ESR1 and breast cancer: In breast cancer, Karan et al. [22] and Kitajima et al. [23] reported that SUVmax was significantly associated with known prognostic factors such as tumor size, histological grade, lymph node status, estrogen receptor status, human epidermal growth factor receptor 2 status, whereas ADC values were not, which concluded that SUVmax may be valuable for predicting the prognosis of breast cancer.