Cancer in patients on dialysis for end-stage renal disease: an international collaborative study

Background Previous studies have suggested that the frequency of cancer is higher in patients with end-stage renal disease (ESRD) than in the general population, but have not established whether this increase is confined to c ertain cancers or to certain categories of ESRD patients. The aim of this s tudy was to examine the risk of cancer in a large cohort of patients treate d by dialysis but not transplantation. Methods We assembled a cohort of 831 804 patients who received dialysis dur ing the period 1980-94 for ESRD in the USA, Europe, Australia, or New Zeala nd. We compared the observed frequency ol: cancer among these patients duri ng 2 045 035 person-years of follow-up with the frequency of cancer in the respective background populations. Findings During average follow-up of 2.5 years, 25 044 (3%) of 831 804 pati ents developed cancer compared with an expected number of 21 185 (standardi sed incidence ratio 1.18 [95% CI 1.17-1.20]). We observed a higher risk of cancer in patients younger than 35 years (3.68 [3.39-3.99]), and the risk g radually decreased with increasing age. High risks were observed for cancer of the kidney (3.60 [3.45-3.76]), bladder (1.50 [1.42-1.57]), and thyroid and other endocrine organs (2.28 [2.03-2.54]). Excess cancers appeared in s everal organs for which viruses have been suspected as causative agents, wh ereas cancers of the lung, colorectum, prostate. breast, and stomach were n ot consistently increased. Interpretation The overall risk of cancer is increased in patients with ESR D, and the distribution of tumour types resembles the pattern seen after tr ansplantation (although we have no data to make the comparison with skin ca ncer). The excess risk can largely be ascribed to effects df underlying ren al or urinary-tract disease, or of loss of renal function, on the kidney an d bladder, and to increased susceptibility to viral carcinogenesis. The rel ative risk, which is especially high in younger patients, gradually diminis hes with age.