Title: Total polyp number may be more important than size and histology of polyps for
prediction of metachronous high-risk colorectal neoplasms
Version: 1 Date: 15 Oct 2021
Reviewer:  Jun Arimoto
Reviewer's report:
This study investigated the total polyp number for the risk of metachronous HR-CRN. This is a
well written study, however, this study has several limitations in the following areas.
1. How many times in a lifetime is the index colonoscopy in this study in each patient? Is the
first colonoscopy for everyone? If not, the data of this study is not reliable. Past history of
colonoscopy in each patient might affect the results of this study. Although authors described
about this issue, I think it is not enough. This is a prospective study. If this study was performed
as a truly prospective study, I think that Past history of colonoscopy in each patient can be found
by interviewing patients. Why did not authors ask the patients? Is this really a prospective study?
2. Authors described ‘after adjusting for risk factors, such as obesity, diabetes, and smoking.’
Male are one of the risk factors for colorectal neoplasms. Why did not authors include this
variable?
3. Why did authors exclude patients >75 years?
4. The description about endoscopists is not enough. More detail clinical information of
colonoscopy is required. If authors usually performed CSP at the time of the colonoscopy, it
means that authors could not to use the magnifying scope in all cases. However, if authors did not
remove the polyps in the first Colonoscopy, authors have been able to observe with magnifying
scope in all cases. It is desirable that every polyp was examined in detail with the magnifying
scope to determine the appropriateness of its resection using CSP or not (EMR, HSP, ESD). It
is important issue in clinical practice. In addition, Authors should add the description about the
endoscopists (skill, number of experiences, ADR, etc).
5. In this study, surveillance colonoscopy was performed within one year. Are all lesions really
metachronous? Is it really possible that you missed it?
6. How did authors distinguish between missed lesion and newly developed lesion?
7. Why did authors set the cutoff value for 5 or more polyps? I think that it is not a prospective
study unless the cutoff value is decided from the beginning. I think that patients just recruited
as prospectively, study design is retrospective.
Title: Total polyp number may be more important than size and histology of polyps for
prediction of metachronous high-risk colorectal neoplasms
Version: 1 Date: 15 Oct 2021
Reviewer:  Jun Arimoto
Reviewer's report:
This study investigated the total polyp number for the risk of metachronous HR-CRN. This is a
well written study, however, this study has several limitations in the following areas.
1. How many times in a lifetime is the index colonoscopy in this study in each patient? Is the
first colonoscopy for everyone? If not, the data of this study is not reliable. Past history of
colonoscopy in each patient might affect the results of this study. Although authors described
about this issue, I think it is not enough. This is a prospective study. If this study was performed
as a truly prospective study, I think that Past history of colonoscopy in each patient can be found
by interviewing patients. Why did not authors ask the patients? Is this really a prospective study?
2. Authors described ‘after adjusting for risk factors, such as obesity, diabetes, and smoking.’
Male are one of the risk factors for colorectal neoplasms. Why did not authors include this
variable?
3. Why did authors exclude patients >75 years?
4. The description about endoscopists is not enough. More detail clinical information of
colonoscopy is required. If authors usually performed CSP at the time of the colonoscopy, it
means that authors could not to use the magnifying scope in all cases. However, if authors did not
remove the polyps in the first Colonoscopy, authors have been able to observe with magnifying
scope in all cases. It is desirable that every polyp was examined in detail with the magnifying
scope to determine the appropriateness of its resection using CSP or not (EMR, HSP, ESD). It
is important issue in clinical practice. In addition, Authors should add the description about the
endoscopists (skill, number of experiences, ADR, etc).
5. In this study, surveillance colonoscopy was performed within one year. Are all lesions really
metachronous? Is it really possible that you missed it?
6. How did authors distinguish between missed lesion and newly developed lesion?
7. Why did authors set the cutoff value for 5 or more polyps? I think that it is not a prospective
study unless the cutoff value is decided from the beginning. I think that patients just recruited
as prospectively, study design is retrospective.
Please review this paper.
user
Title: Total polyp number may be more important than size and histology of polyps for
prediction of metachronous high-risk colorectal neoplasms
Version: 1 Date: 15 Oct 2021
Reviewer:  Jun Arimoto
Reviewer's report:
This study investigated the total polyp number for the risk of metachronous HR-CRN. This is a
well written study, however, this study has several limitations in the following areas.
1. How many times in a lifetime is the index colonoscopy in this study in each patient? Is the
first colonoscopy for everyone? If not, the data of this study is not reliable. Past history of
colonoscopy in each patient might affect the results of this study. Although authors described
about this issue, I think it is not enough. This is a prospective study. If this study was performed
as a truly prospective study, I think that Past history of colonoscopy in each patient can be found
by interviewing patients. Why did not authors ask the patients? Is this really a prospective study?
2. Authors described ‘after adjusting for risk factors, such as obesity, diabetes, and smoking.’
Male are one of the risk factors for colorectal neoplasms. Why did not authors include this
variable?
3. Why did authors exclude patients >75 years?
4. The description about endoscopists is not enough. More detail clinical information of
colonoscopy is required. If authors usually performed CSP at the time of the colonoscopy, it
means that authors could not to use the magnifying scope in all cases. However, if authors did not
remove the polyps in the first Colonoscopy, authors have been able to observe with magnifying
scope in all cases. It is desirable that every polyp was examined in detail with the magnifying
scope to determine the appropriateness of its resection using CSP or not (EMR, HSP, ESD). It
is important issue in clinical practice. In addition, Authors should add the description about the
endoscopists (skill, number of experiences, ADR, etc).
5. In this study, surveillance colonoscopy was performed within one year. Are all lesions really
metachronous? Is it really possible that you missed it?
6. How did authors distinguish between missed lesion and newly developed lesion?
7. Why did authors set the cutoff value for 5 or more polyps? I think that it is not a prospective
study unless the cutoff value is decided from the beginning. I think that patients just recruited
as prospectively, study design is retrospective.
assistant