USE OF RADIOIMMUNOGUIDED SURGERY AFTER INDUCTION CHEMOTHERAPY IN LOCALLY ADVANCED BREAST-CANCER

Twenty-one patients with histologically proven locally advanced breast cancer (LABC) were treated with a combined modality approach based on primary chemotherapy and radical modified mastectomy followed by adju vant chemotherapy. Surgery was performed by using radioimmunoguided su rgery (RIGS) technique with the preoperative injection of Iodine-125 l abeled monoclonal antibodies (MoAbs) B72.3 anti-TAG (11 patients, Grou pA) and F023C5 anti-carcinoembryonic antigen (CEA; 10 patients, Group B). The role of RIGS was defined at surgery by using an intraoperative hand-held gamma-detecting probe (GDP) to locate the primary tumor, po ssible clinically occult multicentric foci and ipsilateral lymph node metastases. In Group A, RIGS correctly defined the primary tumor in se ven out of 11 patients (63.3%) and was able to find multicentric tumor s in two out of four patients (50%). Positive lymph nodes were identif ied by RIGS in three out of eight patients (37.5%). In Group B, patien ts RIGS correctly located the primary in 4/10 cases (40%); in two RIGS -positive cases, the tumor was clinically not evident after primary ch emotherapy (yT0). RIGS correctly identified multicentric foci of tumor in one out of two cases (50%). Correct lymph nodal RIGS assessment wa s observed in three out of nine patients (33.3%). No RIGS false-positi ve findings occurred in the 21 patients included in the study. RIGS ap pears to be a reliable technique for the intraoperative diagnosis and staging of breast cancer with a potential role especially when conserv ative surgery is planned after primary chemotherapy in LABC. Semin. Su rg. Oncol. 25:245-248, 1998. (C) 1998 Wiley-Liss, Inc.