Prognostic Factors Influencing Progression-Free Survival in HER2-Positive Metastatic Breast Cancer Patients Who Were Treated With A Combination of Lapatinib and Capecitabine.

Abstract

The aim was to assess the prognostic variables in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer patients receiving lapatinib plus capecitabine. Retrospective data on HER2-positive metastatic breast cancer patients who received lapatinib and capecitabine were analyzed. Survival outcome was obtained with Cox regression analysis and the Kaplan-Meier method. The study included 102 patients. Forty-four (43.1%) patients had de novo metastatic disease. The most frequent metastatic sites were, in order, bone (61.8%), brain (57.8%), liver (35.3%), and lung (34.3%). All of the patients had previously received chemotherapy based on trastuzumab. With combined lapatinib and capecitabine, complete response was observed in 7.8%, partial response in 30.4%, and stable disease in 24.5%. Progression-free survival was 8 (95% confidence interval, 5.1-10.8) months. In multivariable analysis, endocrine therapy (p = 0.02), de novo metastatic disease (p = 0.02), and age (p = 0.02) were prognostic factors for progression-free survival. However, the number of chemotherapy cycles with trastuzumab, palliative radiotherapy, history of breast surgery, and the number of metastatic sites were not significant in this respect. These results have demonstrated the effectiveness of lapatinib plus capecitabine in metastatic HER2-positive breast cancer patients. Furthermore, unfavorable prognostic factors for progression-free survival were shown to be hormone-negative tumor, de novo metastatic disease, and young age.