A new study has found that past exposure to the hepatitis B virus may be associated with the development of pancreatic cancer.
The study has shown that evidence of past hepatitis B infection was twice as common in people with pancreatic cancer than in healthy controls.
However, researchers have warned that more studies are necessary to evaluate the nature of the link.
"While our findings indicate that past exposure to hepatitis B is associated with the development of pancreatic cancer, more research is needed to determine whether this relationship is one of cause and effect," said lead author Manal M. Hassan, MD, PhD, assistant professor at The University of Texas M. D. Anderson Cancer Center.
"If these findings can be confirmed by other studies, hepatitis B could be another risk factor for pancreatic cancer that is readily modifiable with treatment, and even preventable with a vaccine," Hassan added.
In this study, Hassan and her colleagues compared evidence of hepatitis B and C infection (as determined by blood tests assessing antibodies to these viruses) between 476 patients with pancreatic cancer and 879 matched healthy individuals.
Evidence of past exposure to hepatitis B was found in 7.6 percent of patients with pancreatic cancer versus 3.2 percent of controls.
The association between hepatitis B exposure and pancreatic cancer remained statistically significant even after controlling for other risk factors, such as smoking.
People with both diabetes - an established risk factor for pancreatic cancer - and hepatitis B exposure had a 7-fold increase in pancreatic cancer risk, compared to controls. No association was observed between hepatitis C exposure and pancreatic cancer.
The researchers noted that past studies have reported the presence of hepatitis B antigens in pancreatic fluids; others have identified impaired pancreatic function in people with chronic hepatitis B infection.
These findings suggest that the hepatitis B virus may cause inflammation or DNA damage in the pancreas, which could increase cancer risk.