Prognostic significance of perioperative change of CEA level in colorectal patients when pre-operative level is normal

Background/Aims: The prognostic role of serum carcinoembryonic antigen (CEA) in colorectal cancer patients with normal preoperative level is questionable. We evaluate the perioperative change of serum CEA to elucidate its prognostic effect in these patients. Methodology: We reviewed patients who received curative resection of colorectal cancer during 2000 and 2004 at Taipei Veterans General Hospital. The serum CEA level at diagnosis and one month after curative surgery were recorded. Levels higher than 5ng/mL were defined as abnormal. We divided patients with normal preoperative CEA level into two groups depending on the perioperative change. They were analyzed with clinicopathological factors and disease free survival rate. Results: In patients with stage I to III colorectal cancer, there were 738 patients with normal preoperative CEA level (55.7%). Patients with increased post-operative CEA than pre-operative ones had higher percentage of colon cancer (p=0.007) and more lymphovascular invasion (p=0.038). Besides they also had higher disease recurrent rate (p=0.032) and worse disease-free survival (p=0.019). In multivariate analysis, perioperative CEA change, lymph node metastasis and tumor invasion depth remained independent prognostic factors (p=0.015). Conclusions: When preoperative CEA level is normal, perioperative change is a prognostic factor of colorectal cancer.