Correlation between apparent diffusion coefficient and pathological characteristics of patients with invasive breast cancer

Background There is insufficient research on the correlation between the apparent diffusion coefficient and clinicopathological characteristics of breast cancer patients. The present study is to investigate the correlation between the apparent diffusion coefficient and pathological characteristics of patients with invasive breast cancer. Methods From January 2019 to September 2020, 122 cases of invasive breast cancer and 21 cases of benign tumors were retrospectively enrolled. The apparent diffusion coefficient was compared between the two groups, and the correlation between the apparent diffusion coefficient and the pathological characteristics of the patients with invasive breast cancer were analyzed. Results Compared with the benign tumor group, the apparent diffusion coefficient in the invasive breast cancer group was significantly lower (0.89±0.17 vs. 1.47±0.27 10−3 mm2/s, P=0.000). Using the apparent diffusion coefficient to diagnose patients with invasive breast cancer, the area under receiver operating characteristic (ROC) curve was 0.966±0.021 [95% confidence interval (CI): 0.924–1.000, P=0.000], and the best diagnostic cut-off value was 1.16 (10−3 mm2/s), with sensitivity and specificity of 0.905 and 0.902, respectively. The apparent diffusion coefficient was used to diagnose vascular tumor thrombus in patients with invasive breast cancer. The area under the ROC curve was 0.641±0.068 (95% CI: 0.508–0.774, P=0.047), and the best diagnostic threshold was 0.835 (10−3 mm2/s), with sensitivity and specificity of 0.676 and 0.650, respectively. The apparent diffusion coefficient in patients with high expression of Ki-67 (%) was significantly reduced (0.87±0.17 vs. 1.00±0.16 10−3 mm2/s, P=0.000). The apparent diffusion coefficient was not significantly correlated with age, menopause, lesion size, estrogen receptor, progesterone receptor, or lymph node metastasis in patients with invasive breast cancer (P>0.05). Conclusions In patients with invasive breast cancer the apparent diffusion coefficient was significantly reduced. It was able to differentiate invasive breast cancer and vascular tumor thrombus, and was also related to Ki-67 (%) high expression.