OBJECTIVE/BACKGROUND: This study aimed to analyze the hypothesis that increased percentage drop in serum CEA post curative resection for colon cancer is associated with improved survival.METHODS: Five hundred thirty three patients who underwent colon resection with a curative intent were retrospectively analyzed for their pre- and postoperative CEA levels. The disease-free and overall survival curves were calculated using Kaplan Meier analysis to evaluate cancer related outcomes. For multivariate analysis, the Cox regression model was used.RESULTS: The estimated 5-year overall survival for the preoperative serum CEA > 5 ng/mL group with respect to a postoperative CEA level drop rate of 40%, 50% and 60% were 72.9%, 80.9% and 81.8%, respectively. The estimated 5-year overall survival for the preoperative serum CEA ? 5 ng/mL group with respect to each postoperative CEA level drop rate were 86.6%, 97.1% and 97.7%, respectively (P = 0.257, P = 0.092 and P = 0.073, respectively). The prognostic factors for poor survival were the depth of invasion (p = 0.042, hazard ratio: 2.617, 95% CI = 1.021-3.012) and lymph node metastasis (p = 0.008, hazard ratio: 2.249, 95% CI = 1.231-4.111). A 60% drop of the CEA level was an independent prognostic factor for survival (p = 0.001, hazard ratio: 2.954, 95% CI = 1.686-5.176) for patients with a preoperative CEA level > 5 ng/mL.CONCLUSION: Determining the preoperative CEA level and the early postoperative percent drop of the serum CEA level may be a helpful factor for the prognosis of colon cancer patients. However, the percent drop from the pre to postoperative CEA level from the normal range was not associated with survival difference.
Adult Aged