Is carcino-embryonic antigen useful in the follow-up management of patients with colorectal liver metastases?

BACKGROUND: The role of carcino-embryonic antigen (CEA) in monitoring early detection of recurrent or metastatic colorectal cancer, and its impact on resectability rate and patient survival remains controversial. Our objective was to determine any association between the preoperative level of CEA and prognosis, and the resectability and survival by method of diagnosis of colorectal hepatic metastases.

METHODS: We analyzed patients who underwent exploration for hepatic resection for metastatic colorectal cancer over a 15-year period. The patient population consisted of those patients who had undergone primary colon or rectal resection and were followed up with serial CEA levels and of patients who were followed up with physical examination, liver function tests (LFTs) or computed tomography (CT) of the abdomen and pelvis that led to the diagnosis of liver metastases. Also included in the study were patients who were diagnosed with liver metastases at the time of the primary colon or rectal resection and underwent planned hepatic resection at a later time.

RESULTS: Three hundred and one (301) patients who underwent a total of 345 planned hepatic resections for metastatic colorectal cancer between January 1978 and December 1993 were included in this analysis. The median preoperative CEA level was 24.8 ng/mL in the resected group, 53.0 ng/mL in the incomplete resection group, and 49.1 ng/mL in the nonresected group (P = 0.02). More of the patients who had a preoperative CEA < or =30 ng/mL were in the resected group, while those who had a preoperative CEA >30 ng/mL were likely to be in the nonresected group (P = 0.002). The median survival was 25 months for patients with a preoperative CEA level < or =30 ng/mL and 17 months for patients with a preoperative CEA >30 ng/mL (P = 0.0005). The resectability rate and the survival of patients by method of diagnosing liver metastases-rising CEA versus history and physical, elevated LFTs, CT scan versus diagnosis at the time of primary resection-was not significant (P = 0.06 and P = 0.19, respectively). Given the nonstandardized retrospective nature of the study cohort and relative small groups of patients, the power to detect small differences in survival by method of diagnosis is limited. In the complete resection group of patients with unilobar liver disease (5-year survival of 28.8%) there was no difference in survival between those patients who had normal preoperative CEA and those who had elevated preoperative CEA, and approximately 90% of them had an abnormal preoperative serum CEA level.

CONCLUSIONS: CEA is useful in the preoperative evaluation of patients with hepatic colorectal metastases for assessing prognosis and is complimentary to history and physical examination in the diagnosis of liver metastases. Patients with colorectal liver metastases and preoperative CEA < or =30 ng/mL are more likely to be resectable, and they have the longest survival.