Clinical Pathological Significance Of BRCA1 And Ki67 Expression In Different Molecular Classification Of Breast Cancer

Objective:To investigate the expression of BRCA1 and Ki67 in different molecular subtypes of breast cancer as well as the significance of clinical patholog and study the relationship between BRCA1 and Ki67.Methods:Testing the tumor paraffin blocks by using FISH method which were detected Her2 2+ or 3+ by immunohistochemical method.Only through the FISH method to detect the positive expression of tumor paraffin block is defined as Her2 positive expression,eventually.Classificating breast invasive carcinoma in molecular classification according to the <2013 edition of the Chinese anti-cancer association guidelines and normative standard of diagnosis and treatment of breast cancer> and the breast cancer can be divided into five subtypes in molecular classification:Luminal A subtype group,Luminal B like subtype(Her2 positive)group,Luminal B yang subtype(Her2 negative)group,Her2 over-expression subtype group and basal-like subtype group.selected 20 cases from each subtype,detected BRCA1 protein in each tumor tissue by immunohistochemical SP method and analysed its relationship with the clinical indicators and the relationship between BRCA1 and Ki67.Results:1.Positive expression rate of BRCA1 protein in Luminal A subtype group,Luminal B like subtype(Her2 positive)group,Luminal B yang subtype(Her2negative)group,Her2 over-expression subtype group,basal-like subtype group were95.0%(19/20),85.0%(17/20),55.0%(11/20),80.0%(16/20),75.0%(15/20),the result had obviously significant difference between Luminal A subtype group and Luminal B yang subtype(Her2 negative)group(P < 0.05);2.There were no significant differences with the expression of BRCA1 protein and age,tumor size,tumor distance from the nipple,histological grade and axillarylymph node metastasis,ER/PR status as well as Her2 status(P>0.1);3.High index expression rate of Ki67 in the Luminal A subtype group,Luminal B like subtype(Her2 positive)group,Luminal B yang subtype(Her2 negative)group,Her2 over-expression subtype group,basal-like subtype group were 0(0/20),85.0%(17/20),100%(20/20),75.0%(15/20),85.0%(17/20),the result had obviously significant difference(P < 0.05);High index expression rate of Ki67 in ER/PR negative group and Her2 positive group was more than that in ER/PR positive group and her2-negative group,the statistical significance showed up(P < 0.1);4.High index expression rate of Ki67 in the age < 40 years old group,age 40 to59 years old group and the age more than or equal to 60 years old group were 71.4%(10/14),74.0%(37/50),36.4%(4/11).High index expression rate of Ki67 in the age group less than or equal to 59 years old group was more than that the age more than or equal to 60 years old group,the result had significant difference(P < 0.1);There were no significant differences with the expression of Ki67 protein and tumor size,tumor distance from the nipple,histological grade and the axillary lymph node metastasis(P>0.1);5.The expressions of BRCA1 and Ki67 in different subtypes of breast cancer showed a negative correlation(P < 0.05).Conclusion:1.The expression of BRCA1 protein and ki67 protein is negatively correlated,the expression of missing or decreased BRCA1 protein combined with the high index expression of Ki67 may prompt the poor prognosis of breast cancer patients.2.The expression of BRCA1 protein was not associated with age,tumor size,histology,axillary lymph node metastasis.