OBJECTIVETo explore the clinicopathological characteristics and prognosis of colon cancer patients with extremely elevated serum carcinoembryonic antigen(CEA) level before operation(>50 μg/L).

METHODSClinicopathological and follow-up data of 1250 patients with colonic adenocarcinoma undergoing primary tumor resection between January 2001 and December 2011 were retrospectively analyzed. All the patients were divided into three groups according to the preoperative serum CEA levels as normal group (0-5 μg/L, 721 cases), elevated group(5-50 μg/L, 408 cases) and extremely elevated(>50 μg/L, 121 cases). Kaplan-Meier method was used to analyze the overall survival and disease-free survival. Log-rank test was used to compare the survival between groups. Cox regression was used to screen the independent prognostic factors of colon cancer.

RESULTSCompared with normal and elevated groups, patients with extremely elevated CEA had more advanced T,N,M stages (P<0.01), more palliative surgery (P<0.01) and more lymphovascular invasion(P<0.01). During the follow-up, patients with extremely elevated CEA demonstrated significantly higher ratio of distant metastases and liver metastases (both P=0.001). After radical surgery, 5-year overall survival rate of patients with normal, elevated and extremely elevated CEA levels was 70.1%, 54.4% and 42%, respectively, with statistically significant difference among three groups (P<0.001). Multivariate analysis showed that tumor differentiation, TNM staging, preoperative CEA levels, lymphovascular invasion and adjuvant chemotherapy were independent prognostic factors for colon cancer (all P<0.01).

CONCLUSIONSColon cancer patients with extremely elevated preoperative CEA levels are associated with more unfavorable pathological factors, advanced TNM stage and more distant metastases (especially the liver metastases) during the follow-up. The elevated degree of preoperative CEA level is an independent poor prognostic factor of patients with colon cancer.