Cancer diagnoses after living kidney donation: linking U.S. Registry data and administrative claims.

BACKGROUND: Mortality records identify cancer as the leading cause of death among living kidney donors, but information on the burden of cancer outside death records is limited in this population.
METHODS: We examined a database wherein U.S. Organ Procurement and Transplantation Network identifiers for 4,650 living kidney donors in 1987 to 2007 were linked to administrative data of a U.S. private health insurer (2000-2007 claims) to identify postdonation cancer diagnoses. Skin cancer and non-skin cancer diagnoses were ascertained from International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes on billing claims. Donors were also matched one-to-one with general insurance beneficiaries by sex and age when benefits began. Diagnosis rates within observation windows were compared as rate ratios.
RESULTS: The median time from donation to the end of plan insurance enrollment was 7.7 years, with a median observation period of 2.1 years. Skin cancer rates were similar among prior living donors in the observation period and nondonor controls (rate ratio, 0.91; 95% confidence interval [CI], 0.59-1.40). In contrast, the rate of total non-skin cancers was significantly less common among donors than among controls (rate ratio, 0.74; 95% CI, 0.55-0.99), although reduced relative risk was limited to donors captured earlier in relation to donation. Several cases of cancer diagnosis (uterine, melanoma, "other") were identified within the first year after donation. Prostate cancer diagnosis was significantly more common among living donors compared with controls (rate ratio, 3.80; 95% CI, 1.42-10.2).
CONCLUSIONS: Continued study of cancer after kidney donation is warranted to ensure that evaluation, selection, and long-term follow-up support overall good health of the donor.