Version: 1
Transplantation of blood-forming stem cells, where the donor is either a sibling or an unrelated person with matching tissue, is an established treatment method, eg, for malignant blood diseases. In the new host, stem cells are capable of restoring their bone marrow function and creating a functioning immune defense. Some donor cells are able to kill malignant cells via the so-called Graft-versus-Tumor (GvT) effect. By transplanting stem cells from a donor to a cancer patient, an attempt is made to initiate an immunologic reaction targeted at the tumor. To prevent rejection of the stem cells, transplantation is usually conducted following strongly immunoinhibiting pretreatment. This method is now being tested in patients with advanced kidney cancer. A condition for inclusion in the target group is that the patient must be in good general health. Since patients usually do not receive stem cells from an unrelated donor due to the increased transplantation-related risks, it is necessary for the patient to have a sibling donor. In Sweden, an estimated 150 patients per year are in the target group.
Currently, small series of patients are being followed. There are no controlled studies that draw comparisons with conventional treatment methods, eg, palliative radiotherapy and immunotherapy. An American followup study of 19 patients with metastasized kidney cancer reported that approximately 40% had a partial or complete response following transplantation (ie, that at least half of the tumor mass had disappeared). It was reported that the tumor may grow during the initial period after transplantation when patients are treated with immunoinhibiting drugs. Preparatory treatment with chemotherapy and radiation may have side effects such as nausea, vomiting, and liver damage. The greatest transplantation-related risk is GvH (Graft-versus-Host) disease, which means an immunological attack on the patients healthy organs, mainly the skin, intestines, and liver. When a sibling with the same tissue type is the donor, the risks for severe GvH disease are estimated at 5% to 10%.
There is poor* scientific evidence concerning the short-term and long-term effects of the method. Since the effects are uncertain, no* estimation of the cost-effectiveness has been feasible.
Until further notice, stem cell transplantation for cancer should be considered an experimental treatment and should be provided only within the framework of scientific studies.
*This assessment by SBU Alert uses a 4-point scale to grade the quality and evidence of the scientific documentation. The grades indicate: (1) good, (2) moderate, (3) poor, or (4) no scientific evidence on the subject.
This summary is based on a report prepared at SBU in collaboration with Prof. Olle Ringdén MD PhD, Huddinge University Hospital and has been reviewed by Mats Brune MD PhD Sahlgrenska University Hospital.
The full report is available only in Swedish.
Alert is a joint effort by the Swedish Council on Technology Assessment in Health Care (SBU), the Medical Products Agency, the National Board of Health and Welfare, and the Federation of Swedish County Councils.