Mammographic changes after hormone replacement therapy in patients who have undergone breast irradiation

OBJECTIVE. We examined three patients who began hormone replacement therapy after lumpectomy and breast irradiation. In these women increased tissue d ensity appeared on mammography only or disproportionately in the nonirradia ted breast. To our knowledge, this observation has not been reported. CONCLUSION. Breast irradiation may induce tissue changes that prevent or di minish the proliferative response that can be induced in breast tissue by p ostmenopausal hormone replacement therapy. Because this treatment is now re commended for some women after breast conservation therapy, mammographers m ay recognize this finding with increasing frequency.