Reviewer's report
Title:Gastric cancer is associated with NOS2 -954G/C polymorphism and
environmental factors in a Brazilian population
Version: 1Date:19 February 2010
Reviewer: Asahi Hishida
Reviewer's report:
The paper by Jorge YC et al. investigated the associations of the risk of gastric
cancer and chronic gastritis with the three representative polymorphisms in the
NOS2 gene together with smoking and alcohol drinking habits, and found that
NOS2 -954 G/C polymorphism as well as alcohol intake and tobacco smoking
was associated with gastric cancer risk.
This reviewer thinks that the results of this study are sound, and worth to be
published in BMC Gastroenterology after some revisions as described below.
1. As you may know, H. pylori-induced gastric cancers occur through multi-step
process referred to as Correa’s cascade. The authors should consider that it
would be better if they evaluate the risk of each step of gastric carcinogenesis,
i.e., H. pylori infection, gastric atrophy formation and gastric carcinogenesis in a
stepwise-manner, as previously described (Hamajima N, et al., Cancer Sci 2006;
97: 1129-38).
2. In the Methods section, they claimed that the OR’s were calculated using a
dominant model. In contrast to this, the results in Table 2 seem to calculate the
OR for those with homozygous major allele relative to those with heterozygous or
homozygous minor allele. This reviewer thinks that it would be more popular to
calculate the OR for those with heterozygous or homozygous minor compared
with homozygous minor, isn’t it?
3. As described in the Introduction, H. pylori infection is an established risk factor
for gastric carcinogenesis. In this study, however, H. pylori infection was tested
only in part of the gastric cancer cases and gastritis cases, not tested in controls.
This should be emphasized as a limitation in the Discussion section.
4. This reviewer as well as some part of the readers would be anxious to know
how many percent of H. pylori in your study subjects may have H. pylori virulence
factor cagA, and what type of cagA they might be.
5. In Table 3, the authors had better provide the number of subjects in each
category (age, gender, smoking, alcohol, and so on).
6. The NOS2 C/T (Ser608Leu) polymorphism at exon 16 should not be described
as 608C/T, because 608 is a codon number, not a nucleotide position. The
authors should also provide the rs number of dbSNP for each SNP for the easy
reference of the readers.
7. In Table 2, ‘95%IC’ should be replaced with ‘95%CI’. Also, it would be better if
they provide the spell-outs in the legends, as well as for what factors they
adjusted in calculating ORs in the footnotes.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.
Reviewer's report
Title:Gastric cancer is associated with NOS2 -954G/C polymorphism and
environmental factors in a Brazilian population
Version: 1Date:19 February 2010
Reviewer: Asahi Hishida
Reviewer's report:
The paper by Jorge YC et al. investigated the associations of the risk of gastric
cancer and chronic gastritis with the three representative polymorphisms in the
NOS2 gene together with smoking and alcohol drinking habits, and found that
NOS2 -954 G/C polymorphism as well as alcohol intake and tobacco smoking
was associated with gastric cancer risk.
This reviewer thinks that the results of this study are sound, and worth to be
published in BMC Gastroenterology after some revisions as described below.
1. As you may know, H. pylori-induced gastric cancers occur through multi-step
process referred to as Correa’s cascade. The authors should consider that it
would be better if they evaluate the risk of each step of gastric carcinogenesis,
i.e., H. pylori infection, gastric atrophy formation and gastric carcinogenesis in a
stepwise-manner, as previously described (Hamajima N, et al., Cancer Sci 2006;
97: 1129-38).
2. In the Methods section, they claimed that the OR’s were calculated using a
dominant model. In contrast to this, the results in Table 2 seem to calculate the
OR for those with homozygous major allele relative to those with heterozygous or
homozygous minor allele. This reviewer thinks that it would be more popular to
calculate the OR for those with heterozygous or homozygous minor compared
with homozygous minor, isn’t it?
3. As described in the Introduction, H. pylori infection is an established risk factor
for gastric carcinogenesis. In this study, however, H. pylori infection was tested
only in part of the gastric cancer cases and gastritis cases, not tested in controls.
This should be emphasized as a limitation in the Discussion section.
4. This reviewer as well as some part of the readers would be anxious to know
how many percent of H. pylori in your study subjects may have H. pylori virulence
factor cagA, and what type of cagA they might be.
5. In Table 3, the authors had better provide the number of subjects in each
category (age, gender, smoking, alcohol, and so on).
6. The NOS2 C/T (Ser608Leu) polymorphism at exon 16 should not be described
as 608C/T, because 608 is a codon number, not a nucleotide position. The
authors should also provide the rs number of dbSNP for each SNP for the easy
reference of the readers.
7. In Table 2, ‘95%IC’ should be replaced with ‘95%CI’. Also, it would be better if
they provide the spell-outs in the legends, as well as for what factors they
adjusted in calculating ORs in the footnotes.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.
Please review this paper.
user
Reviewer's report
Title:Gastric cancer is associated with NOS2 -954G/C polymorphism and
environmental factors in a Brazilian population
Version: 1Date:19 February 2010
Reviewer: Asahi Hishida
Reviewer's report:
The paper by Jorge YC et al. investigated the associations of the risk of gastric
cancer and chronic gastritis with the three representative polymorphisms in the
NOS2 gene together with smoking and alcohol drinking habits, and found that
NOS2 -954 G/C polymorphism as well as alcohol intake and tobacco smoking
was associated with gastric cancer risk.
This reviewer thinks that the results of this study are sound, and worth to be
published in BMC Gastroenterology after some revisions as described below.
1. As you may know, H. pylori-induced gastric cancers occur through multi-step
process referred to as Correa’s cascade. The authors should consider that it
would be better if they evaluate the risk of each step of gastric carcinogenesis,
i.e., H. pylori infection, gastric atrophy formation and gastric carcinogenesis in a
stepwise-manner, as previously described (Hamajima N, et al., Cancer Sci 2006;
97: 1129-38).
2. In the Methods section, they claimed that the OR’s were calculated using a
dominant model. In contrast to this, the results in Table 2 seem to calculate the
OR for those with homozygous major allele relative to those with heterozygous or
homozygous minor allele. This reviewer thinks that it would be more popular to
calculate the OR for those with heterozygous or homozygous minor compared
with homozygous minor, isn’t it?
3. As described in the Introduction, H. pylori infection is an established risk factor
for gastric carcinogenesis. In this study, however, H. pylori infection was tested
only in part of the gastric cancer cases and gastritis cases, not tested in controls.
This should be emphasized as a limitation in the Discussion section.
4. This reviewer as well as some part of the readers would be anxious to know
how many percent of H. pylori in your study subjects may have H. pylori virulence
factor cagA, and what type of cagA they might be.
5. In Table 3, the authors had better provide the number of subjects in each
category (age, gender, smoking, alcohol, and so on).
6. The NOS2 C/T (Ser608Leu) polymorphism at exon 16 should not be described
as 608C/T, because 608 is a codon number, not a nucleotide position. The
authors should also provide the rs number of dbSNP for each SNP for the easy
reference of the readers.
7. In Table 2, ‘95%IC’ should be replaced with ‘95%CI’. Also, it would be better if
they provide the spell-outs in the legends, as well as for what factors they
adjusted in calculating ORs in the footnotes.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.
assistant