[De novo malignancy following renal transplantation]

The characteristics and incidence of de novo malignancy was analyzed in 376 renal transplant recipients transplanted between April 1970 and December 1992. Malignancies developed in 21 recipients of living related donor renal allografts. The total number of malignancies was 23, with 2 patients developing 2 malignancies. The mean age at the time of diagnosis was 42 years. The average interval from transplantation to the time of diagnosis was 129 months. Malignancy developed in 12 of 21 patients who survived 10 years with a functioning graft. Nine patients died of their malignancy. The risk of developing malignancy is increased following renal transplantation. Compared with sex- and age-matched Japanese control, the incidence is 6.1 times greater for male, 10.5 times greater for female, and 7.3 times greater overall. The risk was increased at all sites except the stomach. The risk rate of acquiring malignancies at 5-year intervals following transplantation was 6.5 times greater from 0 to 5 years, 10.0 times greater from 5 to 10 years, and 9.3 times greater from 10 to 15 years. These results suggest that annual medical examinations should be performed as part of the routine log-term follow-up of renal transplant recipients to detect malignancies in the early stage.