CEACAM6 Is a Novel Biomarker in Pancreatic Adenocarcinoma and PanIN Lesions

Abstract

The purpose of this study was to test the hypothesis that CEACAM6 expression is an indicator of adverse pathologic features and clinical outcome in pancreatic adenocarcinoma. Previously, we have demonstrated carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) to be an oncoprotein that plays an important role in the biology of pancreatic adenocarcinoma. Suppression of CEACAM6 expression reduces tumorigenesis and metastasis in vivo. A tissue microarray was constructed using tumor specimens obtained from 89 consecutive patients who had undergone pancreatic resection for pancreatic adenocarcinoma with curative intent. A second microarray containing 54 pancreatic intraepithelial neoplasia (PanIN) lesions was constructed using tissues from a separate cohort of 44 patients. Both arrays were immunostained using a specific anti-CEACAM6 monoclonal antibody. Tumoral CEACAM6 expression was dichotomized into negative and positive immunoreactivity groups. The log-rank test was used to evaluate univariate associations of CEACAM6 expression with prognosis. Survival curves were derived using the Kaplan-Meier method. Tumoral CEACAM6 expression was detected in 82 (92%) pancreatic adenocarcinoma specimens. CEACAM6 expression was more prevalent in high-grade than in low-grade PanIN lesions (P = 0.0002). Negative tumoral CEACAM6 expression was associated with absence of lymph node metastases (P = 0.012), lower disease stage (P = 0.008), and longer postoperative survival (P = 0.047). CEACAM6 is a novel biomarker for pancreatic adenocarcinoma. CEACAM6 warrants further evaluation as both a prognostic factor and a therapeutic target in pancreatic cancer.