Diffusion-weighted imaging of breast cancer: Correlation of the apparent diffusion coefficient value with prognostic factors

Purpose: To evaluate the role of diffusion-weighted imaging (DWI) in the detection of breast cancers, and to correlate the apparent diffusion coefficient (ADC) value with prognostic factors. Materials and Methods: Sixty-seven women with invasive cancer underwent breast MRI. Histological specimens were analyzed for tumor size and grade, and expression of estrogen receptors (ER), progesterone receptors, c-erbB-2, p53, Ki-67, and epidermal growth factor receptors. The computed mean ADC values of breast cancer and normal breast parenchyma were compared. Relationships between the ADC values and prognostic factors were determined using Wilcoxon signed rank test and Kruskal-Wallis test. Results: DWI detected breast cancer as a hyperintense area in 62 patients (92.5 %). A statistically significant difference in the mean ADC values of breast cancer (1.09±0.27±10^-5mm²/s) and normal parenchyma (1.59 ± 0.27 ± 10^-5 mm²/s) was detected (P < 0.0001). There were no correlations between the ADC value and prognostic factors. However, the median ADC value was lower in the ER-positive group than the ER negative group, and this difference was marginally significant (1.09 × 10^-5 mm²/s versus 1.15 × 10 ^-5 mm2/s, P <; 0.053). Conclusion: The ADC value was a helpful parameter in detecting malignant breast tumors, but ADC value could not predict patient prognosis.