned that these results might have been skewed by selection of relatively healthy women for the transplants.