Clinical Performance of CEA, CA19-9, CA15-3, CA125 and AFP in Gastrointestinal Cancer Using LOCI™-based Assays

Background/Aim: Few data are available regarding the clinical performance of LOCI (TM)-based tumor marker assays. We investigated the diagnostic power of carcinogenic antigen, carbohydrate antigen 19-9, carbohydrate antigen 15-3, carbohydrate antigen 125 and alpha-fetoprotein for detection of gastrointestinal (GI) cancer. Patients and Methods: We analyzed sera from 204 patients (107 with GI cancer, 73 with benign GI diseases and 24 healthy controls) using the Dimension (TM) Vista1500 analyzer. Results: Levels of biomarkers in healthy controls were in the expected ranges and were only slightly higher in benign GI controls. Established tumor-type-associated markers were elevated in specific cancer types and discriminated well between cancer and benign controls. Best performance was found for CEA in colorectal cancer (area under the curve=0.84, sensitivity=51.7% at 95% specificity vs. benign), CA19-9 in gallbladder/pancreatic cancer (AUC=0.85, sensitivity=60.6%) and AFP in liver cancer (AUC=0.87, sensitivity=68.4%). Conclusion: Our study demonstrated the high diagnostic power of well-known biomarkers. LOCI (TM)-based tumor marker assays give reliable results in routine diagnostics.