De novo malignancy after paediatric renal replacement therapy.

AIMS: To determine frequency, type, determinants, and outcome of malignancies in children with end stage renal failure.

METHODS: All Dutch patients, aged less than 15 years, who started chronic renal replacement therapy between 1972 and 1992 and who were at least 18 years old on 1 January 1997, were retrospectively studied.

RESULTS: Mean follow up from first renal replacement therapy was 15.5 years. Twenty two malignancies were found in 21 of 249 patients. Skin cancer accounted for 59% and non-Hodgkin lymphoma for 23% of malignancies. At 25 years after first renal replacement therapy, the probability of developing a malignancy was 17% (95% CI: 9 to 24%). Compared to the general population the incidence rate for overall cancer was tenfold higher. For non-melanoma skin cancer and non-Hodgkin lymphoma, standardised risks were 222 and 46 respectively. The use of more than 20 mg/kg cyclophosphamide showed an association with increased risk of malignancy. Six patients died as a result of their malignancy, accounting for 9.5% of overall mortality. Whereas four out of five patients with non-Hodgkin lymphoma died, the most frequent malignancy, skin cancer, did not contribute to mortality.

CONCLUSION: The long term risk of certain malignancies is significantly increased in children who have undergone renal replacement therapy. As an important contributor to overall mortality, awareness of this risk of malignancy in these patients is necessary, especially after treatment with cyclophosphamide.