Percent Breast Research Articles

Responses of Cobb×Cobb 500 slow feathering broilers to feeding programs with increasing amino acid densities

An evaluation of the effects of feeding programs with three amino acid (AA) densities given to males and females from a fast growth broiler breed was conducted. A total of 1200 Cobb×Cobb 500 broilers were distributed across 6 treatments in a 2×3 factorial arrangement (Sex×AA Density) with 8 replications of 25 birds per pen. Maize–soybean meal, provided from 1 to 7, 8 to 21, 22 to 35 and 36 to 42d of age, was formulated without crude protein restriction maintaining minimum ratios between essential AA and Lysine (Lys) in a true digestible (dig) basis as follows: total sulfur AA, 0.75; threonine, 0.65, valine, 0.75 (from 1 to 21d) and 0.78 (from 22 to 42d). Experimental treatments were Low (L), Moderate (M) and High (H) AA density diets with M having dig Lys of 1.25, 1.19, 1.09 and 1.05% in the pre-starter to withdrawal phases, respectively. Diets L and H had reductions and increases of 12% dig Lys in relation to the Moderate diet. There were no effects of treatments on mortality (P>0.05) and males had an overall better performance than females (P<0.001). No interactions were observed between Sex×AA density, with the exception of feed intake (1–42 days) and abdominal fat, which were further reduced with males as AA density increased than with females (P<0.01). Body weight gain was affected by AA density (P=0.0308) with birds fed L diets being lighter than those fed H and M diets. Feed conversion ratio (FCR) was improved (P<0.05) as AA density increased. Carcass and breast meat percentages were higher for females (P<0.01) and percent breast yield was highest for the H diet and lowest for the L diet, whereas the M diet was in between. Abdominal fat was reduced with H diet (P<0.05) for males but not for females. The decision making process to change AA density in the diet towards a higher density AA diet will depend on the price of feed ingredients and broiler meat.

Abstract 575: Correlation of serum vitamin D levels and changes in breast density

Abstract Background: Mammographic density is an independent risk factor for breast cancer associated with a large relative and attributable risk for the disease. Given the prevalence of women with increased breast density, the attributable risk may be as high as 33%. The largest factor influencing density is heredity, but various lines of evidence suggest that modification of breast density is associated with a decrease in breast cancer risk. Studies have found vitamin D levels to be inversely related to breast density. Here we present a cross-sectional analysis of vitamin D and breast density in women enrolled in the Vermont Cancer Centers High Risk Breast Program. Longitudinal associations and correlations of vitamin D and breast density were evaluated. Methods: The High Risk Breast Program database, for women with strong family history, BRCA mutations, high risk pathology or prior chemoradiotherapy for Hodgkins Disease, was initiated in 2003 and contains over 500 women. A subset of 51 women ranging in age from 31-69 with a mean lifetime Gail risk of 21% is the subject of this analysis. Data collected included mammograms, a medical and dietary history, BMI, and serum Vitamin D levels. Breast density was interpreted (at baseline, 2 years and 4 years) from mammograms using a visual analogue scale and reliability was evaluated. Univariate and multivariate analyses were performed using SAS statistical software. Results: The intra-observer variability for density determination using a visual analogue scale was comparable to published studies (R=0.82). Baseline BMI showed an inverse univariate trend with percent of dense tissue at both time points (p=0.001). No correlation was found between any determinant and change in breast density measured at the 2 year time point. A subset of patients (n=37) was followed for 2 additional years. A model for change in percent dense tissue was obtained for this subset of patients using multivariate analysis that included baseline BMI and change in serum Vitamin D level (R2=0.23). The other factors with a univariate relationship were not found to contribute to the multivariate model. Conclusions: The HRBP database has become an invaluable resource, significantly reducing the financial resources necessary to complete this study and aiding the expansion of the study when needed. Information has been gained with high potential impact on prevention and early detection of breast cancer; first is the reproducibility of the visual analogue scale, a method of quantifying density which is readily available to clinicians and research staff with little training and minimal resources. Second, this study illuminates the importance of a longer follow up period for the detection of changes in mammographic breast density. Third, this study validates the association between serum vitamin D levels and percent breast density, and more importantly the inverse relationship between change in vitamin D levels and change in breast density. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 575. doi:1538-7445.AM2012-575

Mammographic breast density and breast cancer risk by menopausal status, postmenopausal hormone use and a family history of breast cancer

Few studies have investigated the association between breast density and breast cancer by a family history of breast cancer, menopausal status, and postmenopausal hormone use (PMH). We investigated if associations of breast density and breast cancer differ according to the status of these risk factors. This study included 1,481 incident breast cancer cases diagnosed within the Nurses' Health Study I and II cohorts and 2,779 matched controls. Breast density was measured from digitized film images with computerized techniques. Information on breast cancer risk factors was obtained prospectively from the biennial questionnaires before the date of the cancer diagnosis for cancer cases and their matched controls. The data were analyzed with logistic regression. Breast cancer risk increased with increasing percent breast density in all strata (p for trend in all subsets <0.0001). The density-related risk of breast cancer was similar in women with and without a family history (OR=4.00 [95% CI 2.01-7.94] vs. 3.71 [95% CI 2.79-4.94] for density ≥50% vs. <10%, p for interaction=0.53). The magnitude of the association between density and breast cancer risk, however, appeared to be stronger in premenopausal women than in postmenopausal women without PMH history (OR=5.49 [95% CI 2.44-12.39] vs. 3.02 [95% CI 1.62-5.63] for density ≥50% vs. <10%, p-heterogeneity=0.17) and appeared to be stronger in postmenopausal women currently using hormones compared with postmenopausal women who never used PMH (OR=4.50 [95% CI 2.99-6.78] vs. 3.02, p-heterogeneity=0.20) or with past hormone use (OR=4.50 vs. 3.71 [95% CI 1.90-7.23], p-heterogeneity=0.23). Findings on associations by menopausal status/hormone use are suggestive and should be examined in additional larger studies.

Phenol Xenoestrogens and Mammographic Breast Density

Abstract Concerns have been raised, largely on the basis of laboratory studies, regarding exposure to phenols, particularly bisphenol-A (BPA), in relation to hormone-related cancers. BPA is present in plastic consumer products including canned food linings and #7 polycarbonate plastics. According to recent NHANES data, human exposure as measured in urine is widespread (about 93% of people aged &amp;gt;5) and more common in females than males (Calafat EHP 2008). Concern regarding BPA in relation to breast cancer risk is based on in vivo and in vitro studies that suggest BPA may have a role in estrogen metabolism and mammary gland development. We examined the cross-sectional association of circulating serum levels of 3 phenols with mammographic breast density - a strong marker for breast cancer risk. A total of 264 postmenopausal women ages 55–70 years with no history of postmenopausal hormone use were recruited from mammography clinics in Madison, Wisconsin. Subjects completed a questionnaire regarding known breast cancer risk factors and provided a blood sample that was analyzed for octylphenol, nonylphenol, and BPA. Percent breast density (mean 15.3%, range 0.4–71.2%) was measured from subjects' mammograms using a computer-assisted thresholding method (Cumulus software). Since phenol levels are higher in the urine than in the serum, as expected many women had undetectable levels of the phenols in their serum: 86.7% octylphenol, 58.7% nonylphenol, and 73.1% BPA. After adjusting for age and body mass index in analysis of variance models, women with detectable serum BPA levels above the median (&amp;gt;0.56 ng/mL; N = 35) had higher percent breast density than women with BPA levels below the median (0.01–0.56 ng/mL; N = 36) and women with no detectable BPA (N = 193) in their serum (17.8% vs. 13.3% vs 12.7%, respectively; P = 0.01). Breast density was not associated with serum levels of either octylphenol or nonylphenol (P = 0.77, P = 0.36, respectively). Given that this study suggests that higher levels of BPA were associated with a clinically-relevant 5% greater breast density, further investigation into the potential influence of BPA on breast cancer risk using human populations is warranted. Supported by DOD BC062649, Komen FAS0703857, and NIH R03 CA139548.

Changes in Breast Density and Circulating Estrogens in Postmenopausal Women Receiving Adjuvant Anastrozole

Factors associated with an increased risk of breast cancer include prior breast cancer, high circulating estrogens, and increased breast density. Adjuvant aromatase inhibitors are associated with a reduction in incidence of contralateral breast cancer. We conducted a prospective, single-arm, single-institution study to determine whether use of anastrozole is associated with changes in contralateral breast density and circulating estrogens. Eligible patients included postmenopausal women with hormone receptor-positive early-stage breast cancer who had completed local therapy, had an intact contralateral breast, and were recommended an aromatase inhibitor as their only systemic therapy. Participants received anastrozole 1 mg daily for 12 months on study. We assessed contralateral breast density and serum estrogens at baseline, 6, and 12 months. The primary endpoint was change in contralateral percent breast density from baseline to 12 months. Secondary endpoints included change in serum estrone sulfate from baseline to 12 months. Fifty-four patients were accrued. At 12 months, compared with baseline, there was a nonstatistically significant reduction in breast density (mean change: -16%, 95% CI: -30 to 2, P = 0.08) and a significant reduction in estrone sulfate (mean change: -93%, 95% CI: -94 to -91, P < 0.001). Eighteen women achieved 20% or greater relative reduction in contralateral percent density at 12 months compared with baseline; however, no measured patient or disease characteristics distinguished these women from the overall population. Large trials are required to provide additional data on the relationship between aromatase inhibitors and breast density and, more importantly, whether observed changes in breast density correlate with meaningful disease-specific outcomes.

Comparison of breast density measured on MR images acquired using fat‐suppressed versus nonfat‐suppressed sequences

To investigate the difference of MR percent breast density measured from fat-suppressed versus nonfat-suppressed imaging sequences. Breast magnetic resonance imaging (MRI) with and without fat suppression was acquired from 38 subjects. Breasts were divided into subgroups of different morphological patterns ("central" and "intermingled" types). Breast volume, fibroglandular tissue volume, and percent density were measured. The results were compared using nonparametric statistical tests and regarded as significant at p < 0.05. Breast volume, fibroglandular volume, and percent density between fat-suppressed and nonfat-suppressed sequences were highly correlated. Breast volumes measured on these two sequences were almost identical. Fibroglandular tissue volume and percent density, however, had small (<5%) yet significant differences between the two sequences-they were both higher on the fat-suppressed sequence. Intraobserver variability was within 4% for both sequences and different morphological types. The fibroglandular tissue volume measured on downsampled images showed a small (<5%) yet significant difference. The measurement of breast density made on MRI acquired using fat-suppressed and nonfat-suppressed T1W images was about 5% difference, only slightly higher than the intraobserver variability of 3%-4%. When the density data from multiple centers were to be combined, evaluating the degree of difference is needed to take this difference into account.

The vitamin D pathway and mammographic breast density among postmenopausal women

Laboratory studies have demonstrated that vitamin D has a number of chemopreventive properties, and that these properties may be mediated or modified by other molecules in the vitamin D pathway, such as parathyroid hormone (PTH) or calcium. However, there is little epidemiologic data exploring the effects of vitamin D on breast cancer risk in the context of these other molecules. We examined a panel of molecules in the vitamin D pathway in relation to mammographic breast density, a marker of breast cancer risk, in the Wisconsin Breast Density Study. A total of 238 postmenopausal women (ages 55-70, with no history of postmenopausal hormone use) were enrolled from mammography clinics in Madison, Wisconsin. Subjects provided blood samples that were analyzed for levels of 25-hydroxy vitamin D [25(OH)D], PTH, insulin-like growth factor-1 (IGF-1), IGF-binding protein 3 (IGFBP-3), retinol, and calcium. Percent breast density was measured using Cumulus software. In age-adjusted analyses there was a positive association between 25(OH)D and percent breast density (P = 0.05; mean percent density = 11.3% vs. 15.6% for 1st vs. 4th quartile of 25(OH)D). Breast density was inversely associated with PTH (P = 0.05; 16.0% vs. 11.4% for Q1 vs. Q4) and positively associated with the IGF-1:IGFBP-3 molar ratio (P = 0.02; 11.9% vs. 15.6% for Q1 vs. Q4). However, these associations were all null after further adjustment for body mass index (BMI; P > 0.25). The independent relation between 25(OH)D and breast density remained null among subgroups defined by BMI and serum levels of retinol, calcium, and estradiol. These results suggest no strong independent associations between the circulating molecules of the vitamin D pathway and mammographic breast density in postmenopausal women. While it remains possible that vitamin D could influence breast cancer risk, our results suggest that such an effect would be mediated through pathways other than breast density.

A comparison of breast density measures between mothers and adolescent daughters

BackgroundBased on the importance of breast density as a predictor of breast cancer risk, we examined the heritable component of breast measures in mothers and daughters using Dual Energy X-ray Absorptiometry (DXA).MethodsWe recruited 101 mothers ≥30 years and their daughters aged 10-16 years through Kaiser Permanente Hawaii. Scans of both breasts were taken using a DXA system in research mode, calibrated to distinguish fibroglandular and fatty breast tissue. We calculated correlation coefficients between mothers and daughters for breast volume, absolute fibroglandular volume (FGV), and %FGV and performed multiple linear regression to include relevant covariates.ResultsBreast volume and absolute FGV in daughters were lower than in mothers and were positively associated with % total body fat and Tanner breast stage. In contrast, %FGV in daughters was higher than in mothers and was inversely associated with % total body fat. Although unadjusted correlations between mothers and daughters were significant for breast volume and absolute FGV (r = 0.28 and p < 0.01 for both), models adjusted for demographic variables, Tanner stage, and % total body fat indicated significant associations only among the more mature girls (Tanner stages 4&5). There was no significant association between %FGV of mothers and daughters.ConclusionsThese results indicate that the heritability of breast volume and amount of dense tissue is measurable in adolescence, but percent breast density shows no relation between mothers and daughters at that time. Further study of breast tissue composition during adolescence and in young women may enhance understanding of breast cancer risk later in life.

Mammographic Breast Density and Subsequent Risk of Breast Cancer in Postmenopausal Women According to Tumor Characteristics

Few studies that investigated the associations between breast density and subsequent breast cancer according to tumor characteristics have produced inconclusive findings. We aimed to determine whether the associations between breast density and subsequent breast cancer varied by tumor characteristics. We included 1042 postmenopausal women diagnosed with breast cancer between June 1, 1989, and June 30, 2004, and 1794 matched control subjects from the Nurses' Health Study, an ongoing prospective cohort study of 121 701 registered female nurses across the United States. Breast density was estimated from digitized images using computerized techniques. Information on breast cancer risk factors was obtained prospectively from biennial questionnaires before the date of cancer diagnosis for case subjects and matched control subjects. Polychotomous logistic regression was used to assess associations of breast density with tumor subtypes based on invasiveness, histology, size, grade, receptor status, and involvement of lymph nodes. All tests of statistical significance were two-sided. The risk of breast cancer increased progressively with increase in percent breast density (P(trend) < .001). Women with higher breast density (≥50%) showed a 3.39-fold (odds ratio = 3.39, 95% confidence interval = 2.46 to 4.68) increased risk of breast cancer compared with women with lower breast density (<10%). The associations between breast density and breast cancer risk were stronger for in situ compared with invasive tumors (P(heterogeneity) < .01), high-grade compared with low-grade tumors (P(heterogeneity) = .02), larger (>2 cm) compared with smaller (≤2 cm) tumors (P(heterogeneity) < .01), and estrogen receptor-negative compared with estrogen receptor-positive tumors (P(heterogeneity) = .04). There were no differences in associations by tumor histology, involvement of lymph nodes, and progesterone receptor and HER2 status (P(heterogeneity) > .05). The findings suggest that higher mammographic density is associated with more aggressive tumor characteristics and also with in situ tumors.

Estimation of genetic parameters for carcass traits in Japanese quail using Bayesian methods

The aim of this study was to estimate genetic parameters of some carcass characteristics in the Japanese quail. For this aim, carcass weight (Cw), breast weight (Bw), leg weight (Lw), abdominal fat weight (AFw), carcass yield (CP), breast percentage (BP), leg percentage (LP) and abdominal fat percentage (AFP) were measured on approximately 500 quails (offspring of 60 sires and 180 dams). Gibbs sampling (GS) under a multi-trait animal model was applied to estimate heritability and genetic correlations. Genetic analyses were performed using MTGSAM (Multiple Trait Gibbs Sampling) software. Heritability estimates for all the traits were low to moderate. Point estimates (means of marginal posterior densities) of heritabilities for Cw, Bw, Lw, AFw and CP, BP, LP, AFP were 0.42, 0.36, 0.34, 0.40 and 0.11, 0.18, 0.12, 0.29, respectively. Genetic correlations between the carcass parts (Cw, Bw, Lw, AFw) were high and positive, ranging from 0.65 to 0.87. Direct selection for total carcass weight would increase its component traits. There were moderate to high negative genetic relationships between AFP and LP (-0.27), AFP and BP (-0.34), and AFP and CP (-0.89). Therefore, a decreasing AFP in quail could be reached by direct selection for higher CP.

The Association of Serum Phthalates and Parabens with Mammographic Breast Density

Abstract Humans are exposed to a large number of environmental chemicals which have estrogenic activity, raising concern regarding potential effects on breast tissue and breast cancer risk. Phthalates are commonly found in personal care products, such as shampoos, lotions, and shaving products, and are present in many consumer plastics, adhesives, detergents, and pharmaceuticals. Parabens are also found in personal care products, and are additionally used as antimicrobials in foods. In vitro studies have demonstrated that many phthalates and parabens can bind to the estrogen receptor and initiate estrogenic cellular pathways, and a recent case-control study found that urinary concentrations of mono-ethyl-phthalate were positively associated with breast cancer risk. We examined the cross-sectional association of circulating serum levels of phthalates and parabens with mammographic breast density (a marker for breast cancer risk). A total of 261 postmenopausal women (ages 55–70, with no history of postmenopausal hormone use) were recruited from mammography clinics in Madison, Wisconsin. Patients completed a questionnaire regarding known breast cancer risk factors and provided a blood sample that was analyzed for mono-ethyl-phthalate, mono-butyl-phthalate, mono-benzyl-phthalate, butyl paraben, and propyl paraben. Percent breast density was measured from patients' mammograms as a continuous variable using a computer-assisted thresholding method (Cumulus software). After adjusting for age and body mass index, mono-ethyl-phthalate was positively associated with percent breast density. Women with detectable mono-ethyl-phthalate levels (&amp;gt;0.4 ng/mL; N = 36) had higher percent breast density than women with no detectable mono-ethyl-phthalate (N = 225) in their serum (16.8% vs. 12.8%; P = 0.03). Serum levels of mono-butyl-phthalate and mono-benzyl-phthalate were generally below the limits of detection. Serum levels of butyl-paraben and propyl-paraben were higher (detectable in 55% and 67% of patients, respectively), but neither was associated with breast density (P &amp;gt; 0.20). These results suggest that further investigation into the potential influence of mono-ethly-phthalate (and its parent compound diethyl-phthalate) on breast tissue is warranted.

A randomized, placebo-controlled trial (NCIC CTG MAP.2) examining the effects of exemestane on mammographic breast density, bone density, markers of bone metabolism and serum lipid levels in postmenopausal women

We hypothesized that exemestane (EXE) would reduce mammographic breast density and have unique effects on biomarkers of bone and lipid metabolism. Healthy postmenopausal women were randomized to EXE (25 mg daily) or placebo (PLAC) for 12 months and followed for a total of 24 months. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms and secondary endpoints were changes in serum lipid levels, bone biomarkers, and bone mineral density (BMD). Ninety-eight women were randomized (49 to EXE; 49 to PLAC) and 65 had PD data at baseline and 12 months. Among women treated with EXE, PD was not significantly changed from baseline at 6, 12, or 24 months and was not different from PLAC. EXE was associated with significant percentage increase from baseline in N-telopeptide at 12 months compared with PLAC. No differences in percent change from baseline in BMD (lumbar spine and femoral neck) were observed between EXE and PLAC at either 12 or 24 months. Patients on EXE had a significantly larger percent decrease in total cholesterol than in the PLAC arm at 6 months and in HDL cholesterol at 3, 6, and 12 months. No significant differences in percent change in LDL or triglycerides were noted at any time point between the two treatment arms. EXE administered for 1 year to healthy postmenopausal women did not result in significant changes in mammographic density. A reversible increase in the bone resorption marker N-telopeptide without significant change in bone specific alkaline phosphatase or BMD during the 12 months treatment period and 1 year later was noted. Changes in lipid parameters on this trial were modest and reversible.

Genetic variances, heritabilities and maternal effects on body weight, breast meat yield, meat quality traits and the shape of the growth curve in turkey birds

BackgroundTurkey is an important agricultural species and is largely used as a meat bird. In 2004, turkey represented 6.5% of the world poultry meat production. The world-wide turkey population has rapidly grown due to increased commercial farming. Due to the high demand for turkey meat from both consumers and industry global turkey stocks increased from 100 million in 1970 to over 276 million in 2004. This rapidly increasing importance of turkeys was a reason to design this study for the estimation of genetic parameters that control body weight, body composition, meat quality traits and parameters that shape the growth curve in turkey birds.ResultsThe average heritability estimate for body weight traits was 0.38, except for early weights that were strongly affected by maternal effects. This study showed that body weight traits, upper asymptote (a growth curve trait), percent breast meat and redness of meat had high heritability whereas heritabilities of breast length, breast width, percent drip loss, ultimate pH, lightness and yellowness of meat were medium to low. We found high positive genetic and phenotypic correlations between body weight, upper asymptote, most breast meat yield traits and percent drip loss but percent drip loss was found strongly negatively correlated with ultimate pH. Percent breast meat, however, showed genetic correlations close to zero with body weight traits and upper asymptote.ConclusionThe results of this analysis and the growth curve from the studied population of turkey birds suggest that the turkey birds could be selected for breeding between 60 and 80 days of age in order to improve overall production and the production of desirable cuts of meat. The continuous selection of birds within this age range could promote high growth rates but specific attention to meat quality would be needed to avoid a negative impact on the quality of meat.

Carcass composition and chemical characteristics of meat from broiler chickens reared under intensive and semiintensive systems

Poultry rearing systems have captured the attention of scientists for many years. A number of attempts have been made to introduce new technologies in rearing poultry for meat and egg production aiming at improving rearing conditions, protecting the environment and enhancing the quality of poultry products. Given the above, the objective of this study was to present the results of an evaluation of the effect of rearing system on major meat quality traits (percent yield of primal cuts in cold carcasses, tissue percentage in major primal cuts and chemical composition of muscle tissue). The experiment involved a total of 400 Hybro broilers reared under two different systems (intensive and semi-intensive systems). The fattening period and slaughter and dressing procedures were followed by measurement and meat sampling for chemical analysis. The results obtained show that broilers reared under the semi-intensive system had a somewhat higher percentage of drumsticks and breasts i.e. first class meat, as well as a higher percentage of breast and thigh muscles. Moreover, the protein content of breast, thigh and drumstick muscles was higher in broilers reared under semi-intensive conditions. As for the fat content of primal cuts, it was found to exhibit higher values in broilers reared under the intensive system. Overall, the results suggest better performance for most traits in free range broilers reared under semi-intensive conditions as compared to those reared intensively.

Circulating Sex Hormones and Mammographic Breast Density among Postmenopausal Women

The use of breast density as an intermediate or predictive marker of breast cancer risk is limited by an incomplete understanding of the etiology of breast density. High blood levels of endogenous estrogens and androgens are associated with increased risk of breast cancer among postmenopausal women. We sought to examine whether these hormones are also associated with breast density. The Wisconsin Breast Density Study enrolled 257 postmenopausal women, ages 55-70 years, with no history of postmenopausal hormone use, from mammography clinics in Madison, Wisconsin. Subjects provided a blood sample for sex hormone analysis, and breast density was measured from subjects' screening mammograms using a computer-assisted thresholding method. Numerous sex hormones were associated with breast density in age-adjusted analyses. However, further adjustment for body mass index and other potentially confounding factors substantially attenuated or eliminated these associations. In the fully adjusted model, there remained a positive association between percent breast density and serum progesterone (P=0.03), with percent density rising from 11.9% (95% CI: 9.8, 14.1%) among women in the lowest quartile of serum progesterone to 15.4% (12.9, 18.2%) among women in the highest quartile. There was also a positive association between sex hormone binding globulin and percent breast density (P=0.06). In contrast, there were no independent associations between percent breast density and estradiol (total, free, or bioavailable), estrone, estrone sulfate, or testosterone (total, free, or bioavailable). These results suggest that breast density has a hormonal etiology; however, it may differ in important ways from that of breast cancer risk.

Energy intake and dietary patterns in childhood and throughout adulthood and mammographic density: results from a British prospective cohort

ObjectivesTo examine the role of energy intake and dietary patterns in childhood and throughout adulthood on subsequent mammographic density.MethodsProspective data were available from a cohort of 1161 British women followed up since their birth in 1946. Dietary intakes at age 4 years were determined by 24-hour recalls and during adulthood, average food consumed at ages 36 and 43 years by 5-day food records. Dietary patterns were determined by factor analysis. Associations between energy intake, dietary patterns, and percent breast density were investigated using regression analysis.ResultsDuring adulthood, energy intake was positively associated with percent breast density (adjusted regression coefficient [per SD) (95% CI): 0.12 (0.01, 0.23)]. The effect of the high fat and sugar dietary pattern remained similar when adjusted for total energy intake [0.06 (−0.01, 0.13)]. There was no evidence of an associations for the patterns low fat, high fiber pattern 0.03 (−0.04, 0.11); the alcohol and fish −0.02 (−0.13, 0.17); meat, potatoes, and vegetables −0.03 (−0.10, 0.04). No association was found for dietary pattern at age 4 and percent breast density.ConclusionsThis study supports the hypothesis that overall energy intake during middle life is a determinant of subsequent mammographic breast density measured 15 years later.

Adiposity, adult weight gain and mammographic breast density in US Chinese women

The association of adiposity with dense tissue area in the breast is unclear, but suggests a mechanism by which adiposity might increase breast cancer risk. We examined associations of body mass index (BMI), usual BMI from age 20 to 29, waist circumference and adult weight gain with breast density in a sample of premenopausal United States Chinese immigrant women. Analyses included 415 participants in a longitudinal breast density study in Philadelphia. In addition to detailed questionnaire information, data collection included measures of anthropometry, and assessment of mammographic breast density using a computer-assisted method. We used multivariate linear regression to quantify cross-sectional associations with dense and nondense tissue area and percent breast density assessed at baseline. In adjusted models, BMI and waist circumference were significantly positively associated with nondense tissue area and inversely associated with percent density. BMI was also significantly positively associated with dense tissue area. Adult weight gain was associated with dense tissue area after adjusting for weight from age 20 to 29. In stratified analyses, BMI and adult weight gain were significantly associated with dense tissue area among women with BMI < 23 kg/m², and BMI was associated with nondense tissue area among women with BMI ≥ 23 kg/m². In this sample, adiposity and weight gain were associated with dense breast tissue area, although associations differed by level of adiposity. Given the potential implications of these findings for breast cancer prevention in premenopausal women, comparable studies in other population groups and with longitudinal data are needed. Reasons for the noted differences in associations by level of adiposity also warrant further investigation.

Reduction of breast density following tamoxifen treatment evaluated by 3-D MRI: preliminary study

This study analyzed the change in breast density in women receiving tamoxifen treatment using 3-D MRI. Sixteen women were studied. Each woman received breast MRI before and after tamoxifen. The breast and the fibroglandular tissue were segmented using a computer-assisted algorithm, based on T1-weighted images. The fibroglandular tissue volume (FV) and breast volume (BV) were measured and the ratio was calculated as the percent breast density (%BD). The changes in breast volume (ΔBV), fibroglandular tissue volume (ΔFV) and percent density (Δ%BD) between two MRI studies were analyzed and correlated with treatment duration and baseline breast density. The ΔFV showed a reduction in all 16 women. The Δ%BD showed a mean reduction of 5.8%. The reduction of FV was significantly correlated with baseline FV (P<.001) and treatment duration (P=.03). The percentage change in FV was correlated with duration (P=.049). The reduction in %BD was positively correlated with baseline %BD (P=.02). Women with higher baseline %BD showed more reduction of %BD. Three-dimensional MRI may be useful for the measurement of the small changes of ΔFV and Δ%BD after tamoxifen. These changes can potentially be used to correlate with the future reduction of cancer risk.

Mammographic Breast Density and Tolerance for Short-Term Postmenopausal Hormone Therapy Suspension

Breast density tends to decrease when women stop taking hormone therapy (HT). Some women find HT cessation difficult to tolerate, possibly because of fluctuations in endogenous hormone levels and vasomotor symptoms. We hypothesized that women with dense breasts might have lower tolerance for short-term HT suspension than do women with fatty breasts. As part of the Radiologic Evaluation And breast Density (READ) trial, we randomly assigned 881 women aged 45-80 with a prior screening (index) mammogram to suspend HT for 1 or 2 months before their next screening (study) mammogram. We measured continuous breast density on index mammograms using computer-assisted thresholding. At study mammograms, women indicated tolerance for stopping HT from 1 (extremely difficult) to 7 (very easy). Using linear regression, we evaluated the association between index breast density and tolerance after cessation, adjusting for age, body mass index (BMI), HT type, randomization group, and vasomotor symptoms. A higher percentage of breast density was associated with lower unadjusted mean tolerance scores (tolerance 4.27, 95% confidence interval [CI] 3.77-4.77 for women with > or =50% density, and 4.73, 95% CI 4.45-5.01 for women with <10% density, not a statistically significant difference). In adjusted analyses, neither percent breast density nor dense breast area was associated with tolerance for HT suspension. Although HT use affects breast density, tolerance for suspending HT is not associated with breast density. Women with dense breasts have the greatest potential for decreases in density after HT cessation; they should tolerate stopping HT as well as women with fatty breasts.

Mammographic density, plasma vitamin D levels and risk of breast cancer in postmenopausal women

Mammographic density is a strong risk factor for breast cancer, but the underlying biology for this association is unknown. Studies suggest that vitamin D may reduce breast cancer risk and dietary vitamin D intake has been associated with reduced breast density. We conducted a case-control study nested within the Nurses' Health Study cohort consisting of 463 and 497 postmenopausal cases and controls, respectively. We examined the association between mammographic density and plasma levels of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. We assessed whether plasma vitamin D metabolites modify the association between breast density and breast cancer. Percent mammographic density was measured from digitized film mammograms. Generalized linear models were used to determine mean percent breast density per quartile of vitamin D metabolite. Logistic regression models were used to calculate relative risks and confidence intervals. All models were adjusted for matching variables and potential confounders. We found no cross-sectional association between circulating levels of 25(OH)D or 1,25(OH)(2)D with mammographic density. Women in the highest tertile of mammographic density and lowest tertile of plasma 25(OH)D had 4 times greater risk of breast cancer than women with the lowest mammographic density and highest plasma 25(OH)D levels (RR = 3.8; 95% CI: 2.0-7.3). The overall interaction between mammographic density and plasma 25(OH)D was nonsignificant (p-het = 0.20). These results indicate that the association between mammographic density and breast cancer is independent of plasma vitamin D metabolites in postmenopausal women. Further research examining vitamin D, mammographic density and breast cancer risk is warranted.