Family history plus obesity/hyperglycaemia redoubles renal cell cancer risk

The interaction between genetic and environmental factors, specifically obesity and hyperglycaemia, contributes to an increased risk of renal cell cancer (RCC), suggests a study.

The authors formed a cohort of 5,524,403 individuals with blood-related first-degree relatives (FDRs) and their lifestyle factors from 2002 to 2018 using the National Health Insurance database, which covers the entire Korean population, and the National Health Screening Program.

Familial risk was calculated using incidence risk ratios (IRRs) with 95 percent confidence intervals and compared the risk of individuals with and without FDR. The authors measured the combined effect and interaction of a given risk factor and family history of RCC by the relative excess risk due to interaction.

RCC risk was 2.29-fold higher (95 percent confidence interval [CI], 1.68‒3.13) among individuals with affected FDRs. Familial risk adjusted for lifestyle factors had a minimal decrease (IRR, 2.25, 95 percent CI, 1.65‒3.08), which indicated that genetic predisposition was the main contributor in the familial aggregation of RCC.

Those with both a positive family history and overweight/obesity (IRR, 3.71, 95 percent CI, 2.50‒4.92) or hyperglycaemia (IRR, 4.52, 95 percent CI, 2.59‒6.45) were at substantially increased risk that exceeded the sum of individual risks, suggesting a statistically significant interaction (relative excess risk due to interaction: 0.91, 95 percent CI, ‒0.21 to 2.12; 2.21, 95 percent CI, 0.28‒4.14).

“Individuals with both factors should be considered a high-risk group and advised to undergo genetic counseling,” the authors said.