Perioperative serum carcinoembryonic antigen: Powerful marker for prognostic prediction and adjuvant chemotherapy decision-making in patients with stage II and III colorectal cancer

BACKGROUND Assessment of the prognosis, follow-up monitoring, and adjuvant treatment decision-making for patients with stage II and III colorectal cancer (CRC) are controversial, as CRC harbors tremendous heterogeneity. Carcinoembryonic antigen (CEA) is an important tumor marker; however, the use of this marker in the management of CRC has not garnered adequate attention. AIM To determine the significance of perioperative CEA levels in prognostic stratification and treatment decision making to provide personalized diagnosis and treatment for patients with stage II and III CRC. METHODS Patients in the training and validation cohorts were diagnosed with primary stage II or III CRC. Preoperative CEA (pre-CEA) and postoperative CEA (post-CEA) were collectively defined as perioperative CEA. Kaplan-Meier (K-M) survival analyses were used to describe patient survival. Cox stepwise regression analysis based on Akaike information criterion was used to determine the prognostic value of clinicopathological characteristics. Nomograms were developed to predict the probability of overall survival (OS) and disease-free survival (DFS). Annual hazard curves and pie charts were used to demonstrate the features of recurrence or metastasis. Differences were considered statistically significant at P < 0.05. RESULTS A total of 2496 and 1293 patients were included in the training and validation cohorts, respectively. K-M analysis indicated that patients with elevated perioperative CEA had poorer OS and DFS, with post-CEA being an independent prognostic factor for OS and DFS. Nomograms based on factors associated with prognosis were constructed, which showed good predictive ability for 3-, 5-, and 7-year OS and DFS. Patients with elevated perioperative CEA were more likely to have recurrence or metastasis, and the period of the second year after surgery was the peak time of recurrence or metastasis. OS and DFS were significantly worse in patients without adjuvant chemotherapy when they had elevated perioperative CEA. Adjuvant chemotherapy could significantly improve the OS of patients with elevated perioperative CEA. Patients with elevated post-CEA who received XELOX could achieve better OS and DFS. CONCLUSION Perioperative CEA demonstrate sufficient sensitivity in the prognosis prediction and follow-up of patients with stage II and III CRC. Furthermore, perioperative CEA, especially post-CEA, show promise in guiding adjuvant chemotherapy, suggesting potential for further study.