Diabetes progression linked with increased risk of kidney cancer
Kidney cancer risk was significantly higher in patients with prolonged duration of diabetes, those with diabetic retinopathy or nephropathy, and those with poor glycemic control, a cohort study in South Korea found.
Progression of type 2 diabetes is strongly associated with an increased risk of kidney cancer, according to results of a longitudinal cohort study carried out in South Korea.
To determine the relationship between diabetes and kidney cancer risk, researchers assessed data from 2,365,294 patients with type 2 diabetes who underwent health examinations in 2015 and 2016 and were included in the South Korean National Health Information Database. Any patient who had pre-existing cancer or died within a year was excluded; patients were followed until 2022. Investigators scored patients on their diabetes progression (range 0 to 6) based on the number of oral glucose-lowering drugs they took, diabetes duration, insulin use, and the presence of chronic kidney disease (CKD), diabetic retinopathy, or cardiovascular disease. Findings were published by the Journal of Clinical Endocrinology and Metabolism on June 3.
There were 5,073 incident cases of kidney cancer during a median follow-up of six years. Patients with CKD had a higher risk of kidney cancer (adjusted hazard ratio [HR], 1.78; 95% CI, 1.65 to 1.92), as did patients with a diabetes duration of five or more years (HR, 1.44; 95% CI, 1.36 to 1.52) or with diabetic retinopathy (HR, 1.30; 95% CI, 1.20 to 1.40). The risk of kidney cancer also progressively increased with higher diabetes progression scores. Compared with patients with a score of 0, adjusted HRs for kidney cancer were 1.21 for a score of 1 (95% CI, 1.13 to 1.30), 1.28 for a score of 2 (95% CI, 1.18 to 1.38), 1.37 for a score of 3 (95% CI, 1.23 to 1.51), and 1.73 for scores of 4 or higher (95% CI, 1.49 to 2.01).
Limitations include a lack of data on HbA1c or postprandial glucose levels. In addition, both CKD and retinopathy diagnoses were based on claims data, which made it difficult to accurately gauge their severity or pattern, the researchers cautioned.
“Findings underscore the importance of targeted screening and awareness programs for kidney cancer in individuals with advanced diabetes,” they concluded.