The Prevalence,Risk Factors Of Benign Breast Disease And Its Effect On Breast Cancer Screening In Chinese Women

Aims:To study the epidemic situation and risk factors of benign breast disease(BBD),and the effect of BBD on breast cancer screening in Chinese women through a multi-center breast disease screening program.It will help to provide evidence for selecting high-risk screening groups,choosing optimal breast cancer screening strategies,and improving breast cancer screening results.Methods:The population used in this study was enrolled among 33001 women in five geographical areas(Tianjin,Beijing,Shenyang,Nanchang,and Feicheng)in China between 2008 and 2010.Each participant was examined by clinical breast examination(CBE),breast ultrasound(BUS),and mammography(MAM)independently.We defined a person with BBD if any one of the three methods reported benign finding.We defined a person without BBD if all the methods reported healthy,or all the methods reported suspicious or highly suggestive of a malignancy.The name of all the BBD was further classified into two categories:non-proliferative BBD and proliferative BBD.Mammographic breast density was classified according to the four categories defined by the American College of Radiology Breast Imaging Reporting and Data System(BI-RADS):glandular or almost entirely fat(breast tissue that was less than 25%);glandular or scattered fibro-glandular(breast tissue that was approximately 25–50%);glandular or heterogeneously dense(breast tissue that was 51–75%);and glandular or extremely dense(breast tissue that was more than 75%).The association between epidemiological factors and BBD was measured by?~2test and univariate Unconditional Logistic Regression.Stepwise regression method was used to make a multivariate Unconditional Logistic Regression analysis.Odds ratios(ORs)and 95%confidence intervals(95%CI)were calculated using breast density entirely fat group as the reference group to evaluate the relationship of breast density and BBD,adjusting for potential confounding variables including age at screening,BMI,marital status,education level,family income,family history of cancer,smoking,age at menarche,pregnancy,live birth,breastfeeding,abortion,and menopause status.Stratified analysis of age,BMI,and menopause status was used to evaluate the association between breast density and BBD.All statistical tests were two-sided and P values less than 0.05 were considered statistically significant.A concordance analysis was undertaken to assess the validity of two radiologists'readings and BBD classification for quality control.Analyze the relationship of general demographic factors,physiological reproductive factors and BBD using breast disease screening data nationwide,and study the risk factors of BBD.Study the association between breast density and BBD,and make the analysis of the association between non-proliferative BBD,proliferative BBD and breast density.Analyze the effect of BBD history on breast cancer detection rate and breast cancer pathological stage in the screening population.Make a comparison of pathological stage between the detected breast cancer in screening women and clinical diagnosed breast cancer patients,and analyze the impact of BBD on breast cancer screening results.Results:In this study,a total of 33001 women aged 45-65 were screened.102 cases of breast cancer were detected.There were 23168 actual detected BBD cases.BBD prevalence was 70.2%.In women with actual detected BBD,non-proliferative lesions accounted for 55.5%.Proportion of non-proliferative lesions and proliferative lesions was 2.5:1.Multivariate analysis of BBD risk factors showed that breast density>50%(OR=1.92;95%CI:1.68-2.19)?the number of live births?1(OR=1.64;95%CI:1.43-1.88)?BMI?25(OR=1.40;95%CI:1.24-1.59)?the marriage age>25?(OR=1.26;95%CI:1.11-1.42)?family history of cancer(OR=1.23;95%CI:1.07-1.41)?menopausal age>49 years(OR=1.19;95%CI:1.06-1.34)?menarche age>15 years(OR=1.19;95%CI:1.05-1.35)?income level?2000 yuan(OR=1.17;95%CI:1.03-1.33)were risk factors for BBD.Take breast density<25%as the reference group,breast density 25-50%(OR=1.65;95%CI:1.52-1.80)?50-75%(OR=2.94;95%CI:2.68-3.22)?and>75%(OR=4.10;95%CI:3.55-4.74)gradually increases the risk of BBD.In age<55 and age?55 group,BMI<25 and BMI?25group,premenopausal and postmenopausal group,the risk of BBD gradually increased along with the breast density increases,the conclusion was still valid after multivariate adjustment.The risk of non-proliferative and proliferative BBD gradually increase with the increase of breast density.After age,BMI,and menopausal stratification,the conclusion still holds.In women self-reported without of a history of BBD,we found that 62.2 percent of female were detected to have BBD.The breast cancer detection rate of women with BBD history(282.7/100,000)was lower than women without of a BBD history(327.7/100,000).The result was not statistically significant(P=0.50).In women with a history of BBD,the proportion of carcinoma in situ in screen-detected breast cancer(7.7%)was lower than the proportion(20.3%)in women without a history of BBD.The difference was not statistically significant(P=0.15).In the clinical breast cancer patients,the proportion(5.0%)of carcinoma in situ in women with a history of BBD was higher than the proportion(3.3%)in women without a history of BBD.A statistically significant difference was observed(P<0.01).In women with actual screening detected BBD,the breast cancer detection rate(222.2/100,000)in women who were aware of their sickness was lower than detection rate(223.3/100,000)in women who weren't aware of their sickness.The difference was not statistically significant(P=0.99).In women with actual screening detected BBD,the proportion(11.8%)of carcinoma in situ in women who were aware of their sickness was lower than the proportion(32.1%)of carcinoma in situ in women who weren't aware of their sickness.But the result was not statistically significant(P=0.12).Cross-sectional analysis showed the participation rate(57.1%)of breast health examination in women with a BBD history was higher than the participation rate(29.5%)in women without a BBD history.The proportion(48.7%)of doing regular breast X-ray photograph in women with a BBD history was higher than the proportion(14.6%)in women without a BBD history.Conclusions:In women aged 45-65,the BBD prevalence was 70.2%.The proportion of non-proliferative BBD and proliferative BBD is 2.5:1.Breast density higher than50%,number of live births less than 1 time,BMI higher than 25,marriage age higher than 25,have a family history of cancer,age at menopause higher than 49,age at menarche higher than 15,income level higher than 2000yuan are risk factors for BBD.After age,BMI and menopause stratification,Breast density higher than 50%was still a strong risk factor for BBD.Breast density higher than 50%was also a risk factor for non-proliferative BBD and proliferative BBD,and with the breast density increases,the non-proliferative BBD and proliferative BBD risk increased.The breast cancer detection rate and the proportion of carcinoma in situ in women with a history of BBD were lower than women without a history of BBD.The result was not statistically significant.It suggested that selecting women with a history of BBD as a high risk group for breast cancer screening may not obviously improve the screening effect.A possible reason for the above situation is,BBD cognition affect women breast examination behavior,make timely clinical treatment of breast cancer patients,and thus we can not find more breast cancer patients in the screening group with a history of BBD.