Abstract 4940: Use of whole slide digital image analysis for determination of expression of Twist-1 in normal panceata and stage IV pancreatic ductal adenocarcinomas

Abstract

Abstract Pancreatic cancer is the 4th most common cause of cancer deaths in this country. Close to 50,000 deaths occur every year. This is due to the fact that most patients are not diagnosed until presentation at a stage IV. In a recent study, it is estimated that more than 10 years go by between the first genetic mutation and the formation of invasive cancer. More mutations occur in metastatic lesions after an additional 6 years. Both SNAIL and TWIST have gained more attention as biomarkers because that contribute to E-cadherin dysregulation that allows the tumor cells to invade. In this study we evaluated 17 cases of pancreatic ductal adenocarcinoma using twist-1 antibody to evaluate tumor cell expression in these cases. All paraffin blocks were retrieved from the IU pathology department files via an IRB approved protocol. The unstained slides were stained with primary antibody Twist-1 using the DAKO Flex system. Control sections were treated with an isotype control using the same concentration as primary antibody to verify the staining specificity. The Aperio whole slide system was used to image the slides. Computer-assisted morphometric analysis of digital images was carried out using the Aperio Image scope software using the positive pixel algorithm. The algorithm was used to quantify the Twist-1 positivity of normal pancreas, and pancreatic ductal adenocarcinoma. This algorithm is the only FDA approved algorithm for human clinical trials. The immunostaining of Twist-1 was found only in the ductal epithelial carcinoma cells in the pancreas. There was no staining in the stroma in any of the normal pancreas and ductal pancreatic carcinoma cases. We analyzed 5 normal pancreata, and 12 pancreatic ductal adenocarcinomas. The data from the image analysis was 3.38% expression in normal pancreata and 11.44% expression in the pancreatic ductal adenocarcinoma. In summary, the image analysis data demonstrates the overexpression of Twist-1 in stage IV pancreatic adenocarcinomas compared to the normal pancreas. This suggests that this marker may be a predictor of tumor invasiveness and metastasis. Citation Format: Max Jacobsen, George Sandusky, Kavita Shah. Use of whole slide digital image analysis for determination of expression of Twist-1 in normal panceata and stage IV pancreatic ductal adenocarcinomas. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4940.