ABSTRACT
【Objective】 To predict the expression of human epidermal growth factor receptor 2 (HER2) in urothelial bladder carcinoma based on normalized apparent diffusion coefficient (ADC). 【Methods】 The preoperative pelvic 3.0T magnetic resonance imaging (MRI) images of 127 patients with urothelial bladder carcinoma were retrospectively studied, the ADC was measured, and the HER2 expression in postoperative tissue specimens was determined with immunohistochemistry (IHC). The differences in normalized ADC were analyzed among different HER2 expressions and among different expression divisions. Correlation between normalized ADC and HER2 expression was analyzed. The optimal diagnostic threshold for distinguishing different expression divisions were determined with receiver operating characteristic (ROC) curve. 【Results】 Normalized ADC was negatively correlated with HER2 expression (tau-b=-0.180, P=0.008). Normalized ADC of HER2 overexpression group (IHC 2+, 3+) was lower than that of HER2 negative group (IHC 0, 1+) (P=0.081). Normalized ADC of HER2 expression group (IHC 1+, 2+, 3+) was significantly lower than that of HER2 zero-expression group (IHC 0) (P=0.020). Normalized ADC of HER2 strong positive group (IHC 3+) was significantly lower than that of HER2 non-strong positive group (IHC 0, 1+, 2+) (P=0.024). The optimal diagnostic threshold of HER2 strong positive group was 0.849; the sensitivity, specificity and accuracy were 0.621, 0.909 and 0.765, respectively. The optimal diagnostic threshold of HER2 overexpression group was 0.909; the sensitivity, specificity and accuracy were 0.547, 0.667 and 0.607, respectively. 【Conclusion】 Normalized ADC is negatively correlated with HER2 expression. ADC may be a potential marker for predicting HER2 expression.