Reviewer's report
Title:Loss of PTEN expression is associated with colorectal cancer liver
metastasis and poor patient survival
Version: 1Date:1 June 2008
Reviewer: John Mariadason
Reviewer's report:
Loss of PTEN expression is associated with colorectal cancer liver metastasis
and poor survival.
Sawai et al.
The authors report a potentially important finding that downregulation of PTEN
may be linked to the onset of metastasis in colon cancer. However, there are
several concerns with the study as presented.
First, on multiple occasions the authors present the findings of this study as a
comparison of PTEN expression in primary colorectal cancer and colorectal
cancer liver metastases. However, no evidence of PTEN expression in
metastatic colorectal tumor tissue is presented. Rather, the analysis appears to
be a comparison of PTEN expression in primary colon tumors in patients with
and without metastatic disease. Presentation of the manuscript is therefore highly
confusing.
For patients with liver metastases the authors compare survival time in patients
with high versus low PTEN expression. However, not all patients in this analysis
are stage IV. The validity of the 5 year survival analysis is therefore questionable.
Expression of PTEN in stage matched patients should be performed.
A single “representative” image of PTEN expression from the 2 groups is
presented. This is inadequate as it fails to demonstrate the range of staining
intensities reported. Also, the PTEN expression appears nuclear which based
upon the literature is potentially important. This is not referred to or addressed.
The method of data presentation of data in Tables 1 and 2 is highly confusing
and should be reconsidered.
Discussion: PTEN does not function by dephosphorylating PI3K.
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
'I declare that I have no competing interests'
Reviewer's report
Title:Loss of PTEN expression is associated with colorectal cancer liver
metastasis and poor patient survival
Version: 1Date:1 June 2008
Reviewer: John Mariadason
Reviewer's report:
Loss of PTEN expression is associated with colorectal cancer liver metastasis
and poor survival.
Sawai et al.
The authors report a potentially important finding that downregulation of PTEN
may be linked to the onset of metastasis in colon cancer. However, there are
several concerns with the study as presented.
First, on multiple occasions the authors present the findings of this study as a
comparison of PTEN expression in primary colorectal cancer and colorectal
cancer liver metastases. However, no evidence of PTEN expression in
metastatic colorectal tumor tissue is presented. Rather, the analysis appears to
be a comparison of PTEN expression in primary colon tumors in patients with
and without metastatic disease. Presentation of the manuscript is therefore highly
confusing.
For patients with liver metastases the authors compare survival time in patients
with high versus low PTEN expression. However, not all patients in this analysis
are stage IV. The validity of the 5 year survival analysis is therefore questionable.
Expression of PTEN in stage matched patients should be performed.
A single “representative” image of PTEN expression from the 2 groups is
presented. This is inadequate as it fails to demonstrate the range of staining
intensities reported. Also, the PTEN expression appears nuclear which based
upon the literature is potentially important. This is not referred to or addressed.
The method of data presentation of data in Tables 1 and 2 is highly confusing
and should be reconsidered.
Discussion: PTEN does not function by dephosphorylating PI3K.
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
'I declare that I have no competing interests'
Please review this paper.
user
Reviewer's report
Title:Loss of PTEN expression is associated with colorectal cancer liver
metastasis and poor patient survival
Version: 1Date:1 June 2008
Reviewer: John Mariadason
Reviewer's report:
Loss of PTEN expression is associated with colorectal cancer liver metastasis
and poor survival.
Sawai et al.
The authors report a potentially important finding that downregulation of PTEN
may be linked to the onset of metastasis in colon cancer. However, there are
several concerns with the study as presented.
First, on multiple occasions the authors present the findings of this study as a
comparison of PTEN expression in primary colorectal cancer and colorectal
cancer liver metastases. However, no evidence of PTEN expression in
metastatic colorectal tumor tissue is presented. Rather, the analysis appears to
be a comparison of PTEN expression in primary colon tumors in patients with
and without metastatic disease. Presentation of the manuscript is therefore highly
confusing.
For patients with liver metastases the authors compare survival time in patients
with high versus low PTEN expression. However, not all patients in this analysis
are stage IV. The validity of the 5 year survival analysis is therefore questionable.
Expression of PTEN in stage matched patients should be performed.
A single “representative” image of PTEN expression from the 2 groups is
presented. This is inadequate as it fails to demonstrate the range of staining
intensities reported. Also, the PTEN expression appears nuclear which based
upon the literature is potentially important. This is not referred to or addressed.
The method of data presentation of data in Tables 1 and 2 is highly confusing
and should be reconsidered.
Discussion: PTEN does not function by dephosphorylating PI3K.
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
'I declare that I have no competing interests'
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