Brenda M Rosales, Australia has been granted the TTS Young Investigator Scientific Award
Cancer Mortality in Transplant Recipients in Australia and New Zealand: A National Cohort Study from 1980 to 2013
Brenda Rosales1, Nicole De La Mata1, Patrick J Kelly1, Angela C Webster1,2,3.
1Sydney School of Public Health, University of Sydney, Sydney, Australia; 2Center for Kidney Research, The Children's Hospital at Westmead, Sydney, Australia; 3Nephrology and Transplantation, Westmead Hospital, Sydney, Australia
Introduction:Cancer treatment may be less effective post-transplant due to competing mortality risks and complex immune system interactions. We aimed to compare mortality from all cancer and site-specific cancers between kidney transplant recipients and the general population in Australia and New Zealand.
Materials & Methods: We conducted a national cohort study of incident kidney transplant recipients for Australia, 1980-2013 and New Zealand, 1988-2012. The Australian and New Zealand Dialysis and Transplant Registry was linked to the respective national death registers to determine the primary cause of death. Mortality rates and standardised mortality ratios (SMR) estimated using indirect standardisation, were produced for cancer deaths, stratified by age, sex and calendar year.
Results & Discussion:We included 17, 621 transplant recipients and 160, 332 person-years of follow-up (pys). There were 5,284 deaths, of which 1,063 were cancer deaths (Table 1).The most common cancer deaths were non-melanoma skin cancers (14.5%), lymphoma (12.2%) and, lung and other respiratory (11.6%).
The cancer death rate was 663.0 (95% CI 624.3 - 704.1) per 100 000 pys; 726.9 (95% CI 674.9 - 783.0) per 100 000 pys for men and 568.2 (95% CI 513.0 – 629.5) per 100 000 pys for women. Rates increased with age; between the ages of 30 – 49, cancer mortality rates were 228.6 (95% CI 175.9 – 297.0) per 100 000 pys for women and 271.7 (95% CI 224.0 – 329.6) per 100 000 pys for men, compared to 1705.3 (95% CI 1440.6 – 2018.6) per 100 000 pys in women and 1891.0 (95% CI 1644.0 – 2175.2) per 100 000 pys in men aged 65 - 74 (Figure 1A).
Over calendar years cancer deaths have been increasing; from 421.2 (95% CI 253.9 – 698.7) per 100 000 pys in 1993 to 690.0 (95% CI 518.5 – 918.4) in 2003 and 803.8 (95% CI 633.7 – 1019.4) in 2013 (Figure 2 )
Overall cancer deaths in kidney recipients were over 3 times that expected in the general population (SMR: 3.22, 95% CI 3.03-3.42). Risk of cancer death was greater for transplant recipients of younger age (p<0.001) and varied between sexes (Figure 1B, Table 2).
Conclusion: Cancer mortality is substantially higher among kidney transplant recipients than in the general population, in particular for those of younger age. In addition, the rate of cancer deaths in kidney recipients is steadily increasing over time, despite improvements to cancer treatments. Further studies could evaluate whether cancer treatment is accessed by transplant recipients and whether benefits and harms are different compared to the general population.
Kidney Health Australia. Australian Institute of Health and Welfare. Australia and New Zealand Dialysis and Transplant Registry. New Zealand Ministry of Health.
