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Medline ® Abstract for Reference 42

of 'HER2 and predicting response to therapy in breast cancer'

Her-2/neu overexpression and response to oophorectomy plus tamoxifen adjuvant therapy in estrogen receptor-positive premenopausal women with operable breast cancer.
Love RR, Duc NB, Havighurst TC, Mohsin SK, Zhang Q, DeMets DL, Allred DC
J Clin Oncol. 2003;21(3):453.
PURPOSE: Studies evaluating the relationship of HER-2/neu breast tumor status and response to adjuvant endocrine therapy have reached conflicting conclusions about resistance of HER-2/neu-positive tumors to this treatment. We studied 282 patients participating in a randomized controlled trial of adjuvant oophorectomy and tamoxifen or observation who had estrogen receptor-positive tumors and whose tumors were evaluated for HER-2/neu overexpression by immunohistochemistry.
PATIENTS AND METHODS: Univariate and multivariate Cox proportional hazards regression models and Kaplan-Meier disease-free and overall survival estimate methods were used.
RESULTS: HER-2/neu overexpression was a negative prognostic factor for overall survival. In univariate analyses, in HER-2/neu-positive patients, the hazard ratio (HR) for disease-free survival (DFS) with adjuvant endocrine therapy was 0.37 (95% confidence interval [CI], 0.26 to 0.89); for HER-2/neu-negative patients, the corresponding HR for DFS was 0.48 (95% CI, 0.31 to 0.71). The overall survival (OS) data were HR=0.26 (95% CI, 0.07 to 0.92) and HR=0.68 (95% CI, 0.32 to 1.42) for HER-2/neu-positive and HER-2/neu-negative patients, respectively. In multivariate models, the P values for tests of interaction of HER-2/neu status and response to adjuvant endocrine therapy were 0.18 and 0.07 for DFS and OS, respectively. Kaplan-Meier DFS and OS curves and 3-year DFS estimates were consistent in showing greater benefit to the HER-2/neu-positive subgroup given adjuvant treatment.
CONCLUSION: HER-2/neu overexpression does not adversely and may favorably influence response to adjuvant oophorectomy and tamoxifen treatment in patients with estrogen receptor-positive tumors.
Departments of Medicine and Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI 53726, USA. rrlove@facstaff.wisc.edu