ObjectiveThis study investigated the prognostic value of [F-18]-fluorodeoxyglucose (F-18-FDG) uptake in breast carcinomas by comparing F-18-FDG PET/computed tomography (CT) images with histopathological and immunohistochemical prognostic factors.MethodsThis study included 136 women and four men with positive biopsy breast carcinomas who underwent F-18-FDG PET/CT imaging for initial staging. Maximum standardized uptake values (SUVmax) and tumour-to-background SUVmax ratios were calculated and compared with histopathological and immunohistochemical tumour characteristics, patient properties and axillary lymph node involvement. Calculations of SUVmax for men were performed separately.ResultsFor the tumours in women, the mean SUVmax was 10.066.91 and the median SUVmax was 9.05 (0.7-35.0). Primary tumour F-18-FDG uptake and tumour-to-background SUVmax ratios were correlated with tumour size (P<0.001), histological type (P<0.001), histological grade (P=0.004), pleomorphism (P=0.010), mitosis count (P<0.001), lymphatic invasion (P=0.009), necrosis (P=0.005), oestrogen negativity (P=0.004), high Ki-67 level (P<0.001), axillary lymph node involvement (P<0.001) and triple negativity (P=0.002). High Ki-67 level (odds ratio=16; 95% confidence interval=1.6-160; P=0.016) and tumour size (odds ratio=4; 95% confidence interval=1.5-11; P=0.007) were determining factors for high F-18-FDG uptake values. Other clinicopathological and immunohistopathological parameters including progesterone receptor (P=0.211), CerbB2 overexpression (P=0.170), perineural invasion (P=0.053), intratumoural calcification (P=0.438), desmoplasia (P=0.112), tubular formation (P=0.768) and age (P=0.675) were not significantly correlated with F-18-FDG uptake. No significant relationship was observed between the tumour/contralateral breast SUVmax ratio and mitotic count, oestrogen receptor status or triple negativity.Conclusion(18)F-FDG uptake may serve as a prognostic indicator for biological behaviour in breast tumours. (C) 2013 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.