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

BackgroundSerum 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.MethodsA 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.ResultsThere 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 < 0.001). Patients with both high CEA preoperatively and at recurrence had more local recurrence, but there was no statistical significance (p = 0.053), and the rate of lung metastasis was higher in patients whose CEA remained normal at recurrence (38.3% vs. 24.4%, p = 0.026). The overall survival of patients with elevated CEA at recurrence was worse than those with normal CEA levels (56.9% vs. 42.4%, p = 0.003).ConclusionThe diagnostic accuracy of CEA for detecting recurrence depends on initial CEA level. Regardless of the initial CEA level, elevation at recurrence was significantly associated with overall survival in patients with recurrent CRC.