Subject review: Urologic malignancies in kidney transplantation (urothelial carcinoma) (2018)

Comprehensive review article of urologic malignancy in kidney transplantation. Both renal cell carcinoma (RCC) and urothelial carcinoma (RC) are covered. Lifetime risk of renal cancer is 1.62% in US general population. Compared with the general population, kidney transplant recipients have a 5-7 fold increased risk of renal cancers with RCC accounting for 4.6% of post renal transplantation malignancies. 90% RCC develop in native kidneys, as opposed to the allograft. Current Council of Europe recommendations for these tumors are as follows: Most recent risk assessment for urothelial carcinoma (Council of Europe, 2022): No literature exists regarding newly diagnosed urothelial cancer and organ donation. Therefore, the highest caution is recommended, and the advice of a urologist may be sought in assessing the individual donor tumour transmission risk. National recommendations should be followed since they vary in accepting these tumours. Urothelial cancer in the donor history: Strict follow-up must have been provided after primary diagnosis because these tumours may be multicentric and tend to recur, with a need for repeated cystoscopy and TUR-B, and for restaging. Kidney transplantation will be associated with increased risk, but this has not been classified in the literature yet. After a disease-free interval > 5 years, the transmission risk of invasive urothelial cancer will depend on the probability of cure and must be assessed individually before accepting a potential organ donor. No specific recommendations are available from the literature. Most recent risk assessment for renal cell carcinoma (Council of Europe, 2022): To provide valid histological staging, complete tumour resection (R0) is required for acceptance of all organs; additionally, tumour-free margins are a prerequisite for transplant of the affected kidney. Paraffin section is superior to frozen section for the assessment of such biopsies. The contralateral kidney should always be examined for synchronous RCC (5 % of patients). RCC < 1 cm (stage T1a AJCC 8th ed) and WHO/ISUP grade I/II (Fuhrman grade I/II) can be considered minimal-risk for transmission; RCC 1-4 cm (stage T1a AJCC 8th ed) and WHO/ISUP grade I/II (Fuhrman grade I/II) are considered low-risk; RCC > 4-7 cm (stage T1b AJCC 8th ed) and WHO/ISUP grade I/II (Fuhrman grade I/II) are considered intermediate-risk; RCC > 7 cm (stage T2 AJCC 8th ed) and WHO/ISUP grade I/II (Fuhrman grade I/II) are considered high-risk; RCC with extension beyond the kidney (stages T3/T4 AJCC 8th ed) is considered a contraindication to transplant; All RCC with WHO/ISUP grade III/IV (Fuhrman grade III/IV) are considered high-risk for transmission; Contralateral kidneys and other organs that are un¬involved in carcinoma are considered to represent minimal risk for transplantation when the RCC in the involved kidney is 4 cm or less and WHO/ISUP grade I-II. In all cases, follow-up surveillance is desirable. RCC in the donor history: The transmission risk of treated RCC depends on the histological type of tumour [159] and its recurrence-free follow-up period. In general, in the first 5 years after initial diagnosis, risk categories correspond to those stated above (RCC diagnosed during donor procurement) if there is no suspicion of tumour recurrence in the donor. After this time, the risk of advanced stages may decrease.