Estrogen Receptor-Negative Breast Cancer. NCI
 

<table border="0" cellpadding="0" cellspacing="0" width="100%"><tbody><tr><td align="left" nowrap="nowrap" valign="center">Slide 18

</td><td>http://www.cancer.gov/images/spacer.gif</td><td align="left" height="100%" valign="center" width="1">http://www.cancer.gov/images/red-px.gif</td><td>http://www.cancer.gov/images/spacer.gif</td><td align="left" valign="center" width="100%">Estrogen Receptor-Negative Breast Cancer

</td><td class="pptRightNav" align="right" valign="center"> http://www.cancer.gov/images/UC-leftarrow.gif<img alt="Next Section >" src="http://www.cancer.gov/images/UC-rightarrow.gif" border="0"></td></tr></tbody></table>Unlike normal breast cells, cancer cells arising in the breast do not always have receptors for estrogen.
Breast cancers that DO have estrogen receptors are said to be “estrogen receptor-positive,” while those breast cancers that DO NOT possess estrogen receptors are “estrogen receptor-negative.” In women with estrogen receptor-positive cancers, cancer cell growth is under the control of estrogen. Therefore, such cancers are often susceptible to treatment with tamoxifen (Nolvadex®), because tamoxifen works by blocking the interaction between estrogen and the estrogen receptor.
In contrast, the growth of estrogen receptor-negative cancer cells is not governed by estrogen and is not treated with tamoxifen.
http://www.cancer.gov/PublishedConte...rs/slide19.gif<iframe style="border: 2px inset; width: 540px; height: 250px;" tabindex="1" id="vB_Editor_001_iframe"></iframe>