Trastuzumab Monotherapy Followed By the Combination of Trastuzumab and Letrozole in Post-Menopausal Women With ER-Positive, HER-2 Positive Advanced Breast Cancer Resistant to a Nonsteroidal Aromatase Inhibitor: A Multicenter Two-Step Phase II Trial
Trastuzumab Monotherapy Followed By the Combination of Trastuzumab and Letrozole in Post-Menopausal Women With ER-Positive, HER-2 Positive Advanced Breast Cancer Resistant to a Nonsteroidal Aromatase Inhibitor: A Multicenter Two-Step Phase II Trial
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. Estrogen can cause the growth of breast cancer cells. Hormone therapy using letrozole may fight breast cancer by lowering the amount of estrogen the body makes. Giving trastuzumab together with letrozole after disease progression may be an effective treatment for breast cancer.
PURPOSE: This phase II trial is studying how well giving trastuzumab together with letrozole works in treating postmenopausal women with progressive advanced breast cancer.
OBJECTIVES:
Primary
Secondary
OUTLINE: This is a multicenter study.
Patients receive trastuzumab (Herceptin®) IV over 30-90 minutes once in weeks 1-3 OR once in week 1. Courses repeat every 3 weeks in the absence of disease progression or unacceptable toxicity. Patients experiencing disease progression after 9 weeks receive trastuzumab as before and oral letrozole once daily in the absence of further disease progression or unacceptable toxicity.
After completion of study treatment, patients are followed every 12 weeks until disease progression and then at 6 months.
PROJECTED ACCRUAL: A total of 30-40 patients will be accrued for this study.
DISEASE CHARACTERISTICS:
Histologically or cytologically confirmed breast cancer
Measurable disease, defined as ≥ 1 unidimensionally measurable lesion outside previously irradiated areas that is ≥ 20 mm OR ≥ 10 mm if the slice thickness of the CT scan or MRI is ≤ 5 mm
No nonmeasurable lesions as the only site of measurable disease, including any of the following:
Progressive disease after prior treatment with a nonsteroidal aromatase inhibitor (e.g., letrozole or anastrozole) in an adjuvant or advanced disease setting
HER-2 amplification ≥ 2 by fluorescence in situ hybridization
No clinical symptoms or history of CNS or leptomeningeal metastases (no imaging is required)
No visceral involvement with risk for organ dysfunction
Hormone receptor status:
PATIENT CHARACTERISTICS:
Age
Sex
Menopausal status
Postmenopausal, defined by 1 of the following:
Performance status
Life expectancy
Hematopoietic
Hepatic
Renal
Cardiovascular
No uncontrolled cardiac disease, including any of the following:
No history of congestive heart failure
No myocardial infarction within the past 6 months
LVEF > 50% by echocardiogram
Pulmonary
Other
PRIOR CONCURRENT THERAPY:
Biologic therapy
Chemotherapy
Endocrine therapy
Radiotherapy
Surgery
Other