These women must be identified and alternatively treated. Presently, to identify these defects, requires breast tissue sampling. The women must have a histopathology diagnosis of a proliferative breast lesion. Proliferative lesions with atypia include atypical lobular hyperplasias and atypical ductal hyperplasias. The women will begin tamoxifen therapy for clinical indications independent of this proposal.
Women are postmenopausal.
The MRI study will last approximately 45 minutes. The women will be provided free parking for the MRI studies. The women's breast biopsy tissue will be examined for SERM pathway intactness. The MRI and SERM pathway results will be correlated.