Efficacy of Lapatinib Plus Capecitabine After TDM-1 in HER2-Positive Metastatic Breast Cancer Patients

Different targeted therapy options exist for treating HER2-positive metastatic breast cancer patients. This study evaluated the efficacy and tolerability of the lapatinib plus capecitabine combination after TDM-1 in HER2-positive metastatic breast cancer patients. We retrospectively evaluated the HER2-positive metastatic breast cancer patients’ data. The patients who progressed after trastuzumab-based chemotherapy and TDM-1 were included in the study. We used the Kaplan–Meier for survival analysis. Eighteen patients were involved in the study. The average age was 48 (range 31–65). De novo metastatic patient’s number was 5 (27.8%). The most common metastatic sites were liver (50%), lung (44.4%), and brain (44.4%), respectively. All patients were previously treated with trastuzumab + chemotherapy and TDM-1. Also, seven (38.9%) patients received hormonotherapy and twelve (66.7%) patients received palliative radiotherapy. The complete response ratio was 5.6%, partial response 11.8%, and stable response 29.4%. Median progression-free survival was found as 5.5 (95% CI, 3.2–7.7) months. The hematological and non-hematological toxicity ratio was 41.2% and 52.9%, respectively. Grade 3–4 toxicity (diarrhea, anemia, and mucositis) was observed in four (22.2%) patients. The median OS duration was 8.2 months (95% CI, 4.3–12.0). Treatment options are limited in heavily pretreated HER2-positive breast cancer patients. Despite a small number of patients, this study showed that the lapatinib plus capecitabine combination was effective and well-tolerated in heavily pretreated HER2-positive breast cancer patients after TDM-1.