Predictive value of neoadjuvant chemotherapy failure in breast cancer using FDG-PET after the first course

563 Background: To prospectively evaluate the predictive value of FDG-PET to detect the absence of clinical and pathological response to preoperative chemotherapy in patients (pts) with breast cancer. Methods: 63 consecutive pts with nonmetastatic, noninflammatory advanced breast cancer, eligible for neoadjuvant chemotherapy (3 FEC 100 followed by 3 docetaxel) were enrolled. Fifty-two were assessable (4 non eligible, 7 non evaluable). Median age of assessed pts was 49 years. There were 63% T2 and 37% T3, with 98% invasive ductal carcinomas. FDG-PET was performed before the first and the second course. Metabolic activity (tumor FDG uptake) was measured by standardized uptake value (SUVmax). Patients were classified as non responders (NR) when the decrease of SUVmax in the primary tumor was less than 15% at the time of the second PET (EORTC 1999 criteria). The metabolic response in FDG-PET was correlated with WHO criteria (clinical evaluation and ultrasound and/or mammography) evaluated after 3 cycles, path...