ABSTRACT
<p><b>BACKGROUND</b>Estrogen receptor alpha (ER alpha) is the most important endocrine therapy responsiveness predictor for women with breast cancer. The accuracy of the prediction of the response to endocrine therapy was thought to be affected by involving the estrogen receptor coregulatory proteins and cross-talk between ER and other growth factor-signaling networks. Nuclear corepressor 1 (NCOR1) is one of the ER a transcription repressor. The objective of the study is to investigate the expression of NCOR1 at the protein level and pursue its predictive value for breast cancer endocrine therapy.</p><p><b>METHODS</b>In the present study, the level of expression of NCOR1 protein has been assessed by immunohistochemistry in 104 cases of invasive carcinoma of the breast. Associations between NCOR1 protein expression and different clinicopathological factors and survival were sought.</p><p><b>RESULTS</b>It was found that NCOR1 was expressed at significantly higher levels in responsive patients treated with endocrine therapy as first-line treatment on relapse. Responsive patients also had a significantly longer post-relapse survival and overall survival. No NCOR1 expression difference was found between patient by age, tumor size, lymph node status, different histological grade groups and human epidermal growth factor receptor 2 (HER2) status. Multivariate analysis showed that NCOR1 is an independent prognostic factor for over-all survival.</p><p><b>CONCLUSIONS</b>In breast cancer, NCOR1 protein expression level predicts response to endocrine therapy as first-line treatment for breast cancer patients on relapse and NCOR1 protein level assay may increase the accuracy in the endocrine treatment determination and, therefore, improving the patients survival.</p>
Subject(s)
Female , Humans , Middle Aged , Antineoplastic Agents, Hormonal , Therapeutic Uses , Breast Neoplasms , Drug Therapy , Metabolism , Estrogen Receptor alpha , Metabolism , Gene Expression Regulation , Immunohistochemistry , Nuclear Receptor Co-Repressor 1 , Metabolism , Receptor, ErbB-2 , Metabolism , Receptors, Progesterone , Metabolism , Tamoxifen , Therapeutic UsesABSTRACT
We, as final year medical students at University of Tsukuba, had an opportunity to take some clinical clerkship courses at McMaster University for three months, from April 3 to June 23, 1989. The curriculum was unique and different from the one we have in Japan, especially in regard to its clerkship. We found it very instructive and stimulating to work with McMaster students and staff members at the hospitals. We learned a lot from this wonderful experience and we want to thank everybody who gave us a warm support.