Spring 2009
Study links pancreatic cancer to hepatitis B
An Interview with Harry Aslanian, MD and
Joseph K. Lim, MD
Who is generally diagnosed with pancreatic cancer? And who contracts hepatitis B?
Aslanian: Pancreas cancer is rare before age 45. The incidence increases with age, and is also greater in African-Americans compared to the general population.
Lim: Hepatitis B may be contracted at any age, however chronic liver infection is highly dependent on age. In exposed adults with a normally functioning immune system, the likelihood of chronic hepatitis B is less than 5-10 percent, while the risk of developing chronic hepatitis B is greater than 90 percent in exposed newborn infants who fail to receive vaccination. As such, the greatest burden of disease is among individuals who were infected at birth.
How does someone contract hepatitis B?
Lim: Hepatitis B is contracted through body fluids such as blood or semen. The most common routes of transmission include mother-to-child at birth, contaminated blood products, intravenous or intranasal drug use, contaminated needles used for tattoos or body piercings, and unprotected sex with an infected individual. Dialysis represents a potential source for exposure to hepatitis B, and therefore the U.S. Centers for Disease Control and Prevention (CDC) recommends universal vaccination of people with end-stage renal disease prior to the initiation of dialysis.
Do risk factors play a part in a pancreatic cancer diagnosis, or is it genetics?
Aslanian: Risk factors for pancreatic cancer include smoking, diabetes, obesity, chronic pancreatitis and a genetic predisposition. Predisposing genetic conditions include hereditary chronic pancreatitis, and genetic conditions which lead to an increased risk of a variety of tumors including breast cancer (BRCA2), colon cancer (Peutz-Jeghers syndrome and hereditary non-polyposis colorectal cancer) and melanoma (familial atypical multiple mole melanoma).
Besides limiting risky behaviors, what can people do to avoid contracting hepatitis B?
Lim: Hepatitis B can only be prevented through vaccination. The Advisory Committee on Immunization Practices (ACIP) recommends hepatitis B immunization for all children younger than 18 years old, and for adults over 18 who engage in the risky behaviors mentioned previously. A three-step hepatitis B vaccine is required in 44 of 50 states for all children prior to elementary school entry, and has been mandated in Connecticut since 1996. Unfortunately, most adult Americans have not been immunized for hepatitis B and remain susceptible to infection.
Hepatitis B can lead to liver failure — how is that connected to pancreatic cancer?
Lim: Acute hepatitis B infection is most often associated with few or no symptoms, and if symptoms do occur, they may take the form of flu-like symptoms that are difficult to distinguish from other viral infections. The presence of jaundice (yellow skin or eyes) is not common, but may signal the presence of liver infections such as hepatitis B.
Aslanian: The hepatitis B virus has a tendency for infecting cells within the liver, but may also infect cells in other organs, including the pancreas. It is theorized that the hepatitis B virus may promote the development of mutations which lead to cancer formation. The virus may also promote chronic inflammation in the pancreas, which encourages the development of potentially cancer-promoting mutations.
Why is the survival rate of pancreatic cancer so low?
Aslanian: Pancreatic cancer is often detected at an advanced stage when surgery is no longer an option. Of the 20 percent of patients who are candidates for pancreatectomy, the five-year survival rate is about 30 percent. Effective chemotherapies have been difficult to identify. However, there are ongoing improvements in the diagnosis and medical and surgical therapies. Referral to a multidisciplinary team is important for all patients with pancreas cancer, to ensure a thorough review of therapeutic options.
Dr. Aslanian is an attending physician and associate director of Endoscopy at Yale-New Haven Hospital; and associate professor of Internal Medicine/Digestive Diseases at Yale School of Medicine.
Dr. Lim is an attending physician at Yale-New Haven Hospital; and assistant professor of Internal Medicine/Digestive Diseases and director of the Yale Viral Hepatitis Program at Yale School of Medicine.
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 study, recently published 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 control subjects. 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 don't want to be alarmist," said James Abbruzzese, MD, the lead author of the study and chairman of gastrointestinal medical oncology at the MD 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 the United States, and the disease has a high mortality rate.
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, in turn, 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.
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, by exercising, eating a healthy diet and not smoking. Smoking is a major risk factor for pancreatic cancer, and obesity and diabetes have also been linked to the disease.
Tune in to
Yale Cancer Center Answers
or online at wnpr.org).
Yale-New Haven Hospital made
U.S. News & World Report's
2008 Honor Roll for best hospitals.
Find out more
and online resources
Cancer resources:
• Cancer Services, YNHH
• Yale Cancer Center
• Journal of Clinical Oncology
• YNHH Health Library:
Cancer - Home Page
• YNHH Health Library:
Cancer - Diagnosis
• YNHH Health Library:
Cancer - Treatment
• YNHH Health Library:
Cancer Types
• YNHH Health Library:
Genetics and Cancer
• YNHH Health Library:
Nutrition and Cancer
• YNHH Health Library:
Pediatric Cancers
• YNHH Health Library:
Pain Management
• YNHH Health Library:
Alternative Therapy
• About Clinical Trials: Information from the National Cancer Institute