BACKGROUND & OBJECTIVE: Carcinoembryonic antigen (CEA) monitoring plays an important role in the management of malignancies, especially in colorectal cancer (CRC). The half-life (T1/2) of CEA has also been applied as a new predictor in the surveillance of some malignancies. This study was to examine the preoperative and early postoperative levels of CEA in CRC patients and calculate postoperative T1/2 of CEA to evaluate its potential role in prognosis prediction. METHODS: In this retrospective study, 98 CRC patients who had preoperatively elevated levels of CEA (>or=5 microg/L) and serum CEA surveillance after radical operation were included. Postoperative T1/2 of CEA was calculated. Its correlation to prognosis was analyzed. RESULTS: Of the 98 patients, 21 had local recurrence or distant metastasis (recurrence group), 77 had no recurrence (non-recurrence group). The median value of preoperative CEA level was significantly higher in recurrence group than in non-recurrence group (23.9 microg/L vs. 12.3 microg/L, P=0.010); the median value of postoperative T1/2 of CEA was significantly longer in recurrence group than in non-recurrence group (6.2 days vs. 4.7 days, P=0.042); the later the TNM stage was, the poorer the prognosis was (P<0.001). The 3-year disease-free survival (DFS) rate and overall survival (OS) rate were significantly higher in the patients with postoperative T1/2 of CEA of <4.8 days than in those with T1/2 of >or=4.8 days (87% vs. 66%, P=0.017; 90% vs. 80%, P=0.032). The patients at earlier TNM stage had survival benefits both in DFS and OS: the 3-year DFS rates in stage I, II, and III patients were 100%, 93%, and 55%, respectively (P<0.001); the 3-year OS rates were 100%, 98%, and 77%, respectively (P=0.192). In Cox regression analysis, both TNM stage and postoperative T1/2 of CEA were confirmed to be independent prognostic factors of CRC patients with preoperatively elevated CEA level. CONCLUSIONS: In addition to TNM stage, the T1/2 of CEA may be an independent prognostic factor in CRC patients with preoperatively elevated CEA level. The patients with longer T1/2 of CEA after radical operation have poorer prognosis.
BACKGROUND & OBJECTIVE:Carcinoembryonic antigen (CEA) monitoring plays an important role in the management of malignancies, especially in colorectal cancer (CRC). The half-life (T1/2) of CEA has also been applied as a new predictor in the surveillance of some malignancies. This study was to examine the preoperative and early postoperative levels of CEA in CRCpatients and calculate postoperative T1/2 of CEA to evaluate its potential role in prognosis prediction. METHODS: In this retrospective study, 98 CRCpatients who had preoperatively elevated levels of CEA (>or=5 microg/L) and serum CEA surveillance after radical operation were included. Postoperative T1/2 of CEA was calculated. Its correlation to prognosis was analyzed. RESULTS: Of the 98 patients, 21 had local recurrence or distant metastasis (recurrence group), 77 had no recurrence (non-recurrence group). The median value of preoperative CEA level was significantly higher in recurrence group than in non-recurrence group (23.9 microg/L vs. 12.3 microg/L, P=0.010); the median value of postoperative T1/2 of CEA was significantly longer in recurrence group than in non-recurrence group (6.2 days vs. 4.7 days, P=0.042); the later the TNM stage was, the poorer the prognosis was (P<0.001). The 3-year disease-free survival (DFS) rate and overall survival (OS) rate were significantly higher in the patients with postoperative T1/2 of CEA of <4.8 days than in those with T1/2 of >or=4.8 days (87% vs. 66%, P=0.017; 90% vs. 80%, P=0.032). The patients at earlier TNM stage had survival benefits both in DFS and OS: the 3-year DFS rates in stage I, II, and III patients were 100%, 93%, and 55%, respectively (P<0.001); the 3-year OS rates were 100%, 98%, and 77%, respectively (P=0.192). In Cox regression analysis, both TNM stage and postoperative T1/2 of CEA were confirmed to be independent prognostic factors of CRCpatients with preoperatively elevated CEA level. CONCLUSIONS: In addition to TNM stage, the T1/2 of CEA may be an independent prognostic factor in CRCpatients with preoperatively elevated CEA level. The patients with longer T1/2 of CEA after radical operation have poorer prognosis.