Steroid hormone receptor expression in male breast cancer C.E. Murphy a , P.J. Carder b , M.R.J. Lansdown c , V. Speirs a, * a Molecular Medicine Unit, St James’s University Hospital, University of Leeds, Clinical Sciences Building, Leeds LS9 7TF, UK b Department of Pathology, St James’s University Hospital, Leeds, UK c Breast Unit, St James’s University Hospital, Leeds, UK Accepted 22 September 2005 Available online 2 November 2005 Abstract Aims: To investigate expression of the steroid hormone receptors estrogen receptor (ER)-a and -b, progesterone receptor (PR) and androgen receptor (AR) in male breast cancer. Methods: Specimens from 16 male breast cancers were immunostained for ERa, ERb, PR and AR. Findings: Eighty-seven percent of tumours expressed ERa, 93% PR, 87% ERb and 87% AR. Staining for ERa and PR was confined exclusively to the nuclei of epithelial cells with some heterogeneity. Nuclear immunoreactivity was also observed with AR. Again this was restricted to epithelial cells but tended to be more uniform. ERb was seen in the nuclei of epithelial cells and also in stromal fibroblasts and lymphocytes. Analysis of serial sections revealed a similar pattern of staining with ERb and AR in epithelial cells. Conclusions: In addition to expression of the better known steroid receptors, ERa, PR and AR, we have demonstrated a high rate of expression of ERb in male breast cancer. This is in keeping with the generally high steroid receptor expression seen in males. However, the abundance of ERb expressed in this small series of male breast cancer is in contrast to female breast cancer where ERb expression is often reduced. q 2005 Elsevier Ltd. All rights reserved. Keywords: Male breast cancer; Hormone receptors Introduction A new member of the steroid receptor superfamily was described in 1996 1 and is a second estrogen receptor (ER), called ERb to distinguish it from the original receptor, now re-christened ERa. Although both ER subtypes share homology at the DNA and ligand-binding domains 1 they are functionally distinct since they are the located on different genes. ERa is located on chromosome 6q 2 while ERb is found on chromosome 14q. 3 We have previously reported ERb protein expression in a series of normal and malignant female breast tissues. It is abundantly expressed in normal gland 4 with reduced expression in tumours where it appears to be associated with positive ERa and PR and low biological aggressiveness. 5–7 It is not known if this receptor is expressed in male breast cancer. The aim of this study was to examine the steroid receptor profile, including ERa, ERb, PR and AR in a small cohort of male breast cancers. Materials and methods Ethical approval Following LREC approval, 16 male breast cancers were obtained from the archives of the Leeds Teaching Hospitals NHS Trust. Sections were stained with haematoxylin–eosin and graded using the modified Bloom and Richardson criteria developed for female breast cancer. Three tumours were grade 1, 10 grade 2 and three grade 3. Fourteen tumours were ductal, with one showing mixed ductal and lobular features and a single papillary tumour. Immunohistochemistry Immunohistochemical analysis of sections from formalin fixed paraffin embedded breast cancers was carried out using standard techniques with details of antibodies in Table 1. Appropriate positive and negative controls were also included. EJSO 32 (2006) 44–47 www.ejso.com 0748-7983/$ - see front matter q 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.ejso.2005.09.013 * Corresponding author. Tel.: C44 113 2065261; fax: C44 113 2444475. E-mail address: v.speirs@leeds.ac.uk (V. Speirs).