Retrospective study of MRI images to examine the effects of estrogen supplementation on breast tissue: A pilot study in Asian Taiwan

MRI provides a highly sensitive technique for early detection of abnormal breast tissue. It is useful for identifying a status of proliferation, angiogenesis, and microvascular permeability, which may indicate early breast neoplasm formation. We retrospectively studied 2005 breast MRI images from Taiwanese women and classified them as either healthy or unhealthy according to BI-RADS categories. A subgroup of our study patients had received estrogen supplements, containing estrogen components or phytoestrogen, for at least 3 months. These patients’ images were also classified into the healthy and unhealthy groups. These two groups were compared and a significant difference was found between them (P < 0.002). Comparison of the MRI images also identified certain cases that demonstrated a typical estrogen/phytoestrogen effect or a withdrawal effect. The overuse of estrogen or phytoestrogen supplements can increase breast glandular tissue proliferation, as reflected on MRI images. Such proliferation may increase the patient’s risk of future breast cancer.