Molecular Subtypes Of Breast Cancer And Chemotherapy Resistance Gene Correlation Analysis

Objective: Breast cancer was regarded as a heterogeneous disease classified into different molecular subtypes, resulting in different biologic behavior and sensitivity to treatment respectively.this experiment would investigate the clinical and pathological features of different molecular subtypes of breast cancer, and differential expression of different molecular types of resistance genes was studied to analyze the different molecular subtypes of breast cancer on the correlation between chemosensitivity, which aim to provide guidance for clinical breast cancer chemotherapy. Method:From January 2011 to December 2012, clinical and pathological data of operable female breast cancer patients in our hospital were retrospectively analyzed. In all of 440 cases, the age was between 26-81,with a mean age of 47 years old. According to the estrogen receptor(ER), progesterone receptor(PR), human epidermal growth factor receptor 2(Her-2) status and histological grade,all of 440 breast cancer patients were classified into four different molecular subtypes: Luminal A, Luminal B, Her-2 over-expression and Basal-Like.At the same time, with the available experimental data of Pathology Department as reference, analyzed the expression deference between different molecular subtypes drug resistance genes, such as P- gp(P-glycoprotein), TS(Thymidylate Synthase), GST-Ï€(Glutathione S-Transferase-Ï€), Topo II(Topoisomerase II). Results:Luminal A were the majority,180 cases(40.91%),Luminal B,Basal-like and Her-2 overexpression were 115 cases(26.14%), 85 cases(19.32%)and 60 cases(13.63%) respectively. There was statistical difference between breast cancer molecular subtypes age and tumor size(P<0.05).The molecular subtypes differed significantly in lymph node status,ER status,PR status,Her-2 status,overall survival of different molecular subtypes were significantly different(P<0.05).The expression of drug resistance genes were significant difference in the different molecular subtypes: P-gp was the more positive rate in the Luminal B subtype,whereas the lowest in the luminal A(P<0.05); TS was the more positive rate in the Her-2 subtype,whereas the lowest in the luminal A subtype(P<0.05); GST-Ï€ was the more positive rate in the Her-2 subtype,whereas the lowest in the luminal A subtype(P<0.05);Topo II was the more positive rate in the Luminal B subtype,whereas the lowest in the Basal-like subtype(P<0.05). Conclusions: The molecular subtypes are closely related to clinical outcomes and better reflect the biological behavior of breast cancer,which will be useful for guiding clinical individualized treatment options.