Trastuzumab for 6 Months or 1 Year in Treating Women With Nonmetastatic Breast Cancer That Can Be Removed By Surgery

Overview

RATIONALE: Monoclonal antibodies, such as trastuzumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. It is not yet known whether giving trastuzumab for 6 months is as effective as giving trastuzumab for 1 year in treating patients with breast cancer. PURPOSE: This randomized phase III trial is studying trastuzumab to see how well it works when given for 6 months compared to 12 months in treating women with nonmetastatic breast cancer that can be removed by surgery.

OBJECTIVES: Primary * Compare the disease-free survival of women with nonmetastatic, resectable breast cancer treated with adjuvant trastuzumab (Herceptin®) for 6 months vs 12 months. Secondary * Compare cardiotoxicity in patients receiving these regimens. * Compare the cardiotoxicity and disease-free survival of patients receiving concurrent trastuzumab and chemotherapy vs sequential administration. * Correlate HER-2 polymorphism with disease-free survival/cardiotoxicity in these patients. OUTLINE: This is a randomized, controlled, multicenter study. Patients are stratified according to participating center, modality of adjuvant chemotherapy (concurrent vs sequential), and adjuvant hormonal therapy (yes vs no). Patients are randomized to 1 of 2 treatment arms. * Arm I (control arm, 12-month therapy): Patients continue to receive trastuzumab (Herceptin®) IV until a total of 12 months of therapy is completed in the absence of disease progression or unacceptable toxicity. * Arm II (experimental arm, 6-month therapy): Patients continue to receive trastuzumab\* IV until a total of 6 months of therapy is completed in the absence of disease progression or unacceptable toxicity. NOTE: \*Patients who have already finished 6 months of trastuzumab at randomization do not receive further trastuzumab. Some patients undergo blood collection for HER-2 polymorphism analysis. After completion of study therapy, patients are followed periodically for approximately 5 years. PROJECTED ACCRUAL: A total of 7,000 patients will be accrued for this study.