The Related Study Of Female Breast Structural Features And Breast Cancer Incidence In Mianyang Region

objective:1.To summary the characteristics of the structure ofthe female breast of Mianyang region by the discussion on female breast X-rayfeatures and its sub-type based on mammography.2.To analyze the factors ofmammographic density of Mianyang region.3.To explore the risk factors offemale’s breast cancer and establish a risk prediction model of Mianyangregion.Methods:To develop the survey questionnaire and calculate the samplesize of at least1690cases according to the document on clinical epidemiologyof breast and related literature method.To obtain a final sample size of1700cases (including1020outpatient cases and680physical examination cases)from systematic sampling of the target population who not only met theinclusion criteria but also came Mianyang Central Hospital for physicalexamination or out-patient treatmnt. The description of size,thickness, density(four levels), etc. is according to the standard called as Breast ImagingReporting and developed data system (BI-RADS)20034th edition whichdeveloped by American College of Radiology (ACR).According to the testpurpose,1,2-stage breast density were defined as low-density group and3,4-stage were defined as high-density group.Sixty-two patients were confirmedbreast cancer which not considered pathological type with pathologically. Allthe data has been analized by SPSS17.0statistical software.To analyze therelated factors of mammographic density and breast cancer by using χ2testfor count data,t-test for other measurement data and logistic regression analysisfor multivariate analysis.To establish risk prediction model through stepwisemethod (backward method) which selected the risk factors of breastcancer.And then the level variables into the model and from the model were0.05and0.10, useing two-sided test and the test level wereα=0.05. Results:1.The X-ray features of breast structure in Mianyang region isthat among these1700cases,1065are classified large amounts of gland-type,occupying62.65%;282are classified compact type, occupying16.59%;280areclassified small amounts of gland-type, occupying16.47%;73are classified fattype, occupying4.29%.The characteristics of the structure of the female breastof Mianyang region is that their’s breast is relatively smaller and more compactthan European and American women.2.Significant factors in the univariateanalysis are age（p<0.001）,BMI（p<0.001）, age at menarche（p<0.001）,parity（p<0.001）,number of abortion（sp<0.001）,occupation（p<0.001）,marital status（P=0.005）, educational level （p<0.001）,psychological quality（p<0.001）,characte（rP=0.016）,alcohol consumption（P=0.008）and whetherthere had been a sexual relationship （P=0.034）,production（P=0.002）,menopause（p<0.001） and taking contraceptives（P=0.046）.Theunconditional logistic regression analysis shows that the significant risk factorsare age（p<0.001）,BMI（p<0.001）,Parity（P=0.073）,Number of abortions（p<0.001）,Profession（P=0.042）,anxiety（P=0.013）and Menopause（p<0.001）.3.Univariate analysis showed that risk factors for breast cancerwere age （P=0.006）， BMI （P=0.007）， age at menarche （P=0.039），occupation （P=0.001）,domicile place （p<0.001）， educational level（P=0.001），age at first birth（P=0.014）， whether menopause（P=0.003），and age at menopause（P=0.006）. The unconditional logistic regressionanalysis showed that the signifi cant risk factors were age（P=0.003）， age atfi rst birth（p<0.001）， occupation（P=0.010）， and domicile place（p<0.001）， and the protective factor was age at menarche（p<0.001）. Theinitially established risk prediction model in the region which fitting related riskfactors was y=-5.557＋0.042x1-0.375x2＋1.206x3＋0.509x4＋2.135x5. The fitting coeffi cient（R square）=0.170，it could refl ect17%of the actual situation.Conclusions1.Chinese women’s breasts are smaller and more dense,it haslead a certain degree of restriction in the use of breast cancer screening bymammography in China.2.The classification according to BI-RADS (Breastimaging reporting and data system) which classifid mammography into fourtypes can be used as a means of breast cancer screening.3.Age,BMI,age atmenarche,parity,number of abortions,occupation,marital status,educationallevel,psychological quality,character,alcohol consumption and whether therehad been a sexual relationship,production,menopause and taking contraceptivesare influencing factors of mammographic density.Looking for a reliablequantitative assessment of mammographic density is the direction of futureresearch.4.Dense breast has been a warning signal of breast cancer.In clinicaldiagnosis of high-density population,results of other imagings of breast shouldbe considered for comprehensive analysis,which by this way can improvebreast cancer screening and is necessary.5. The multi-level healthy guidelinesfor breast cancer prewention for individuals, small and medium sized cities andthe doctors have been developed by analysis on related risk factors of breastcancer of women in Mianyang region.6.The breast cancer risk prediction modelwhich established by using related risk factors analysis and epidemiologicalinvestigation could guide the future clinical work，but there is still need thevalidation studies of large populations for the model.