Factors For Eradicating Gastric Cancer Causing Bacterium H Pylori

Editor's Choice
Academic Journal
Main Category: Infectious Diseases / Bacteria / Viruses
Also Included In: Cancer / Oncology
Article Date: 13 Feb 2013 - 0:00 PDT


The bacterium Helicobacter pylori is one of the leading causes of gastric cancer worldwide, researchers analyzed the results of interventions that tried to eradicate the bacterium in several different Latin American population groups.

The findings, which were recently published in JAMA, indicated that not only is the antibiotic regimen important in H pylori intervention, but also demographic factors, infection recurrence, the geographic site of the intervention, and adherence to initial therapy.

Close to fifty percent of the world's adult population is infected with Helicobacter pylori. Chronic infection of the bacterium is responsible for close to two-thirds of all gastric cancer cases.

According to the background information of the article:

"Gastric adenocarcinoma is the second leading cause of cancer death worldwide. Although gastric cancer rates are declining in some areas, the number of deaths is expected to increase over the coming decades due to growing and aging populations in high-incidence regions such as Latin America and eastern Asia.

The feasibility of large-scale programs is uncertain and success in specific populations will depend on the efficacy of the antibiotic regimen used and the risk of recurrent infection following eradication."

The research team, led by Douglas R. Morgan, M.D., M.P.H., of Vanderbilt Medical Center, evaluated the risk of H pylori recurrence and looked at the factors associated with successful eradication of the bacterium following 1 year of effective treatment.

A total of 1,463 people who were treated for H pylori participated in the study, from 7 different communities in Latin America. They were all randomly put into one of the following treatment groups:

• 4-day lansoprazole, amoxicillin, and clarithromycin (triple therapy)
• 5-day lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant)
• 5-day lansoprazole and amoxicillin followed by 5-day lansoprazole, clarithromycin, and metronidazole (sequential)

1,133 of the participants were not infected with H pylori - who appeared urea breath test (UBT) negative - at the end of the initial treatment period. 1,091 of these participants received follow up UBT tests for a year, of whom 125 became infected again - becoming UBT positive, resulting in a recurrence rate of 11.5 percent.

The recurrence rate differed significantly among study sights - ranging from 6.8 percent in Costa Rica to 18.1 percent in Colombia. In addition to this, the researchers noted that the number of children in the household was also a factor, as well as non adherence to therapy.

The overall treatment effectiveness in the primary analysis was 79.3 percent.

The authors conclude: 

"In a single-treatment course analysis that ignored the effects of re-treatment, the percentage of UBT-negative results at 1 year was 72.4 percent and was significantly associated with study site, adherence to initial therapy, male sex, and age. One-year effectiveness among all 1,463 enrolled participants, considering all missing UBT results as positive, was 72.7 percent.

In our current study, adherence, study site, sex, and age were significantly associated with the probability of a successful 1-year outcome. From the public health perspective, a 'one size fits all' intervention strategy may not be optimal."

Given the expected increase in the prevalence of gastric cancer in Latin America over the coming years and the fact that eradication of H pylori can reduce gastric cancer risk, more research initiatives are necessary.

Interestingly, despite the bacterium being known to cause gastric cancer, researchers from NYU School of Medicine have reported that H. pylori may actually help prevent certain types of cancers, as well as stroke.

Written by Joseph Nordqvist


Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

• Additional
• References
• Citations