الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Carcinoma of colon and rectum is a common and lethal disease. As 50% of cases of colorectal cancer (CRC) will develop distant metastasis particularly liver metastasis, understanding the process of metastasis and its inducers is important for the development of proper strategies to treat CRC.
Epithelial mesenchymal transition (EMT) gain the attraction because of its pivotal role in inducing distant metastasis.
TWIST basic helix-loop-helix transcription factor (TWIST) is considered as one of the master regulators of EMT, possibly through indirect suppression of E-cadherin.E-cadherin plays an important role in EMT, as its downregulation was found to be associated with increased invasiveness of tumor cells. Investigating the relation between E-cadherin and TWIST in CRC might uncover some of the possible mechanisms involved in EMT in this tumor.
The present study was conducted to investigate the immunohistochemical expression of TWIST and E-cadherin in primary colorectal carcinoma (metastatic and non metastatic) as well as colonic adenoma, and to correlate the expression of TWIST and E-cadherin to the relevant clinicopathological parameters.
The present study comprised forty colorectal carcinoma surgical specimens and ten colorectal adenoma endoscopic polypectomy specimens submitted to the Department of Pathology, Faculty of Medicine, Alexandria University and Damanhor Oncology Center during the period from January 2013 to December 2015. Clinical data about the patients’ age, gender, clinical presentation, anatomical location of the tumors and also the presence or absence of distant metastasis were collected from their files.
Representative formalin-fixed paraffin-embedded tissue sections of the tumor in each case were stained with H&E to determine the tumor type and grade according to WHO classification of tumors of the colon and rectum, 5th edition (2019). Adenomas were graded into: adenomas with low grade dysplasia and adenomas with high grade dysplasia. Colorectal adenocarcinomas were graded according to the WHO and the AJCC recommendations into low grade adenocarcinomas (well differentiated and moderately differentiated tumors) and high grade adenocarcinomas (poorly differentiated tumors). Regarding the tumor type, adenomas were divided into: tubular, tubulo-villous and villous adenomas; and colorectal carcinomas were divided into: adenocarcinoma NOS and mucinous carcinoma. In addition, in cases of CRC, the tumor invasion (T stage) was determined according to the AJCC Cancer Staging TNM system for CRC cancer (8th edition). Lymphovascular invasion, perineural invasion and the lymphocytic response in CRCs were also assessed.