Risk for tumor and other disease transmission by transplantation: a population-based study of unrecognized malignancies and other diseases in organ donors.

BACKGROUND: Organ donation may involve the risk of transmittal of unwanted host factors such as infections and malignancy. These may be concealed in the emergent donation process. It may be unavoidable if first observed in a donor postmortem. A number of reports on transferred cancers have been published, but quantification of the risk has never been reliably performed. We report here the first population-based analysis of unrecognized malignancies and other diseases in cadaveric or living-related donors and the possible consequences for the recipients.
METHODS: We compiled a cohort of all organ donors through 27 years (1969-1996) in one single kidney transplant center covering a population on one million people. This cohort was linked to the Danish Cancer Registry, the Danish National Hospital Register, and the Danish Register of Causes of Death by means of the unique personal identification number, and all cancers, diagnosis from hospital admissions, and causes of death were identified. Follow-up was to the end of 1996.
RESULTS: A total of 626 donors (491 cadaveric and 135 living-related donors) was included in the study. Ten carcinoma in situ or dysplasia cervix uteri (by definition nonmalignant), and 13 malignant tumors (5 of these were detected in living-related donors after donation) were detected by linkage to the cancer registry. All together, 17 recipients received organs from donors with carcinoma in situ or dysplasia cervix uteri and 20 from donors with malignancies. Two recipients from organ donors with carcinoma in situ or dysplasia of the cervix uteri and two recipients from donors with malignancies had a cancer detected; however, these were likely unrelated. One died 1 year after transplantation from a melanoma transmitted from the donor. Two cadaveric donors had previous admissions for glomerulonephritis, five for pyelonephritis, five for nephrolithiasis or ureterolithiasis, four for cystitis, and one for hydronephrosis.
CONCLUSION: Despite all efforts to secure a safe organ for transplantation, transmission of donor malignancy and other diseases nevertheless can happen, as is recorded many times in the literature. We have quantified the risk using the population-based cancer registry and found a risk of 8 in 626 (1.3%) for having a donor with undetected malignancy and a risk of 1 in 626 (0.2%) for transmitting a cancer. The risk for getting some transmitted glomerulonephritis is 2 in 626 (0.3%). None of the donors with cerebral malignancies transmitted any tumors to the recipients. Compared with the benefits of organ transplantation, these risks are small; however, if time allows, a search for additional medical information from registries could further minimize the risk of transmission of malignancies or other diseases. However, this requires updated, accurate, and accessible registries and legislation that allows access to personal data and transmission of such data across administrative borders.