Three timepoint perioperative CEA levels are a prognostic factor for recurrence after adjuvant chemotherapy in patients with Stage II and III colorectal cancer

Aim To investigate the relationship between the three timepoint perioperative CEA (ttpCEA) calculated at three timepoints and recurrence during the perioperative period in Stage II and III colorectal cancer (CRC) patients. Methods We performed a multi‐institutional retrospective analysis of patients with Stage II and III CRC who underwent surgery and adjuvant chemotherapy from 2010 to 2020. Patient data from three facilities were used as training data, and data from three other facilities were used as validation data. The primary endpoint was the time to recurrence (TTR). Results A total of 538 patients were included for the training data. To validate the feasibility of ttpCEA, 329 patients were included for the validation data. Training data patients were categorized as ttpCEA low ( n = 365) and ttpCEA high ( n = 173). The 5‐y TTR was significantly greater in the ttpCEA‐low subgroup than in the ttpCEA‐high subgroup (84.3% vs. 69.6%, respectively; p < 0.001). Validation data patients were categorized as ttpCEA low ( n = 221) and ttpCEA high ( n = 108). The 5‐y TTR was significantly greater in the ttpCEA‐low subgroup than in the ttpCEA‐high subgroup (82.9% vs. 68.7%, respectively; p = 0.003). Conclusion The ttpCEA calculated from perioperative CEA levels at different timepoints was a prognostic factor for recurrence in Stage II and III CRC patients who underwent adjuvant chemotherapy according to both the training and validation data.