ROLE OF CARCINOEMBRYONIC ANTIGEN IN PREDICTING RESECTABILITY OF RECURRENT COLORECTAL-CANCER

The reported low resectability rate for patients with recurrent colore ctal cancer who have carcinoembryonic antigen (CEA) levels > 11 has le d us to perform this study. One hundred twenty-four patients who under went Radioimmunoguided Surgery(R) (RIGS) procedures for recurrent colo rectal cancer from 1986 to the present were studied. In surgery, all p atients underwent a traditional exploration followed by survey with a hand-held, gamma-detecting probe to detect preinjected radiolabeled mo noclonal antibodies attached to cancer cells. Sites of metastases incl uded: 72 liver (58.1 percent), 23 pelvis (18.5 percent), 1 5 distant l ymph nodes ( 1 2. 1 percent), 2 anastomotic (1.6 percent), and 12 othe r sites (9.7 percent). The resectability rate was 43.5 percent (54 pat ients). The mean preoperative CEA level for patients with resectable d isease was significantly lower than for patients with unresectable dis ease (P = 0.0 1 7): unresectable-mean, 87.1; SD, 141.0; minimum, 0.3; maximum, 501; resectable-mean, 36.6; SD, 59.3; minimum, 0.3; maximum, 329. The CEA level for patients with liver metastasis did not vary sig nificantly from those patients without metastasis: 70 vs. 58.2 (P = 0. 58). Those patients with resectable liver tumors had lower mean CEA le vels than those with unresectable liver, approaching significance: 41. 6 vs. 91.9 (P = 0.065). Other metastatic sites had a mean CEA level of : pelvic, 72.6; distant lymph nodes, 47.8; anastomotic, 2.7; and other sites, 53.8. These data suggest that there is a significant differenc e between the preoperative CEA level of the resectable and unresectabl e recurrent colorectal cancer patients, but the large standard deviati on does not justify abandonment of exploration for any CEA level.