Risk factors for renal cell carcinoma in the VITAL study

The incidence of renal cell carcinoma is increasing worldwide. Cited risk factors include obesity, smoking and hypertension but few others have been confirmed in prospective studies. We used a prospective cohort to validate established renal cell carcinoma risk factors and evaluate more controversial risk factors for incident renal cell carcinoma.

A total of 77,260 residents of Washington 50 to 76 years old completed a questionnaire between 2000 and 2002 on demographic, lifestyle and health data. Incident renal cell carcinoma cases were determined by linkage to the regional cancer registry through December 31, 2009. Multivariate methods using covariates and cutoffs selected a priori were applied to analyze the association between renal cell carcinoma and previously studied factors related to lifestyle (body mass index, smoking and alcohol/fruit/vegetable consumption) and health (hypertension, diabetes, kidney disease and viral hepatitis).

There were 249 incident cases of renal cell carcinoma. Independent renal cell carcinoma risk factors in the fully adjusted model were body mass index (35 or greater vs less than 25 kg/m2 HR 1.71, 95% CI 1.06-2.79), smoking (greater than 37.5 pack-years vs never HR 1.58, 95% CI 1.09-2.29), hypertension (HR 1.70, 95% CI 1.30-2.22), kidney disease (HR 2.58, 95% CI 1.21-5.50) and viral hepatitis (HR 1.80, 95% CI 1.03-3.14). Diabetes was associated with renal cell carcinoma (HR 1.83, 95% CI 1.26-2.65) in a base model adjusting for age and gender but not in the multivariate model. We found no association between alcohol, fruit or vegetable intake and renal cell carcinoma.

We identified a significant association of renal cell carcinoma with obesity, smoking, hypertension, renal disease and viral hepatitis. Identifying risk factors offers an opportunity for targeted education and intervention.