Review for 10.1186/1471-230X-9-65 (2009)

Reviewer's report
Title:Stromal Regulatory T-Cells are associated with a Favorable Prognosis in
Gastric Cancer of the Cardia
Version: 1Date:2 June 2009
Reviewer: Christoph Loddenkemper
Reviewer's report:
In this study, the authors analyzed tumor infiltrating lymphocytes (TIL) and
macrophages in intestinal-type adenocarcinoma of the gastric cardia by
immunohistochemistry. Using tissue microarrays (TMAs) of 52 cases, they
describe an improved survival associated with higher density of FOXP3 positive
regulatory T-cells in the tumor stroma. Furthermore, a low stromal CD68/FOXP3
ratio was also associated with improved survival. The immunohistochemical
stainings are of high quality and the detailed analyses are well performed. The
paper by Haas et al. adds important data to the field of tumor immunology
regarding the frequency of FOXP3 positive cells in a common solid tumor type.
Major Compulsory Revisions
None
Minor Essential Revisions
Tumor infiltrating macrophages are included within the tumor infiltrating
lymphocyte (TIL) subgroups. Precisely, the analyzed immune cells should be
referred to seperately as TIL (CD3, CD8, CD20, GranzB, FOXP3) and
macrophages throughout the manuscript (including Figure legends and Tables).
As the CD68 macrophage/FOXP3 Treg ratio was associated with prognosis, the
authors should also discuss whether the more commonly used CD8/FOXP3 ratio
was also associated with significant differences in survival.
The suggestion “...that a specific immune recognition of tumour cells may not be
clinically relevant in gastric carcinogenesis (p.7, discussion)” can not be made
from the presented data and should be omitted or rephrased. Stromal T cells
may also be specific for tumor associated antigens and differences compared to
their previous work on anal carcinomas (solid growth pattern, less stroma) might
also be attributed to differences in the histomorphology of these two tumor
entities.
The association of a higher number of Granzyme B positive cytotoxic T cells in
uninvolved lymph nodes with a better outcome should be discussed.
Functional studies are required to elucidate the role of the FOXP3 positive cells
in gastric adenocarcinoma of the cardia and this should be clearly stated in the
discussion. In addition, a proportion of the FOXP3 positive cells might not be
natural regulatory T-cells with stable FOXP3 expression and a novel method
capable of determining the frequency of natural Tregs in paraffin embedded
tissue by analysis of the Treg-cell specific demethylated region (TSDR) should
be mentioned (reviewed in Huehn et al. Nature Reviews Immunology 2009).
The authors need to include a recent publication by Salama et al. (J Clin Oncol
2008;27:186-192) where higher numbers of FOXP3 positive Tregs were also
found to be associated with better survival in colorectal cancer.
Discretionary Revisions
CD4 can be omitted from Tab. 3 as numbers are only provided for uninvolved
lymph nodes (CD4 staining also not mentioned in Material and Method section).
The order of the references should be carefully checked (e.g. No. 17, p.7)
Some spelling mistakes need to be corrected (e.g. dendritic cells, p.3)
DakoCytomation has changed to Dako again
Level of interest: An article whose findings are important to those with closely
related research interests
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'