Evaluating the Efficacy of Lapatinib in Combination With Chemotherapy in Patients With Trastuzumab-refractory Metastatic HER2-positive Breast Cancer.

Some studies has demonstrated that even in trastuzumab pretreated patients with HER-2 positive breast cancer, might benefit from the treatment of trastuzumab. However, there is small benefit for some patients having short disease-free survival after adjuvant trastuzumab or short progression-free survival after first-line trastuzumab-based therapy. In clinical practice, the investigators also found it is fact. And the investigators have a scientific rationale for clinical testing of lapatinib plus chemotherapy in patients with trastuzumab-refractory, metastatic HER2-positive breast cancer.

Inclusion Criteria:

• Metastatic breast cancer
• Eastern Cooperative Oncology Group (ECOG) 0 or 1
• HER2-expressing primary or metastatic tumor
• Recurrence within 1 year completing adjuvant trastuzumab OR rapid progress following first-line trastuzumab-based care.
• Measurable disease with Response Evaluation Criteria in Solid Tumors (RECIST) 1.1
• Normal organ function, including bone marrow function, renal function, liver function, and cardiac function
• Signed and dated an informed consent form
• Life expectancy of at least 12 weeks

Exclusion Criteria:

• Pregnant or breast feeding
• left ventricular ejection fraction (LVEF) < 45% by echocardiogram
• Disease-free interval (DFI) less than 12 months
• Uncontrolled medical problems
• Any previous malignancy exceptions for carcinoma of the cervix, squamous carcinoma of the skin, or basal cell carcinoma of the skin
• Patients were unable or unwilling to comply with program requirements