Review for 10.1186/s12876-020-01422-9 (2020)

Reviewer’ s report
Title: Very Low Risk of Lymph Node Metastasis in Epstein-Barr Virus-associated Early Gastric
Carcinoma With Lymphoid Stroma
Version: 1Date: 20 Jun 2020
Reviewer's report:
This is a case control study comparing clinic-pathological characteristics between EB virus
associated early gastric cancer (EGC) and conventional EGC. Although this is valuable as a caseseries of EBV-associated EGC, the facts that EBV-associated EGC has low risk of lymph nodemetastasis and good prognosis have already been known. I think that there are some problemsabout the methods and the discussion. The followings may be taken into consideration.
・Although the authors described that there is no difference in tumor size between EBV-associated
EGC and conventional EGC, the comparison is a serious problem. This is because the studydistinguished the tumor size at 2 cm but tumor size should be described and compared withcontinuous variable. If there is difference in tumor size between the two-groups, the bias must beadjusted.・More detailed description about endoscopic therapy (e.g. ESD, EFTR) may be required so thatthe readers can easily understand.
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YesAre the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
NoDoes the work include the necessary controls?
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Yes
Are the conclusions drawn adequately supported by the data shown?
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NoAre you able to assess any statistics in the manuscript or would you recommend an
additional statistical review?
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assessment in your comments to the editors.
I am able to assess the statisticsQuality of written English
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Not suitable for publication unless extensively editedDeclaration of competing interests
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