Background:
Cancer incidence in people with chronic kidney disease (CKD) who do not require kidney replacement therapy remains inadequately characterised. This systematic review aimed to establish if there is an elevated incidence of cancer in people with CKD.

Methods:
A systematic search of three online bibliographic databases until January 17, 2023, identified studies reporting cancer incidence in CKD cohorts (PROSPERO CRD42022359690). Meta-analyses using inverse variance method compared incidence rates in individuals with low eGFR (<60 mL/min/1.73m2) with available cohorts with normal eGFR (≥60 mL/min/1.73m2 or both 60–89 and ≥ 90 mL/min/1.73m2) for all cancers and site-specific cancers. Multiple meta-regression analyses explored associations of eGFR and age.

Results:
In 27 studies (5 519 778 people with CKD), from 10 countries spanning 2009–2022, incidence rates of cancer were associated with worse CKD severity. Incidence rate ratio (IRR) comparing people with an eGFR < 60 mL/min/1.73m2 to ≥ 60 mL/min/1.73m2 was 1.35 [95% CI:1.12–1.63, P = 0.002, I2 = 99.9%]. People with eGFR < 60 mL/min/1.73m2 were at elevated rate of cancer compared with eGFR ≥ 90 mL/min/1.73m2 (IRR 1.48 [95% CI:1.04–2.10, P = 0.03, I2 = 100%]) and those with eGFR 60–89 mL/min/1.73m2 (IRR 1.21 [95% CI:1.11–1.33, P < 0.01, I2 = 92%]). Age was associated with increased cancer incidence (β=0.31, P = 0.02) on multiple meta-regression analysis. There was no association between site-specific cancer incidence in CKD patients, but these had wide confidence intervals.

Conclusion:
Individuals with CKD have an elevated incidence of cancer, with increasing age contributing to this association. These findings emphasise the importance of investigating whether CKD independently elevates cancer risk, building evidence for tailored cancer screening into CKD patient care.