Relationship Between Expression Pattern of Beta- catenin and Clinicopathological Features of Colon Tumors

Abstract

This is a hospital based descriptive retrospective case study aimed at evaluating the association between beta catenin expression and clinicopathological characters of colon (benign and polyps) and colorectal carcinoma (grade and stage). The study was conducted in Khartoum state in National Public Health laboratory during the period from March to July 2013. Fifty paraffin blocks of different bowel disorders were taken and histopathological diagnosis revealed 10 benign colons, 10 polyps, 20 colorectal carcinoma (CRC) and 10 sentinel lymph nodes. Sections stained by immunohistochemical method using indirect technique for evaluation of β-catenin subcellular localization among stages of colorectal tumorigenesis process. The ages of the study population ranged between one year to 90 years old with mean age of 40, the study reported that most of the patients were older than 40 years, they were 25 (62.5%) they divided into 6(15%), 2(5%) and 17 (42.5%) for benign, polyps and malignant CRC respectively, while patients younger than 40 years were 15 (37.5%) distributed as 4 (10%), 8 (20%) and 3 (7.5%) for benign, polyps and CRC respectively with significant age group distribution (p value <0.05). In this study male patients were 27 (67.5%) and female patients were 13 (32.5%); there was insignificant association between the gender and histopathological diagnosis ( P value >0.05). This study revealed good association between clinicopathological characters (benign, polyp and colorectal cancer) and cellular localization of β-catenin (membranous, cytoplasmic and nuclear) with (P value <0.05); as the stages of colorectal tumorigenesis sequence from benign to malignant showed different stages of subcellular localization of β-catenin from membranous localization to cytoplasmic to nuclear translocation. This study reported that the association between the clinicopathological features ( grade and stage) of colorectal carcinoma and expression pattern of β-catenin were insignificant for grading (p value >0.05) reflecting lake of association between expression pattern and tumor differentiation, on the other hand there was significant association between pattern of expression and staging of CRC (p value <0.05). β- catenin showed good association with metastasis to regional lymph nodes; as 7 out of 10 (70%) non metastasized nodes were β-catenin negative and only 2 of 3 (20%) known metastasized nodes were β-catenin positive; thus β-catenin would be good metastatic marker to detect metastasis to the regional lymph node (p value <0.05).