RADIOIMMUNOASSISTED FOLLOW-UP AND SURGERY VS TRADITIONAL EXAMINATIONSAND SURGERY AFTER RADICAL EXCISION OF COLORECTAL-CANCER

The authors report their experience in the radioimmunodetection of rec urrent colorectal cancer in comparison with traditional examinations. 485 patients were studied after radical surgery for colorectal cancer: 168 (group 1) were studied with a radioimmunoassisted follow-up plan including: Immunoscintigraphy (IS), serum markers assays, Radioimmunog uided Endoscopy (RIGE), Intraoperative Radioimmuno-localization (IORIL ) in case of reoperation; 317 (Group 2) underwent a protocol with trad itional examination. In 24 patients of Group U IS was performed even a t the time of their admission for primary cancer. 7 patients underwent RIGE for primary cancer and 16 in the follow-up. IORIL was performed in 12 patients with primary cancer and in 16 in the course of reoperat ion. The radioimmuno-diagnostic methods were performed after a single administration of the radiolabeled MAb (111In F(ab')2 a-CEA and 111In B72.3). The radioimmunoassisted follow-up plan detected a greater numb er of recurrences than traditional examinations (27% vs 13%). The rate s of radical reoperatin in Group 1 and 2 were 61% and 37% respectively . 33% of the patients of group 2 were alive 24 months after radical re operation vs 62.5% of the patients of Group 1. Immunoscintigraphy demo nstrated a good sensitivity and specificity, mainly in the detection o f pelvic recurrences (sens. 92%, spec. 84%). The radioimmunoassisted f ollow-up plan was well accepted by the patients management. IORIL dete cted minimal tumor foci (2 mm.) where pre and intraoperative study wer e negative, while the histopathologic examination gave evidence of tum or. Considering that the costs of the radioimmunodiagnostic methods an d of traditional examinations are very similar, we can conclude that t he radioimmunoassisted follow-up plan has a favorable cost/benefit rat e and a remarkable impact on the treatment of patients with colorectal cancer.