Perioperative Serum Carcinoembryonic Antigen Ratio Is a Prognostic Indicator in Patients With Stage II Colorectal Cancer.

PURPOSE: The aim of this study was to evaluate whether the perioperative carcinoembryonic antigen (CEA) ratio could be used as a determinant for adjuvant therapy after curative surgery in stage II colorectal cancer. METHODS: Data for 119 patients with stage II colorectal cancer who underwent radical surgery between 2010 and 2013 were collected. The perioperative CEA ratio was defined as the postoperative/preoperative serum CEA level, and the patients were grouped according to their perioperative CEA ratios: high ratio (≥0.5) and low ratio (<0.5). Overall survival rates were calculated, and their prognostic significances were analyzed. RESULTS: The overall survival rates of the high and the low perioperative CEA groups were 68.2% and 86.8%, respectively (P = 0.033). In patients with normal preoperative CEA levels (<5 ng/mL), the high perioperative CEA ratio group showed a worse survival rate than the low perioperative CEA ratio group (71.7% vs. 100.0%, P = 0.007). In patients with high preoperative CEA levels (≥5 ng/mL), the high perioperative CEA ratio group showed a worse survival rate than the low perioperative CEA ratio group (33.3% vs. 75.0%, P = 0.036). In the multivariate analysis, perioperative CEA ratio (P = 0.046), age (P = 0.034), and venous invasion (P = 0.015) were independent prognostic factors for survival. CONCLUSION: The perioperative CEA ratio is a prognostic indicator for stage II colorectal cancer. Patients with normal preoperative serum CEA levels might also be considered for adjuvant therapy if their perioperative CEA ratios are higher than 0.5.