Original paper DOI: 10.5114/pm.2015.54341

Introduction: Trastuzumab therapy significantly improves progression-free and overall survival in HER2-pos-itive [HER2(+)] breast cancer (BC) patients. However, in most patients with HER2(+) metastatic BC, the disease progress occurred. The aim of this study was to evaluate the clinicopathological risk factors for progression in HER2-positive breast cancer patients during trastuzumab therapy. Material and methods: The analysis included medical records of HER2(+) metastatic BC patients treate