The development of renal cell carcinoma within the native kidneys of renal transplant recipients and the significance of annual screening

Background and aims: The risk of developing renal cell carcinoma (RCC) is 50 times greater in renal transplant recipients than in the general population. Our study set out to determine the prevalence and prognosis of each subtype of native-kidney RCC, while making evidence-backed recommendations for screening. Methods: We retrospectively examined the charts of 2,538 renal transplant recipients and identified 71 patients who developed RCC within their native kidneys post transplantation. Analysis of variance (ANOVA) was used to calculate means and standard deviations, while Fisher’s test was used to compare groups. Kaplan-Meier estimates were used to determine patient survival rates. The Cox-Mantel test was used to determine significance, with p Results: Four histopathological subtypes of RCC were detected: clear cell (n=41, 57.75%); papillary (n=24, 33.80%); sarcomatoid (n=4, 5.63%); and, chromophobe (n=2, 2.81%). Patient survival rates for the RCC subtypes varied: sarcomatoid = 34.1% one-year and 0.80% 10-year; clear cell = 65.2% one-year and 38.5% 10-year; papillary = 85.3% one-year and 62.0% 10-year; and, chromophobe = 99.4% one-year and 85.0% 10-year. Conclusions: Due to our hospital’s annual ultrasound screening protocol, our cumulative patient mortality rates were significantly lower in comparison to healthcare institutions with triennial or no screening protocols. We advocate for all transplant centre protocols to include annual ultrasound screening of all renal transplant recipients.