An analysis of the association between breast density and body mass index with breast cancer molecular subtypes in early breast cancer: data from a Spanish population

PURPOSE

Breast cancer is an important health problem, like obesity and dyslipidemia, with a strong association between body mass index (BMI) and breast cancer incidence and mortality. The risk of breast cancer is also high in women with high mammographic breast density (MBD). The purpose of this study was to analyze the association between BMI and MBD according to breast cancer molecular subtypes.

METHODS

This transversal, descriptive, multicenter study was conducted at three Spanish breast cancer units from November 2019 to October 2020 in women with a recent diagnosis of early breast cancer. Data were collected at the time of diagnosis.

RESULTS

The study included 162 women with a recent diagnosis of early breast cancer. The median age was 52 years and 49.1% were postmenopausal; 52% had normal weight, 32% overweight, and 16% obesity. There was no association between BMI and molecular subtype but, according to menopausal status, BMI was significantly higher in postmenopausal patients with luminal A (p = 0.011) and HER2-positive (p = 0.027) subtypes. There was no association between MBD and molecular subtype, but there were significant differences between BMI and MBD (p < 0.001), with lower BMI in patients with higher MBD. Patients with higher BMI had lower HDL-cholesterol (p < 0.001) and higher insulin (p < 0.001) levels, but there were no significant differences in total cholesterol or vitamin D.

CONCLUSIONS

This study showed higher BMI in luminal A and HER2-positive postmenopausal patients, and higher BMI in patients with low MBD regardless of menopausal status.

Temporal changes in mammographic breast density and breast cancer risk among women with benign breast disease

INTRODUCTION

Benign breast disease (BBD) and high mammographic breast density (MBD) are prevalent and independent risk factors for invasive breast cancer. It has been suggested that temporal changes in MBD may impact future invasive breast cancer risk, but this has not been studied among women with BBD.

METHODS

We undertook a nested case-control study within a cohort of 15,395 women with BBD in Kaiser Permanente Northwest (KPNW; 1970-2012, followed through mid-2015). Cases (n = 261) developed invasive breast cancer > 1 year after BBD diagnosis, whereas controls (n = 249) did not have breast cancer by the case diagnosis date. Cases and controls were individually matched on BBD diagnosis age and plan membership duration. Standardized %MBD change (per 2 years), categorized as stable/any increase (≥ 0%), minimal decrease of less than 5% or a decrease greater than or equal to 5%, was determined from baseline and follow-up mammograms. Associations between MBD change and breast cancer risk were examined using adjusted unconditional logistic regression.

RESULTS

Overall, 64.5% (n = 329) of BBD patients had non-proliferative and 35.5% (n = 181) had proliferative disease with/without atypia. Women with an MBD decrease (≤ - 5%) were less likely to develop breast cancer (Odds Ratio (OR) 0.64; 95% Confidence Interval (CI) 0.38, 1.07) compared with women with minimal decreases. Associations were stronger among women ≥ 50 years at BBD diagnosis (OR 0.48; 95% CI 0.25, 0.92) and with proliferative BBD (OR 0.32; 95% CI 0.11, 0.99).

DISCUSSION

Assessment of temporal MBD changes may inform risk monitoring among women with BBD, and strategies to actively reduce MBD may help decrease future breast cancer risk.

A scoping review of programme specific mammographic breast density related guidelines and practices within breast screening programmes

INTRODUCTION

High mammographic breast density (MBD) is an independent breast cancer risk factor. In organised breast screening settings, discussions are ongoing regarding the optimal clinical role of MBD to help guide screening decisions. The aim of this scoping review was to provide an overview of current practices incorporating MBD within population-based breast screening programmes and from professional organisations internationally.

METHODS

This scoping review was conducted in accordance with the framework proposed by the Joanna Briggs Institute. The electronic databases, MEDLINE (PubMed), EMBASE, CINAHL Plus, Scopus, and Web of Science were systematically searched. Grey literature sources, websites of international breast screening programmes, and relevant government organisations were searched to identify further relevant literature. Data from identified materials were extracted and presented as a narrative summary.

RESULTS

The search identified 78 relevant documents. Documents were identified for breast screening programmes in 18 countries relating to screening intervals for women with dense breasts, MBD measurement, reporting, notification, and guiding supplemental screening. Documents were identified from 18 international professional organisations with the majority of material relating to supplemental screening guidance for women with dense breasts. Key factors collated during the data extraction process as relevant considerations for MBD practices included the evidence base needed to inform decision-making processes and resources (healthcare system costs, radiology equipment, and workforce planning).

CONCLUSIONS

This scoping review summarises current practices and guidelines incorporating MBD in international population-based breast screening settings and highlights the absence of consensus between organised breast screening programmes incorporating MBD in current breast screening protocols.

Lipidome of mammographic breast density in premenopausal women

BACKGROUND

High mammographic breast density (MBD) is a strong risk factor for breast cancer development, but the biological mechanisms underlying MBD are unclear. Lipids play important roles in cell differentiation, and perturbations in lipid metabolism are implicated in cancer development. Nevertheless, no study has applied untargeted lipidomics to profile the lipidome of MBD. Through this study, our goal is to characterize the lipidome of MBD in premenopausal women.

METHODS

Premenopausal women were recruited during their annual screening mammogram at the Washington University School of Medicine in St. Louis, MO. Untargeted lipidomic profiling for 982 lipid species was performed at Metabolon (Durham, NC®), and volumetric measures of MBD (volumetric percent density (VPD), dense volume (DV), and non-dense volume (NDV)) was assessed using Volpara 1.5 (Volpara Health®). We performed multivariable linear regression models to investigate the associations of lipid species with MBD and calculated the covariate-adjusted least square mean of MBD by quartiles of lipid species. MBD measures were log10 transformed, and lipid species were standardized. Linear coefficients of MBD were back-transformed and considered significant if the Bonferroni corrected p-value was < 0.05.

RESULTS

Of the 705 premenopausal women, 72% were non-Hispanic white, and 23% were non-Hispanic black. Mean age, and BMI were 46 years and 30 kg/m2, respectively. Fifty-six lipid species were significantly associated with VPD (52 inversely and 4 positively). The lipid species with positive associations were phosphatidylcholine (PC)(18:1/18:1), lysophosphatidylcholine (LPC)(18:1), lactosylceramide (LCER)(14:0), and phosphatidylinositol (PI)(18:1/18:1). VPD increased across quartiles of PI(18:1/18:1): (Q1 = 7.5%, Q2 = 7.7%, Q3 = 8.4%, Q4 = 9.4%, Bonferroni p-trend = 0.02). The lipid species that were inversely associated with VPD were mostly from the triacylglycerol (N = 43) and diacylglycerol (N = 7) sub-pathways. Lipid species explained some of the variation in VPD. The inclusion of lipid species increased the adjusted R2 from 0.45, for a model that includes known determinants of VPD, to 0.59.

CONCLUSIONS

We report novel lipid species that are associated with MBD in premenopausal women. Studies are needed to validate our results and the translational potential.

Hormone and receptor activator of NF-κB (RANK) pathway gene expression in plasma and mammographic breast density in postmenopausal women

Background

Hormones impact breast tissue proliferation. Studies investigating the associations of circulating hormone levels with mammographic breast density have reported conflicting results. Due to the limited number of studies, we investigated the associations of hormone gene expression as well as their downstream mediators within the plasma with mammographic breast density in postmenopausal women.

Methods

We recruited postmenopausal women at their annual screening mammogram at Washington University School of Medicine, St. Louis. We used the NanoString nCounter platform to quantify gene expression of hormones (prolactin, progesterone receptor (PGR), estrogen receptor 1 (ESR1), signal transducer and activator of transcription (STAT1 and STAT5), and receptor activator of nuclear factor-kB (RANK) pathway markers (RANK, RANKL, osteoprotegerin, TNFRSF18, and TNFRSF13B) in plasma. We used Volpara to measure volumetric percent density, dense volume, and non-dense volume. Linear regression models, adjusted for confounders, were used to evaluate associations between gene expression (linear fold change) and mammographic breast density.

Results

One unit increase in ESR1, RANK, and TNFRSF18 gene expression was associated with 8% (95% CI 0–15%, p value = 0.05), 10% (95% CI 0–20%, p value = 0.04) and % (95% CI 0–9%, p value = 0.04) higher volumetric percent density, respectively. There were no associations between gene expression of other markers and volumetric percent density. One unit increase in osteoprotegerin and PGR gene expression was associated with 12% (95% CI 4–19%, p value = 0.003) and 7% (95% CI 0–13%, p value = 0.04) lower non-dense volume, respectively.

Conclusion

These findings provide new insight on the associations of plasma hormonal and RANK pathway gene expression with mammographic breast density in postmenopausal women and require confirmation in other studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-022-01522-2.

Factors associated with mammographic breast density among women in Karachi Pakistan

Background

There are no studies done to evaluate the distribution of mammographic breast density and factors associated with it among Pakistani women.

Methods

Participants included 477 women, who had received either diagnostic or screening mammography at two hospitals in Karachi Pakistan. Mammographic breast density was assessed using the Breast Imaging Reporting and Data System. In person interviews were conducted using a detailed questionnaire, to assess risk factors of interest, and venous blood was collected to measure serum vitamin D level at the end of the interview. To determine the association of potential factors with mammographic breast density, multivariable polytomous logistic regression was used.

Results

High-density mammographic breast density (heterogeneously and dense categories) was high and found in 62.4% of women. There was a significant association of both heterogeneously dense and dense breasts with women of a younger age group < 45 years (OR 2.68, 95% CI 1.60–4.49) and (OR 4.83, 95% CI 2.54–9.16) respectively. Women with heterogeneously dense and dense breasts versus fatty and fibroglandular breasts had a higher history of benign breast disease (OR 1.90, 95% CI 1.14–3.17) and (OR 3.61, 95% CI 1.90–6.86) respectively. There was an inverse relationship between breast density and body mass index. Women with dense breasts and heterogeneously dense breasts had lower body mass index (OR 0.94 95% CI 0.90–0.99) and (OR 0.81, 95% CI 0.76–0.87) respectively. There was no association of mammographic breast density with serum vitamin D levels, diet, and breast cancer.

Conclusions

The findings of a positive association of higher mammographic density with younger age and benign breast disease and a negative association between body mass index and breast density are important findings that need to be considered in developing screening guidelines for the Pakistani population.

Mammographic Breast Density and Acculturation: Longitudinal Analysis in Chinese Immigrants

Breast cancer is the most common cancer in women. Asian American women have experienced steadily increasing breast cancer incidence rates over the past several decades. The increased rate might be in part due to acculturation. We tested the hypothesis that higher level of acculturation was associated with higher mammographic breast density (MBD), an indicator of breast cancer risk, in a cohort of 425 premenopausal Chinese immigrant women in Philadelphia. Generalized estimating equations accounted for repeated observations and adjusted for age, type of mammographic image, body mass index, months of breastfeeding, number of live births, age at first birth, and menopausal stage (pre, early peri, late peri, post). Results indicated that acculturation level was not associated with any of the MBD measures. Findings were contrary to our hypothesis and previous, cross-sectional studies. In this study population, reproductive factors had a greater effect on MBD than acculturation-related behaviors in adulthood.

Classification of mammographic breast density and its correlation with BI-RADS in elder women using machine learning approach

INTRODUCTION

Mammographic breast density (MBD) is a known risk factor for breast cancer and older women have higher incidence rates of breast cancer occurrence. The Breast Imaging Reporting and Data System (BI-RADS) is a commonly used MBD classification tool for mammogram reporting. However, they have limitations since there are reading inconsistencies between different radiologists with the visual assessment of breast density.

METHODS

Digitised film-screen mammographic images were extracted from the Digital Database for Screening Mammography (DDSM). A machine learning project was developed using commercially available software with several predictive models applied to classify different amount of MBD on mammograms into different density groups. The effectiveness of different predictive models used in classifying the mammograms were tested by receiver operator characteristics (ROC) curve with comparison to the gold standard of BI-RADS classification.

RESULTS

Three predictive models, Decision Tree (Tree), Support Vector Model (SVM) and k-Nearest Neighbour (kNN) showed high AUC values of 0.801, 0.805 and 0.810 respectively. High AUC values for the three predictive models indicates that the accuracy of the model is approaching that of the BI-RADS method.

DISCUSSION

Our machine learning project showed to have capabilities to be potentially used in the clinical settings to help categorise mammograms into extremely dense breasts (BI-RADS Group A) from entirely fatty breasts (BI-RADS Group D).

CONCLUSION

Findings from the present study suggest that the machine learning method is potentially useful to quantify the amount of MBD in mammograms.

Role of digital breast tomosynthesis in the evaluation of focal breast pain

RATIONAL AND OBJECTIVE

To investigate the utility of digital breast tomosynthesis (DBT) in the evaluation of focal breast pain, considering breast density and breast cancer risk.

METHODS

Ninety-one cases of focal breast pain evaluated with DBT and ultrasound (US) from 12/30/2014 to 11/9/2017 with 2-year follow-up were identified. Exclusion criteria were non-focal, axillary, or radiating pain; palpable or skin changes; pregnancy or lactation; and history of ipsilateral cancer, trauma, or infection. Demographic data, Tyrer-Cuzick Score (TCS), medical history, breast density, imaging results, and pathology were recorded. Descriptive statistics were reported.

RESULTS

Eighteen percent (16/91) of cases demonstrated findings, all benign. Of these, 6% (1/16) were detected by DBT only, 88% (14/16) by US only, and 6% (1/16) by DBT and US. US resulted in 3 benign biopsies. Ninety-nine percent (75/76) of cases with no findings at the site of pain on US also had no findings on DBT. Ninety-eight percent (89/91) of cases with no cancer detected at the site of pain on US also did not have cancer on DBT. DBT detected 2 incidental cancers not associated with pain. DBT and US agreed that there was no finding at the site of pain in 82% (75/91) of cases. A high degree of agreement between DBT and US was seen when stratified by breast density and TCS.

CONCLUSION

DBT may be appropriate for the evaluation of focal pain. Low breast cancer incidence was observed at the site of focal pain across all mammographic breast densities and breast cancer risks.

Does circulating progesterone mediate the associations of single nucleotide polymorphisms in progesterone receptor (PGR)-related genes with mammographic breast density in premenopausal women?

Progesterone is a proliferative hormone in the breast but the associations of genetic variations in progesterone-regulated pathways with mammographic breast density (MD) in premenopausal women and whether these associations are mediated through circulating progesterone are not clearly defined. We, therefore, investigated these associations in 364 premenopausal women with a median age of 44 years. We sequenced 179 progesterone receptor (PGR)-related single nucleotide polymorphisms (SNPs). We measured volumetric percent density (VPD) and non-dense volume (NDV) using Volpara. Linear regression models were fit on circulating progesterone or VPD/NDV separately. We performed mediation analysis to evaluate whether the effect of a SNP on VPD/NDV is mediated through circulating progesterone. All analyses were adjusted for confounders, phase of menstrual cycle and the Benjamini-Hochberg false discovery (FDR) adjusted p-value was applied to correct for multiple testing. In multivariable analyses, only PGR rs657516 had a direct effect on VPD (averaged direct effect estimate = - 0.20, 95%CI = - 0.38 ~ - 0.04, p-value = 0.02) but this was not statistically significant after FDR correction and the effect was not mediated by circulating progesterone (mediation effect averaged across the two genotypes = 0.01, 95%CI = - 0.02 ~ 0.03, p-value = 0.70). Five SNPs (PGR rs11571241, rs11571239, rs1824128, rs11571150, PGRMC1 rs41294894) were associated with circulating progesterone but these were not statistically significant after FDR correction. SNPs in PGR-related genes were not associated with VPD, NDV and circulating progesterone did not mediate the associations, suggesting that the effects, if any, of these SNPs on MD are independent of circulating progesterone.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12672-021-00438-1.

Fatty liver disease and changes in dense breasts in pre- and postmenopausal women: the Kangbuk Samsung Health Study

PURPOSE

While increased breast density is a risk factor for breast cancer, the effect of fatty liver disease on breast density is unknown. We investigated whether fatty liver is a risk factor for changes in breast density over ~ 4 years of follow-up in pre- and postmenopausal women.

METHODS

This study included 74,781 middle-aged Korean women with mammographically determined dense breasts at baseline. Changes in dense breasts were identified by more screening mammograms during follow-up. Hepatic steatosis (HS) was measured using ultrasonography. Flexible parametric proportional hazards models were used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs), and a Weibull accelerated failure time model (AFT) was used to determine the time ratios (TRs) and 95% CIs.

RESULTS

During a median follow-up of 4.1 years, 4022 women experienced resolution of the dense breasts. The association between HS and dense breast resolution differed by the menopause status (P for interaction < 0.001). After adjusting for body mass index and other covariates, the aHRs (95% CI) for dense breast resolution comparing HS to non-HS were 0.81 (0.70-0.93) in postmenopausal women, while the association was converse in premenopausal women with the corresponding HRs of 1.30 (1.18-1.43). As an alternative approach, the multivariable-adjusted TR (95% CI) for dense breast survival comparing HS to non-HS were 0.81 (0.75-0.87) and 1.19 (1.06-1.33) in premenopausal and postmenopausal women, respectively.

CONCLUSION

The association between HS and changes in dense breasts differed with the menopause status. HS increased persistent dense breast survival in postmenopausal women but decreased it in premenopausal women.

Medication use and mammographic breast density

PURPOSE

A dense breast on mammogram is a strong risk factor for breast cancer. Identifying factors that reduce mammographic breast density could thus provide insight into breast cancer prevention. Due to the limited number of studies and conflicting findings, we investigated the associations of medication use (specifically statins, aspirin, and ibuprofen) with mammographic breast density.

METHODS

We evaluated these associations in 775 women who were recruited during an annual screening mammogram at Washington University School of Medicine, St. Louis. We measured mammographic breast density using Volpara. We used multivariable-adjusted linear regressions to determine the associations of medication use (statins, aspirin, and ibuprofen) with mammographic breast density. Least squared means were generated and back-transformed for easier interpretation.

RESULTS

The mean age of study participants was 52.9 years. Statin use in the prior 12 months was not associated with volumetric percent density or dense volume, but was positively associated with non-dense volume. The mean volumetric percent density was 8.6% among statin non-users, 7.2% among women who used statins 1-3 days/week, and 7.3% among women who used statins ≥ 4 days/week (p trend = 0.07). The non-dense volume was 1297.1 cm³ among statin non-users, 1368.7 cm³ among women who used statins 1-3 days/week, and 1408.4 cm³ among those who used statins ≥ 4 days/week (p trend = 0.02). We did not observe statistically significant differences in mammographic breast density by aspirin or ibuprofen use.

CONCLUSION

Statin, aspirin, and ibuprofen use was not associated with volumetric percent density and dense volume, but statin use was positively associated with non-dense volume. Any potential associations of these medications with breast cancer risk are unlikely to be mediated through an effect on volumetric percent density.

Mammographic density and prognosis in primary breast cancer patients

PURPOSE

Mammographic density (MD) is one of the strongest risk factors for breast cancer (BC). However, the influence of MD on the BC prognosis is unclear. The objective of this study was therefore to investigate whether percentage MD (PMD) is associated with a difference in disease-free or overall survival in primary BC patients.

METHODS

A total of 2525 patients with primary, metastasis-free BC were followed up retrospectively for this analysis. For all patients, PMD was evaluated by two readers using a semi-automated method. The association between PMD and prognosis was evaluated using Cox regression models with disease-free survival (DFS) and overall survival (OS) as the outcome, and the following adjustments: age at diagnosis, year of diagnosis, body mass index, tumor stage, grading, lymph node status, hormone receptor and HER2 status.

RESULTS

After median observation periods of 9.5 and 10.0 years, no influence of PMD on DFS (p = 0.46, likelihood ratio test (LRT)) or OS (p = 0.22, LRT), respectively, was found. In the initial unadjusted analysis higher PMD was associated with longer DFS and OS. The effect of PMD on DFS and OS disappeared after adjustment for age and was caused by the underlying age effect.

CONCLUSIONS

Although MD is one of the strongest independent risk factors for BC, in our collective PMD is not associated with disease-free and overall survival in patients with BC.

Pre-diagnostic DNA methylation patterns differ according to mammographic breast density amongst women who subsequently develop breast cancer: a case-only study in the EPIC-Florence cohort

PURPOSE

Mammographic breast density (MBD) is a marker of increased breast cancer (BC) risk, yet much remains to be clarified about the underlying mechanisms. We investigated whether DNA methylation patterns differ between high- vs. low-MBD women who developed BC during an 8.9-year median follow-up in the Florence section of the European Prospective Investigation into Cancer and Nutrition.

METHODS

We analysed 96 pairs of women with BC arising on high- vs. low-MBD breasts (BI-RADS category III-IV vs. I). DNA methylation was determined on pre-diagnostic blood samples using the Illumina Infinium MethylationEPIC BeadChip assay. The statistical analysis was conducted by performing an epigenome-wide association study (EWAS), by searching differentially methylated regions (DMRs) in gene promoters (followed by functional enrichment and gene annotation analysis); and through a "candidate pathways" approach focusing on pre-defined inflammation-related pathways.

RESULTS

In EWAS, no single CpG site was differentially methylated between high- and low-MBD women after correction for multiple testing. A total of 140 DMRs were identified, of which 131 were hyper- and 9 hypo-methylated amongst high-MBD women. These DMRs encompassed an annotation cluster of 35 genes coding for proteins implicated in transcription regulation and DNA binding. The "apoptosis signalling" was the only inflammation-related candidate pathway differentially methylated between high- and low-MBD women.

CONCLUSION

Pre-diagnostic methylation patterns differ between high- vs. low-MBD women who subsequently develop BC, particularly, in genes involved in the regulation of DNA transcription and cell apoptosis. Our study provides novel clues about the mechanisms linking MBD and BC.

Benign breast disease and changes in mammographic breast density

Background

Mammographic breast density (MBD) and benign breast disease (BBD) are two of the strongest risk factors for breast cancer. Understanding trends in MBD by age and parity in women with BBD is essential to the clinical management and prevention of breast cancer.

Methods

Using data from the Early Determinants of Mammographic Density (EDMD) study, a prospective follow-up study of women born in 1959–1967, we evaluated MBD in 676 women. We used linear regression with generalized estimating equations to examine associations between self-reported BBD and MBD (percent density, dense area, and non-dense area), assessed through a computer-assisted method.

Results

A prior BBD diagnosis (median age at diagnosis 32 years) was reported by 18% of our cohort. The median time from BBD diagnosis to first available study mammogram was 9.4 years (range 1.1–27.6 years). Women with BBD had a 3.44% higher percent MBD (standard error (SE) = 1.56, p-value = 0.03) on their first available mammogram than women without BBD. Compared with parous women without BBD, nulliparous women with BBD and women with a BBD diagnosis prior to first birth had 7–8% higher percent MBD (β = 7.25, SE = 2.43, p-value< 0.01 and β = 7.84, SE = 2.98, p-value = 0.01, respectively), while there was no difference in MBD in women with a BBD diagnosis after the first birth (β = −0.22, SE = 2.40, p-value = 0.93).

Conclusion

Women with self-reported BBD had higher mammographic breast density than women without BBD; the association was limited to women with BBD diagnosed before their first birth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01426-7.

Serum concentrations of DDE, PCBs, and other persistent organic pollutants and mammographic breast density in Triana, Alabama, a highly exposed population

INTRODUCTION

Although some persistent organic pollutants (POPs) are considered human carcinogens, results from studies evaluating exposures and breast cancer risk have been inconsistent, potentially related to varying ages at exposure. Additionally, few studies evaluated the association between POPs exposure and mammographic breast density (MBD), an intermediate biomarker of breast cancer risk. We carried out a cross-sectional study to investigate associations between serum POPs concentrations and MBD measured in 1998 in female residents of Triana, Alabama, in a predominately African American population with high POPs exposures, particularly to p,p'-DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane).

METHODS

We measured lipid-adjusted serum concentrations (ng/g lipid) of p,p'-DDT and its main metabolite p,p'-DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene), polychlorinated biphenyls (PCBs), β-hexachlorocyclohexane (β-HCCH), heptachlor epoxide, oxychlordane, trans-nonachlor, mirex, and aldrin for each woman in our study (n = 210). We also measured two MBD metrics, percent MBD (%MBD) and area of MBD (aMBD). Using adjusted Spearman correlation coefficients (rs) we evaluated correlations between %MBD and aMBD with individual POPs in the overall population and by age group (19-40, 41-54, and 55-91 years) and also estimated adjusted mean measures of MBD with 95% confidence intervals across tertiles of analytes using generalized linear models (GLM). We calculated p-values for multiplicative interaction by age group using GLM. Additional analyses excluded women with current hormone replacement therapy (HRT) use and evaluated early-life exposure (prior to age 18) during the heaviest contamination period in Triana (1947-90).

RESULTS

Among all women, we found no correlation between p,p'-DDE and %MBD, but after age stratification and exclusion of HRT users, there was a suggestion of a difference by age group, with younger women having a weak positive correlation (rs = 0.12, p = 0.37) and older women having a weak negative correlation (rs = -0.12, p = 0.43); pinteraction = 0.06. In contrast, PCBs were weakly positively correlated with %MBD among all women, with the correlation magnitudes increasing after excluding current HRT users (rs-total PCBs = 0.17, p = 0.03). After age stratification and exclusion of HRT users, correlations for PCBs were higher among younger and middle-age women, with only a handful of these correlations being statistically significant. For β-HCCH, the strongest finding was a negative correlation among older women (rs = -0.26, p = 0.07). Correlations were positive predominantly in the younger age group for heptachlor epoxide (rs = 0.27, p = 0.04), oxychlordane (rs = 0.35, p = 0.006), and trans-nonachlor (rs = 0.37, p = 0.003), and largely null for the middle and older age groups; pinteraction range: 0.03-0.05. Similar patterns were found in GLM analyses using tertiles of exposure and aMBD as the metric for MBD. Women exposed during the heaviest chemical contamination period in Triana prior to age 18 had positive correlations between %MBD and PCBs, heptachlor epoxide, mirex, oxychlordane, and trans-nonachlor.

CONCLUSIONS

In this population, despite high exposures to p,p'-DDT and thus high serum concentrations of its main metabolite, p,p'-DDE, we did not find strong evidence of a positive association with MBD. In fact, there was some evidence of a negative association among older women for p,p'-DDE; a similar pattern was found for β-HCCH. However, younger women with higher serum levels of PCBs, heptachlor epoxide, oxychlordane, and trans-nonachlor, who were likely exposed in early life, had higher MBD. These findings should be replicated in larger studies.

Placental morphometry in relation to daughters' percent mammographic breast density at midlife

Intrauterine and early-life exposures, including intrauterine smoke exposures and infant growth are associated with mammographic breast density (MBD), a strong breast cancer risk factor. We investigated whether placental morphometry, which is affected by intrauterine smoke exposure and also influences infant growth, predicts %MBD at ages 37-47. In 247 daughters in the Child Health and Development Studies, we found that larger placental surface area and placental thickness were associated with lower %MBD (-0.32 per cm², 95% CI -0.6, -0.05; -37.8 per 0.5 cm, 95% CI= -73.3, -2.3 respectively) independent of mothers' smoking, age, weight, parity and daughters' birthweight and age at mammogram. We also observed a positive interaction between placental surface area and thickness (p < 0.05) such that the highest breast dense area was observed for offspring with the thickest and largest placentas. Factors that impact placental morphometry, in addition to in utero smoke exposure, may influence adult breast architecture and breast cancer risk.

In utero DDT exposure and breast density before age 50

Prior studies in the Child Health and Development Studies (CHDS) found in utero exposure to the pesticide, dichlorodiphenyltrichloroethane (DDT), increased breast cancer risk by age 52. Mammographic density is considered a primary risk factor for breast cancer. We conducted a study of 309 daughters from the CHDS to examine in utero DDT exposure and mammographic density in midlife. Among daughters with high (>75th percentile) exposure to p,p'-Dichlorodiphenyldichloroethylene (DDE), p,p'-DDT was significantly correlated with increased dense area and percent density regardless of her body mass in midlife. In the subset of women with lower (<75th percentile) p,p-DDE, p,p'-DDT was associated with increased non-dense breast area. This was explained by adjustment for midlife BMI suggesting that p,p'-DDT may be obesogenic. In aggregate our findings indicate that early life p,p'-DDT exposure impacts breast density in a complex way that depends on the hosts biological ability to sequester and process DDT and levels of exposure.

In utero DDT exposure and breast density in early menopause by maternal history of breast cancer

We examined the relationship between intrauterine dichlorodiphenyltrichloroethane (DDT) exposure (o,p'-DDT, p,p'-DDT, and p,p'-DDE) and mammographic breast density (MBD) in midlife, one of the strongest risk factors for breast cancer. We focused our analyses on o,p'-DDT exposure given our previous report of a positive association between intrauterine o,p'-DDT exposure and daughter's breast cancer (BC) risk. Here we estimated associations of intrauterine serum DDTs with MBD in 224 daughters of women in the Child Health and Development Studies pregnancy cohort whose mothers did not develop BC (MBCa-) and 156 daughters whose mothers did develop BC (MBCa+). In MBCa+ daughters, highest relative to lowest quartile of o,p'-DDT exposure was associated with a 17-unit higher dense area (95% CI = 2.6-31.2; P_trend = 0.01). We did not observe an association between o,p'-DDT and density measures in MBCa- daughters. MBD, an intermediate marker of BC risk, may be affected by intrauterine DDT exposures; MBCa status may modify the association.

Associations of mammographic breast density with breast stem cell marker-defined breast cancer subtypes

PURPOSE

High mammographic breast density is a strong, well-established breast cancer risk factor. Whether stem cells may explain high breast cancer risk in dense breasts is unknown. We investigated the association between breast density and breast cancer risk by the status of stem cell markers CD44, CD24, and ALDH1A1 in the tumor.

METHODS

We included 223 women with primary invasive or in situ breast cancer and 399 age-matched controls from Mayo Clinic Mammography Study. Percent breast density (PD), absolute dense area (DA), and non-dense area (NDA) were assessed using computer-assisted thresholding technique. Immunohistochemical analysis of the markers was performed on tumor tissue microarrays according to a standard protocol. We used polytomous logistic regression to quantify the associations of breast density measures with breast cancer risk across marker-defined tumor subtypes.

RESULTS

Of the 223 cancers in the study, 182 were positive for CD44, 83 for CD24 and 52 for ALDH1A1. Associations of PD were not significantly different across t marker-defined subtypes (51% + vs. 11-25%: OR 2.83, 95% CI 1.49-5.37 for CD44+ vs. OR 1.87, 95% CI 0.47-7.51 for CD44-, p-heterogeneity = 0.66; OR 2.80, 95% CI 1.27-6.18 for CD24+ vs. OR 2.44, 95% CI 1.14-5.22 for CD24-, p-heterogeneity = 0.61; OR 3.04, 95% CI 1.14-8.10 for ALDH1A1+ vs. OR 2.57. 95% CI 1.30-5.08 for ALDH1A1-, p-heterogeneity = 0.94). Positive associations of DA and inverse associations of NDA with breast cancer risk were similar across marker-defined subtypes.

CONCLUSIONS

We found no evidence of differential associations of breast density with breast cancer risk by the status of stem cell markers. Further studies in larger study populations are warranted to confirm these associations.

Are mammographic density phenotypes associated with breast cancer treatment response and clinical outcomes? A systematic review and meta-analysis

Mammographic density (MD) increases breast cancer (BC) risk, however, its association with patient outcomes is unclear. We examined the association of baseline MD (BMD), and MD reduction (MDR) following BC treatment with patient outcomes. Six databases (CINAHL, Scopus, PubMed, Web of Science, MEDLINE, and Embase) were used to identify relevant articles. The PRISMA strategy was used to extract relevant details. Study quality and risk of bias were assessed using the "Quality In Prognosis Studies" (QUIPS) tool. A Meta-analysis and pooled risk estimates were performed. Results showed that BMD is associated with contralateral breast cancer (CBC) risk (HR = 1.9; 95%CI: 1.3-3.0, p = 0.0007), recurrence (HR = 2.0; 95%CI: 1.0-4.0, p = 0.04), and mortality (HR = 1.4; 95%CI: 1.1-1.9, p = 0.003). No association was found between BMD and prognosis (HR = 3.2; 95%CI: 0.9-11.2, p = 0.06). Data on risk estimates (95%CI) from BMD for survival [RR: 1.75; 0.99-3.1 to 2.4; 1.4-4.1], ipsilateral BC [HR: 1; 0.6-1.6 to 3; 1.2-7.5], and treatment response (OR, 1.8; 0.98-3.3) are limited. MDR showed no association with mortality (HR = 0.5; 95%CI: 0.2-1.2, p = 0.13). MDR is associated with a reduced risk of recurrence [HR/RR: 0.35; 0.17-0.68 to 1.33; 0.67-2.65)], however data on MDR and outcomes such as mortality [HR/RR: 0.5; 0.27-0.93 to 0.59; 0.22-0.88], and CBC risk [RR/HR: 0.53; 0.24-0.84 to 1.3; 0.6-2.7] are limited. Evidence, although sparse, demonstrates that high BMD is associated with an increased risk of recurrence, CBC, and mortality. Conversely, MDR is associated with a reduced risk of BC recurrence, CBC, and BC-related mortality.

The association between mammographic density and breast cancer risk in Western Australian Aboriginal women

PURPOSE

Mammographic density is an established breast cancer risk factor within many ethnically different populations. The distribution of mammographic density has been shown to be significantly lower in Western Australian Aboriginal women compared to age- and screening location-matched non-Aboriginal women. Whether mammographic density is a predictor of breast cancer risk in Aboriginal women is unknown.

METHODS

We measured mammographic density from 103 Aboriginal breast cancer cases and 327 Aboriginal controls, 341 non-Aboriginal cases, and 333 non-Aboriginal controls selected from the BreastScreen Western Australia database using the Cumulus software program. Logistic regression was used to examine the associations of percentage dense area and absolute dense area with breast cancer risk for Aboriginal and non-Aboriginal women separately, adjusting for covariates.

RESULTS

Both percentage density and absolute dense area were strongly predictive of risk in Aboriginal women with odds per adjusted standard deviation (OPERAS) of 1.36 (95% CI 1.09, 1.69) and 1.36 (95% CI 1.08, 1.71), respectively. For non-Aboriginal women, the OPERAS were 1.22 (95% CI 1.03, 1.46) and 1.26 (95% CI 1.05, 1.50), respectively.

CONCLUSIONS

Whilst mean mammographic density for Aboriginal women is lower than non-Aboriginal women, density measures are still higher in Aboriginal women with breast cancer compared to Aboriginal women without breast cancer. Thus, mammographic density strongly predicts breast cancer risk in Aboriginal women. Future efforts to predict breast cancer risk using mammographic density or standardize risk-associated mammographic density measures should take into account Aboriginal status when applicable.

Body mass index, mammographic density, and breast cancer risk by estrogen receptor subtype

Background

Obesity and elevated breast density are common risk factors for breast cancer, and their effects may vary by estrogen receptor (ER) subtype. However, their joint effects on ER subtype-specific risk are unknown. Understanding this relationship could enhance risk stratification for screening and prevention. Thus, we assessed the association between breast density and ER subtype according to body mass index (BMI) and menopausal status.

Methods

We conducted a case-control study nested within two mammography screening cohorts, the Mayo Mammography Health Study and the San Francisco Bay Area Breast Cancer SPORE/San Francisco Mammography Registry. Our pooled analysis contained 1538 ER-positive and 285 ER-negative invasive breast cancer cases and 4720 controls matched on age, menopausal status at time of mammogram, and year of mammogram. Percent density was measured on digitized film mammograms using computer-assisted techniques. We used polytomous logistic regression to evaluate the association between percent density and ER subtype by BMI subgroup (normal/underweight, < 25 kg/m² versus overweight/obese, ≥ 25 kg/m²). We used Wald chi-squared tests to assess for interactions between percent density and BMI. Our analysis was stratified by menopausal status and hormone therapy usage at the time of index mammogram.

Results

Percent density was associated with increased risk of overall breast cancer regardless of menopausal status or BMI. However, when analyzing breast cancer across ER subtype, we found a statistically significant (p = 0.008) interaction between percent density and BMI in premenopausal women only. Specifically, elevated percent density was associated with a higher risk of ER-negative than ER-positive cancer in overweight/obese premenopausal women [OR per standard deviation increment 2.17 (95% CI 1.50–3.16) vs 1.33 (95% CI 1.11–1.61) respectively, P_{heterogeneity} = 0.01]. In postmenopausal women, elevated percent density was associated with similar risk of ER-positive and ER-negative cancers, and no substantive differences were seen after accounting for BMI or hormone therapy usage.

Conclusions

The combination of overweight/obesity and elevated breast density in premenopausal women is associated with a higher risk of ER-negative compared with ER-positive cancer. Eighteen percent of premenopausal women in the USA have elevated BMI and breast density and may benefit from lifestyle modifications involving weight loss and exercise.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1129-9) contains supplementary material, which is available to authorized users.

Childhood body size and midlife mammographic breast density in foreign-born and U.S.-born women in New York City

PURPOSE

We investigated whether childhood body size is associated with midlife mammographic density, a strong risk factor for breast cancer.

METHODS

We collected interview data, including body size at age 10 years using a pictogram, and measured height and weight from 518 women, recruited at the time of screening mammography in New York City (ages 40-64 years, 71% Hispanic, 68% foreign-born). We used linear regression models to examine childhood body size in relation to percent density and areas of dense and nondense tissue, measured using a computer-assisted method from digital mammograms.

RESULTS

In models that adjusted for race/ethnicity, and age and body mass index at mammogram, the heaviest relative to leanest childhood body size was associated with 5.94% lower percent density (95% confidence interval [CI]: -9.20, -2.29), 7.69 cm² smaller dense area (95% CI: -13.94, -0.63), and 26.17 cm² larger nondense area (95% CI: 9.42, 43.58). In stratified analysis by menopausal status and nativity, the observed associations were stronger for postmenopausal and U.S.-born women although these differences did not reach statistical significance.

CONCLUSIONS

Heavy childhood body size is associated with lower mammographic density, consistent with its associations with breast cancer risk. Suggestive findings by nativity require confirmation in larger samples.

Assessment of mammographic breast density after sleeve gastrectomy

BACKGROUND

Mammographic breast density (BD) is an independent risk factor for breast cancer. The effects of bariatric surgery on BD are unknown.

OBJECTIVES

To investigate BD changes after sleeve gastrectomy (SG).

SETTING

University hospital, United States.

METHODS

Fifty women with mammograms before and after SG performed from 2009 to 2015 were identified after excluding patients with a history of breast cancer, hormone replacement, and/or breast surgery. Patient age, menopausal status, co-morbidities, hemoglobin A1C, and body mass index were collected. Craniocaudal mammographic views before and after SG were interpreted by a blinded radiologist and analyzed by software to obtain breast imaging reporting and data system density categories, breast area, BD, and absolute dense breast area (ADA). Analyses were performed using χ², McNemar's test, t test, and linear regressions.

RESULTS

Radiologist interpretation revealed a significant increase in breast imaging reporting and data system B+C category (68% versus 54%; P = .0095) and BD (9.8 ± 7.4% versus 8.3 ± 6.4%; P = .0006) after SG. Software analyses showed a postoperative decrease in breast area (75,398.9 ± 22,941.2 versus 90,655.9 ± 25,621.0 pixels; P < .0001) and ADA (7287.1 ± 3951.3 versus 8204.6 ± 4769.9 pixels; P = .0314) with no significant change in BD. Reduction in ADA was accentuated in postmenopausal patients. Declining breast area was directly correlated with body mass index reduction (R² = .4495; P < 0.0001). Changes in breast rather than whole body adiposity better explained ADA reduction. Neither diabetes status nor changes in hemoglobin A1C correlated with changes in ADA.

CONCLUSIONS

ADA decreases after SG, particularly in postmenopausal patients. Software-generated ADA may be more accurate than radiologist-estimated BD or breast imaging reporting and data system for capturing changes in dense breast tissue after SG.

racially diverse population screened for breast cancer

PURPOSE

Type II diabetes mellitus (T2DM) has consistently been associated with an increased risk of breast cancer, but the association of gestational diabetes mellitus (GDM) with breast cancer is less clear. T2DM and GDM may influence breast cancer risk through mammographic breast density, a strong risk factor for breast cancer. We examined whether T2DM and GDM are associated with higher mammographic breast density in a largely racial/ethnic minority sample.

METHODS

We collected digital mammograms, anthropometric measures, and interview data from 511 racially diverse women recruited during screening mammography appointments between 2012 and 2016 (mean age 51 years; 70% Hispanic). We examined the associations of self-reported GDM, T2DM, and medication use (metformin and insulin) with mammographic breast density, measured as percent and area of dense tissue using Cumulus software.

RESULTS

In multivariable linear regression models, history of T2DM and/or GDM and length of time since diagnosis were not associated with percent density or dense breast area, either before or after adjustment for current BMI. Use of metformin in diabetic women was associated with lower percent density (β = - 5.73, 95% CI - 10.27, - 1.19), only before adjusting for BMI. These associations were not modified by menopausal status.

CONCLUSIONS

Our results do not support associations between T2DM and/or GDM and higher amount of mammographically dense breast tissue, suggesting that the mechanism linking diabetes with breast cancer risk may not include mammographic breast density in midlife.

Residential traffic noise and mammographic breast density in the Diet, Cancer, and Health cohort

OBJECTIVES

Traffic is the most important source of community noise, and it has been proposed to be associated with a range of disease outcomes, including breast cancer. As mammographic breast density (MD) is one of the strongest risk factors for developing breast cancer, the present study investigated whether there is an association between residential exposure to traffic noise and MD in a Danish cohort.

METHODS

We included women with reproductive and lifestyle information available from the Diet, Cancer, and Health cohort, who also participated in the Copenhagen Mammography Screening Programme (n = 5,260). Present and historical addresses from 1987 to 2011 were found in national registries, and traffic noise was modeled 5 years before mammogram. Analyses between residential traffic noise and MD were performed using logistic regression.

RESULTS

We found no association between residential road and railway noise exposure 5 years before mammogram, and having a mixed/dense versus a fatty mammogram, and no interaction with menopausal status, BMI, HRT use, and railway noise exposure, for analyses on road traffic noise.

CONCLUSION

The present study does not suggest an association between residential traffic noise exposure and subsequent MD in a cohort of middle-aged Danish women.

Affinity proteomic profiling of plasma for proteins associated to area-based mammographic breast density

Background

Mammographic breast density is one of the strongest risk factors for breast cancer, but molecular understanding of how breast density relates to cancer risk is less complete. Studies of proteins in blood plasma, possibly associated with mammographic density, are well-suited as these allow large-scale analyses and might shed light on the association between breast cancer and breast density.

Methods

Plasma samples from 1329 women in the Swedish KARMA project, without prior history of breast cancer, were profiled with antibody suspension bead array (SBA) assays. Two sample sets comprising 729 and 600 women were screened by two different SBAs targeting a total number of 357 proteins. Protein targets were selected through searching the literature, for either being related to breast cancer or for being linked to the extracellular matrix. Association between proteins and absolute area-based breast density (AD) was assessed by quantile regression, adjusting for age and body mass index (BMI).

Results

Plasma profiling revealed linear association between 20 proteins and AD, concordant in the two sets of samples (p < 0.05). Plasma levels of seven proteins were positively associated and 13 proteins negatively associated with AD. For eleven of these proteins evidence for gene expression in breast tissue existed. Among these, ABCC11, TNFRSF10D, F11R and ERRF were positively associated with AD, and SHC1, CFLAR, ACOX2, ITGB6, RASSF1, FANCD2 and IRX5 were negatively associated with AD.

Conclusions

Screening proteins in plasma indicates associations between breast density and processes of tissue homeostasis, DNA repair, cancer development and/or progression in breast cancer. Further validation and follow-up studies of the shortlisted protein candidates in independent cohorts will be needed to infer their role in breast density and its progression in premenopausal and postmenopausal women.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0940-z) contains supplementary material, which is available to authorized users.

Hair product use, age at menarche and mammographic breast density in multiethnic urban women

BACKGROUND

Select hair products contain endocrine disrupting chemicals (EDCs) that may affect breast cancer risk. We hypothesize that, if EDCs are related to breast cancer risk, then they may also affect two important breast cancer risk factors: age at menarche and mammographic breast density.

METHODS

In two urban female cohorts (N = 248): 1) the New York site of the National Collaborative Perinatal Project and 2) the New York City Multiethnic Breast Cancer Project, we measured childhood and adult use of hair oils, lotions, leave-in conditioners, root stimulators, perms/relaxers, and hair dyes using the same validated questionnaire. We used multivariable relative risk regression models to examine the association between childhood hair product use and early age at menarche (defined as <11 years of age) and multivariable linear regression models to examine the association between childhood and adult hair product use and adult mammographic breast density.

RESULTS

Early menarche was associated with ever use of childhood hair products (RR 2.3, 95% CI 1.1, 4.8) and hair oil use (RR 2.5, 95% CI 1.2, 5.2); however, additional adjustment for race/ethnicity, attenuated associations (hair products RR 1.8, 95% CI 0.8, 4.1; hair oil use RR 2.3, 95% CI 1.0, 5.5). Breast density was not associated with adult or childhood hair product or hair oil use.

CONCLUSIONS

If confirmed in larger prospective studies, these data suggest that exposure to EDCs through hair products in early life may affect breast cancer risk by altering timing of menarche, and may operate through a mechanism distinct from breast density.

Mammographic breast density and risk of breast cancer in women with atypical hyperplasia: an observational cohort study from the Mayo Clinic Benign Breast Disease (BBD) cohort

Background

Atypical hyperplasia (AH) and mammographic breast density (MBD) are established risk factors for breast cancer (BC), but their joint contributions are not well understood. We examine associations of MBD and BC by histologic impression, including AH, in a subcohort of women from the Mayo Clinic Benign Breast Disease Cohort.

Methods

Women with a diagnosis of BBD and mammogram between 1985 and 2001 were eligible. Histologic impression was assessed via pathology review and coded as non-proliferative disease (NP), proliferative disease without atypia (PDWA) and AH. MBD was assessed clinically using parenchymal pattern (PP) or BI-RADS criteria and categorized as low, moderate or high. Percent density (PD) was also available for a subset of women. BC and clinical information were obtained by questionnaires, medical records and the Mayo Clinic Tumor Registry. Women were followed from date of benign biopsy to BC, death or last contact. Standardized incidence ratios (SIRs) compared the observed number of BCs to expected counts. Cox regression estimated multivariate-adjusted MBD hazard ratios.

Results

Of the 6271 women included in the study, 1132 (18.0%) had low MBD, 2921 (46.6%) had moderate MBD, and 2218 (35.4%) had high MBD. A total of 3532 women (56.3%) had NP, 2269 (36.2%) had PDWA and 470 (7.5%) had AH. Over a median follow-up of 14.3 years, 528 BCs were observed. The association of MBD and BC risk differed by histologic impression (p-interaction = 0.03), such that there was a strong MBD and BC association among NP (p < 0.001) but non-significant associations for PDWA (p = 0.27) and AH (p = 0.96). MBD and BC associations for AH women were not significant within subsets defined by type of MBD measure (PP vs. BI-RADS), age at biopsy, number of foci of AH, type of AH (lobular vs. ductal) and body mass index, and after adjustment for potential confounding variables. Women with atypia who also had high PD (>50%) demonstrated marginal evidence of increased BC risk (SIR 4.98), but results were not statistically significant.

Conclusion

We found no evidence of an association between MBD and subsequent BC risk in women with AH.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3082-2) contains supplementary material, which is available to authorized users.

Early life socioeconomic environment and mammographic breast density

Background

Early life social environment may influence breast cancer through shaping risk factors operating in early life, adolescence and adulthood, or may be associated with breast cancer risk independent of known risk factors. We investigated the associations between early life socioeconomic status (SES) and mammographic density, a strong risk factor for breast cancer, and the extent to which these associations were independent of risk factors across the lifecourse.

Methods

We used data from an adult follow-up study of two U.S. birth cohorts of women (average age = 43 years) with prospectively collected data starting during the pregnancy of the mother and continuing through early childhood of the offspring. We collected data on factors in later life periods through computer-assisted interviews with the offspring as adults, and obtained routine clinical mammograms for measurement of percent density and dense and nondense breast areas using a computer assisted method. We used generalized estimating equation models for multivariable analysis to account for correlated data for sibling sets within the study sample (n = 700 composed of 441 individuals and 127 sibling sets).

Results

Highest vs. lowest family income level around the time of birth was associated with smaller dense breast area after adjustment for early life factors (e.g., birthweight, maternal smoking during pregnancy) and risk factors in later life periods, including adult body mass index (BMI) and adult SES (β = −8.2 cm², 95% confidence interval [CI]: −13.3, −3.2). Highest vs. lowest parental educational attainment was associated with higher percent density in models that adjusted for age at mammogram and adult BMI (e.g., β = 4.8, 95% CI = 0.6, 9.1 for maternal education of college or higher degree vs. less than high school), but the association was attenuated and no longer statistically significant after further adjustment for early life factors. There were no associations between early life SES indicators and non-dense area after adjustment for adult BMI. Neither adult education nor adult income was statistically significantly associated with any measure of mammographic density after adjusting for age and adult BMI.

Conclusions

We did not observe consistent associations between different measures of early life SES and mammographic density in adulthood.

High mammographic breast density predicts locoregional recurrence after modified radical mastectomy for invasive breast cancer: a case-control study

Background

We aimed to evaluate the influence of mammographic breast density at diagnosis on the risk of cancer recurrence and survival outcomes in patients with invasive breast cancer after modified radical mastectomy.

Methods

This case-control study included 121 case-control pairs of women diagnosed with invasive breast cancer between 2004 and 2009, and who had undergone modified radical mastectomy and had mammographic breast density measured before or at diagnosis. Women with known locoregional recurrence or distant metastasis were matched by pathological disease stage, age, and year of diagnosis to women without recurrence. Locoregional recurrence was defined as recurrence in the ipsilateral chest wall, or axillary, internal mammary, or supraclavicular nodes. The median follow-up duration was 84.0 months for case patients and 92.9 months for control patients.

Results

Patients with heterogeneously dense (50–75% density) and extremely dense (>75% density) breasts had an increased risk of locoregional recurrence (hazard ratios 3.1 and 5.7, 95% confidence intervals 1.1–9.8 and 1.2–34.9, p = 0.043 and 0.048, respectively) than did women with less dense breasts. Positive margins after surgery also increased the risk of locoregional recurrence (hazard ratio 3.3, 95% confidence interval 1.3–8.3, p = 0.010). Multivariate analysis that included dense breasts (>50% density), positive margin, no adjuvant radiotherapy, and no adjuvant chemotherapy revealed that dense breasts were significant factors for predicting locoregional recurrence risk (hazard ratio 3.6, 95% confidence interval 1.2–11.1, p = 0.025).

Conclusions

Our results demonstrate that dense breast tissue (>50% density) increased the risk of locoregional recurrence after modified radical mastectomy in patients with invasive breast cancer. Additional prospective studies are necessary to validate these findings.

Trial registration

The study is retrospectively registered with ClinicalTrials.gov, number NCT02771665, on May 11, 2016.

The relationship of obesity, mammographic breast density, and magnetic resonance imaging in patients with breast cancer

PURPOSE

The purpose was to evaluate the relationship between body mass index (BMI), mammographic breast density, magnetic resonance (MR) background parenchymal enhancement (BPE), and MR fibroglandular tissue (FGT) in women with breast cancer.

METHODS

Our institutional database was queried for patients with preoperative mammography and breast MR imaging.

RESULTS

There were 573 women eligible for analysis. Elevated BMI was associated with advanced stage of disease (P=.01), lower mammographic density (P<.0001), lower FGT (P<.0001), higher BPE (P=.005), and nonpalpable lesions (P=.04).

CONCLUSIONS

Higher BMI was associated with decreased breast density and FGT. Higher BMI was also associated with advanced stage disease and nonpalpable tumors on clinical exam.

Mammographic density and structural features can individually and jointly contribute to breast cancer risk assessment in mammography screening: a case-control study

Background

Mammographic density is a well-established risk factor for breast cancer. We investigated the association between three different methods of measuring density or parenchymal pattern/texture on digitized film-based mammograms, and examined to what extent textural features independently and jointly with density can improve the ability to identify screening women at increased risk of breast cancer.

Methods

The study included 121 cases and 259 age- and time matched controls based on a cohort of 14,736 women with negative screening mammograms from a population-based screening programme in Denmark in 2007 (followed until 31 December 2010). Mammograms were assessed using the Breast Imaging-Reporting and Data System (BI-RADS) density classification, Tabár’s classification on parenchymal patterns and a fully automated texture quantification technique. The individual and combined association with breast cancer was estimated using binary logistic regression to calculate Odds Ratios (ORs) and the area under the receiver operating characteristic (ROC) curves (AUCs).

Results

Cases showed significantly higher BI-RADS and texture scores on average than controls (p < 0.001). All three methods were individually able to segregate women into different risk groups showing significant ORs for BI-RADS D3 and D4 (OR: 2.37; 1.32–4.25 and 3.93; 1.88–8.20), Tabár’s PIII and PIV (OR: 3.23; 1.20–8.75 and 4.40; 2.31–8.38), and the highest quartile of the texture score (3.04; 1.63–5.67). AUCs for BI-RADS, Tabár and the texture scores (continuous) were 0.63 (0.57–0–69), 0.65 (0.59–0–71) and 0.63 (0.57–0–69), respectively. Combining two or more methods increased model fit in all combinations, demonstrating the highest AUC of 0.69 (0.63-0.74) when all three methods were combined (a significant increase from standard BI-RADS alone).

Conclusion

Our findings suggest that the (relative) amount of fibroglandular tissue (density) and mammographic structural features (texture/parenchymal pattern) jointly can improve risk segregation of screening women, using information already available from normal screening routine, in respect to future personalized screening strategies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2450-7) contains supplementary material, which is available to authorized users.

Anthropometric factors, adult weight gain, and mammographic features

PURPOSE

To evaluate the association between anthropometric factors, weight gain during adulthood, and mammographic features among 1,435 women recruited at screening mammography.

METHODS

Spearman's partial coefficients were used to evaluate the correlation of anthropometric factors with mammographic features (percent density, absolute dense area, and non-dense area). Multivariate generalized linear models were used to evaluate the associations between weight change categories and mammographic features.

RESULTS

Body mass index was inversely correlated with percent density (r = -0.49, p < 0.0001) or absolute dense area (r = -0.21, p < 0.0001) and positively correlated with absolute non-dense area (r = 0.69, p < 0.0001). However, body mass index was positively correlated with absolute dense area when adjusting for absolute non-dense area (r = 0.16, p < 0.0001). Similar results were observed for weight, waist circumference, and waist-to-hip ratio with mammographic features. Within increasing categories of weight change, percent density (p trend < 0.0001) and absolute dense area (p trend = 0.025) increased, while absolute non-dense area decreased (p trend < 0.0001). After stratification by the median of non-dense area, the positive association between weight gain and absolute dense area remained only among women with higher non-dense area.

CONCLUSIONS

Adiposity seems positively associated with both dense and non-dense areas following adjustment for each other. Our findings suggest a higher breast dense area among women who gained weight and that a minimum of breast fat may be needed to promote the proliferation of this fibroglandular tissue.

The metabolic syndrome and mammographic breast density in a racially diverse and predominantly immigrant sample of women

PURPOSE

The metabolic syndrome [MetS, clustering of elevated blood pressure, triglycerides and glucose, reduced high-density lipoprotein cholesterol (HDL-C), abdominal obesity] has been associated with increased breast cancer risk, but less is known about its association with mammographic breast density, a strong risk factor for breast cancer.

METHODS

We collected data on risk factors, body size, and blood pressure via in-person interviews and examinations and measured glucose, triglycerides, and HDL-C from dried blood spots from women recruited through a mammography screening clinic (n = 373; 68 % Hispanic, 17 % African-American, 63 % foreign born). We performed linear regression models to examine the associations of each MetS component and the MetS cluster (≥3 components) with percent density and dense breast area, measured using a computer-assisted technique and Cumulus software.

RESULTS

About 45 % of women had the MetS, with the prevalence of the individual components ranging from 68 % for abdominal obesity to 33 % for elevated triglycerides. The prevalence of the MetS increased with higher body mass index (BMI) and postmenopausal status, but did not vary substantially by ethnicity, immigrant generational status, parity, age at menarche, or alcohol consumption. Low HDL-C (<50 mg/dL), but not the MetS cluster or the other MetS components, was associated with larger dense breast area after adjusting for age, BMI, fasting time, and educational attainment (β = 8.77, 95 % CI 2.39, 15.14). The MetS and its individual components were not associated with BMI-adjusted percent density.

CONCLUSIONS

HDL-C alone may have an influence on dense breast tissue that is independent of BMI, and may be in the same direction as its association with breast cancer risk.

Mammographic density estimation with automated volumetric breast density measurement

OBJECTIVE

To compare automated volumetric breast density measurement (VBDM) with radiologists' evaluations based on the Breast Imaging Reporting and Data System (BI-RADS), and to identify the factors associated with technical failure of VBDM.

MATERIALS AND METHODS

In this study, 1129 women aged 19-82 years who underwent mammography from December 2011 to January 2012 were included. Breast density evaluations by radiologists based on BI-RADS and by VBDM (Volpara Version 1.5.1) were compared. The agreement in interpreting breast density between radiologists and VBDM was determined based on four density grades (D1, D2, D3, and D4) and a binary classification of fatty (D1-2) vs. dense (D3-4) breast using kappa statistics. The association between technical failure of VBDM and patient age, total breast volume, fibroglandular tissue volume, history of partial mastectomy, the frequency of mass > 3 cm, and breast density was analyzed.

RESULTS

The agreement between breast density evaluations by radiologists and VBDM was fair (k value = 0.26) when the four density grades (D1/D2/D3/D4) were used and moderate (k value = 0.47) for the binary classification (D1-2/D3-4). Twenty-seven women (2.4%) showed failure of VBDM. Small total breast volume, history of partial mastectomy, and high breast density were significantly associated with technical failure of VBDM (p = 0.001 to 0.015).

CONCLUSION

There is fair or moderate agreement in breast density evaluation between radiologists and VBDM. Technical failure of VBDM may be related to small total breast volume, a history of partial mastectomy, and high breast density.

Multiple metabolic risk factors and mammographic breast density

PURPOSE

We examined whether obesity and a history of diabetes, hypertension, and elevated cholesterol, individually and in combination, are associated with breast density, a strong risk factor for breast cancer.

METHODS

We measured percent density and dense area using a computer-assisted method (n = 191; age range = 40-61 years). We used linear regression models to examine the associations of each metabolic condition and the number of metabolic conditions (zero, one, two, and three or four conditions) with breast density.

RESULTS

Among individual metabolic conditions, only high blood cholesterol was inversely associated with percent density (β = -5.4, 95% confidence interval [CI]: -8.5, -2.2) and dense area (β = -6.7, 95% CI = -11.1, -2.4). Having multiple metabolic conditions was also associated with lower breast density, with two conditions and three or four conditions versus zero conditions associated with 6.4% (95% CI: -11.2, -1.6) and 7.4% (95% CI: -12.9, -1.9) reduction in percent density and with 6.5 cm(2) (95% CI: -13.1, -0.1) and 9.5 cm(2) (95% CI: -17.1, -1.9) decrease in dense area.

CONCLUSIONS

A history of high blood cholesterol and multiple metabolic conditions were associated with lower relative and absolute measures of breast density. The positive association between metabolic abnormalities and breast cancer risk may be driven by pathways unrelated to mammographic breast density.