An Exploratory Study to Identify Potential Surrogate Endpoint Biomarkers That Are Modulated by Tamoxifen vs. Placebo in Women With an Increased Risk for Breast Cancer

Brief Summary

Detailed Description

OBJECTIVES: * Compare molecular markers of proliferation and apoptosis in breast epithelial tissue of women at increased risk for breast cancer treated with tamoxifen vs placebo. * Compare the modulation of markers of genomic instability in breast epithelial tissue of patients treated with these drugs. * Compare serum levels of IGF-1, IGF-2, and IGFBP-3 of these patients at baseline and after treatment with these drugs. OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients are stratified according to estimated 5-year breast cancer risk (1.67-5% vs ≥ 5%), presence of atypical ductal hyperplasia (yes vs no), and menopausal status (premenopausal vs postmenopausal). Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive oral tamoxifen once daily. * Arm I: Patients receive oral placebo once daily. Treatment in both arms continues for 3 months in the absence of invasive breast cancer or unacceptable toxicity. Patients undergo core needle biopsy and fine needle aspiration biopsy at baseline and then at the completion of study treatment (for premenopausal patients); exactly 84 days after the first biopsy (for postmenopausal patients); or on the first or second day of the menstrual cycle on or after 84 days (during the third menstrual cycle) after the first dose of study medication (for patients with irregular menses). Patients are followed at 30 days. PROJECTED ACCRUAL: A total of 130 patients (65 per arm) will be accrued for this study within 30 months.

Primary Outcomes