Arimidex/Anostrozole It lowering the levels of certain estrogens in the body. It does this by a process known as aromatase inhibition. Reducing estrogen levels in those patients suffering from estrogen receptor positive early breast cancer is vitally important because the tumour cells use the estrogen to grow. As breast tissue is stimulated by estrogens, decreasing their production is a way of suppressing recurrence of the breast tumour tissue. Arimidex’s approved use is for breast cancer treatment in post-menopausal women – but the process of aromatization also occurs in men because men also have estrogens in their bodies just as females have testosterone in theirs. As with women, it’s important that the levels of estrogen in the male body are kept in balance.