ABSTRACT
The tumours of 55 patients with colorectal carcinoma were evaluated for tissue carcinoembryonic antigen (CEA) by immunoperoxidase staining. It was shown that 33/35 patients with increased preoperative serum CEA levels above 5 ng/ml had positive tissue CEA. The other 17/20 patients who had serum CEA levels less than 5 ng/ml could be demonstrated CEA in tissue. The results of tissues CEA were compared with their preoperative serum CEA levels in the pathologic grading, histologic type and staging of cancer. It was found that tissue CEA was more sensitive than serum CEA and was correlated with serum CEA in all respects. The finding in this study suggests that tissue CEA should be performed along with preoperative serum CEA in all patients suspected of having colorectal carcinoma. The postoperative serum CEA should be determined serially in the patients who have more than 5 ng/ml serum CEA and/or tissue CEA positive although their preoperative serum CEA is less than 5 ng/ml.