Trastuzumab in Treating Women With Metastatic Breast Cancer

OBJECTIVES:

Primary

• To evaluate the predictive value of genetic factors on the toxicity and efficacy of a trastuzumab-based therapy in women with metastatic breast cancer.

Secondary

• To analyze tumor factors potentially related to the efficacy of trastuzumab (i.e., expression of proteins involved in cell proliferation and survival).

OUTLINE: This is a multicenter study.

Patients receive standard treatment with trastuzumab. Blood is collected periodically for pharmacogenetic analysis.

DISEASE CHARACTERISTICS:

• Histologically confirmed breast cancer

• Metastatic disease, defined by the existence of a secondary tumor localization radiologically (i.e., by radiography, CT scan, MRI scan, or ultrasound) or scintigraphically confrimed
• Evaluable disease
• Beginning first-line metastatic treatment with trastuzumab (Herceptin®) with or without chemotherapy
• Primary tumor must overexpress HER2 (IHC 3+ OR IHC 2+ and FISH+ OR FISH+)
• Hormone receptor status not specified
• No brain metastasis

PATIENT CHARACTERISTICS:

• Menopausal status not specified
• Life expectancy > 3 months
• Able to undergo cardiotoxicity evaluation every 4 months by measuring LVEF via an isotopic method or ultrasound with systematic registration
• No chronic uncontrolled disease
• No heart failure
• No respiratory failure or hypoxemia
• No history of another primary cancer except for basal cell carcinoma of the skin
• No severe uncontrolled infection
• No psychological incapacity

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics