Sex differences in cancer outcomes across the range of eGFR

Background: People with chronic kidney disease (CKD) have increased incidence and mortality of most cancer types. We hypothesized that the odds of presenting with advanced cancer may vary according to differences in estimated glomerular filtration rate (eGFR), that this could contribute to increased all-cause mortality and that sex differences may exist. Methods: Data were from Secure Anonymised Information Linkage Databank, including people with de novo cancer diagnosis (2011-17) and two kidney function tests within 2 years prior to diagnosis to determine baseline eGFR (mL/min/1.73 m²). Logistic regression models determined the odds of presenting with advanced cancer by baseline eGFR. Cox proportional hazards models tested associations between baseline eGFR_Cr and all-cause mortality. Results: eGFR <30 was associated with higher odds of presenting with advanced cancer of prostate, breast and female genital organs, but not other cancer sites. Compared with eGFR >75-90, eGFR <30 was associated with greater hazards of all-cause mortality in both sexes, but the association was stronger in females [female: hazard ratio (HR) 1.71, 95% confidence interval (CI) 1.56-1.88; male versus female comparison: HR 0.88, 95% CI 0.78-0.99]. Conclusions: Lower or higher eGFR was not associated with substantially higher odds of presenting with advanced cancer across most cancer sites, but was associated with reduced survival. A stronger association with all-cause mortality in females compared with males with eGFR <30 is concerning and warrants further scrutiny.