Objective To investigate the relationship between molecular typing and pathological features in young breast cancer patients,and the differences in that in middle aged and elderly breast cancer. Methods Clinical data of 177 young patients(≤35years)with invasive breast cancer-visited the Affiliated Hospital of Qingdao University during April 2012—August 2015-were collected.The association of its histological grading,tumor size,lymph node involvement,the expressions of EGFR,TopoⅡα,and Ki-67 with the molecular...