Disease analysis

Disease Analysis: HER2+ Breast Cancer

Amplification of the HER2/neu oncogene and related genetic elements on chromosome 17 increases HER2 expression and accelerates tumorigenesis. The natural disease progression meant that, historically, women with breast cancer who overexpressed HER2 were found to have significantly shorter disease-free survival and overall survival compared with women without HER2 amplification; however, the introduction of trastuzumab in 1998 drastically changed patient outcomes, to the point where HER2+ breast cancer patients now have the longest median survival of all breast cancer subtypes. HER2 is overexpressed in approximately 20% of breast cancers.