Breast Cancer Molecular Subtyping And P53 And PIK3CA Gene Mutation Analysis

Objective This study aimed to detect the P53 expression level,p53 and PIK3CA gene mutation status in breast cancer,so as to provide theoretical foundation for clinical prognosis and therapy.Methods 88 breast cancer specimens were collected from The People's First Hospital of Yunnan Province.Immunohistochemistry assays were performed to reveal the expression of estrogen receptor(ER),progestrogen receptor(PR),human epidermal growth factor receptor 2(HER2),Ki67 and P53.At the same time,RNA and DNA were extracted to perform PCR and consequent sequencing.Results According to the immunohistochemistry results,these breast cancers could be divided into Luminal A,Luminal B,HER2 over expression,TNBC subtype groups.Clinical prognosis of patients are mainly invasive ductal breast cancer and WHO ?.The most frequent mutations of p53 are indel and nonsense,but the PIK3CA are p.E545A and p.S553fs*7 double-mutations.Among these 88 patients,Luminal A subtype accounts for 13 cases(14.8%),p53 positive rate is 7.69%,p53 mutation rate is 15.38%,PIK3CA mutation rate is 46.15%;Luminal B accounts for 41 cases(46.6%),p53 positive rate is 21.95%,p53 mutation rate is 7.32%,PIK3CA mutation rate is 53.66%;HER2 over expression subtype accounts for 12 cases(13.6%),p53 positive rate is 41.67%,p53 mutation rate is 25.00%,PIK3CA mutation rate is 41.67%;TNBC accounts for 22 cases(25.0%),p53 positive rate is 18.18%,p53 mutation rate is 13.64%,PIK3CA mutation rate is 50.00%.Conclusion p53 positive rate and mutation rate are significantly higher in HER2 over expression subtype than other subtype groups,suggesting that there may be some potential correlation between aberrant p53 status and HER2 over expression.PIK3CA mutation plays an important role in breast cancer patients of Yunnan province,but has no remarkable discrepancy among these 4 subtype groups.