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

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.