Risk for renal cell carcinoma in chronic hepatitis C infection.

BACKGROUND Chronic infection with hepatitis C virus (HCV) confers increased risk for chronic renal disease, and numerous reports suggest an association with renal cell carcinoma (RCC), a cancer with rapidly rising global incidence. We sought to determine whether HCV infection confers an increased risk for developing RCC. METHODS With the use of administrative data from a large, integrated, and ethnically diverse healthcare system, we did a cohort study of 67,063 HCV-tested patients between 1997 and 2006 who were followed for the development of RCC until April 2008. RESULTS A search of the health system cancer registry for patients with the diagnosis of kidney cancer showed that RCC was diagnosed in 0.6% (17 of 3,057) of HCV-positive patients versus 0.3% (177 of 64,006) of HCV-negative patients. The mean age at RCC diagnosis was much younger in HCV-positive individuals (54 versus 63; P < 0.001). The univariate hazard ratio for RCC among HCV patients was 2.20 (95% confidence interval, 1.32-3.67; P = 0.0025). In a multivariate model that included the risk factors age, African-American race, male gender, and chronic kidney disease, the overall hazard ratio for RCC among HCV patients was 1.77 (95% confidence interval, 1.05-2.98; P = 0.0313). CONCLUSION Chronic HCV infection confers a risk for the development of RCC. IMPACT Clinicians should consider newly identified renal lesions in patients with chronic HCV infection with a heightened suspicion for neoplasm, and newly diagnosed cases of RCC may require more careful surveillance for the presence of HCV infection. Additional studies are required to confirm these findings and to explore potential mechanisms of oncogenesis.