Cancer incidence before and after kidney transplantation.
BACKGROUND
Immune suppression after organ transplantation is associated with a markedly increased risk of nonmelanoma skin cancer and a few virus-associated cancers. Although it is generally accepted that other cancers do not occur at increased rates, there have been few long-term population-based cohort studies performed.


OBJECTIVE
To compare the incidence of cancer in patients receiving immune suppression after kidney transplantation with incidence in the same population in 2 periods before receipt of immune suppression: during dialysis and during end-stage kidney disease before renal replacement therapy (RRT).


METHODS
A population-based cohort study of 28,855 patients with end-stage kidney disease who received RRT, with 273,407 person-years of follow-up. Incident cancers (1982-2003) were ascertained by record linkage between the Australia and New Zealand Dialysis and Transplant Registry and the Australian National Cancer Statistics Clearing House.


METHODS
Standardized incidence ratios (SIRs) of cancer, using age-specific, sex-specific, calendar year-specific, and state/territory-specific population cancer incidence rates.


RESULTS
The overall incidence of cancer, excluding nonmelanoma skin cancer and those cancers known to frequently cause end-stage kidney disease, was markedly increased after transplantation (n = 1236; SIR, 3.27; 95% confidence interval [CI], 3.09-3.46). In contrast, cancer incidence was only slightly increased during dialysis (n = 870; SIR, 1.35; 95% CI, 1.27-1.45) and before RRT (n = 689; SIR, 1.16; 95% CI, 1.08-1.25). After transplantation, cancer occurred at significantly increased incidence at 25 sites, and risk exceeded 3-fold at 18 of these sites. Most of these cancers were of known or suspected viral etiology.


CONCLUSIONS
Kidney transplantation is associated with a marked increase in cancer risk at a wide variety of sites. Because SIRs for most types of cancer were not increased before transplantation, immune suppression may be responsible for the increased risk. These data suggest a broader than previously appreciated role of the interaction between the immune system and common viral infections in the etiology of cancer.
Vajdic
Claire M
CM
National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, Australia. cvajdic@nchecr.unsw.edu.au
McDonald
Stephen P
SP
McCredie
Margaret R E
MR
van Leeuwen
Marina T
MT
Stewart
John H
JH
Law
Matthew
M
Chapman
Jeremy R
JR
Webster
Angela C
AC
Kaldor
John M
JM
Grulich
Andrew E
AE
D000293:Adolescent; D000328:Adult; D000368:Aged; D001315:Australia; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000628:therapy; D016030:Kidney Transplantation / Q000276:immunology / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D009520:New Zealand; D012042:Registries; D017582:Renal Replacement Therapy; D012306:Risk; D014777:Virus Diseases