The Effectiveness of Lapatinib in HER2-Positive Metastatic Breast Cancer Patients Pretreated With Multiline Anti-HER2 Treatment: A Retrospective Study in China

Background: The aim of this study was to evaluate the effectiveness of lapatinib in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. Methods: We retrospectively reviewed the medical records of patients who received lapatinib for salvage treatment at any line setting from January 1, 2007 to August 31, 2019 at Shandong Cancer Hospital and Institute. Results: A total of 115 (89.1%) patients were included in the study. In the overall cohort, the median disease-free survival (DFS) was 19.0 months; the median progression-free survival (PFS), 6.3 months; and median overall survival (OS), 88.0 months, with 32.2% of patients alive at 5 years. In the second line setting, the median PFS among trastuzumab, lapatinib, and trastuzumab plus lapatinib were 4.2 months, 5.2 months, and 7.3 months, respectively (P = 0.004). No significant differences between the median PFSs and OSs of the different line salvage treatments with lapatinib was observed (all P > 0.05). For brain metastasis patients, the median PFSs in first line, second line, and more than 3 lines were 7.2 months, 4.5 months, and 6.3 months, respectively. Conclusions: Our findings suggest that patients would benefit more from trastuzumab plus lapatinib than from lapatinib or trastuzumab alone for second line treatment in the advanced stages of the disease. Lapatinib could be used as an alternative selection for HER2-positive metastasic breast cancer patients when there is disease progression after trastuzumab or pyrotinib treatment, which is used as part of China's national health insurance.