Published online Nov 15, 2017. doi: 10.4251/wjgo.v9.i11.444
Peer-review started: July 19, 2017
First decision: August 7, 2017
Revised: August 17, 2017
Accepted: September 4, 2017
Article in press: September 5, 2017
Published online: November 15, 2017
To test the validity of tumour thickness measurement in distinguishing between the different infiltration depths, especially when the duplication of muscularis mucosae cannot be demarcated clearly.
We re-evaluated 100 completely embedded Barrett’s adenocarcinomas regarding m-classification, maximum tumour thickness, and muscularis mucosae duplication. For validation, smoothelin staining was performed on a subset of cases.
The m1-, m2- and m3-classified adenocarcinomas showed a significant lower tumour thickness compared to the m4- and sm1-classified lesions (P < 0.001). Smoothelin staining determined a clear muscularis mucosae duplication in 64% of the tested samples and enabled the differentiation of the two layers in diffuse and merged splits.
Tumour thickness in early oesophageal adenocarcinoma significantly correlates with the depth of infiltration and demonstrates its worth as an accurate pT classification in non-polypoid lesions. We created a new algorithm, which combines histomorphology with morphometric analyses. It is noteworthy that it facilitates the assessment of mucosal vs submucosal infiltration depth. The smoothelin staining strengthened our results of the tumour thickness evaluation and can be used in cases of doubt.
Core tip: The aim of this study was to determine whether histomorphometric measurement of tumor thickness and immunohistochemical staining for smoothelin facilitate the exact pT substaging in early oesophageal adenocarcinoma. Our data showed that there is clear cut-off of 1000 μm to distinguish advanced early lesions (M4/sm1) from such lesions that do not reach the deep muscularis mucosae or the submucosa. Moreover, smoothelin staining is of help to distinguish the superficial from the deep muscularis mucosa by different staining intensities. Therfore, both methods could be shown to be of help for the often challenging task to T-classify early oesophageal adenocarcinomas.