An important indicator of your long term health (also called your prognosis) are the results of your hormone receptor tests. Hormone receptors are chemicals present in tumor cells that help control cell growth. It is standard for most biopsied breast cancers to be tested for the hormone receptors. If they are "negative," then this shows your type of cancer will be better treated with chemotherapy than hormonal therapy. If they are "positive," then treatment with a drug like Tamoxifen may be recommended.

Some cancers need the hormone estrogen to grow, and Tamoxifen is an "estrogen blocker." Tamoxifen stops cancer's growth by blocking the effects of the estrogen on the breast. Estrogen may otherwise stimulate some types of cancers to grow. Tamoxifen is taken as a pill, once or twice a day.