THE CLINICOPATHOLOGICAL FEATURES OF COLORECTAL CANCERS WITH HIGH SERUM CONCENTRATION OF CEA, AND THE CLINICAL USEFULNESS OF POSTOPERATIVE CEA DETERMINATION FOR THE PREDICTION OF RECURRENT FOCI

Abstract

We investigated the clinicopathological features of colorectal cancers with positive serum CEA level in resected cases, and clinical value of postoperative CEA measurement for the prediction of recurrent foci. Positive CEA was defined as the serum concentration of more than 2.6 ng/ml. Of all colorectal cancer cases during the investigation period, 47% of them showed positive serum CEA level preoperatively. The incidence of preoperative serum CEA showed significant correlations with clinicopathological features such as a degree of venous invasion, hepatic metastasis and depth of invasion. However, histological type, maximum diameter of the tumor, lymphatic invasion or lymphnode metastasis showed no correlation with preoperative CEA level. Among the patients with positive preoperative CEA level followed by curative resection, 91% showed negative CEA level one or two months after operation. On the contrary, when the resection was non-curative one, only 25% of positive preoperative CEA turned to negative following the operation. In the light of this fact it was suggested that if positive CEA level didn't return to normal postoperatively, a possible presence of residual cancer lesion may be suspected. In 88% of patients with recurrence positive CEA level was noted. There was little difference in this incidence whether or not the preoperative CEA level showed positive. Most cases with recurrent foci showed the elevation in CEA prior to the appearance of clinical manifestations. Therefore it is concluded that postoperative CEA monitoring is considered to be very useful for the early detection of colorectal cancer recurrence.