A Study On The Expression Of SHBG And AR In Breast Cancer Patients Accompanied With Diabetes Mellitus

BackgroundIn present，the incidence of breast cancer is taking on a increasing trend in ourcountry and its onset age tend to be early. According to statistics from relateddepartments, breast cancer is killing40000people one year.Although in more thanone hundred years, clinical workers engage in exploring the research of breastcancer,including the mechanism and the cure manners, the treatment measures forhigh risk factors are still immaturity.Diabetes mellitus wich is characterized by hyperglycemia is a chronic metabolicdisorders disease. It always promotes many complications of kidney， retina，vessels and nerves and increases the risk of cardiovascular disease.China has thelargest number of people with diabetes in the world.According to thepathogenesis,diabetes mellitus can be divided into type1and type2diabetes.Type2diabetes, which accounts for more than90%～95%of cases, is a high insulin statecaused by insulin resistance in fat and muscle tissues and leads to an inadequate,compensatory increased production of insulin.Decompensation of β cells and lowabsolute insulin concentrations eventually develop in type2diabetes, but only in laterstages of disease.A growing body of research suggests that diabetes is now a recognised risk factor forseveral types of cancer,including lung,colorectal,pancreatic and endometrial cancer，at the same time,the relationship between breast cancer and diabetes receives more attention.Association between diabetes mellitus and breast cancer was first reported in1950s. Preclinical and clinical data suggest complex associations between diabetes,especially type2diabetes and breast cancer.Most of the data suggest diabetics have ahigher morbidity and a worse outcome.Three mechanisms are thought to contribute tothe association between type2diabetes and breast cancer: activation of the insulinpathway; activation of the insulin-like-growth-factor pathway; and impairedregulation of endogenous sex hormones,including estrogen and androgen.The thirdmechanism mainly refers to the influence on the role of androgen and estrogen causedby diabetes mellitus.Sex hormone binding globulin(SHBG) is produced in hepatocytes.It can unite withsex hormone specifically.The bond between dissociative estrogen and estrogenreceptor can promote the emergence and development of breast cancer. For type2diabetes, the high insulin state can decrease liver production of SHBG,wich canindirectly increase the dissociative estrogen.This has been suggested as the mainmechanism that connects postmenopausal breast-cancer risk.Androgen receptor(AR) is one of nuclear receptors.There were androgenreceptoron both normal breast and breast cancer tissue,so mammary epithelial cellshave a response to androgen.Unlike estrogen,the role of androgen in the emergenceand development of breast cancer is unsure. The bond between androgen andandrogen receptor also can activate kinase in cells.Most study support this bond canprevent the emergence and development of breast cancer. At the same time, somestudy support that the positive expression rate of AR is lower,which may be onemechanism that connects postmenopausal breast-cancer risk.ObjectiveBy comparing the expression of SHBG and AR in tissue of breast cancersaccompanied with and without diabetes mellitus, analyze the relationship betweenbreast cancer and diabetes millitus; and guide the therapy for the high risk of breastcancer.MethodsChoose45breast cancer patients accompanied with type2diabetes mellitus,whowere confirmed by pathological after operation at the first Affiliated Hospital ofZhengzhou University between Jun2011and December2013,aging from52to78years(mean age:60years),as the experimental group. While choose anothercontemporaneous45breast cancer patients without type2diabetes mellitus,aging from50to73years(mean age:52years),as the control group. They all werepostmenopausal women,did not accompany with other high metabolic diseases,anddid not accept chemotherapy,radiation,endocrine therapy and targeted therapy.At thesame time,according to the IHC,group the patients of ER/PR(+) into Epgroup,patients of ER and PR(-) into En group. The expression of SHBG and AR inthese tissue samples were detected by Immunohistochemical SP method. The data wasanalyzed by SPSS17.0statistical software and chi-square test with P<0.05as thedifference have statistically significant.Results1.The positive expression rate of SHBG in the group of diabetics was significantlylower than the group of nondiabetic patients,respectively was24.4%,62.2%,thedifference had statistically significan（tP=0.000）.The positive expression rate of AR inthe group of diabetics and nondiabetic patients was respectively60.0%,68.9%,thedifference did not have statistically significant（P=0.378）2.The positive expression rate of SHBG in the Ep,En group respectively was40.3%,52.2%,the difference did not have statistically significant（P=0.273）; Thepositive expression rate of AR in the Ep was significantly higher than the En group,respectively was67.2%,56.5%,the difference had statistically significant（P=0.042).Conclusion1.In the breast cancer tissue,the positive expression rate of SHBG is lower forpatients accompanied with type2diabetes；the positive expression rate of AR haslittle difference.2.The positive expression rate of AR is related to ER and PR.