Reduced Kidney Function Linked to Increased Cancer Risk

People with low levels of estimated GFR (eGFR) have higher cancer mortality, suggests a report in the American Journal of Kidney Diseases.

The researchers analyzed follow-up data on 4077 predominantly white participants from the Australian, population-based Blue Mountains Eye Study. Baseline eGFR was analyzed for association with the risk of cancer death, including the kidney function threshold at which the excess risk of death begins. Reduced eGFR was also assessed as a prognostic factor for death after cancer diagnosis.

Three hundred seventy cancer deaths occurred during a median follow-up time of 12.8 years. With adjustment for other factors, for each 10 mL/min per 1.73 m2 reduction in eGFR, the hazard ratio (HR) for cancer-specific mortality was 1.18. Compared with an eGFR of 60 mL/min per 1.73 m2 , the HR associated with eGFR less than 60 mL/min per 1.73 m2 was 1.27.

Hazard ratios increased further at lower levels of kidney function. The excess risk was highest for breast and urinary tract cancers: HR 1.99 and 2.54, respectively. On analysis limited to participants in whom cancer developed, the overall cancer mortality was more than twice as high at an eGFR less than 45 mL/min per 1.73 m2.

Cancer risk is known to be increased in patients with chronic kidney disease. However, the association between reduced kidney function and cancer mortality has been unclear.

This study finds that an eGFR less than 60 mL/min per 1.73 m2 is associated with an increased risk of death from cancer, and that reduced kidney function predicts poor outcomes among older patients with cancer. The authors call for further studies of the association between eGFR and cancer, including intervention and prevention strategies [Iff S, et al. Reduced estimated GFR and cancer mortality. Am J Kidney Dis 2014; 63: 23–30].