University of New South Wales' Dr. Vajdic reported her findings in the Dec. 20 issue of the Journal of the American Medical Association. Her research indicated that following transplantation, there was a significant increase in risk of cancer.
Immune suppression after transplantation is recognized as a risk factor for non-melanoma skin cancer, non-Hodgkin's lymphoma, and Kaposi's sarcoma, but Dr. Vajdic and colleagues said it had been assumed that there was no increase in other cancers. Dr. Vajdic noted that this issue had never been studied in a large population with long-term follow-up.
There were 1,236 observed cancers in patients who received kidney transplants, excluding non-melanoma skin cancer, non-Hodgkin's lymphoma, and Kaposi's sarcoma. The team only expected to find 378 cases.
The study performed by Dr. Vajdic was limited by some specifics, such as the need to retrospectively define the "period before transplantation." This may have caused an underestimation of the incidence of cancer, because some patients may not have been referred for transplant because of their cancer history. In addition, the heightened cancer surveillance in the transplant population may also have introduced bias.