@Article{Litwiniuk2007,
journal="Contemporary Oncology/Współczesna Onkologia",
issn="1428-2526",
volume="11",
number="5",
year="2007",
title="Expression of hormone receptors ER\α, ER\β and PgR in HER-2-positive breast cancer",
abstract="  Background:    HER-2/neu gene is amplified and overexpressed in 15\&#8211;20% of invasive breast cancers. HER2-positive breast cancers have a worse prognosis than HER-2-negative tumors and distinctive clinical features. They express hormone receptors for estrogen (ER\&#945;) and for progesterone (PgR) less frequently than HER-2-negative tumors. The identification of the other human estrogen receptor, receptor beta (ER\&#946;), raises a question of ER\&#946; occurrence in  HER-2-positive breast cancer.    Materials and methods:    Formalin-fixed, paraffin embedded tissues from 90 patients with invasive HER-2-positive breast cancer and from 99 patients with HER2-negative breast cancer were used in this study. The HER-2 status was analyzed using HercepTest TM  (IHC), and IHC 2+ results were confirmed with FISH test. Immunostaining for ER\&#945;, ER\&#946; and PgR was performed using monoclonal antibodies against ER\&#945;, PgR (DakoCytomation) and against ER\&#946; (CHEMICON). The data were analyzed using nonparametric Fisher-Freeman-Halton test.    Results:    Only 33% of the HER2-positive breast cancers were ER\&#945;-positive compared with 62,6% in the HER2-negative group (p<0.001). The expression of ER\&#945; protein was observed in almost equal frequency in both groups (57% of  HER2-positive breast cancers and 57.6% of HER2-negative tumors, p=0.889). The expression of PgR was observed in 30% of HER2-positive breast cancers and in 68.7% of HER2-negative tumors (p<0.001).   Conclusion:   The expression of ER\&#946; (unlike that of ER\&#945; and PgR) was similar in HER-2-positive and in HER-2-negative breast cancers. Thus, ER\&#946; may be a potential target in future endocrine therapy for women with HER2-positive breast cancers.",
author="Litwiniuk, Maria",
pages="235--239",
url="https://www.termedia.pl/Expression-of-hormone-receptors-ER-945-ER-946-and-PgR-in-HER-2-positive-breast-cancer,3,8607,1,1.html"
}