These potent inhibitors of oestrogen synthesis may be superior to tamoxifen

Breast cancer is the commonest malignant disease among Western women, and, although overall survival has improved with earlier diagnosis by mammography and with adjuvant therapy, it still represents a leading cause of cancer related death. Endocrine treatment is recommended as first line therapy in patients with hormone sensitive tumours (oestrogen and progesterone receptor positive) as most forms of endocrine treatment cause fewer side effects than chemotherapy. No curative treatment is currently available for patients with distant metastases, and the goal of therapy is palliative. This stresses the need for treatments with low toxicity.

Aromatase inhibitors and inactivators are drugs that suppress oestrogen production in postmenopausal women through inhibition of the final step in their synthesis, conversion of androgens to oestrogens. While oestrogen synthesis in the ovary ceases at the menopause, oestrogens are still produced in different peripheral tissues, including benign and malignant breast tissue. Aromatase inhibitors are non-steroidal …