By Genevra Pittman
NEW YORK (Reuters Health) - People infected with chronic hepatitis C are less likely to develop liver cancer if they are taking cholesterol-lowering drugs, new research from Taiwan suggests.
The report doesn't prove statins ward off cancer, and one researcher not involved in the study says it's not reason enough to recommend using the popular medications solely for liver cancer prevention.
Previous studies have come to ambiguous and conflicting conclusions on the question of statins' cancer-preventing abilities, researchers noted.
"Observational studies do suggest a significant, modest reduction in the risk of (liver cancer) among patients with chronic liver disease who take statins," said Dr. Hashem El-Serag, a liver disease researcher from the Baylor College of Medicine and Michael E. DeBakey VA Medical Center in Houston.
Those trials, which follow different groups of patients to see who develops cancer over time, can't prove cause-and-effect.
"The downside to the observational studies, including this study, is because they are non-randomized, the decision to give statins to a patient with hepatitis C may or not may depend on factors that have a lot to do with severity of liver disease," El-Serag told Reuters Health.
For their study, Dr. Pau-Chung Chen from the National Taiwan University College of Public Health in Taipei and his colleagues used nationwide data to track about 261,000 people with hepatitis C from 1999 through 2010.
During that span, about 13 percent of them filled a prescription for statins.
A total of 28,000 people were diagnosed with liver cancer by 2011 - or about one percent of those with hepatitis C each year. After the researchers accounted for patients' age, gender and other diseases, they found those who took statins were about half as likely to get cancer as non-statin users.
Higher doses of statins, as well as longer-term use, were linked to a further drop in cancer risk, according to the findings published this week in the Journal of Clinical Oncology.
The researchers said statins may prevent the hepatitis C virus from replicating or slow the growth of malignant cells. But they can't prove the drugs stopped people from getting cancer.
One limitation, they noted, is that they weren't able to measure other health and lifestyle factors that influence people's risk of liver cancer, including their weight and whether they smoked or drank heavily.
Chen said a large study in which people with hepatitis C are assigned to take statins or not, known as a randomized clinical trial, is needed to clarify the drugs' effects in those patients.
In the United States, about 3.2 million people are chronically infected with hepatitis C, which is spread through blood. Having hepatitis C increases a person's chance of liver cancer up to 20-fold, Chen's team wrote.
The National Cancer Institute estimates 30,640 Americans will be diagnosed with liver cancer in 2013 and 21,670 will die of the disease.
The researchers did not find a link between statins and any serious complications.
"We feel more confident that statins do not cause harm in patients with liver disease," Chen told Reuters Health in an email.
Until recently, El-Serag said, many doctors feared prescribing statins to people with liver disease, believing they might cause liver-related complications. He agreed that the new study should allay those concerns.
"Do not avoid statins because of underlying liver disease, because you may help the statin-related indication, such as cholesterol and heart disease, but you may still get additional benefit for reducing the risk of liver cancer," he advised.
Still, El-Serag said, "I would stop shy of recommending it just to (prevent) liver cancer."
SOURCE: http://bit.ly/Ze6jf8 Journal of Clinical Oncology, online March 18, 2013.