Tan R1,2, Clayton P1,2,3, Faull R1,2
1Royal Adelaide Hospital, Adelaide, Australia, 2School of Medicine, University of Adelaide, Adelaide , Australia, 3Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
Aim: To determine the incidence and survival rates of Merkel cell cancer (MCC) in kidney-only transplant recipients (KTR) in Australia and New Zealand.
Background: MCC is a rare and highly aggressive neuroendocrine skin cancer with a 5-year mortality rate of 15-33%. In the general Australia and New Zealand population, MCC has a higher overall annual incidence compared to other countries, that ranges between 0.8 and 2.5 per 100,000-person years. In this group, the median age was reported between 75.5 and 79.5 years, with a five-year MCC-specific survival of 56-66%. The epidemiology of MCC in KTR in Australia and New Zealand is unknown.
Methods: We included all KTR in Australia and New Zealand between 1963-2019 from the Australia and New Zealand Dialysis and Transplant Registry (n=31,857). Two analyses were performed using the Kaplan Meier method. The incidence of MCC was analysed for KTR transplanted from 1980 onwards (n=28,182) and the survival outcomes were analysed from 1963 onwards. This adjustment was taken into account as MCC was first described in 1972.
Results: 126 KTR were diagnosed with post-transplant MCC in Australia and New Zealand from 1963 to 2019. The median age was 62.5 years (IQR 55-71). 67.4% (n=85) were male. 92% (n=116) were Caucasian. The incidence rate was 37.9 per 100,000-person years. There were 104 patient deaths, of which 71.1% (n=74) were attributed to MCC. The overall median survival following MCC diagnosis was 1.4 years. Five-year MCC-specific survival was 26%.
Conclusions: Compared to the general population in Australia and New Zealand, kidney-only transplant recipients have a higher incidence of developing MCC post-transplantation. They are also younger and have poorer survival outcomes.
Dr Rachel Tan is a Renal Fellow at the Royal Adelaide Hospital. She obtained her FRACP (Nephrology) in November 2020. Her interests include haemodialysis, amyloid and stone related kidney disease and country health.