Hepatitis C Infection Doubles Risk for Renal Cell Carcinoma

Hepatitis C Infection Doubles Risk for Renal Cell Carcinoma


Roxanne Nelson

Medscape Medical News

April 8, 2010 — Chronic hepatitis C virus (HCV) is a major cause of cirrhosis, liver failure, and hepatocellular carcinoma, but a new study suggests that it is also associated with a higher incidence of renal cell carcinoma (RCC).


Researchers at Henry Ford Hospital in Detroit, Michigan, found that during a 10-year period, patients infected with hepatitis C had nearly double the risk of developing RCC.


The study was published online March 23 in Cancer Epidemiology, Biomarkers & Prevention.


Until now, there have only been anecdotal reports that suggested an association between HCV and an increased risk for kidney cancer, said lead author Stuart C. Gordon, MD, director of hepatology at Henry Ford Hospital. "But this is the first report to evaluate the association in a comprehensive manner," he told Medscape Oncology.


Dr. Gordon explained that he has observed increased rates of RCC in patients infected with HCV in his own practice. Thus, the results of this study were "exciting and reassuring and validated what we had suspected and what we had seen in the literature," he said.


The authors note that patients with chronic HCV infection can manifest extrahepatic complications, such as cryoglobulinemia, vasculitis, and various renal disorders. Infection also confers an increased risk for non-Hodgkin's lymphoma and other hematopoietic malignancies.


HCV has been isolated in kidney glomerular and tubular structures, Dr. Gordon pointed out. "Hepatitis C is a systemic disease, and its impact is not restricted to the liver," he said. "Independent of liver disease, it can also cause kidney disease."


Independent Risk Factor for RCC


The new findings come from a cohort study of administrative data from the large, integrated, and ethnically diverse Henry Ford Hospital. The study consisted of 67,063 patients who were tested for HCV between 1997 and 2006, and who were followed for the development of RCC until April 2008.


Of this population, 3057 (4.6%) patients were HCV-positive, and were older than those who were seronegative (52 vs 48 years; P < .001). Patients with HCV were more likely to have kidney disease than uninfected patients (14.5% vs 10.4%; P < .001) and, as expected, their risk of developing hepatocellular carcinoma was much higher (27.5 of 1000 HCV-positive patients vs 1.4 of 1000 HCV-negative patients).


A diagnosis of RCC was made in 0.6% (17 of 3057) of HCV-positive patients and in 0.3% (177 of 64,006) of HCV-negative patients. The mean age at diagnosis was much younger in those who were HCV-positive (54 vs 63; P < .001). The univariate hazard ratio for RCC among HCV patients was 2.20 (95% confidence interval [CI], 1.32 - 3.67; P = .0025). In a multivariate model that included risk factors such as age, race, sex, and chronic kidney disease, the overall hazard ratio for RCC among HCV patients was 1.77 (95% CI, 1.05 - 2.98; P = .0313).


Kidney cancer is relatively rare, explained Dr. Gordon, and it is premature to recommend more comprehensive screening of HCV-positive patients. "However, physicians should be aware of this relationship," he said, "and patients with RCC may need to be more carefully screened for HCV infection."


"Additional studies are required to confirm these findings and to explore potential mechanisms of oncogenesis," the authors conclude.


No outside agencies or sponsors provided funding for this study. The researchers have disclosed no relevant financial relationships.


Cancer Epidemiol Biomarkers Prev. Published online March 23, 2010.