Lapatinib in combination with capecitabine versus continued use of trastuzumab in breast cancer patients with trastuzumab-resistance: a real-world study

• DOI: 10.21203/rs.2.16713/v1
• Publication Date: 2019-11-01T19:37:10Z
• Authors: fan Yang; Xiang Huang; Chunxiao Sun; Jianbin Li; Biyun Wang; Min Yan; Feng Jin; Haibo Wang; Jin Zhang; Peifen Fu; Tianyu Zeng; Jian Wang; Wei Li; Yongfei Li; Mengzhu Yang; Jun Li; Hao Wu; Ziyi Fu; Yongmei Yin; zefei jiang
• Keywords: 03 medical and health sciences; 0302 clinical medicine; 3. Good health

Abstract Background: The efficacy and safety of lapatinib plus capecitabine (LC or LX) versus trastuzumab plus chemotherapy in patients with HER-positive metastatic breast cancer who were resistant to trastuzumab is largely unknown. Methods: we retrospectively analyzed breast cancer patients who began the treatment with regimen of lapatinib plus capecitabine (LC or LX) or trastuzumab beyond progression (TBP) at eight hospitals between May 2010 and October 2017. Results: Among 554 patients who had developed resistance to trastuzumab, the median PFS was 6.77 months in the LX group compared with 5.6 months in the TBP group (hazard ratio 0.804; 95% CI, 0.67 to 0.96; P=0.019). The central nervous system progression rate during treatment was 5.9% in LX group and 12.5% in TBP group, respectively (P=0.018). PIK3CA and TP53 are the most common mutations in resistant patients, but do not significantly differ between primary resistant cancers and secondary resistant cancers. Conclusion: The combination of lapatinib and capecitabine has shown a prolonged PFS compared with TBP in patients who had progressed on trastuzumab.