Abstract:
Objective To explore the characteristics of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and apparent diffusion coefficient (ADC) of different molecular subtypes of breast cancer.
Methods The clinical data of one hundred thirty-eight women aged 27–71 (56.1±5.6) years and diagnosed with breast cancer, which was confirmed via immunohistochemical examination, at the Affiliated People's Hospital of Inner Mongolia Medical University were retrospectively analyzed from January 2018 to January 2020. All patients underwent routine breast MRI scanning before operation. DCE-MRI features of different molecular subtypes of breast cancer were analyzed using the breast imaging report and data system. ADC was measured and its characteristics were analyzed. The breast cancer was divided into non molecular subtypes via immunohistochemical staining after operation. Chi-square test and Fisher test was used to analyze the relationship between DCE-MRI features and molecular subtypes of breast cancer. The ADC of each molecular subtype was compared using one-way ANOVA.
Results The immunohistochemical results showed that 138 cases of breast cancer are composed of 14 cases of Luminal A, 62 cases of Luminal B, 33 cases of HER-2 overexpression, and 29 cases of Basal-like subtypes. Among the four molecular subtypes of breast cancer, Basal-like subtype is the largest type of tumor (χ2=0.70, 15.21, 6.87; all P<0.01). Edges of Luminal A type are smooth, and those of the other types are irregular (χ2=26.41, 7.23, 7.88; all P<0.01). Basal-like subtype breast cancer showed ring enhancement, while Luminal A type breast cancer presented homogeneous enhancement. The dynamic enhanced scan time signal intensity curve (TIC) was mostly type Ⅱ, while the three other types of TIC were mainly type Ⅲ (χ2=12.325, P<0.01). The ADC range of lesions in all patients was (0.497×10−3–1.367×10−3) mm2/s (0.865±0.021)×10−3 mm2/s. HER-2 overexpressing breast cancer presented the highest ADC at (1.023±0.027)×10−3 mm2/s, followed by Basal-like subtype breast cancer at (0.957±0.025)×10−3 mm2/s) and Luminal A type breast cancer at (0.902±0.033)×10−3 mm2/s, Luminal B type breast cancer had the lowest at (0.852±0.013)×10−3 mm2/s. ADC demonstrated a significant difference between HER-2 overexpressing and Basal-like subtype and Luminal B type breast cancers (F=11.80,12.40; both P<0.01). A significant difference was also observed between Luminal B and Luminal A type breast cancers (F=25.50, P<0.01).
Conclusion DCE-MRI imaging signs and ADC of each molecular subtype of breast cancer have certain characteristics, which can provide reference basis for preoperative prediction, treatment plan formulation and prognosis evaluation of breast cancer patients.