Abstract 1088: Characterizing the effects of alcohol on the ER-alpha status of HER2 breast cancer

• Published in: Cancer research (Chicago, Ill.) Ill.), 2011-04, Vol.71 (8_Supplement), p.1088-1088
• Main Authors: Wong, Amy W., Smith, Sarah M., Nunez, Nomeli P.
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2011-1088

Alcohol consumption is a major risk factor for breast cancer. Approximately 400,000 cases of cancer in 2002 were attributable to alcohol consumption worldwide. In women, breast cancer accounts for 60% of these alcohol-related cancers. Over 25% of all breast cancer cases are HER2 (ErbB2) positive and have poor prognosis. Unfortunately, the mechanism by which alcohol promotes breast cancer is unclear. Our research focuses on characterizing the effects of alcohol on HER2 positive breast cancer. More specifically, we determine if and how alcohol affects the ER-alpha status of ErbB2-expressing tumors in the presence and absence of ovarian hormones using the MMTV-neu mouse model of ErbB2-induced breast cancer. We show alcohol consumption increases tumor incidence as well as tumor proliferation as demonstrated by Ki67 immunohistochemical staining. We measure systemic estrogen levels and ER-alpha expression in the mammary tumors developed from alcohol and water consuming mice to determine if their levels are associated with the higher tumor incidence in alcohol consuming mice. We show that both systemic estrogen and ER-alpha expression levels are elevated in alcohol consuming mice. Our data suggest that alcohol increases tumor development in HER2 transgenic mice via the estrogen pathway. In fact, the effects of alcohol on tumor incidence were blocked with ovariectomy, suggesting that indeed the effects of alcohol on HER2 tumors are mediated via the estrogen pathway. Our results suggest that the effects of alcohol on HER2 positive breast cancers can be prevented by targeting or blocking the estrogen pathway. For this purpose, we will determine in future studies if the effects of alcohol can be prevented with tamoxifen, a selective ER modulator (SERM), and letrozole, an aromatase inhibitor, both of which blocks the estrogen pathway. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1088. doi:10.1158/1538-7445.AM2011-1088