The Expressionand Significance Of Estrogen Transmembrane Receptor Gpr30in Primary And Recurrent Breast Cancer

Background and PurposeThe endocrine therapy in breast cancer treatment has animportant position, for pre-menopausal estrogen receptor-positive breastcancer patients, tamoxifen (TAM) is still the first selection drugs; TAM isalso important therapy for unresectable advanced breast cancer. However,in clinical also observed that about25%of ER-positive breast cancertreatment for TAM is invalid, secondary resistance of long-term applicationof TAM greatly limits its clinical application. Recent studies found thatGPR30(G protein-coupled receptor30) was a novel membrane-boundestrogen receptor.This new estrogen receptor was independent of theclassic ERα and β. It can specifically combined with estrogen，andInvolved in mediating the effect of rapid non-genomic estrogen andgenome transcription reaction.In vitro experiments have confirmed thatGPR30plays an important role in the development of TAM resistance inbreast cancer.In this study, immunohistochemistry was used to detect theGPR30and EGFR（epidermal growth factor receptor） expression in primary and recurrent breast cancer specimens.This article aimed toanalyze the role of GPR30in primary and recurrent breast cancer patientsand its correlation with clinicopathological parameters.MethodsImmunohistochemical method was used to detect the GPR30andEGFR expression in191of primary and53of recurrence and metastasisbreast cancer paraffin-embedded tissue, and to analyze their correlationwith clinicopathological parameters as well as between.ResultsGPR30expression was63.4%, EGFR expression was18.3%. Duringthe follow-up time,there were77(40.3%) patients local recurrence ordistant metastasis.53(68.8%) of which treated with TAM,only21(27.3%)tumors having recurred during treatment with chemotherapy. In39patientstreated with TAM,the GPR30expression scores increased in29of39(74.4%).GPR30and EGFR expression was positively correlated（P＜0.05）. No significant relationship was observed between GPR30andclinicopathological parameters including patients’age，menstruation status，tumour size， pathological lymph node classification, clinical andpathological stage, histological grade, ERα, PR and HER2status.ConclusionGPR30and EGFR overexpression may be associated with breastcancer recurrence and metastasis. GPR30and EGFR expression in breast carcinoma was positively correlated with each other, there could beinteractions between the two.The breast cancer patients who treated withTAM, high GPR30and EGFR expression levels may be associated withpoor prognosis, both the prognostic evaluation of breast cancer patients hasimportant reference value. The " cross-talk " pathway could become moreeffective novel clinical therapeutic targets in patients with breast cancer.