Clinical Significance of Preoperative High Serum CEA Value in Patients with Colorectal Cancer

ABSTRACT

PURPOSE: The preoperative s-CEA level are correlated to the extent of the tumor and distant metastasis in patients with colorectal cancer. This study was performed to analyze patterns of distant metastasis and survival rate according to the levels of preoperative s-CEA and evaluate the significance of chest CT and bone scan as methods of preoperative staging work-up in patients with high s-CEA level (>or=20 ng/ml). METHODS: A retrospective study was performed on 1,136 colorectal cancer patients who underwent surgery in Asan medical center between 1989 and 1995. These patients were classified into 3 groups according to preoperative s-CEA level (group A or=6,or=20). We scrutinized the patterns of metastasis and compared the survival rates between the groups. Another study was, then, conducted prospectively on the basis of the above results. One hundred and sixty nine patients with s-CEA level (>or=20 ng/ml) were routinely examined by chest CT and bone scan for preoperative metastatic work-up in addition to the conventional work-up. Statistical analysis was performed by chi-squared test, Kaplan-Meier and log-rank test. RESULTS: The preoperative s-CEA level and the tumor stages were significantly correlated (P=0.009). The distant metastasis rates in group A, B, and C were 22.7% (163/719), 49.1% (115/234), 76.5% (140/183), respectively (P=0.000). Five year survival rate of each group were significantly different in far advanced stage, stage III (0.71 vs. 0.61 vs. 0.51 P=0.002) and stage IV (0.21 vs. 0.10 vs. 0.05 P=0.004). In stage I and II, however, we couldn't find statistical differences. Among 169 patients with s-CEA level above 20ng/ml, 52 (30.7%) had liver metastasis. Twenty three patients (13.6%) had lung metastasis. Twenty (11.8%) cases of pulmonary metastasis were found on chest CT scan and 3 cases on chest X-ray or abdominal CT scan. Only 4 (2.4%) cases, however, had bone metastasis on bone scan. CONCLUSIONS: These results suggest that the high preoperative s-CEA level seemed to be closely correlated with distant metastasis and prognosis. A meticulous preoperative staging work-up including chest CT scan is recommended in patients with high preoperative s-CEA level.