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    Posted: 06/19/2001
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H. pylori and Pancreatic Cancer: Fact Sheet

Key Points
  • Why was this study of "Helicobacter pylori (H. pylori) Seropositivity as a Risk Factor for Pancreatic Cancer" initiated? We know relatively little about what causes cancer of the pancreas. The idea for the study arose from observational findings that many people who had surgery to treat peptic ulcers (sores on the lining of the stomach or duodenum, which is the beginning of the small intestine) developed pancreatic cancer up to 20 years later.
  • What is H. pylori? H. pylori is a common bacterium in humans. It is estimated that about 40 percent to 50 percent of people in developed countries and more than 90 percent of people in developing countries have the bacterium.
  • What are the principal findings of the study? People in the study who were infected with H. pylori appeared to be at higher risk of pancreatic cancer.
  • Who participated in the study? What was the design of the study? Participants for this study were drawn from the 29,133 male smokers living in Finland, aged 50 to 69, who participated in a trial called the Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study.


1. Why was this study of "Helicobacter pylori (H. pylori) Seropositivity as a Risk Factor for Pancreatic Cancer" initiated?

We know relatively little about what causes cancer of the pancreas. The idea for the study arose from observational findings that many people who had surgery to treat peptic ulcers (sores on the lining of the stomach or duodenum, which is the beginning of the small intestine) developed pancreatic cancer up to 20 years later. Now, it is known that almost all of these ulcers are caused by the bacterium H. pylori and patients are now treated for H. pylori infection instead of with surgery.

2. What is H. pylori?

H. pylori is a common bacterium in humans. It is estimated that about 40 percent to 50 percent of people in developed countries and more than 90 percent of people in developing countries have the bacterium.

The majority of people with H. pylori will not develop disease. However, H. pylori has been associated with peptic ulcer disease and with gastric cancer. Some strains of the bacterium have a greater likelihood of causing disease and complications. It has been estimated that two percent to 20 percent of people with H. pylori will develop peptic ulcers and less than one percent of people with the infection will develop gastric cancer. If there is indeed a connection between H. pylori and pancreatic cancer, the proportion of people with H. pylori infection who develop pancreatic cancer would be small.

Since the turn of the century, a smaller percentage of people in developed countries have the infection likely due to changes in diet, refrigeration, and better hygiene. With that decline in developed countries has come a decrease in gastric cancer.

Researchers are not certain how people become infected with H. pylori. In most populations, the bacterium appears to be mainly acquired during childhood. Children who live in crowded conditions seen most often in those in larger families and lower socioeconomic status are more likely to acquire H. pylori. In the industrialized world, the bacterium is thought to be transmitted orally (mouth to mouth).

3. What are the principal findings of the study?

People in the study who were infected with H. pylori appeared to be at higher risk of pancreatic cancer. Specifically, infection with what are called cytotoxin-associated gene A positive (CagA+) strains was associated with an approximately two-fold increase in risk over people in the study who were not infected with H. pylori.

4. Who participated in the study? What was the design of the study?

Participants for this study were drawn from the 29,133 male smokers living in Finland, aged 50 to 69, who participated in a trial called the Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study. The study subjects were followed from 1984 to 1995. As smoking is the most consistent risk factor for pancreatic cancer, a larger number of subjects developed pancreatic cancer cases in the ATBC study than in most other study populations.

The authors compared the levels of antibodies to H. pylori from blood samples taken at the start of the study (before the cancer was diagnosed) in a group of 121 men who developed pancreatic cancer to a subgroup of 226 men who did not develop cancer but were similar in age and other characteristics.

5. What other studies have examined the possible connection between H. pylori and pancreatic cancer?

One previous study examined the relationship between H. pylori and pancreatic cancer. Although that study used a different design and examined a smaller population, those researchers also found a positive association between H. pylori and pancreatic cancer (Raderer, Wrba, et al., 1998).

6. What do these results mean for the general public?

More studies are needed to evaluate the possible link between H. pylori and pancreatic cancer, as well as with other diseases, before public health recommendations can be considered or made.

7. What are the next steps?

As this study examined only male smokers in Finland, future research should examine the association between H. pylori and pancreatic cancer in other populations. Additional studies should examine nonsmoking populations, since the fact that all of the participants were smokers and smoking is a consistent risk factor for pancreatic cancer might have influenced the observed association.

Researchers have speculated how gastric hormones or other factors influenced by H. pylori may affect pancreatic cells. Further studies are needed to understand biological mechanisms for the association.

8. How common is pancreatic cancer?

It is estimated that 32,180 new cases of pancreatic cancer will be diagnosed in the United States in 2006. Only 20 percent of patients survive one year after diagnosis; an estimated 31,800 people will die from the disease this year, making it the fifth leading cause of cancer deaths in the United States. Very little is known about what causes the disease or how to prevent it. However, smokers are twice as likely as nonsmokers to be diagnosed with pancreatic cancer.

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The study is titled: "Helicobacter pylori Seropositivity as a Risk Factor for Pancreatic Cancer." The authors are Rachael Z. Stolzenberg-Solomon, Martin J. Blaser, Paul J. Limburg, Guillermo Perez-Perez, Philip R. Taylor, Jarmo Virtamo, and Demetrius Albanes. Journal of the National Cancer Institute, June 20, 2001;93(12):937-941.

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