The Relationship Between MRI Findings and Molecular Subtypes in Women With Breast Cancer.

Objective: To determine the preoperative MRI findings of patients with breast cancer according to molecular subtypes.

Materials And Methods: MRI findings of women diagnosed with breast cancer in our department between January 2013 and June 2017 who had preoperative breast MRI examinations were evaluated and histopathological findings were recorded retrospectively. The findings were classified according to the BI-RADS MRI classification by three radiologists. Correlations of MRI findings with the molecular subtypes were evaluated using Chi-square and t-tests.

Results: Among 234 lesions in a total of 224 cases diagnosed with breast cancer, subtypes of breast cancer as following: Luminal (162 cases, 69%), triple negative (39 cases, 17%) and HER2 positive (33 cases, 14%), respectively. Lesions of patients with luminal, triple negative and HER2 positive invasive ductal cancer were round or lobular in shape (9.9%, 42.9%, 20.7%), had high/very high intratumoral T2 signal intensity (24.8%, 54.2%, 31%) and rim enhancement pattern (9.2%, 51.4%, 24.1%), respectively. The difference between the triple negative cases and the other subtypes was statistically significant (p < 0.05).

Conclusion: One of the most important factors that determine the prognosis and treatment in breast cancer is the molecular subtype of the tumor. Morphologic findings of MRI can be a useful tool for differentiating triple negative breast cancer from other subtypes.