Antibody-guided diagnosis: an Italian experience on CEA-expressing tumours.

Within the Italian CNR Biomedical Technology programmes a large multicentre clinical trial on CEA-expressing carcinomas has been carried out. F(ab')2 fragments of anti-CEA monoclonal antibody (MAb) FO23C5, radiolabelled with either 131I or 111In, were supplied to 10 different Italian nuclear medicine departments. Over 500 patients with gastrointestinal, lung, breast, and other carcinomas have been investigated. The results obtained in our nuclear medicine department are reported here. In GI cancer group, the 131I compound showed better results except in liver metastases detected only in 28/57 patients. In the lung cancer group, very satisfactory results were achieved in primary tumours and local or systemic recurrences: 111In tracer was preferentially used. In the breast cancer group immunoscintigraphy proved to be helpful in differential diagnosis of neoplastic and benign bone lesions. Significant improvements of diagnostic sensitivity were achieved in GI cancer patients by means of i.p. administration. Finally, 12 patients with advanced disease were given different 131I radioiodinated MAbs (100 mCi average dose). Administration route was either i.v. (3 cases) or i.p. (9 cases). Clinical and instrumental evidence of complete (1) or partial (7) response was observed in 8 patients.