High preoperative serum carcinoembryonic antigen predicts metastatic recurrence in potentially curative colonic cancer: Results of a five-year study

Abstract

INTRODUCTION: Serum carcinoembryonic antigen is used mainly for tumor follow-up to detect recurrence of colonic cancer. However, raised preoperative carcinoembryonic antigen levels may be helpful for the identification of understaged cases and of patients meriting more intensive preoperative and postoperative diagnostic workup. METHODS: From a prospectively collected database, the data on 261 patients who had curative colonic carcinoma with a minimal follow-up of five years and who had preoperative carcinoembryonic antigen levels assessed were retrieved and analyzed. Outcome parameters were local and/or distant recurrence and time to recurrence. These parameters were correlated with Dukes staging and preoperative carcinoembryonic antigen levels. RESULTS: The cumulative diseasefree survival of patients with a preoperative carcinoembryonic antigen level within the normal range was significantly better than that of those whose carcinoembryonic antigen was 5 ng/ml or more (P=0.001). No patient with carcinoembryonic antigen levels less than 1 ng/ml developed metastatic recurrence. Twenty-three percent of all patients with a raised carcinoembryonic antigen above 5 ng/ml compared with 2.1 percent of patients with carcinoembryonic antigen below 5 ng/ml developed a metastasis at two years. At five years, these figures were 37.2 percent and 7.5 percent, respectively. Dukes staging and carcinoembryonic antigen levels were found to be directly correlated (P<0.001) when all patients were included. Carcinoembryonic antigen of more of 15 ng/ml was found to be a significant adverse prognostic indicator for disease-free survival irrespective of Dukes staging (P<0.02). Raised carcinoembryonic antigen levels predicted distant metastatic recurrence (P<0.001) but did not predict local recurrence (P=0.72). CONCLUSIONS: High preoperative carcinoembryonic antigen levels above 15 ng/ml predicted an increased risk of metastatic recurrence in potentially curative colonic cancer and may indicate undetectable disseminated disease. Preoperative carcinoembryonic antigen levels predict understaging and the possibility of distant recurrence. Such patients may therefore be selected for adjuvant therapy where indicated. Therefore, carcinoembryonic antigen is complementary to conventional Dukes staging for the prediction of recurrence and survival.