Clinical Usefulness of Postoperative Serum Carcinoembryonic Antigen in Patients with Colorectal Cancer with Liver Metastases

Background Colorectal cancer with liver metastasis (CLM) has high postoperative recurrence rates; therefore, optimizing perioperative treatment is imperative. Postoperative carcinoembryonic antigen (CEA) can aid in detecting minimal residual disease in colon cancer following curative resection. This study aimed to identify the potential role of serum CEA following liver resection in patients with CLM. Methods This retrospective study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 2004 to 2018 and enrolled patients with CLM who underwent complete resection of primary tumors and CLM. Associations between perioperative CEA levels and characteristics of recurrence were investigated. Results Recurrence was detected during a median follow-up period of 90.1 months in 343 (54.2%) out of 633 analyzed patients. Patients in the postoperative CEA level > 5 ng/ml group had a significantly higher recurrence rate (75.7% versus 50.0%, p < 0.01) and shorter time until recurrence (4.4 versus 36.9 months, p < 0.01) than those in the postoperative CEA level ≤ 5 ng/ml group. Multivariate analysis revealed that postoperative CEA level > 5 ng/ml was an independent predictor, with hazard ratios of 2.77 ( p < 0.01) for recurrence-free survival (RFS) and 3.18 ( p < 0.01) for overall survival (OS). Additionally, RFS was significantly shorter among patients in the postoperative CEA level > 5 ng/ml group who did not have normalized CEA levels following adjuvant chemotherapy than among those in the normalized CEA group. Conclusions The postoperative and post-adjuvant chemotherapy CEA levels in the CEA level > 5 ng/ml group may be predictors of RFS and OS.