Maximum standardized uptake value of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography could replace pathological diagnosis in luminal breast cancer

Background: The maximum standardized uptake value (SUVmax) of 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is an essential tool for making a diagnosis and determining treatment response. This study aimed whether the SUVmax of 18 F-FDG PET/CT could replace pathological diagnosis in luminal type breast cancer. Methods: We retrospectively enrolled 85 patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer (luminal-type) between August 2013 and January 2018 who underwent 18 F-FDG PET/CT scans before surgery and had not received any treatment before surgery at Fujisawa City Hospital. We evaluated the relationship between the SUVmax of 18 F-FDG PET/CT and the Ki-67 labeling index (LI) or other clinicopathological features in luminal-type breast cancer; furthermore, we evaluated whether the SUVmax of PET/CT can help determine whether adjuvant chemotherapy is indicated. Results: The SUVmax differed significantly between the positive and negative groups that showed lymphatic invasion (P=0.018), nuclear grade (P=0.019), and lymph node metastasis (P=0.035). In addition, a significant correlation was observed between the SUVmax and Ki-67 LI (r=0.516, P Conclusions: The SUVmax of 18 F-FDG PET/CT could replace pathological diagnosis in luminal breast cancer.