Send letter to journal:
Re: Association of preneoplastic gastric lesions and H. pylori

Dear Editor,

In 1994, Helicobacter pylori was declared a type 1 carcinogen—a definite cause of human cancer—by the International Agency for Research on Cancer (IARC).[1]

We read with interest the study by Mera et al.[1] on the effect of eradicating H. pylori infection on precancerous gastric lesions. Here the author Mera et al conclude that “Preneoplastic gastric lesions regress at a rate equal to the square of time in patients rendered free of H pylori infection. Our findings suggest that patients with preneoplastic gastric lesions should be treated and cured of their H pylori infection”. I would like to focus other studies done before to find out the association of H pylori and gastric neoplasm.

In Fujian Province, China a large study[2] was conducted by Benjamin Chun-Yu Wong at el on 1630 healthy carriers of H pylori infection. The Objective was to determine whether treatment of H pylori infection reduces the incidence of gastric cancer. The study was Prospective, randomized, placebo-controlled, recruited in July 1994 and followed up until January 2002. Benjamin Chun-Yu Wong at el concluded that “the incidence of gastric cancer development at the population level was similar between participants receiving H pylori eradication treatment and those receiving placebo during a period of 7.5 years in a high-risk region of China. In the subgroup of H pylori carriers without precancerous lesions, eradication of H pylori significantly decreased the development of gastric cancer. Further studies to investigate the role of H pylori eradication in participants with precancerous lesions are warranted”.

Information of the individual metaplasia and atrophy scores at baseline and at twelve years in both groups also needed to find out independent analysis and interpretation of this important study, which is unavailable here in this study. This is important as these are the lesions most strongly associated with cancer risk.

References:

1. International Agency for Research on Cancer Working Group on the Evaluation of Carcinogenic Risks to Humans. Schistosomes, Liver Flukes and Helicobacter pylori: Views and Expert Opinions of an IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Lyon, France: IARC Press; 1994:177-240.

Send letter to journal:
Re: Effect of H. pylori eradication on precancerous lesions

Dear Editor

We read with interest the paper by Mera et al1 on the effect of eradicating H. pylori infection on precancerous gastric lesions. However, we have concern regarding the extent to which the limited data provided in the paper support the authors’ conclusions of regression of atrophy and intestinal metaplasia following H. pylori eradication.

The main outcome reported was the average histological score. This is an arbitrary ordinal scale, which is based upon the presence of superficial gastritis, atrophic gastritis, intestinal metaplasia, dysplasia or cancer as the most advanced lesion found in the four gastric biopsies performed at each time-point. The average score was 3.77 at baseline and following eradication of the infection fell to 3.18 after twelve years. The extent to which resolution of the different components of the average histological score contributed to the fall in the score is not made clear in the paper. However, the authors do present data showing that the acute polymorphonuclear cell infiltration fully resolved and the chronic mononuclear cell infiltration partially resolved. The magnitude of the resolution of the inflammatory infiltrate would appear to be adequate to explain the fall in the average histological score without any associated resolution of the intestinal metaplasia or atrophy. The Results section does not give information on the score for atrophy or intestinal metaplasia at baseline versus twelve years.

In the Discussion section comment is made to changes in atrophy and intestinal metaplasia. However, insufficient data to draw any meaningful conclusions or perform statistical analysis. In addition, there is clearly an error in the data provided is the Discussion section as 70/182 is called 20%.

We would be grateful if the authors would provide the individual metaplasia and atrophy scores at baseline and at twelve years in the two groups in order to allow independent analysis and interpretation of this important study. This is important as these are the lesions most strongly associated with cancer risk.

Our interpretation of the limited data made available in the current version of the paper is that there is evidence of early complete resolution of the acute polymorphonuclear infiltration and partial resolution of the chronic mononuclear cell infiltration but no convincing evidence presented of resolution of the intestinal metaplasia or atrophy. The findings are therefore consistent with a number of previous studies showing no evidence of reversal of the important precancerous lesions. We also note that during the twelve years of follow-up five cancers occurred in the H. pylori treatment group and four in the non-treatment group. Contrary to the conclusions of the authors, the benefits of eradicating H. pylori infection in patients with advanced gastritis as a means of preventing cancer remains far from clear.

References

1. Mera R, Fontham E T H, Bravo L E et al. Long-term follow up of patients treated for Helicobacter pylori infection. Gut, 2005; 54: 1536- 1540.