Trastuzumab in Treating Older Women With Early-Stage Breast Cancer

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. PURPOSE: This phase II trial is studying the side effects of trastuzumab and to see how well it works in treating older women with early-stage breast cancer.

OBJECTIVES: Primary * To evaluate the 3-year cumulative incidence of cardiac events in women 60 years and older with HER2-positive breast cancer who receive single agent trastuzumab (Herceptin®) in the adjuvant setting. Secondary * To evaluate the 1-year cumulative incidence of asymptomatic cardiac left ventricular dysfunction in women 60 years and older with Her2-positive breast cancer who receive single agent trastuzumab in the adjuvant setting. * To evaluate long-term cardiac toxicity (5-year cumulative incidence of cardiac events) in women 60 years and older with Her2-positive breast cancer who receive single agent trastuzumab in the adjuvant setting. * To assess the relation between physiologic markers of chronic heart failure and trastuzumab-related cardiac dysfunction in women 60 years and older with Her2-positive breast cancer who receive single agent trastuzumab. * To assess the relation between pro-inflammatory cytokines and trastuzumab-related cardiac dysfunction in women 60 years and older with Her2-positive breast cancer. * To determine the effect of this drug on the health-related quality of life and functional, cognitive, and mental status of women 60 years and older with Her2-positive breast cancer. * To determine the 5-year disease-free survival and overall survival of women 60 years and older with Her2-positive breast cancer who receive single agent trastuzumab in the adjuvant setting. OUTLINE: This is a multicenter study. Patients receive trastuzumab (Herceptin®) IV over 30-90 minutes on day 1. Treatment repeats every 3 weeks for up to 52 weeks in the absence of disease progression or unacceptable toxicity. Blood is collected every 6 weeks during treatment. Samples are assessed for plasma cardiac markers (N-terminal brain natriuretic protein and troponin-I) and pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor-α). Patients complete Quality of Life and Quality of Health and Comprehensive Geriatric assessments of functional, cognitive, and mental status changes at baseline, weeks 26, and 52. After completion of study therapy, patients are followed periodically for 4 years.