Review for 10.1186/s12876-020-01375-z (2020)

Reviewer’ s report
Title: Endoscopic severe mucosal atrophy indicates the presence of gastric cancer after
Helicobacter pylori eradication -Analysis based on the Kyoto classification
Version: 1Date: 24 May 2020
Reviewer's report:
The authors conducted a retrospective case control study to find out the specific pattern indicated
of presense of gastric cancer in patients after HP eradication. The idea is novel and interesting. Thearticle was well-written with good grammar and clear descriptions. However, there are somedisconcordance between the title and the finding. As in the title, it sounds like the authors foundsome new endoscopic characteristics such as VS pattern in magnifying NBI image that indicatedthe presence of cancer. The article in fact was aimed to find out the high risk population of gastriccancer using Kyoto score subscore as risk scores.There are several issues which may be further clarified.1. What is the rationale for patients younger than 58 years needed to be excuded? How large wasthe population excluded ?2. It had been many years between the index date and H.pylori eradication in over 100 patients,did any patient had recurrent infection? or any patient was excluded due to this reason?3. In discussion, the authors mentioned about gastric atrophy score A2, easily assessedendoscopically by atrophic border. Is the cancer noted in this study, loacated inside the area orgastric atrophy, adjacent to gastric atrophy, or somewhere far away? Is there any example figurefor illustration?4. Is there any clinical evidence showeing that early HP eradication when atrophy is not severe canprevent gastric atrophy progression? If not, why this study can show HP eradication when atrophy
is not severe can reduce the the risk of gastric cancer later in life?
5. Comparing Shichijo S' s study and this study, did they also showed that HP eradication inpatients with severe gastric strophy can't prevent its progression to gastric cancer and thereforeneeded to be followed up frequently? What is the optimal follow-up schedule in this setting?6. In this study, the authors selected some patients with early gastric cancer and patients withoutearly gastric cancer but all recived H.pylori eradication history. Selection bias existed in this settin.If the authors also reviewed the images of those patients with early gastric cancer one year before,the study result may changed markedly since their endoscopy images analysis according to Kyotoclassification grading should be similiar one year before, but just without gastric cancer and all themarkers regarded as risk factors for gastric cancers in this study will be analyzed as non-riskfactors. Since the hypothesis in this study suggested that after H.pylori eradication, the gastritismay improved slowly, but not worsening. Also, for those patients without gastric cancer, if theauthors followed them one year after, some patients may also be found with gastric cancer, theresult may changes.
Minor issues.
1. The year of IRB approval may be added since date was alreaded by added.2. In Table 3, the number of decimal places may be synchorized between different values.
3. In discussion, the author mentioned about a recent study also observed that the advanced
atrophy can be arisk factor for gastric cancer after HP eradication. What is the study?4. Table 5 ROC curve, may be drawn for better visualization.
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
YesAre the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
NoAre you able to assess any statistics in the manuscript or would you recommend an
additional statistical review?If an additional statistical review is recommended, please specify what aspects require furtherassessment in your comments to the editors.
I am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
AcceptableDeclaration of competing interests
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