Title: Threshold of Main Pancreatic Duct for Malignancy in Intraductal Papillary  Mucinous
Neoplasm at Head-neck and Body-tail
Version: 1 Date: 05 Aug 2022
Reviewer's report:
This manuscript titled “Threshold of main pancreatic duct for malignancy in intrapapillary
mucinous neoplasm at head-neck and body-tail” is intriguing and informative. Li et al. showed
an informative retrospective study where different threshold of MPD diameter was determined
between IPMN in the pancreatic head-neck and in the pancreatic body-tail.  Although I partially
agree with the authors’ opinions, there were some problems in this manuscript. In addition,#
think that their interpretation and method of analyses are not enough to draw these conclusions.
Therefore, I regret to inform that this manuscript is not suitable for publication of BMC
gastroenterology. My suggestions are described below:
1) In general, a retrospective study is affected by the characteristics of its population and the
study concerning surgical specimen, like this study, is influenced by surgical indication of each
institution. In this study, about 40% of patients had no high-risk stigmata and/or worrisome
features. Therefore, the authors should clearly describe their institutional indication of surgery
in the treatment of IPMN.
2) The authors performed retrospective analysis including BD-IPMN. However, most BD-IPMN
does not have dilated MPD because malignant cells and plentiful mucin are not present in the
MPD. Therefore, I think it is not reasonable to determine the threshold of MPD to discriminate
malignant IPMN from benign one using all IPMNs including BD-IPMN. Rather than that, it
would be better to determine thresholds separately, between BD-IPMN and MPD-involved
IPMNs, and between the pancreatic head-neck and body-tail, respectively.
3) In multivariate analysis, factors should be determined by univariate analysis. However, in
this study, only specific factors were included in multivariate analysis. For example, univariate
analysis in the head-neck IPMN shown in Table 3 should include the factors which have
significant statistical significance in Table 1 such as serous CEA level, the presence or absence
of mural nodule, Diabetes mellitus, and so on.
4) The authors recommended the cut-off value of MPD diameter to distinguish malignant IPMN
as 6.45 mm in the pancreatic head-neck IPMN and 7.7 mm in the pancreatic body-tail. In
addition, in cases with MPD-involved IPMNs, 8.2 mm was suggested as threshold. In practice,
these values are too minute to measure in MRI and/or CT image. They should discuss about it.
5) In Table 1 and 2, only the number of patients was filled in some cells. It is quite difficult to
understand these cells, therefore, percentage should be added in them.
6) It would be better to add tangent line in receiver operating curve in figures.
Title: Threshold of Main Pancreatic Duct for Malignancy in Intraductal Papillary  Mucinous
Neoplasm at Head-neck and Body-tail
Version: 1 Date: 05 Aug 2022
Reviewer's report:
This manuscript titled “Threshold of main pancreatic duct for malignancy in intrapapillary
mucinous neoplasm at head-neck and body-tail” is intriguing and informative. Li et al. showed
an informative retrospective study where different threshold of MPD diameter was determined
between IPMN in the pancreatic head-neck and in the pancreatic body-tail.  Although I partially
agree with the authors’ opinions, there were some problems in this manuscript. In addition,#
think that their interpretation and method of analyses are not enough to draw these conclusions.
Therefore, I regret to inform that this manuscript is not suitable for publication of BMC
gastroenterology. My suggestions are described below:
1) In general, a retrospective study is affected by the characteristics of its population and the
study concerning surgical specimen, like this study, is influenced by surgical indication of each
institution. In this study, about 40% of patients had no high-risk stigmata and/or worrisome
features. Therefore, the authors should clearly describe their institutional indication of surgery
in the treatment of IPMN.
2) The authors performed retrospective analysis including BD-IPMN. However, most BD-IPMN
does not have dilated MPD because malignant cells and plentiful mucin are not present in the
MPD. Therefore, I think it is not reasonable to determine the threshold of MPD to discriminate
malignant IPMN from benign one using all IPMNs including BD-IPMN. Rather than that, it
would be better to determine thresholds separately, between BD-IPMN and MPD-involved
IPMNs, and between the pancreatic head-neck and body-tail, respectively.
3) In multivariate analysis, factors should be determined by univariate analysis. However, in
this study, only specific factors were included in multivariate analysis. For example, univariate
analysis in the head-neck IPMN shown in Table 3 should include the factors which have
significant statistical significance in Table 1 such as serous CEA level, the presence or absence
of mural nodule, Diabetes mellitus, and so on.
4) The authors recommended the cut-off value of MPD diameter to distinguish malignant IPMN
as 6.45 mm in the pancreatic head-neck IPMN and 7.7 mm in the pancreatic body-tail. In
addition, in cases with MPD-involved IPMNs, 8.2 mm was suggested as threshold. In practice,
these values are too minute to measure in MRI and/or CT image. They should discuss about it.
5) In Table 1 and 2, only the number of patients was filled in some cells. It is quite difficult to
understand these cells, therefore, percentage should be added in them.
6) It would be better to add tangent line in receiver operating curve in figures.
Please review this paper.
user
Title: Threshold of Main Pancreatic Duct for Malignancy in Intraductal Papillary  Mucinous
Neoplasm at Head-neck and Body-tail
Version: 1 Date: 05 Aug 2022
Reviewer's report:
This manuscript titled “Threshold of main pancreatic duct for malignancy in intrapapillary
mucinous neoplasm at head-neck and body-tail” is intriguing and informative. Li et al. showed
an informative retrospective study where different threshold of MPD diameter was determined
between IPMN in the pancreatic head-neck and in the pancreatic body-tail.  Although I partially
agree with the authors’ opinions, there were some problems in this manuscript. In addition,#
think that their interpretation and method of analyses are not enough to draw these conclusions.
Therefore, I regret to inform that this manuscript is not suitable for publication of BMC
gastroenterology. My suggestions are described below:
1) In general, a retrospective study is affected by the characteristics of its population and the
study concerning surgical specimen, like this study, is influenced by surgical indication of each
institution. In this study, about 40% of patients had no high-risk stigmata and/or worrisome
features. Therefore, the authors should clearly describe their institutional indication of surgery
in the treatment of IPMN.
2) The authors performed retrospective analysis including BD-IPMN. However, most BD-IPMN
does not have dilated MPD because malignant cells and plentiful mucin are not present in the
MPD. Therefore, I think it is not reasonable to determine the threshold of MPD to discriminate
malignant IPMN from benign one using all IPMNs including BD-IPMN. Rather than that, it
would be better to determine thresholds separately, between BD-IPMN and MPD-involved
IPMNs, and between the pancreatic head-neck and body-tail, respectively.
3) In multivariate analysis, factors should be determined by univariate analysis. However, in
this study, only specific factors were included in multivariate analysis. For example, univariate
analysis in the head-neck IPMN shown in Table 3 should include the factors which have
significant statistical significance in Table 1 such as serous CEA level, the presence or absence
of mural nodule, Diabetes mellitus, and so on.
4) The authors recommended the cut-off value of MPD diameter to distinguish malignant IPMN
as 6.45 mm in the pancreatic head-neck IPMN and 7.7 mm in the pancreatic body-tail. In
addition, in cases with MPD-involved IPMNs, 8.2 mm was suggested as threshold. In practice,
these values are too minute to measure in MRI and/or CT image. They should discuss about it.
5) In Table 1 and 2, only the number of patients was filled in some cells. It is quite difficult to
understand these cells, therefore, percentage should be added in them.
6) It would be better to add tangent line in receiver operating curve in figures.
assistant