Abstract 3152: Distribution of hormone receptors (estrogen receptor, progesterone receptor and androgen receptor) in epithelial malignancies
Authors: Gargi D. Basu, Ariane Kemkes, Rebecca A. Feldman, David R. Arguello, Alan Wright, David Loesch, Raheela Ashfaq
Journal: Cancer Research (2011)

Abstract The importance of steroid hormone receptors to the biology of breast cancer was recognized over 40 years ago. New insights into hormone receptor biology and the increasing array of proteins that can modify their function have already translated into better therapies for breast cancer. The responsiveness of a tumor to hormone therapy is an important parameter in cancer management. Besides breast cancer, other cancers also express steroid hormone receptors. Hence, the purpose of this study was to capture the relative distribution of hormone receptors in all types of cancer including breast cancer. In a total cohort of 9,491 patient samples, hormone receptors ER, PR and AR were assayed by immunohistochemistry on a Ventana platform using antibodies ER (SP 1), PR (I E 2) and AR (AR 27). The slides were read manually by pathologists using the cutoff of (&amp;gt;=1+ and &amp;gt;=10% as positive) for AR, PR and ER. Based on these cutoffs, samples were deemed positive or negative. Our preliminary observations indicate that the frequency of ER is highest in breast (40.8%), followed by ovary (25.0%), and uterus (14.9%), with marginal frequencies in lung (4.0%) and peritoneum (2.2%). The most common cancer types with negative ER expression are lung (14.7%), colon (13.3%), pancreas (10.5%), breast (9.4%) and skin (4.2%) The cancer distribution of PR mimics that of ER, albeit with a slightly lower prevalence (breast 25.5%, ovary 22.0%, uterus 13.3%, lung 5.6%, and pancreas 3.9%). The most common cancer types in which PR was negatively expressed are lung (14.0%), colon (12.6%), breast (12.2%), pancreas (9.5%) and ovary (7.6%) The frequency of AR, surprisingly, is higher in breast cancers (45.7%) as opposed to prostate cancer (5.8%). Other cancer types with overexpression of AR are ovary (18.5%), uterus (3.4%) and lung (3.0%). In contrast, low expression of AR is most often found in lung (14.3%), colon (12.0%), pancreas (9.7%), breast (9.6%), and skin (3.7%). All distributional differences by HR status were analyzed by Pearson's chi-square (χ2) test and showed statistical significance (p&amp;lt; 0.001). To our knowledge, this is the first study involving a large patient pool in which hormone receptors have been investigated in a single clinical laboratory with standardized IHC. Cancer is a heterogeneous disease with different molecular drivers regulating its growth, survival and response to therapy. This study shows that hormone receptors are frequently expressed in cancer types outside of breast, which merits the inclusion of therapeutic strategies using hormone therapy in such tumors. 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 3152. doi:10.1158/1538-7445.AM2011-3152