ABSTRACT
Objective To compare cancer incidence in kidney
transplant recipients during periods of transplant
function (and immunosuppression) and after transplant
failure (when immunosuppression is ceased or reduced).
Design, setting, and participants Nationwide, population
based retrospective cohort study of 8173 Australian
kidney transplant recipients registered on the Australia
and New Zealand Dialysis and Transplant Registry who
first received a transplant during 1982-2003. Incident
cancers were ascertained using linkage with national
cancer registry records.
Main outcome measures Cancer-specific standardised
incidence ratios for periods of transplant function and for
dialysis after transplant failure. Incidence was compared
between periods using multivariate incidence rate ratios
adjusted for current age, sex, and duration of
transplantation.
Results All cases of Kaposi’s sarcoma occurred during
transplant function. Standardised incidence ratios were
significantly elevated during transplant function, but not
during dialysis after transplant failure, for non-Hodgkin’s
lymphoma, lip cancer, and melanoma. For each of these
cancers, incidence was significantly lower during dialysis
after transplant failure in multivariate analysis (incidence
rate ratios 0.20 (95% CI 0.06 to 0.65) for non-Hodgkin’s
lymphoma, 0.04 (0.01 to 0.31) for lip cancer, and 0.16
(0.04 to 0.64) for melanoma). In contrast, standardised
incidence ratios during dialysis after transplant failure
remained significantly elevated for leukaemia and lung
cancer, and cancers related to end stage kidney disease
(kidney, urinary tract, and thyroid cancers), with thyroid
cancer incidence significantly higher during dialysis after
transplant failure (incidence rate ratio 6.77 (2.64 to
17.39)). There was no significant difference in incidence
by transplant function for other cancers.
Conclusions The effect of immunosuppression on cancer
risk is rapidly reversible for some, but not all, cancer
types. Risk reversal was mainly observed for cancers with
a confirmed infectious cause. Risk of other cancers,