Cancer risks in recipients of renal transplants: a meta-analysis of cohort studies

Renal transplantation is associated with an increased risk of cancers at multiple sites; however, the relationships between increased cancer risk and participant characteristics remain unclear. We searched PubMed, Embase, and the Cochrane Library to identify prospective observational studies performed up to July 2017. Totally 11 prospective studies reported data on 79,988 renal transplant recipients were included. Renal transplant recipients were found to display a higher risk of all cancers (standard incidence ratio [SIR]: 2.89; 95% CI: 2.13–3.91; P < 0.001), gastric cancer (SIR: 1.93; 95% CI: 1.60–2.34; P < 0.001), colon cancer (SIR: 1.85; 95% CI: 1.53–2.23; P < 0.001), pancreatic cancer (SIR: 1.53; 95% CI: 1.23–1.91; P < 0.001), hepatocellular carcinoma (SIR: 2.45; 95% CI: 1.63–3.66; P < 0.001), lung cancer (SIR: 1.68; 95% CI: 1.29–2.19; P < 0.001), thyroid cancer (SIR: 5.04; 95% CI: 3.79–6.71; P < 0.001), urinary bladder cancer (SIR: 3.52; 95% CI: 1.48–8.37; P = 0.004), renal cell cancer (SIR: 10.77; 95% CI: 6.40–18.12; P < 0.001), non-melanoma skin cancer (SIR: 12.14; 95% CI: 6.37–23.13; P < 0.001), melanoma (SIR: 2.48; 95% CI: 1.08–5.67; P = 0.032), Hodgkin's lymphoma (SIR: 4.90; 95% CI: 3.09–7.78; P < 0.001), non-Hodgkin lymphoma (SIR: 10.66; 95% CI: 8.54–13.31; P < 0.001), lip cancer (SIR: 29.45; 95% CI: 17.85–48.59; P < 0.001), breast cancer (SIR: 1.11; 95% CI: 1.00–1.24; P = 0.046), and ovarian cancer (SIR: 1.60; 95% CI: 1.23–2.07; P < 0.001). However, renal transplantation did not significantly influence the risks of uterine cancer (P = 0.171), and prostate cancers (P = 0.188). Our findings suggest that patients who receive renal transplantation have an increased risk of cancer at most sites, apart from uterine and prostate cancers patients.