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

INTRODUCTION: Serum carcinoembryonic antigen is used mainly for tumor follo w-up to detect recurrence of colonic cancer. However, raised preoperative c arcinoembryonic antigen levels may be helpful for the identification of und erstaged cases and of patients meriting more intensive preoperative and pos toperative diagnostic workup. METHODS: From a prospectively collected datab ase, the data on 261 patients who had curative colonic carcinoma with a min imal follow-up of five years and who had preoperative carcinoembryonic anti gen levels assessed were retrieved and analyzed. Outcome parameters were lo cal and/or distant recurrence and time to recurrence. These parameters were correlated with Dukes staging and preoperative carcinoembryonic antigen le vels. RESULTS: The cumulative disease-free survival of patients with a preo perative carcinoembryonic antigen level within the normal range was signifi cantly 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 p atients with a raised carcinoembryonic antigen above 5 ng/ml compared with 2.1 percent of patients with carcinoembryonic antigen below 5 ng/ml develop ed a metastasis at two years. At five years, these figures were 37.2 percen t 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 irres pective of Dukes staging (P < 0.02). Raised carcinoembryonic antigen levels predicted distant metastatic recurrence (P < 0.001) but did not predict lo cal recurrence (P = 0.72). CONCLUSIONS: High preoperative carcinoembryonic antigen levels above 15 ng/ml predicted an increased risk of metastatic rec urrence in potentially curative colonic cancer and may indicate undetectabl e disseminated disease. Preoperative carcinoembryonic antigen levels predic t understaging and the possibility of distant recurrence. Such patients may therefore be selected fur adjuvant therapy where indicated. Therefore, car cinoembryonic antigen is complementary to conventional Dukes staging for th e prediction of recurrence and survival.