The Food and Drug Administration (FDA) has approved Femara, a new hormone drug treatment option for women with late-stage breast cancer. Currently, tamoxifen is most often used to treat breast cancer in its later stages. An international study found the Swiss made drug to give women with late-stage breast cancer as much as 9 months before the cancer progressed. Women treated with tamoxifen generally have six months before disease progression. The additional time is crucial, allowing women to postpone more toxic chemotherapy treatment. Femara works by blocking an enzyme related to tumor growth, while tamoxifen stops estrogen from binding to tumor receptors.