Abstract Type : Oral presentation
Abstract Submission No.: A-0962
Abstract Topic : Transplantation

Urologic Cancer Stage and Survival in Kidney Transplant Recipients: A Nationwide Comparative Cohort with Dialysis and Non-Kidney Replacement Therapy Patients

Heajung Lee², Eunjeong Kang¹, Minsang Kim³, Jeongin Song⁴, Subin Jeong⁵, Hojoon Sohn⁶, Hajeong Lee⁷
¹Department of Internal Medicine-Nephrology, Seoul National University Hospital, Korea, Republic of
²Department of Transplantation Center, Seoul National University Hospital, Korea, Republic of
³Department of Internal Medicine-Nephrology, Seoul National University Hospital, Korea, Republic of
⁴Department of Internal Medicine-Nephrology, Dongguk University Ilsan Hospital, Korea, Republic of
⁵Department of Biomedical Research Institute, Seoul National University Hospital, Korea, Republic of
⁶Department of Preventive Medicine, Seoul National University College of Medicine, Korea, Republic of
⁷Department of Internal Medicine-Nephrology, Seoul National University College of Medicine, Korea, Republic of

Objectives : Kidney transplant (KT) recipients have substantially elevated risks of urologic cancers, yet population-based data on their stage at diagnosis and stage-adjusted survival compared with patients on dialysis or without kidney replacement therapy (non-KRT) are limited. Using a nationwide cancer registry linked to the national health insurance database, we primarily evaluated stage distribution and stage-adjusted survival of de novo urologic cancers in KT recipients, with maintenance dialysis and non-KRT patients as comparator groups.
Methods : We identified KT recipients, dialysis patients, and non-KRT patients newly diagnosed with kidney, upper tract urothelial carcinoma (UTUC), or bladder cancer in the K-CURE database. SEER Summary Stage defined advanced (regional/distant) versus localized disease; multivariable logistic regression estimated adjusted odds of advanced stage, and stage-adjusted Cox and Fine–Gray models evaluated all-cause and cancer-specific mortality.
Results : Kidney cancer was the most common subtype in KT recipients as well as in comparator groups. Compared with non-KRT patients, KT recipients had higher odds of presenting with advanced UTUC (adjusted odds ratio [OR] 2.79; 95% confidence interval [CI] 1.23–6.33), whereas stage distribution for kidney cancer was broadly similar across modalities. Overall treatment uptake was high in KT recipients and non-KRT patients, while dialysis patients were less likely to receive definitive treatment for UTUC or bladder cancer. After stage adjustment, KT recipients showed intermediate survival: cancer-specific mortality was increased for kidney cancer but was comparable to non-KRT patients for UTUC and bladder cancer. In contrast, dialysis patients experienced the worst outcomes, with markedly higher all-cause and cancer-specific mortality across sites.
Conclusions : KT recipients in this nationwide cohort showed a distinctive pattern of urologic cancer presentation, with a propensity toward advanced UTUC but relatively preserved, site-dependent cancer-specific survival compared with non-KRT patients. These findings underscore site-specific diagnostic challenges in KT recipients and highlight the need for tailored, modality- and site-specific surveillance strategies in high-risk KRT populations.