Characteristics of adenocarcinomas of the colorectum with low levels of preoperative plasma carcinoembryonic antigen (CEA).

Carcinoembryonic antigen (CEA) is evaluated preoperatively and then serially postoperatively in 97 patients with colorectal carcinoma. CEA is initially elevated (greater than 2.5 ng/ml) only in 58% of the these patients. The group without preoperative CEA elevation has a statistically significant higher proporation of Dukes A lesions (p less than 0.05), seems less likely to suffer recurrence or have CEA elevation at the time of recurrence, and has a longer disease-free interval, than the group with preoperative CEA elevation. However, no distinction between the two groups can be made on the basis of the patients age, sex, presenting signs and symptoms, or location and size of their primary lesions. Higher postoperative CEA values are associated with liver metastases in both groups.