The Clinical And Pathological Features Of Breast Cancer Molecular Subtypes And The Significance Of P53Protein Expression

Objective: The incidence of breast cancer in female malignancyaccounted for the first place in China. In2012, the National CancerRegistration latest data showed that the incidence of breast cancer female rateof42.55/10million, and the incidence showed an increasing trend. Breastcancer is a highly heterogeneous disease from clinical, genetic and phenotypicpoints of view. It brought many difficulties to the diagnosis and treatment ofbreast cancer. One of this is, to many of the same type of clinical orpathological characters of patients, the clinical outcome is quite defferentfrom using the similar treatment. After entering the21st century, many studiesof breast cancer molecular typing divide breast cancer into the following fivetypes: LuminalA type, LuminalB type include LuminalB1type andLuminalB2type， triple negative type, HER-2over-expression type andnormal breast-like cells. Normal breast-like cells is classified as triplenegative type in clinical. According to the conventional histological type,molecular subtype could provide more reliable and accurate prognostic andpredictive evidence and could be stronger guidance to individual treatment ofbreast cancer patients.P53gene is a tumor suppressor gene. The p53protein can be tested byimmunohistochemical test. The protein expression by the P53gene mutationis a cancer-promoting factor. The P53gene is a very in-depth gene, and thestudy of the relationship between the molecular subtypes of breast cancer andP53protein is rarely reported. This study evaluates clinical and pathologicfeatures and survival of the five molecular subtypes in patients from BreastCenter of Hebei Province with IHC makers. Since the purpose of this study,the patient case files of breast cancer receiving surgery areare re-checked, test, accurate breast cancermolecular typing classified,to understand the differentsubtypes of breast cancer in the study of the distribution, clinicalcharacteristics, and P53protein expression characteristics of the differentmolecular subtypes of breast cancer forfuture individualized treatment ofbreast cancer mustreference.Methods: A retrospective analysis of all women diagnosed with breastcancer from2009to2011who had assessable data for ER, PR, Ki-67andHER2status. Molecular subtype classification was done based on IHCrrogates for ER, PR, Ki-67and HER2status obtained from Department ofBreast Surgery tumor registry for each patient. The molecular subtypes weredefined as: Luminal A (ER/PR+，HER2-,Ki-67<14%), Luminal B1(ER/PR+，HER2-,Ki-67≥14%), Luminal B2(ER/PR+，HER2+, Ki-67any level), triplenegative(ER-, PR-, Her-2-, Ki-67any level) and HER2+(ER-，PR-, HER-2(+),Ki-67any level). Pathological information is unclear, but retained availableparaffin file cases,503cases, immunohistochemical test of HER-2(2+) cases,316cases, in view of the funding for this experiment, not line FISHdetectionor. According to the screening criteria for the experiment,1170casesultimately enter into the group, the average age is51.2years (range20-83years). The group of premenopausal women has594cases, and the group ofpostmenopausal women has576cases. Based on ER/PR and HER-2andKi-67test results, the breast cancer was divided into five subtypes: LuminalA-type (ER/PR+, Ki-67-,HER-2-). Luminal B1(ER/PR+, Ki-67+,HER-2-), LuminalB2(ER/PR+, of HER-2+, Ki-67-/+), triple negativetype (ER-, PR-, HER-2-, Ki-67-/+) and of HER-2over-expression of type(ER-, PR-, HER-2+, Ki-67-/+). Based on the P53protein test results, wedivided the cases into four groups, P53(-), P53(+), P53(++), P53(+++).Results:1Distribution of molecular subtypes of breast cancer: LuminalA16.8%(196/1170), LuminalB147.2%(551/1170), LuminalB213.8%(161/1170),triple negative11.6%(135/1170), HER-2over-expression of type10.6%(127/1170). 2There were significant diffences on breast cancer subjects by age,menopausal status, tumor size, histological grade, pathological type, TNMpathological stage, vascular invasion and P53protein expression levels(P<0.05). There were no significant diffences by tumor location and axillarylymph node involvement(P>0.05).3Distribution of P53protein expression levels,27.4%(321/1170)werethe P53(-) group,36.8%(430/1170) were P53(+) group,16.8%(196/1170)were P53(2+) group,19.1%(223/1170) were P53(3+) group.4There were nosignificant diffences on P53protein expression levelsby age, menopausal status, tumor size, pathological type, TNM pathologicalstage and vascular invasion and (P>0.05). There were significant diffences byER/PR/HER-2/Ki-67expression levels and histological grade (P<0.05).Conclusion:Different molecular subtypes of breast cancer in the following aspects aredifferent. The difference was statistically significant, such as: age, menopausalstatus, tumor size, histological grade, pathological type, TNM pathologicalstaging, vascular invasion. No significant difference in tumor location andaxillary lymph node involvement, but the analysis of statistical data can befound in triple negative breast cancer Luminal A type breast cancer lymphnode metastasis is relatively uncommon, contrary Luminal HER-2withHER-2over-expression of the type of lymph node metastasis is relativelycommon. From the other side to prove of HER-2positive breast cancerpatients more inclined to lymph node metastasis.P53protein expression levels in different molecular subtypes of breastcancer, while its expression was related with histological, ER/PR expressionlevels, K-67expression levels and HER-2expression levels of certain, wasnot related with menopausal status, tumor size, lymph node involvement,histological type, TNM stage, vascular invasion, tumor location. So that wecan put the level of expression of the P53protein and breast cancer molecular subtypes as the important judegment indicators of the degree of malignancy ofbreast cancer, to provide a reference for the clinical treatment of breast cancer.