Correlations between apparent diffusion coefficient values and histopathologic factors in breast cancer

Breast cancer is the most common malignancy dia-gnosed in women, and the incidence gradually increases. Magnetic resonance imaging (MRI) is become widely used to identify benign and malignant breast tumors. Objective: The aim of this study was to evaluate the relationships between apparent diffusion coefficient (ADC) values and histopathologic prognostic factors in breast cancer. Forty-nine breast carcinoma patients were included evaluated for prognostic factors, including histological type, histo-logical grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and molecular subtype. Minimum (ADCmin) and mean (ADCmean) ADC values were compared among prognostic factor groups by Mann-Whitney U test and Kruskal-Wallis test. Lower mean ADCmin and ADCmean values were observed for no special type (NST) than for invasive lobular carcinoma (ILC) type (0.81 ± 0.03 × 10-3 and 0.96 ± 0.03 × 10-3 mm2/s, P= 0.002 and 0.03, respectively). The mean ADCmin and ADCmean values for the high-level Ki-67 group were significantly lower than those for the low-level Ki-67 group (P = 0.001 and 0.008, respectively). No correlations were observed between ADC values and histological grades, ER, PR, HER2, and molecular subtypes. ADCmin and ADCmean values correlated with the pro-liferation marker Ki-67 and histological grade. ADC values can serve as noninvasive indicators of cell proliferation in breast cancer.