RADIOIMMUNOGUIDED SURGERY BENEFITS IN CARCINOEMBRYONIC ANTIGEN-DIRECTED 2ND-LOOK SURGERY IN THE ASYMPTOMATIC PATIENT AFTER CURATIVE RESECTION OF COLORECTAL-CANCER

Radioimmunoguided surgery (RIGS) with radiolabeled monoclonal antibodi es (MoAbs) has been reported as useful in second-look colorectal cance r procedures to improve surgical decision-making by helping avoid need less extensive surgery and expanding curative resection to sites of re currence that have been missed previously. Sixteen asymptomatic patien ts with an history of colorectal cancer surgery underwent second-look surgery using the RIGS system, solely on the basis of rising serum lev els of carcinoembryonic antigen (CEA). All patients were injected preo peratively with the anti-tumor-associated glycoprotein (TAG) I-125-lab eled MoAb B72.3. Both traditional and RIGS exploration were used to de termine the extension of a possible recurrence and its resectability f or cure. Recurrent disease was observed in 14 of the 16 patients as th e result of this combined exploration. Exploration alone showed the pr esence of recurrent disease in 9 of 16 patients (56.2%). Thus, RIGS fo und overlooked tumor in five patients (31.2%). All the additional RIGS -detected tumor sites were locoregional recurrences resectable for cur e; conversely, no diagnostic improvements were shown in patients with liver metastases. Resection for cure was obtained by this approach in 9 of 16 patients (56.2%). Two patients without disease at the explorat ory laparotomy recurred within 2 months at sites away from the abdomen . RIGS improved the results of colorectal cancer CEA-guided second-loo k procedures in asymptomatic patients by recruiting one-third of patie nts to curative resections. Semin. Surg. Oncol. 15:263-267, 1998. (C) 1998 Wiley-Liss, Inc.