Human epidermal growth factor receptor 2 borderline mortality in breast cancer patients: Evidence from surveillance, epidemiology, and end results program population-based study

Background: Breast cancers with Human Epidermal Growth Factor Receptor 2 (HER2) borderline outcomes are very puzzling for patient management. To whether HER2 borderlines are having different prognostic status in comparison to HER2 positive/negative. Methods: This is a study among women diagnosed with invasive breast cancer from 1973 to 2014 who were identified in the Surveillance, Epidemiology, and End Results (SEER) of 9 registries database and having diagnosed with HER2 status (N=102167), i.e. HER2 positive (N=14678), HER2 negative (N=85354) and HER2 borderline (N=2135). Results: This Surveillance, Epidemiology, and End Results (SEER) study represents the largest report of prospective invasive breast cancer with HER2 status till five years from the date of registration. The five years survival rate among HER2 borderline was found completely separate with HER2 positive and HER2 negative patients. In several subtypes of analysis, it has been found that status of survival among HER borderline patients is significantly poor than HER2 positive and HER2 negative. The likelihood of death in HER2 borderline is found high (15.06%) in comparison to HER2 positive (14.24%) and HER2 negative (6.49%) at the end of five years. Different types of metastasis like Bone, Brain, Liver, and Lung are also observed with the higher rate in HER2 borderline in comparison to HER2 negative. (C) 2017 Published by Elsevier, a division of RELX India, Pvt. Ltd on behalf of INDIACLEN.