88PEpithelial-mesenchymal transition of tumour buds: A histopathological parameter with potential implication in oncological therapy of colorectal carcinoma

Abstract Background The most recent histopathological guideliness recommend evaluation of tumor buds, as an independent prognostic factor of colorectal carcinoma (CRC). In the present paper, we examined the immunoprofile of tumor buds, using three markers of epithelial mesenchymal transition (EMT): E-cadherin, β-catenin and vimentin, which were evaluated in both tumor core and buds. Methods In 157 CRCs specimens, consecutive cases with curative resection, without preoperative therapy, three molecular subtypes were defined: epithelial (positive for E-cadherin, membrane expression for β-catenin and negative for vimentin, in core and buds), mesenchymal (loss of E-cadherin staining and vimentin positivity and/or nuclear β-catenin, in core and buds) and hybrid cases (epithelial tumor core and mesenchymal tumor buds). Based on the number of buds, which were evaluated at high power field (HPF), cases were divided in two groups: group A or low grade (≤5 buds/HPF) and and group B or high-grade CRCs (>5 buds/HPF). Results It was a similar distribution between the two groups: 74 cases (47.13%) in group A and 83 cases in group B (52.87%). Most of the cases (n = 76; 48.41%) were classified as epithelial-type, followed by hybrid- (n = 63; 40.13%) and mesenchymal-type CRCs (n = 18; 11.46%). On both groups, a similar distribution was seen between epithelial- and hybrid-type cases but 14 out of the 18 mesenchymal-type CRCs belonged to group B (p = 0.01). All of the mesenchymal-type CRCs from group B showed lymph node metastases. Both lymph node status and budding degree proved to be independent prognostic factors. Conclusions In daily practice, the immunoprofile of CRC buds might have a prognostic impact. Further studies are necessary to check the prognostic role of mesenchymal-immunoprofile of tumor buds. Legal entity responsible for the study University of Medicine, Pharmacy, Sciences and Technology, Tirgu-Mures, Romania. Funding University of Medicine, Pharmacy, Sciences and Technology, Tirgu-Mures, Romania. Disclosure All authors have declared no conflicts of interest.