People with pancreatic cancer are more likely than those without the disease to have been infected with the hepatitis B virus, a study has shown for the first time.
The finding suggests that hepatitis B already known to cause liver cancer in some patients may also increase the risk of pancreatic cancer, one of the deadliest types of tumor. But while the study showed an association, it did not prove cause and effect, the researchers said. More work is needed to determine whether the virus really can cause pancreatic cancer.
We dont want to be alarmist, said Dr. James L. Abbruzzese, the lead author of the study and the chairman of gastrointestinal medical oncology at the M.D. Anderson Cancer Center in Houston.
Pancreatic cancer is not common, and most people have less than a 1 percent risk of ever developing it. There are about 38,000 new cases a year in this country, but the death rate is high, and most patients die within months or a few years.
By contrast, there are 1.25 million people in the United States who have chronic hepatitis B, and hundreds of millions around the world. Globally, it is a major cause of liver cancer. A vaccine can prevent the infection and the cancer. But when an unvaccinated person develops a chronic infection, it cannot be cured, though antiviral drugs may help control it in some cases.
Dr. Abbruzzese said it might be a good idea for people who have had hepatitis B to take extra measures to try to reduce their risk of pancreatic cancer, like not smoking and trying to watch their weight. Smoking is a major risk factor factor for pancreatic cancer, and obesity and diabetes have also been linked to the disease.
The study, being published today in the Journal of Clinical Oncology, compared 476 people who had pancreatic cancer with 879 healthy control subjects. All were tested to see if they had ever been infected with the viruses that cause hepatitis B or hepatitis C. There was no connection to hepatitis C, but the cancer patients were twice as likely as the healthy ones to have had hepatitis B. Among those with cancer, 7.6 percent had had hepatitis B, as opposed to only 3.2 percent of the controls. So the virus may contribute somehow to the cancer, the researchers suggest.
Dr. Eileen OReilly, an expert on pancreatic cancer at Memorial Sloan Kettering Cancer Center in Manhattan, said the study was well done and the interpretation reasonable, though she emphasized that more research was needed to verify it. She said there had been previous suggestions in the medical literature of a connection between hepatitis B and pancreatic ca