Survival of HER2-positive advanced breast cancer patients treated with lapatinib plus capecitabine: A national population-based study: Long-term analysis

Abstract

Background: In Poland, governmental policy was to offer a uniform, national therapeutic programme for the treatment of HER2‐positive advanced breast cancer (ABC) patients (pts). Accordingly, the Polish Breast Cancer Treatment Programme was introduced. Herein, we present first results of this effort from the cohort of previouslytreated patients who underwent anti‐HER2 palliative therapy with lapatinib plus capecitabine. Methods: The aim of the study was to assess the population‐based value of lapatinib plus capecitabine therapy of HER2‐positive ABC patients treated within the Polish Breast Cancer Treatment Programme during the years 2008‐2015. Patients have been prospectively enrolled into aforementioned programme and treated according to the specified protocol. We used Kaplan‐Meier method to evaluate progression‐free survival (PFS), time to tumor progression (TTP) and overall survival (OS). The effects of clinical and demographic factors on PFS and OS were assessed using Cox's proportional hazards regression model. Results: A total of 1018 HER2‐positive ABC women were enrolled into the Polish Breast Cancer Treatment Programme on a national level. Patients who progressed after regimens that included, but were not limited to, anthracyclines, taxanes, and trastuzumab were eligible to this study. Median age of the patients was 56.6 years (range, 22.8 to 86.1). Previous adjuvant therapy: 35.7% pts; ER(+)/PgR(+): 47.5% pts; number of metastatic sites≤2: 45.9% pts. The median PFS was 6.4 months and median TTP was 6.7 months. The median OS was 11.76 months (range, 0.36‐70.32). The overall response rate was 13%. Cox regression model data will be presented. Conclusions: To our knowledge this study represents one of the first reports assessing the population‐based value of a lapatinib/capecitabine treatment in clinical practice. Our data essentially corroborated findings obtained from randomized clinical trials. It seems that treatment with lapatinib and capecitabine is associated with a meaningful clinical effectiveness and therefore warrants consideration in the treatment algorithm of HER2‐positive ABC patients.