Background:Kidney transplant recipients (KTRs) experience improved survival and quality of life compared to dialysis treatment, but chronic immunosuppression may increase the risk of de novo post-transplant cancer. Colorectal cancer (CRC) is increasingly recognized in this population. This systematic review aims to synthetize contemporary evidence on CRC epidemiology, outcomes, and risk determinants among KTRs.Methods:A comprehensive search for observational and registry-based studies reporting CRC in adult KTRs was conducted on PubMed, Scopus, Web of Science, and ProQuest. The studies found were subsequently subjected to screening, data extraction, and the risk-of-bias appraisal process. Due to heterogeneity, findings were synthesized narratively.Results:Twenty-six studies encompassing 863,005 KTRs met inclusion criteria: 22 retrospective cohorts, 1 prospective cohort, 2 cross-sectional, and 1 case-control. Absolute CRC occurrence varies by geography, population, and follow-up. Reported risks ranged from no excess to modestly elevated standardized incidence ratios (SIRs): ~0.76–3.60 overall, with a right-sided colon predominance. Overall, higher mortality and worse prognosis were reported in kidney transplant recipients with colorectal cancer compared to the general population, as a result of later-stage diagnosis and more aggressive histologies. Consistent risk factors included older age, time since transplantation, diabetes and metabolic comorbidities, prior dialysis duration/graft failure, and smoking; the female sex showed higher relative CRC risk in some cohorts. The remarkable role of immunosuppression profiles was consistently highlighted: cyclosporine—azathioprine maintenance and alemtuzumab induction were associated with higher CRC risk in large registries, whereas tacrolimus—mycophenolate regimens showed lower risk signals and mTOR inhibitors suggested possible protective effects.Conclusions:Contemporary evidence suggests a modest, heterogenous increase in CRC risk among KTRs, a proximal (right-sided) predominance, and a tendency toward advanced-stage presentation with reduced survival. These findings justify the need to consider risk-tailored, lifelong surveillance strategies anchored in a full colonoscopy, with earlier initiation in younger or otherwise high-risk recipients, alongside careful optimization and periodic re-evaluation of immunosuppression. Prospective multicenter studies and cost-effectiveness analyses should refine screening thresholds and therapeutic strategies. PROSPERO ID: CRD420251071658.
背景：与透析治疗相比，肾移植受者（KTRs）的生存率和生活质量均有所改善，但长期免疫抑制治疗可能增加移植后新发癌症的风险。结直肠癌（CRC）在该人群中的发生率日益受到关注。本系统综述旨在综合当代关于KTRs中CRC流行病学特征、临床结局及风险决定因素的证据。 方法：在PubMed、Scopus、Web of Science和ProQuest数据库中全面检索报告成人KTRs发生CRC的观察性研究及基于登记数据的研究。对检索到的研究进行筛选、数据提取和偏倚风险评估。由于存在异质性，采用叙述性方法综合研究结果。 结果：共26项研究（涵盖863,005例KTRs）符合纳入标准，包括22项回顾性队列研究、1项前瞻性队列研究、2项横断面研究和1项病例对照研究。CRC的绝对发生率因地域、人群和随访时间而异。报告的风险范围从无超额风险到标准化发病率比（SIR）轻度升高（总体约0.76–3.60），且以右侧结肠癌为主。总体而言，与普通人群相比，患有CRC的KTRs因诊断时分期较晚、组织学类型更具侵袭性，其死亡率和预后更差。一致的风险因素包括高龄、移植后时间、糖尿病及代谢合并症、既往透析时长/移植失败史以及吸烟；在某些队列中女性显示出更高的相对CRC风险。免疫抑制方案的作用被一致强调：大型登记数据显示，环孢素-硫唑嘌呤维持方案和阿仑单抗诱导方案与较高的CRC风险相关，而他克莫司-霉酚酸酯方案显示出较低的风险信号，mTOR抑制剂则提示可能具有保护作用。 结论：当代证据表明KTRs的CRC风险存在轻度但异质性的升高，以近端（右侧）结肠癌为主，且倾向于晚期诊断并伴有生存率降低。这些发现证明有必要考虑基于全结肠镜检查的风险分层终身监测策略，对年轻或其他高危受者应更早启动监测，同时需谨慎优化并定期重新评估免疫抑制方案。未来需通过前瞻性多中心研究和成本效益分析来完善筛查阈值和治疗策略。PROSPERO注册号：CRD420251071658。
Epidemiological Overview of Colorectal Cancer in Kidney Transplant Recipients: A Systematic Review
肿瘤(癌症)患者之家