Ahmed Abd Temur - Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq.
Farah Aqeel Rashid - Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq.

Background: Carcinoembryonic antigen (CEA) is a common gastrointestinal tumor biomarker. Irisin is adipo-myokines that has been suggested to have a potential role in cancer development. However, limited studies test irisin as biomarker in gastric and colorectal cancers. Therefore, this study aims to investigate whether CEA and irisin could be a potential diagnostic biomarker in gastric and colorectal cancer. Methods: A case-control study consists of ۹۰ subjects, ۲۱ gastric cancer patients, ۴۹ colorectal cancer patients and ۲۰ control. Serum CEA was detected by fluorescence immunoassay (FIA) kit. Serum irisin was determined by enzyme-linked immunosorbent assay (ELISA) kit. Results: Serum CEA increases significantly and serum irisin decreases significantly in gastric and colorectal cancer patients. According to Receiver  Operating Characteristic (ROC) curve analysis, in gastric cancer, the area under curve of CEA is ۱.۰۰ (۹۵% CI, ۱.۰۰۰-۱.۰۰۰, p< ۰.۰۰۰۱). The diagnostic cut-off of CEA is< ۳.۰۸ ng/ml with %۱۰۰ sensitivity and ۱۰۰% specificity. The area under curve of irisin is ۰.۹۴ (۹۵% CI, ۰.۸۱۷۷-۱.۰۰۰, p< ۰.۰۰۰۱). The cut-off of irisin is> ۳۰.۲ ng/ml with %۹۰ sensitivity and ۱۰۰%, specificity. In colorectal cancer, the area under curve of CEA is ۰.۹۹ (۹۵% CI, ۰.۹۸۶۶-۱.۰۰۰, p<۰.۰۰۰۱) and the diagnostic value< ۲.۶ ng/ml with %۹۸ sensitivity and %۱۰۰ specificity. The area under curve of irisin is ۰.۹۶ (۹۵% CI, ۰.۹۱۵۵-۱.۰۰۰, p< ۰.۰۰۰۱). The diagnostic cut-off of irisin is> ۴۱.۹ ng/ml with ۸۸.۱sensitivity and ۹۰.۵ specificity. Conclusions: CEA and irisin could be powerful potential diagnostic biomarkers which would be use for early detection of gastric and colorectal cancers.

Biomarker, Carcinoembryonic antigen (CEA), Colorectal cancer, Gastric cancer, Irisin.