Intramammary edema of invasive breast cancers on MRI T-weighted fat suppression sequence: Correlation with molecular subtypes and clinical-pathologic prognostic factors.

Objective: To investigate the associations between different patterns of intramammary edema on preoperative 3.0 T magnetic resonance imaging (MRI) T-weighted fat suppression sequence and invasive breast cancer molecular subtypes and clinical-pathologic prognostic factors.

Methods: Between May 2014 and December 2020, 191 patients with invasive breast cancer who had undergone preoperative MRI and mastectomy or breast-conserving surgery were retrospectively enrolled. The relationships between different patterns of intramammary edema and invasive breast cancer molecular subtypes and clinical-pathologic features were evaluated using the Student's t-test or Mann-Whitney U test and the χ2 test or Fisher's exact test.

Results: Patients with luminal B (HER2 positive), HER2-enriched and triple negative breast cancers respectively had different patterns of intramammary edema (P < 0.001). There was a significant association between intramammary edema and clinical-pathologic factors, including larger tumor size, higher Ki-67 index, lymph node metastasis and lymphovascular invasion (all P < 0.001).

Conclusions: Intramammary edema may provide added values of predicting molecular subtypes and clinical-pathologic prognosis, enhancing the ability to individualize the treatment of patients with invasive breast cancer.