Diagnostic Accuracy of Carcinoembryonic Antigen (CEA) in Detecting Colorectal Cancer Recurrence Depending on Its Preoperative Level

Background Serum carcinoembryonic antigen (CEA) increase in patients with colorectal cancer (CRC) recurrence was observed to vary depending on their initial values. This study aimed to evaluate the diagnostic accuracy of CEA for detecting CRC recurrence in patients with normal and elevated initial CEA levels. Methods A total of 261 CRC recurrence patients who underwent curative resection were included and divided into two groups, normal and elevated initial CEA. Analysis was performed comparing patient, tumor, and recurrence characteristics retrospectively. Results There were 192 patients with normal and 69 with high initial CEA levels. Patient and tumor characteristics were similar. Eighty-six patients had elevated CEA at the time of recurrence, and the overall sensitivity of CEA for recurrence was 33.0%. In the high initial CEA group, 59.4% exhibited increased CEA level at recurrence, whereas in patients with normal initial CEA levels, only 23.4% showed elevated levels ( p