Hepatitis C Linked to Increased Risk of Kidney Cancer
People with chronic hepatitis C virus (HCV) infection
have double the risk of developing renal cell carcinoma,
or kidney cancer, according to a study published in
2010 issue of Cancer Epidemiology, Biomarkers and
Prevention. While the reason for this link remains
unclear, the researchers recommended that clinicians
should carefully monitor and follow up on signs of kidney
problems in hepatitis C patients, and people newly diagnosed
with kidney cancer should be tested for HCV.
hepatitis C is primarily a disease of the liver, but it
can also contribute to problems elsewhere in the body. HCV infection
has been linked to kidney disease in the past. Stuart Gordon
from Henry Ford Hospital and Wayne State University School of
Medicine and colleagues aimed to determined whether this was
true specifically for renal cell carcinoma (RCC).
The investigators analyzed data from the large racially/ethnically
diverse Henry Ford healthcare system in Detroit The study cohort
included 67,063 participants who were tested for HCV between
1997 and 2006, and followed to monitor development of RCC until
April 2008; about 5% were HCV positive. The researchers used
the health system's cancer registry to identify patients diagnosed
with kidney cancer.
of HCV positive patients (17 out of 3057) developed renal
cell carcinoma during follow-up, compared with 0.3% of HCV
negative participants (177 out of 64,006).
RCC cases in HCV positive patients included 8 clear cell
cancers, 6 papillary cancers, 2 mixed clear cell/papillary,
and 1 undifferentiated.
participants diagnosed with RCC, HCV positive patients were
of a significantly younger average age than HCV negative
patients (54 vs 63 years; P < 0.001).
a univariate analysis, the hazard ratio for developing RCC
among HCV positive patients was 2.20.
a multivariate analysis that adjusted for other known kidney
cancer risk factors including older age, male sex, black
race, and chronic kidney disease, the hazard ratio for hepatitis
C patients was 1.77, or a 77% increase in risk.
were 2.4 more likely to develop RCC than women.
had about a 40% higher risk of developing RCC than other
additional year of age increased kidney cancer risk by about
on these findings, the study authors concluded, "Chronic
HCV infection confers a risk for the development of RCC."
"The results of this study would suggest a more careful
surveillance of newly diagnosed RCCs for the presence of HCV
infection," they advised. "It is premature to recommend
more comprehensive screening of HCV positive patients for this
relatively uncommon neoplasm. However, a heightened awareness
of an increased kidney cancer risk should dictate more careful
follow-up of incidental renal defects when detected on imaging
procedures in patients with chronic hepatitis C."
"These results add to growing literature that shows that
the hepatitis C virus causes disease that extends beyond the
liver, and in fact most of our HCV-infected kidney cancer patients
had only minimal liver damage," Dr. Gordon said in a press
release issued by Henry Ford Hospital.
Investigator affiliations: Division of Gastroenterology and
Hepatology, and Departments of Urology and Biostatistics and
Research Epidemiology, Henry Ford Hospital, Detroit, MI; Wayne
State University School of Medicine, Detroit, MI.
SC Gordon, D Moonka, KA Brown, and others. Risk for renal cell
carcinoma in chronic hepatitis C infection. Cancer Epidemiology,
Biomarkers and Prevention 19(4): 1066-1073 (Abstract).
Ford Health System. Hepatitis C Infection Doubles Risk for Kidney
Cancer. Press release. April 6, 2010.