UM researcher among first to study treatment of common stomach bacteria in U.S. patients
David Goldberg, M.D., MSCE, associate professor of medicine in the Division of Digestive Health and Liver Diseases at the University of Miami Miller School of Medicine, led several recently published studies that were among the first to look at treating Helicobacter pylori in U.S. patients.
About 50% of the world’s population has Helicobacter pylori, or H. pylori. While many of those affected don’t have symptoms, H. pylori infection is a known risk factor for gastric cancer and many gastrointestinal disorders.
Providers treat and potentially cure H. pylori infection by prescribing two or more antibiotics in combination with acid suppressive therapy. But questions remain about the need for widespread treatment, including whether the risks associated with using antibiotics outweigh the benefit of cure.
“Almost all of the work in terms of impact of H. pylori treatment and survival of those treated had been done in Asia, because that’s where H. pylori and gastric cancer are very prevalent. There really haven’t been any U.S. studies due to limitations in data,” Dr. Goldberg said. “We studied a national Veterans Affairs cohort of people with H. pylori to look at the risk factors for developing cancer and the impact of treating patients.”
Dr. Goldberg collaborated with researchers at Perelman School of Medicine at the University of Pennsylvania on a groundbreaking study published in February in Gastroenterology.
The retrospective analysis of nearly 372,000 veterans diagnosed with H. pylori infection revealed significantly higher risks of gastric cancer in racial and ethnic minorities and smokers.
“The risk of getting the cancer from H. pylori is maybe about 1% to 2% overall over 20 years, depending on the population. That’s relatively low but not inconsequential,” Dr. Goldberg said. “But being successfully treated for H. pylori had a significant impact on future development of gastric cancer, lowering the risk from 4% over 20 years to less than 1%, or more than a 75% decreased risk.”
The New England Journal of Medicine published results of a clinical trial at about the same time showing a similar reduction in the development of gastric cancer among those successfully treated for H. pylori.
That study set the groundwork for research looking at the potential consequences of H. pylori treatment.
In a second study published in April in Alimentary Pharmacology and Therapeutics, Dr. Goldberg and colleagues questioned historical data suggesting H. pylori might actually have a protective effect on esophageal cancer.
“There have been studies that suggest we shouldn’t treat H. pylori because the infection may decrease the risk of esophageal cancer and treating it may increase that risk. It was thought that stomachs damaged by H. pylori produce less acid,” Dr. Goldberg said. “We showed, however, that if you treat people for H. pylori, it doesn’t lead to an increased risk of esophageal cancer.”
In a study in press in the American Journal of Gastroenterology, Dr. Goldberg and coauthors studied the risk of clostridium difficile, or C. diff, infection in VA patients treated for H. pylori. They found no increased risk of C. diff in patients treated with antibiotics for H. pylori.
In yet another study in press in Clinical Gastroenterology and Hepatology, Dr. Goldberg and colleagues looked at whether providers follow the treatment guideline recommendation to retest patients treated for H. pylori to confirm they are cured.
“H. pylori treatment is not 100% effective. Providers should confirm the infection has been eradicated. But does this actually happen in the U.S.?” Dr. Goldberg said.
Unfortunately, in their study of more than 27,000 U.S.-treated patients, only about 24% were retested.
“We found retesting rates were better if the initial diagnosis was made by a gastroenterologist or a non-physician provider — a nurse practitioner or physician assistant working in a gastroenterology practice,” he said.
The next step is to study the feasibility and impact of widespread H. pylori screening and treatment in a community-based study.
“H. pylori is more common in people from Asia, Africa, Central and South America and the Caribbean and in places where the sanitation is not as good,” Dr. Goldberg said. “We plan to do a community-based screening for H. pylori, targeting the immigrant population here. We’re not suggesting screening everyone, but if people have the infection it should be treated and confirmed that it’s cured because, as we’ve shown, that leads to reductions in gastric cancer without increasing the risks of esophageal cancer or C. diff.”