Review for 10.1186/s12876-023-02662-1 (2023)

Title: Chronic atrophic gastritis in different ages in South China: a 10-year retrospective analysis
Version: 2 Date: 28 Dec 2022
Reviewer's report:
The Authors performed a large, retrospective, study in China, looking at the prevalence of
chronic atrophic gastritis (CAG) in two different time spans. They found a progressive increase
of this condition, specifically, autoimmune gastritis is increasing; additionally, they describe 82
cases of gastric cancer arising in the context of autoimmune atrophic gastritis.
Overall, I think that the paper, although limited by the retrospective nature, is worth publishing,
as is very informative and provides novel data in an underrepresented geographical area.
However, my following comments should be thoroughly addressed, as some parts of the paper
are not clear.
General comments:
1. As a general comment, the Authors should revised the English grammar and expression, as
there are some awkward sentences and many grammatical errors (for example; "prevalences"
should be "prevalence")
2. The abstract is not clear: please add all raw numbers, and not only the percentages.
3. A table with additional data regarding pathology (i.e., gastric histopathology, including
site and degree of atrophy and metaplasia, G  and ECL cell hyperplasia) would be helpful.
Additionally, a table reporting differences between autoimmune and non-autoimmune gastritis
would be helpful.
Specific comments:
1. My main concern is the nomenclature used by the Authors. Actually, the latest, internationally-
accepted classifications of gastritis are the Sydney-Houston (+ the updated version) and the
Kyoto global consensus. I have read with interest the Chinese  guidelines, which are authoritative
and very informative, but yet I would stick to the Kyoto consensus for the nomenclature. I the
Kyoto consensus, there have been Asian authors as well, and the specific aim of the consensus
was to avoid confusion with the nomenclature. Please, reword  "autoimmune-related CAG" with
"autoimmune atrophic gastrits". In case of H. pylori, please use H.pylori-related CAG.
2. "Patients were classified as the more serious group according to pathological results, if both
sites were atrophied or intestinal metaplasia." I don't agree with this sentence. If both the antrum
and the corpus are atrophied, the patient actually has an atrophic pangastritis.
3.  The authors put together the cases of neuroendocrine tumours and gastric epithelial cancer.
Please, split these groups, as they have completely different prognosis.
4.  The methods section is not detailed enough. The authors must clearly state all the diagnostic
criteria. Particularly: How many biopsies were taken per each patient ? How many patients were
excluded due to incomplete data ? How were patients with antrum or corpus atrophy classified in
case of H. pylori negativity (i.e., how did they know they had a previous HP infection or not ?) ?
5. Table 2 is hard to read in this way. Please, compare all variables with a student t test and
add a p value.
6. Were all patients with autoimmune gastritis positive to anti-intrinsic factor or anti-parietal
cells autoantibodies ?
7. There is no comparison, in the discussion, with previously published papers of the Western
world. Please, enrich the bibliography, by comparing your series with the many publushed
series, particularly those described by Rugge et al. (see his latest paper published in Gut
focusing on cancer in autoimmune gastritis),  Miceli et al. (see the natural history paper and the
clinical characteristics), Lenti et al. (see the diagnostic delay  paper, the immunological studies
comparing HP and autoimmune gastritis, and Nature Primer), Massironi et al., Lahner et al.