Estrogen receptor‐positive/human epidermal growth factor receptor 2‐negative breast tumors

Abstract

BACKGROUND The objective of this prospective study was to evaluate the ability of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) to predict chemosensitivity in patients with estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer. METHODS Sixty-four consecutive patients underwent 18F-FDG PET/CT scanning at baseline and after the second course of neoadjuvant chemotherapy (NAC). The evolution (Δ) between the 2 scans of image parameters (maximum standardized uptake value [SUV max], SUVmean, metabolic tumor volume, and total lesion glycolysis [TLG]) was measured. Correlations between early changes in PET-derived parameters and pathologic response observed in surgical specimens after the completion of 8 courses of NAC were estimated with Mann-Whitney U tests. Response prediction on the basis of clinical data, histologic type, or molecular markers also was assessed (Fisher exact test). Receiver operating characteristic (ROC) analysis was used to compare the area under the curve (AUC) of each parameter. RESULTS The best prediction of chemosensitivity was obtained with ΔTLG (-49% ± 31% in nonresponders vs -73% ± 25% in responders; P