en بیوشیمی Biochemistry مقالات اصلی Original Article <div style="text-align: justify;"><strong><em>Background:</em></strong> Carcinoembryonic antigen (CEA) is a common gastrointestinal tumor biomarker. Irisin is&nbsp;adipo-myokines that has been suggested to have a potential role in cancer development. However, limited&nbsp;studies test irisin as biomarker in gastric and colorectal cancers. Therefore, this study aims to investigate&nbsp;whether CEA and irisin could be a potential diagnostic biomarker in gastric and colorectal cancer.<br> <br> <strong><em>Methods:</em></strong> A case-control study consists of 90 subjects, 21 gastric cancer patients, 49 colorectal cancer&nbsp;patients and 20 control. Serum CEA was detected by fluorescence immunoassay (FIA) kit. Serum&nbsp;irisin was determined by enzyme-linked immunosorbent assay (ELISA) kit.<br> <br> <strong><em>Results:</em></strong> Serum CEA increases significantly and serum irisin decreases significantly in gastric and&nbsp;colorectal cancer patients. According to Receiver&nbsp; Operating Characteristic (ROC) curve analysis, in&nbsp;gastric cancer, the area under curve of CEA is 1.00 (95% CI, 1.000-1.000, p< 0.0001). The diagnostic<br> cut-off of CEA is< 3.08 ng/ml with %100 sensitivity and 100% specificity. The area under curve of irisin&nbsp;is 0.94 (95% CI, 0.8177-1.000, p< 0.0001). The cut-off of irisin is> 30.2 ng/ml with %90 sensitivity and&nbsp;100%, specificity. In colorectal cancer, the area under curve of CEA is 0.99 (95% CI, 0.9866-1.000, p<0.0001) and the diagnostic value< 2.6 ng/ml with %98 sensitivity and %100 specificity. The area under&nbsp;curve of irisin is 0.96 (95% CI, 0.9155-1.000, p< 0.0001). The diagnostic cut-off of irisin is> 41.9 ng/ml&nbsp;with 88.1sensitivity and 90.5 specificity.<br> <br> <em><strong>Conclusions:</strong></em> CEA and irisin could be powerful potential diagnostic biomarkers which would be use&nbsp;for early detection of gastric and colorectal cancers.</div> Biomarker, Carcinoembryonic antigen (CEA), Colorectal cancer, Gastric cancer, Irisin. 488 494 http://rbmb.net/browse.php?a_code=A-10-707-2&slc_lang=en&sid=1 Ahmed Abd Temur 100319475328460012575 100319475328460012575 No Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq. Farah Aqeel Rashid far@sc.nahrainuniv.edu.iq. 100319475328460012576 100319475328460012576 Yes Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq.