Panel Releases New Data on H pylori and Gastric Cancer

WASHINGTON--An international panel of medical experts convened by theAmerican Digestive Health Foundation released information, during DigestiveDisease Week 1997, on the epidemiology, diagnosis, and treatment of Helio-bacterpylori, the bacterium known to cause most ulcers and also to be closelyassociated with gastric cancer.

The panel met earlier this year to update the information presentedat the 1994 NIH Consensus Development Conference on H pylori. Highlightsof the panel's findings, discussed at a recent press briefing, include:

• H pylori infection is frequently acquired during childhood.
• There is a link between H pylori and cancer as well as otherdiseases.
• New tests are available for diagnosis, and various therapies are availablefor treatment of H pylori infection.
• Research is needed to answer emerging questions, especially with respectto gastric cancer.

More than half of the world's population is infected with H pylori,and persons typically acquire it early in life.

"Humans are the major reservoir of H pylori, and evidencesuggests that it is transmitted from person to person," said DavidA. Peura, MD, panel chair and professor of internal medicine at the Universityof Virginia Health Sciences Center.

There is strong evidence from population studies showing an associationbetween H pylori and atrophic gastritis, a precursor to gastriccancer, Dr. Peura noted. Furthermore, recent blood sample studies showan association between H pylori and gastric cancer itself. The bacteriais also linked to 95% of mucosa-associated lymphoid tissue (MALT) lymphomasof the stomach.

Studies From Japan

Gastric cancer is relatively rare in the United States, said Colin Howden,MD, professor of medicine, University of South Carolina.

"We have to look to South America, Southeast Asia, and Japan, wherethe incidences of H pylori and gastric cancer are much higher,"Dr. Howden said. "There are studies in progress involving the treatmentof large numbers of people with H pylori to determine what effect thattreatment will have on the occurrence of gastric cancer. The results areawaited with intense interest."

Since the 1994 NIH consensus conference, the FDA has approved two non-invasivetests for H pylori that are quick and reliable: an in-office bloodtest and a urea breath test, Dr. Peura said. Both tests are widely availableand relatively inexpensive, but the urea breath test is more sensitiveand specific than the blood test, he added.

Endoscopy also is a useful diagnostic tool, but not always clinicallynecessary in patients who have a known cause for their symptoms.

The panel recommended testing for H pylori in patients with anactive or documented duodenal/gastric ulcer or complicated duodenal/gastriculcer. The decision to test other patients should be made on a case-by-casebasis.

Treat With Combination Regimens

Further, the panel recommended treatment of H pylori with combinationregimens, including up to three antibiotics along with an acid blocker,for all those who test positive. The panel could not conclude that anyone FDA-approved treatment regimen offers an advantage over another.

The need for further research was labeled a high priority, and the panelidentified several potential areas of study, including the impact of Hpylori eradication on atrophic gastritis and gastric cancer, mechanismsof H pylori acquisition among children, and the possibility of vaccinedevelopment.