[Prognostic factors: Degree of subserosal invasion, tumor-serosal distance and subserosal elastic boundary invasion in colonic adenocarcinoma].

The aim was to study the prognostic impact of tumor infiltration of the subserosa in colonic adenocarcinoma, by evaluating the degree of tumor infiltration in the subserosa (DISS), tumor-serosa distance (DTS), and invasion of the elastic boundary of the subserosa (ILE) after elastic fiber staining.

Material and methods: All patients operated on for colonic adenocarcinoma classified as pT3 without lymph node or visceral metastasis operated on at the CHU d'Amiens between 2004 and 2017 were included. All slides were reviewed by 2 pathologists. Bivariate and subgroup analyses were performed according to the presence of a DISS≤5mm or>5mm, a DTS≤1mm or>1mm and the presence or absence of an ILE. These statistical analyses were then correlated with the 5-year survival.

Results: One hundred and one patients were included in the study. We performed elastic fiber staining on an average of 2 tumor blocks per case and 39.6% of patients had invasion of the elastic boundary. However, bivariate and subgroup analyses showed no statistically significant association between DISS, DTS or ILE and 5-year survival.

Conclusion: None of these three histopathological criteria proved to have prognostic value in our series, contrary to some results in the literature. However, as these data are subject to a number of confounding factors, we do not recommend that pathologists specify these different criteria in their reports.