WASHINGTON--An international panel of medical experts convened by the
American Digestive Health Foundation released information, during Digestive
Disease Week 1997, on the epidemiology, diagnosis, and treatment of Helio-bacter
pylori, the bacterium known to cause most ulcers and also to be closely
associated with gastric cancer.
The panel met earlier this year to update the information presented
at the 1994 NIH Consensus Development Conference on H pylori. Highlights
of 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 other
- New tests are available for diagnosis, and various therapies are available
for treatment of H pylori infection.
- Research is needed to answer emerging questions, especially with respect
to 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 evidence
suggests that it is transmitted from person to person," said David
A. Peura, MD, panel chair and professor of internal medicine at the University
of Virginia Health Sciences Center.
There is strong evidence from population studies showing an association
between H pylori and atrophic gastritis, a precursor to gastric
cancer, Dr. Peura noted. Furthermore, recent blood sample studies show
an association between H pylori and gastric cancer itself. The bacteria
is also linked to 95% of mucosa-associated lymphoid tissue (MALT) lymphomas
of 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, where
the incidences of H pylori and gastric cancer are much higher,"
Dr. Howden said. "There are studies in progress involving the treatment
of large numbers of people with H pylori to determine what effect that
treatment will have on the occurrence of gastric cancer. The results are
awaited with intense interest."
Since the 1994 NIH consensus conference, the FDA has approved two non-invasive
tests for H pylori that are quick and reliable: an in-office blood
test and a urea breath test, Dr. Peura said. Both tests are widely available
and relatively inexpensive, but the urea breath test is more sensitive
and specific than the blood test, he added.
Endoscopy also is a useful diagnostic tool, but not always clinically
necessary in patients who have a known cause for their symptoms.
The panel recommended testing for H pylori in patients with an
active or documented duodenal/gastric ulcer or complicated duodenal/gastric
ulcer. The decision to test other patients should be made on a case-by-case
Treat With Combination Regimens
Further, the panel recommended treatment of H pylori with combination
regimens, including up to three antibiotics along with an acid blocker,
for all those who test positive. The panel could not conclude that any
one FDA-approved treatment regimen offers an advantage over another.
The need for further research was labeled a high priority, and the panel
identified several potential areas of study, including the impact of H
pylori eradication on atrophic gastritis and gastric cancer, mechanisms
of H pylori acquisition among children, and the possibility of vaccine