In 2008, there were approximately 1,380,000 cases of female breast cancer worldwide (1, 2). According to the American Society of cancer the trend of female breast cancer are increasing. The approximate number of female breast cancer in US in 2013 was 232,340 cases (account for 29% of all female cancer in US) (3). In Thailand, there was approximate number of 12,000 new female breast cancer cases per year (4). Thus breast cancer is still one of the most important female cancers.
It is a consensus that breast cancer is systemic disease. Multimodality treatment is needed to cure from the residual cancer after the surgery (5-11). Three well established systemic ...view middle of the document...
There are evidenced that androgen receptor might be a new target for systemic breast cancer treatment (24-26). By studying the function of androgens, there is much clinical evidence suggesting that androgens normally inhibit mammary epithelial proliferation and breast growth. Consequently, androgens have been hypothesized to influence the risk of breast cancer by many mechanisms, including their conversion to estradiol or their ability to bind estrogen receptor and/or androgen receptor (AR) in the breast (24, 25). From our previous report showed that non-aromatized androgen can inhibit both hormonal positive and triple negative breast cancer cell growth (27).
The aims of this study were to find the prevalence of androgen receptor expression and the factors which affected the expression of androgen receptors in Thai breast cancer patients.
A descriptive study enrolled total 95 Thai breast cancer patients in Charoenkrung Pracharuk Hospital between October 2011 and October 2013. Clinical and pathological data were collected from the patients’ profiles. The Clinical and pathological data included in this study were age, menstrual status, BMI, pre-operative pathology, previous diagnosis method, tumor size, tumor location, clinical nodal status, operation, stage, final pathology, pathological nodal metastasis, nuclear grade, margin, lymphovascular invasion (LVI), neural invasion, estrogen receptor (ER), progesterone receptor (PR), HER2/neu, proliferative index (Ki-67). For androgen receptor, the leftover pathological specimens of breast cancer tissue were bind with anti-androgen receptor (SP107) rabbit monoclonal primary antibody (Cell-Marque, Roche, CA, USA) and stain by immunoperoxidase method. The immunohistochemistry staining process was done by Bench Mark GX automatic machine (Ventana, Roche, Indiana, USA). The number of androgen receptor was reported by Thai board qualified pathologist. Any positive of androgen staining on the tumors were consider as androgen receptor positive. Figure 1 and 2 demonstrated the positive and negative stained Thai breast cancer tissue.
Figure 1 Stained androgen receptors in breast cancer tissue (Positive androgen receptors; brown color) Figure 2 Androgen receptor negative breast cancer tissue
All patients who enrolled in the study gave the written informed consents. They had received the information and the explanation about the objectives, the obligations, the rights and the responsibilities that the patients had before enrolled in the study. The study was approved by the Ethics Committee for Researches Involving Human Subjects, the Bangkok Metropolitan Administration (Charoenkrung Pracharuk Hospital).
Sample size calculation
According to primary objective, sample size formula for single proportion was applied.
Formula: n = z2(p)(1-p)/d2
Z = 1.96 at alpha 0.05 or 95% confidence interval
p = proportion of androgen receptor positive; 70% according to Ren Q, et al. (28)