Incidence of renal cell carcinoma after solid organ transplantation: a systematic review and meta-analysis

The incidence rate of malignant tumors after solid organ transplantation is higher than the normal population. The aim of our study is to identify the risk of renal cell carcinoma (RCC) after liver, kidney, heart and lung transplantation, respectively, and suggest that transplant patients can be screened early for tumors to avoid risk. PubMed, Embase and the Cochrane Library from their inception until August 16,2023. Retrospective and cohort studies which focus on the statistical data of standardized incidence ratios (SIRs) of RCC after solid organ transplantation (SOT) more than one year have been included and extracted. The study was registered with PROSPERO, CRD4202022343633. Sixteen original studies have been included for meta-analysis. Liver transplantation could increase the risk of RCC (SIR = 0.73, 95%CI: 0.53 to 0.93) with no heterogeneity(P = 0.594, I = 0.0%). And kidney transplantation could increase the risk of RCC(8.54, 6.68 to 10.40; 0.000,90.0%). Besides, heart and lung transplantation also could increase the risk of RCC(SIR = 0.73, 95%CI: 0.53 to 0.93; SIR = 1.61, 95%CI:0.50 to 2.71). Moreover, significance could also be found in most subgroups, especially the European group and retrospective study group. What's more, after removing studies which have a greater impact on the overall outcome in RCC rate after kidney transplantation, heterogeneity did not solve and significant different was also observed in the European group (7.15, 5.49 to 8.81; 0.000, 78.6%). Liver, kidney, heart and lung transplantation patients have an increased risk of processing RCC compared to the general population and most subgroups, especially in geographic location of European subgroup, which suggested that patients should be screened frequently after transplantation.