Breast cancer has become a leading health concern in the United States, accounting for 30% of all cancers among women.¹ Oestrogen is an important hormone involved in the development and growth of breast tumours.² It has been found that 60–70% of breast cancers have oestrogen receptors.² Following tumour resection, receptor positive patients are commonly treated with hormone therapy such as tamoxifen. Tamoxifen is a competitive antagonist of oestrogen at its receptor site. It is most often used for postmenopausal patients with oestrogen receptor positive breast cancers. However, tamoxifen also has a partial oestrogen agonist effect which could be detrimental, because it can lead to increased risk for uterine cancer, thromboembolism, and treatment failure.³

The third generation aromatase inhibitors, including anostrozole, letrozole, and vorozole, have emerged as a new treatment for postmenopausal women with oestrogen receptor positive breast cancer. Their mechanism differs from that of tamoxifen as they minimise peripheral conversion of circulating androgen to oestrogen.³ We report one patient with choroidal metastasis …