Cutoff value of carcinoembryonic antigen and carbohydrate antigen 19-9 elevation levels for monitoring recurrence in patients with resectable gastric adenocarcinoma

Background The aim of this longitudinal study was to try and improve the specificity of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in monitoring tumor recurrence in patients with resectable gastric adenocarcinoma by setting suitable elevation levels. Methods One hundred eighty-one patients with resectable gastric adenocarcinoma were considered. Serum samples were obtained preoperatively and every 3 months postoperatively. Results Preoperative CEA and CA19-9 positivity rates were 19.9% and 18.2%. The specificity and sensitivity of CEA elevation to monitor recurrence were 92.9% and 23.4% versus 76.5% and 78.9% in CEA-negative versus CEA-positive patients, respectively. For CA19-9 the specificity and sensitivity were 95.0% and 18.8% versus 60.0% and 83.3% in CA19-9-negative versus CA19-9-positive patients, respectively. When we set the elevation level of CEA at 5 ng/mL, the specificity of CEA elevation to monitor recurrence increased to 94.1% for CEA-positive patients. The specificity increased to 93.3% for CA19-9-positive patients when the CA19-9 elevation level was set at 100 U/mL. Conclusions For CEA- or CA19-9-positive patients with resectable gastric adenocarcinoma we can increase the specificity of CEA and CA19-9 by setting the elevation level of CEA at 5 ng/mL and CA19-9 at 100 U/mL.