Reviewer's report
Title:Polymorphisms of genes coding for ghrelin and its receptor in relation to
colorectal cancer risk: a two-step gene-wide case-control study.
Version: 1Date:17 June 2010
Reviewer: Barbara A Leggett
Reviewer's report:
This is a well written manuscript which reports sound and interesting data. This
field is significant since colorectal cancer is a common disease and if genetic
susceptibility was better understood, screening could be better directed.
Some major compulsory revisions need to be addressed:
1. I do not think it is valid or helpful to combine the 2 populations in a joint
analysis of data. It would be better to accept that the 2 populations show different
results and explore possible reasons why. These may include
- the very different characteristics of the German population. These subjects are
on average very young and were selected as possibly having HNPCC. They may
have different genetic causes of colorectal cancer to older sporadic cases. In
addition if ghrelin acts indirectly through the effects of increased BMI, these
subjects may not be old enough to have had sufficient exposure to increased
BMI to show the increased incidence of cancer
- data re possible ethnic differences is not given. The German data is not
presented and it is not clear if data was collected in the Czech population.
- there may different environmental factors in the 2 countries. For example, if the
Czech diet was higher in calories and fat, the effects of genetic predispostion
acting through BMI would be greater
2 The conclusions need modification in light of the above
3. Do the 2 positively associated SNPs in the Czexh population constitute a
haplotype? Or are there 2 separate functional ghrelin variants which may
predispose to colorectal cancer?
Minor Essential revisons:
1. In Background of the abstract indicate should be indicates
2. In the 5th paragraph of the discussion he should be the.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
'I declare that I have no competing interests'
Reviewer's report
Title:Polymorphisms of genes coding for ghrelin and its receptor in relation to
colorectal cancer risk: a two-step gene-wide case-control study.
Version: 1Date:17 June 2010
Reviewer: Barbara A Leggett
Reviewer's report:
This is a well written manuscript which reports sound and interesting data. This
field is significant since colorectal cancer is a common disease and if genetic
susceptibility was better understood, screening could be better directed.
Some major compulsory revisions need to be addressed:
1. I do not think it is valid or helpful to combine the 2 populations in a joint
analysis of data. It would be better to accept that the 2 populations show different
results and explore possible reasons why. These may include
- the very different characteristics of the German population. These subjects are
on average very young and were selected as possibly having HNPCC. They may
have different genetic causes of colorectal cancer to older sporadic cases. In
addition if ghrelin acts indirectly through the effects of increased BMI, these
subjects may not be old enough to have had sufficient exposure to increased
BMI to show the increased incidence of cancer
- data re possible ethnic differences is not given. The German data is not
presented and it is not clear if data was collected in the Czech population.
- there may different environmental factors in the 2 countries. For example, if the
Czech diet was higher in calories and fat, the effects of genetic predispostion
acting through BMI would be greater
2 The conclusions need modification in light of the above
3. Do the 2 positively associated SNPs in the Czexh population constitute a
haplotype? Or are there 2 separate functional ghrelin variants which may
predispose to colorectal cancer?
Minor Essential revisons:
1. In Background of the abstract indicate should be indicates
2. In the 5th paragraph of the discussion he should be the.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
'I declare that I have no competing interests'
Please review this paper.
user
Reviewer's report
Title:Polymorphisms of genes coding for ghrelin and its receptor in relation to
colorectal cancer risk: a two-step gene-wide case-control study.
Version: 1Date:17 June 2010
Reviewer: Barbara A Leggett
Reviewer's report:
This is a well written manuscript which reports sound and interesting data. This
field is significant since colorectal cancer is a common disease and if genetic
susceptibility was better understood, screening could be better directed.
Some major compulsory revisions need to be addressed:
1. I do not think it is valid or helpful to combine the 2 populations in a joint
analysis of data. It would be better to accept that the 2 populations show different
results and explore possible reasons why. These may include
- the very different characteristics of the German population. These subjects are
on average very young and were selected as possibly having HNPCC. They may
have different genetic causes of colorectal cancer to older sporadic cases. In
addition if ghrelin acts indirectly through the effects of increased BMI, these
subjects may not be old enough to have had sufficient exposure to increased
BMI to show the increased incidence of cancer
- data re possible ethnic differences is not given. The German data is not
presented and it is not clear if data was collected in the Czech population.
- there may different environmental factors in the 2 countries. For example, if the
Czech diet was higher in calories and fat, the effects of genetic predispostion
acting through BMI would be greater
2 The conclusions need modification in light of the above
3. Do the 2 positively associated SNPs in the Czexh population constitute a
haplotype? Or are there 2 separate functional ghrelin variants which may
predispose to colorectal cancer?
Minor Essential revisons:
1. In Background of the abstract indicate should be indicates
2. In the 5th paragraph of the discussion he should be the.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
'I declare that I have no competing interests'
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