Original Article

Purpose: The serum level of carcinoembryonic antigen (CEA) is a clinical prognostic factor in the follow-up evaluation of patients with colon cancer. We aimed to evaluate the prognostic significance of the rate of decrease of the perioperative serum CEA level in patients with colon cancer after a curative resection. Methods: A total of 605 patients who underwent a curative resection for colon cancer between January 2000 and Decem-ber 2007 were enrolled retrospectively. The rate of decrease was calculated using the following equation: ([preoperative CEA – postoperative CEA]/[preoperative CEA] ×100). Results: In the group with a preoperative serum CEA level of>5 ng/mL, the normalized group with a postoperative serum CEA level of ≤5 ng/mL showed a better overall survival (OS) rate and disease-free survival (DFS) rate than those of the non-normalized group (P ≤ 0.0001). The “cutoff values ” of the rate of decrease in the perioperative serum CEA that determined the OS and the DFS were 48.9 % and 50.8%, respectively. In the multivariate analysis of preoperative serum CEA levels>5 ng/mL, the prognostic factors for the OS and the DFS were the cutoff value (P < 0.0001) and the pN stage (P < 0.0001). Conclusion: A rate of decrease of more than 50 % in the perioperative serum CEA level, as well as the normalization of the postoperative serum CEA level, may be useful factors for determining a prognosis for colon cancer patients with high pre-operative CEA levels