Correlation between 18F Fluorodeoxyglucose (FDG) Uptake and Tumor Characteristics in Locally Advanced Breast Cancers.

Background: This study analysed the correlation between [ 18 F]fluorodeoxyglucose (FDG) uptake, assessed by positron emission tomography (PET), and prognostic factors in locally advanced breast cancers Material and Methods: All locally advanced breast cancers seen at Saint Louis hospital and treated with neo-adjuvant chemotherapy (NAC) have a FDG PET after core needle biopsy and before chemotherapy. We correlated the tumor characteristics: T-stage, histological grade, estrogen and progesterone receptors, c-erbB2 over-expression (immuno-histochemistry determination) and P53 (determinate on frozen biopsies by the FASAYmethod) to FDG standardized uptake value (SUV max). The statistics tests used are student test (comparison of 2 means) and kendall correlation. Results: From June 2006 to April 2009, 91 patients with locally advanced breast tumors have both PET scan and frozen tissue before NAC. Median age at diagnosis is 48 (26-81) and 45 % are post menopausal. Conclusion: This study indicates that FDG-PET uptake is correlated with the phenotype of breast tumours. Over-expression of c-erbB2 does not influence FDG uptake. Triple negative tumours and p53 mutated tumors have a high initial SUV which can reflect their aggressiveness and their chemotherapy sensitivity. The knowledge of SUV uptake according to tumor characteristics allows a better understanding of the role of FDG-PET in the prediction of neoadjuvant chemotherapy response. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5010.