Effect of urinary total arsenic level and estimated glomerular filtration rate on the risk of renal cell carcinoma in a low arsenic exposure area

Purpose: We explored the relationship between urinary total arsenic and risk of renal cell carcinoma, and investigated whether having hypertension or a low estimated glomerular filtration rate would modify the risk of renal cell carcinoma. Materials and Methods: The case-control study was conducted between November 2006 and May 2009 with 132 patients with renal cell carcinoma, and 260 sex and age matched controls from a hospital based pool. Pathological verification of renal cell carcinoma was completed by image guided biopsy or surgical resection of renal tumors. Urinary arsenic species, including inorganic arsenic, monomethylarsonic acid and dimethylarsinic acid, were determined with a high performance liquid chromatography linked hydride generator and atomic absorption spectrometry. Estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease Study equation. Results: Urinary total arsenic was significantly associated with renal cell carcinoma risk in a dose-response relationship after multivariate adjustment. Low estimated glomerular filtration rate or hypertension was significantly related to renal cell carcinoma risk. Estimated glomerular filtration rate was significantly negatively related with urinary total arsenic. A significant interaction was seen between the urinary total arsenic and hypertension on renal cell carcinoma risk. The greatest odds ratio (6.01) was seen in the subjects with hypertension, low estimated glomerular filtration rate and high urinary total arsenic. A trend test indicated that the risk of renal cell carcinoma increased along with the accumulating number of these 3 risk factors (p <0.0001). Conclusions: Higher urinary total arsenic level was a strong predictor of renal cell carcinoma, and estimated glomerular filtration rate or hypertension interacts with urinary total arsenic in modifying the risk of renal cell carcinoma.