Association of cancer with moderately impaired renal function at baseline in a large, representative, population-based cohort followed for up to 30 years
Christensson A., Savage C., Sjoberg DD., Cronin AM., Frank O'Brien M., Lowrance W., Nilsson PM., Vickers AJ., Russo P., Lilja H.
Patients with chronic renal failure show a greater incidence of malignancies. We evaluated whether moderately impaired renal function at baseline influenced risk of all cancers during long-term follow in young persons. Our cohort included 33,346 subjects, aged 26-61 years at baseline, in a representative, population-based study enrolling subjects from 1974 to 1992. Median follow-up time was 28 years. Plasma creatinine was analyzed as a single measure at baseline. Incident cases of cancer were identified from the Swedish Cancer Registry. We studied 24,552 subjects from the cohort. To account for the unique sampling design, participants were divided by sex and age at baseline into 1,132 older men (age 60), 14,254 younger men (age 40-52), 7,498 older women (age 47-57) and 1,688 younger women (age 35-43). Glomerular filtration rate (GFR) was estimated using the CKD-EPI formula. Patients were classified as having either normal to mildly impaired kidney function (eGFR ≥ 60 mL/min/1.73 m2), or moderate kidney dysfunction (eGFR<60 mL/min/1.73 m2). We calculated the risk of all cancers using competing risks regression. Overall, 6,595 participants were diagnosed with cancer, and 854 subjects (3.5%) had moderately impaired renal dysfunction at baseline. There was a significant association between moderately decreased GFR and subsequent risk of kidney cancer in younger men (hazard ratio, 3.38; 95% CI, 1.48 to 7.71; p = 0.004). However, we found no association with overall long-term cancer risk. Our confirmation of an association between moderately impaired renal function and risk of kidney cancer in younger men requires further exploration of high-risk groups and biological mechanisms. What's new? Previous reports have described intriguing links between chronic kidney disease and increased risk of cancer, though the nature of the associations has remained largely uncharacterized. This investigation of the long-term risk of all cancers in relation to decreased kidney function sheds light on those earlier findings, revealing that both terminal renal failure and moderately reduced renal function are associated with an increased risk of kidney cancer specifically. Overall long-term risk of other cancers was insignificant in the study population. The findings warrant further study to identify possibly pathological mechanisms of carcinogenesis in the kidney. Copyright © 2013 UICC.