Prognostic factors influencing progression-free survival in HER2 positive metastatic breast cancer patients who treated with lapatinib and capecitabine combination.

Abstract

e13031 Background: Her2 positivity is detected in about 20% of breast cancer patients. After trastuzumab-based therapy, lapatinib and capecitabine combination is a treatment option in HER2-positive metastatic patients. The study aimed to evaluate the prognostic factors in HER2 positive metastatic breast cancer patients treated lapatinib and capecitabine combination. Methods: We evaluated data of the HER2 positive metastatic breast cancer patients who were treated with lapatinib and capecitabine retrospectively. The patients' clinical, pathological, and treatment features were recorded from the hospital database. Kaplan Meier and Cox regression analysis were used for survival analysis. Results: 102 patients were included in the study. The median age was 47 (range, 24-87), and 99 (97.1%) patients were female. The number of de-novo metastatic patients was 44 (43.1%). The most common metastatic sites were bone (62.4%), brain (58.6%), liver (35.6%), and lung (34.7%), respectively. All patients were previously treated with trastuzumab-based chemotherapy. 44 (44.1%) patients received hormonotherapy (tamoxifen or aromatase inhibitor), and 23 (22.5%) patients palliative radiotherapy. Complete response was 8.2%, partial response 32%, and stable disease 25.8% with lapatinib and capecitabine combinations. At a median follow of 11.6 months, progression-free survival was 8 (95% CI, 5.1-10.8) months. In multivariate analysis, age (p = 0.020), de-novo metastatic disease (p = 0.028), and endocrine therapy (p = 0.020) were statistically significant prognostic factors for progression-free survival. However, history of breast surgery (p = 0.060), number of chemotherapy used with trastuzumab (p = 0.338), number of metastatic sites (p = 0.257), and palliative radiotherapy (p = 0.394) were not significant. Conclusions: We showed real-life outcomes of the lapatinib and capecitabine combination in metastatic HER2-positive breast cancer patients. Also, we detect that being under age 50 years, de-novo metastatic disease, and hormone-negative tumor were poor prognostic factors of progression-free survival.