Ductal Lavage in Assessing Women With Early Breast Cancer or at High Risk of Developing Breast Cancer and Who Are Eligible For Tamoxifen Therapy

RATIONALE: Chemoprevention therapy is the use of certain drugs to try to prevent the development of or treat early cancer. Diagnostic procedures, such as ductal lavage, may improve the ability to assess the effectiveness of chemopreventive drugs, such as tamoxifen, on breast cells and may help doctors plan more effective treatment. PURPOSE: This phase II trial is studying how well ductal lavage works in assessing changes in breast cells in women with early breast cancer or in those at high risk of developing breast cancer who are eligible for tamoxifen therapy. OBJECTIVES: * Evaluate cell morphology and protein expression of breast epithelial cells in ductal lavage samples as a marker of tamoxifen effect from women with breast cancer or from women at high risk for developing breast cancer. * Evaluate methylation status of genes previously identified to be related to neoplastic progression of cells in ductal lavage samples from these participants. * Evaluate the protein profile of nipple aspiration fluid from these participants before and after treatment with tamoxifen. OUTLINE: This is a multicenter study. Participants who are eligible for tamoxifen chemoprevention therapy undergo ductal lavage. Participants are informed of cytological findings and choose to receive oral tamoxifen once daily for 5 years vs observation only. All participants undergo repeat ductal lavage at 6 months. Participants with atypical cytology undergo a third ductal lavage at 12 months. Mammographic density is measured at study entry and at 12 months. Ductal cells are analyzed for methylation status of candidate genes. Participants are followed as clinically indicated. PROJECTED ACCRUAL: A total of 200 participants will be accrued for this study.