Oestrogen receptor-alpha and -beta expression in breast implant capsules: Experimental findings and clinical correlates

Myofibroblasts provide a force to decrease the surface area of breast implant capsules as the collagen matrix matures. 17-beta-Oestradiol promotes myofibroblast differentiation and contraction. The aim of the study was to investigate the expression of oestrogen receptors alpha and beta in capsular tissue. The study enrolled 70 women (80 capsules) who underwent expander or implant removal, following breast reconstruction. Specimens were stained with haematoxylin/eosin, Masson trichrome and immunohistochemistry and immunofluorescence stainings for alpha-smooth muscle actin (alpha-SMA), oestrogen receptor-alpha (ER-alpha) and oestrogen receptor-beta (ER-beta). The relationship between anti-oestrogenic therapy and capsula severity was evaluated. A retrospective analysis of 233 cases of breast reconstruction was conducted. Myofibroblasts expressed ER-alpha, ER-beta or both. In the whole sample, alpha-SMA score positively correlated with ER-alpha (p = 0.022) and ER-beta expression (p < 0.004). ER-beta expression negatively correlated with capsular thickness (p < 0.019). In capsules surrounding expanders alpha-SMA and ER-alpha, expressions negatively correlated with time from implantation (p = 0.002 and p = 0.016, respectively). The incidence of grade III-IV contracture was higher in patients who did not have anti-oestrogenic therapy (p < 0.036); retrospective analysis of 233 cases confirmed this finding (p < 0.0001). This study demonstrates the expression of oestrogen receptors in myofibroblasts of capsular tissue. A lower contracture severity was found in patients who underwent anti-oestrogenic therapy. (C) 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.