The Value of Postoperative Serum Carcinoembryonic Antigen and Carbohydrate Antigen 19-9 Levels for the Early Detection of Gastric Cancer Recurrence after Curative Resection

Purpose: This study aimed to evaluate the value of serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels to detect gastric cancer recurrence. Materials and Methods: We retrospectively reviewed 154 patients who developed recurrence within 2 years after curative gastric cancer surgery and analyzed the relationship between postoperative CEA and CA19-9 levels and recurrence. We readjusted the cut-off values to improve the detection of recurrence. Subgroup analysis according to clinicopathologic variables was performed to further investigate the relationship between recurrence and CEA and CA19-9 levels. Results: The sensitivity and specificity for elevated CEA levels to detect recurrence were 40.6% and 89.5%, respectively, and those for CA19-9 were 34.2% and 93.6%, respectively. The sensitivity and specificity for elevation of either tumor marker were 54.3% and 84.0%, respectively; those for elevation of both tumor markers were 19.2% and 98.4%, respectively. By readjusting the cut-off values from 5.0 ng/ml to 5.2 ng/ml for CEA and from 37.00 U/ml to 30.0 U/ml for CA19-9, the sensitivity was increased from 34.2% to 40.2% for CA19-9, while there was no increase in sensitivity for CEA. In subgroup analysis, the sensitivity of CEA was higher in patients with elevated preoperative CEA levels than in patients with normal preoperative CEA levels (86.7% versus 33.7%; P<0.001). Furthermore, the sensitivity of CA19-9 was higher in patients with elevated preoperative CA19-9 levels than in patients with normal preoperative CA19-9 levels (82.61% versus 26.83%; P<0.001). Conclusions: CEA and/or CA19-9 measurement with the readjusted cut-off values allows for more effective detection of gastric cancer recurrence.