Biopsy-confirmed Benign Breast Disease Research Articles

Associations of early-life and adult anthropometric measures with the expression of stem cell markers CD44, CD24, and ALDH1A1 in women with benign breast biopsies.

According to the stem cell hypothesis, breast carcinogenesis may be related to the breast stem cell pool size. However, little is known about associations of breast cancer risk factors, such as anthropometric measures, with the expression of stem cell markers in non-cancerous breast tissue. The analysis included 414 women with biopsy-confirmed benign breast disease (BBD) in the Nurses' Health Study (NHS) and NHSII. Birthweight, weight at age 18, current weight, and current height were reported via self-administered questionnaire. Immunohistochemical staining of stem cell markers (CD44, CD24, ALDH1A1) in histopathologically normal epithelial and stromal breast tissue was quantified with an automated computational image analysis system. Linear regression was used to examine the associations of early-life and adult anthropometric measures with log-transformed stem cell marker expression, adjusting for potential confounders. Birthweight (≥10.0 vs. <5.5 lbs: β [95% CI]=4.29 [1.02, 7.56]; p-trend=0.001 in stroma) and adult height (≥67.0 vs. <63.0 inch: 0.86 [0.14, 1.58]; p-trend=0.02 in epithelium and stroma combined) were positively associated with CD44 expression. Childhood body fatness was inversely (p-trend=0.03) and adult height was positively associated with CD24 expression in combined stroma and epithelium (p-trend=0.03). Our data suggest that anthropometric measures, such as birthweight, adult height, and childhood body fatness, may be associated with the stem cell expression among women with BBD. Anthropometric measures, such as birthweight, height, and childhood body fatness, may have long-term impacts on stem cell population in the breast.

Associations of reproductive breast cancer risk factors with expression of stem cell markers in benign breast tissue.

We investigated the associations of reproductive factors known to influence breast cancer risk with the expression of breast stem cell markers CD44, CD24, and ALDH1A1 in benign breast biopsy samples. We included 439 cancer-free women with biopsy-confirmed benign breast disease within the Nurses' Health Study (NHS) and NHSII. The data on reproductive and other breast cancer risk factors were obtained from biennial questionnaires. Immunohistochemistry (IHC) was performed on tissue microarrays. For each core, the IHC expression was assessed using a semi-automated platform and expressed as % of cells that stained positive for a specific marker out of the total cell count. Generalized linear regression was used to examine the associations of reproductive factors with a log-transformed expression of each marker (in epithelium and stroma), adjusted for other breast cancer risk factors. In multivariate analysis, the time between menarche and age at first birth was inversely associated with CD44 in epithelium (β per 5 years = -0.38, 95% CI -0.69; -0.06). Age at first birth and the time between menarche and age at first birth were inversely associated with ALDH1A1 (stroma: β per 5 years = -0.43, 95% CI -0.76; -0.10 and β = -0.47, 95% CI -0.79; -0.15, respectively; epithelium: β = -0.15, 95% CI -0.30; -0.01 and β = -0.17, 95% CI -0.30; -0.03, respectively). Time since last pregnancy was inversely associated with stromal ALDH1A1 (β per 5 years = -0.55, 95% CI -0.98; -0.11). No associations were found for CD24. The observed associations were similar in premenopausal women. In postmenopausal women, lifetime duration of breastfeeding was inversely associated with stromal ALDH1A1 expression (β for ≥24 vs. 0 to <1 months = -2.24, 95% CI 3.96; -0.51, p-trend = 0.01). Early-life reproductive factors may influence CD44 and ALDH1A1 expression in benign breast tissue.

Associations of alcohol consumption with breast tissue composition

BackgroundWe investigated the associations of alcohol with percentage of epithelium, stroma, fibroglandular tissue (epithelium + stroma), and fat in benign breast biopsy samples.MethodsWe included 857 cancer-free women with biopsy-confirmed benign breast disease within the Nurses’ Health Study (NHS) and NHSII cohorts. Percentage of each tissue was measured on whole slide images using a deep-learning algorithm and then log-transformed. Alcohol consumption (recent and cumulative average) was assessed with semi-quantitative food frequency questionnaires. Regression estimates were adjusted for known breast cancer risk factors. All tests were 2-sided.ResultsAlcohol was inversely associated with % of stroma and fibroglandular tissue (recent ≥ 22 g/day vs. none: stroma: β = − 0.08, 95% Confidence Interval [CI] − 0.13; − 0.03; fibroglandular: β = − 0.08, 95% CI − 0.13; − 0.04; cumulative ≥ 22 g/day vs. none: stroma: β = − 0.08, 95% CI − 0.13; − 0.02; fibroglandular: β = − 0.09, 95% CI − 0.14; − 0.04) and positively associated with fat % (recent ≥ 22 g/day vs. none: β = 0.30, 95% CI 0.03; 0.57; cumulative ≥ 22 g/day vs. none: β = 0.32, 95% CI 0.04; 0.61). In stratified analysis, alcohol consumption was not associated with tissue measures in premenopausal women. In postmenopausal women, cumulative alcohol use was inversely associated with % of stroma and fibroglandular tissue and positively associated with fat % (≥ 22 g/day vs. none: stroma: β = − 0.16, 95% CI − 0.28; − 0.07; fibroglandular: β = − 0.18, 95% CI − 0.28; − 0.07; fat: β = 0.61, 95% CI 0.01; 1.22), with similar results for recent alcohol use.ConclusionOur findings suggest that alcohol consumption is associated with smaller % of stroma and fibroglandular tissue and a greater % of fat in postmenopausal women. Future studies are warranted to confirm our findings and to elucidate the underlying biological mechanisms.

Reliability of CD44, CD24, and ALDH1A1 immunohistochemical staining: Pathologist assessment compared to quantitative image analysis.

The data on the expression of stem cell markers CD44, CD24, and ALDH1A1 in the breast tissue of cancer-free women is very limited and no previous studies have explored the agreement between pathologist and computational assessments of these markers. We compared the immunohistochemical (IHC) expression assessment for CD44, CD24, and ALDH1A1 by an expert pathologist with the automated image analysis results and assessed the homogeneity of the markers across multiple cores pertaining to each woman. We included 81 cancer-free women (399 cores) with biopsy-confirmed benign breast disease in the Nurses' Health Study (NHS) and NHSII cohorts. IHC was conducted with commercial antibodies [CD44 (Dako, Santa Clara, CA, USA) 1:25 dilution; CD24 (Invitrogen, Waltham, MA, USA) 1:200 dilution and ALDH1A1 (Abcam, Cambridge, United Kingdom) 1:300 dilution]. For each core, the percent positivity was quantified by the pathologist and Definiens Tissue Studio. Correlations between pathologist and computational scores were evaluated with Spearman correlation (for categorical positivity: 0, >0-<1, 1-10, >10-50, and >50%) and sensitivity/specificity (for binary positivity defined with 1 and 10% cut-offs), using the pathologist scores as the gold standard. Expression homogeneity was examined with intra-class correlation (ICC). Analyses were stratified by core [normal terminal duct-lobular units (TDLUs), benign lesions] and tissue type (epithelium, stroma). Spearman correlation between pathologist and Definiens ranged between 0.40-0.64 for stroma and 0.66-0.68 for epithelium in normal TDLUs cores and between 0.24-0.60 for stroma and 0.61-0.64 for epithelium in benign lesions. For stroma, sensitivity and specificity ranged between 0.92-0.95 and 0.24-0.60, respectively, with 1% cut-off and between 0.43-0.88 and 0.73-0.85, respectively, with 10% cut-off. For epithelium, 10% cut-off resulted in better estimates for both sensitivity and specificity. ICC between the cores was strongest for CD44 for both stroma and epithelium in normal TDLUs cores and benign lesions (range 0.74-0.80). ICC for CD24 and ALDH1A ranged between 0.42-0.63 and 0.44-0.55, respectively. Our findings show that computational assessments for CD44, CD24, and ALDH1A1 exhibit variable correlations with manual assessment. These findings support the use of computational platforms for IHC evaluation of stem cell markers in large-scale epidemiologic studies. Pilot studies maybe also needed to determine appropriate cut-offs for defining staining positivity.

Abstract P3-12-19: Associations of alcohol consumption with benign breast tissue composition

Abstract Objectives: Alcohol is a known breast cancer risk factor and it is also associated with increased mammographic breast density, a well-established, strong breast cancer risk factor. Despite some evidence on the associations of alcohol use with tissue composition on mammograms, no studies have examined these associations using direct measurement of tissue composition in normal breast tissue of cancer-free women. We investigated the associations of recent and cumulative average alcohol use with percentage of epithelium, stroma, fibroglandular (epithelium+stroma), and fat tissue in benign breast biopsy samples. Methods: This study included 859 cancer-free women with biopsy-confirmed benign breast disease (BBD) within the Nurses’ Health Study and Nurses’ Health Study II cohorts. Percentage of each tissue type was measured on whole section images with a deep-learning technique. All tissue measures were log-transformed. The data on alcohol use was obtained from semi-quantitative food frequency questionnaires. Information on other covariates was collected on initial questionnaire and updated biennially thereafter. We examined associations for recent (at the time of biopsy) and cumulative average alcohol use (from all questionnaire preceding the biopsy), both of which were modeled as a continuous (g/day) and categorical (using various approaches: 0, 0-&amp;lt;5, and ≥5 g/day; non-drinkers, &amp;lt;11 g/day [&amp;lt;1 drink/day], 11-&amp;lt;22g/day [1-&amp;lt;2 drinks/day], and ≥ 22 g/day [≥2 dinks/day]; and quartiles based on the distribution in the study sample). Generalized linear regression was used to examine the associations of alcohol with % of tissue types, while adjusting for known breast cancer risk factors and BBD subtype. Results: In this study of 859 cancer-free women, 260 (30.3%) had non-proliferative disease, 485 (56.5%) had proliferative disease without atypia, and 114 (13.3%) had atypical hyperplasia, consistent with previously reported distributions of these BBD subtypes. In our study, 30.3% of women consumed ≥5 g/day of alcohol at the time of biopsy and 18.1% consumed ≥11 g (≥1 drinks) of alcohol per day. The average % of epithelium, stroma, and fat in our study was 9.0% (range 0.7-52.2%), 72.4% (range 23.6-99.0%), and 18.6% (range 0-71.3%), respectively. Both recent and cumulative alcohol use were inversely associated with % of stroma and fibroglandular tissue; these associations were most pronounced for recent use of ≥22 g (≥2 drinks) per day (stroma: β=-0.08, 95% Confidence Interval [CI] -0.13;-0.03; fibroglandular: β=-0.09, 95% CI -0.13;-0.04) and cumulative average use of ≥22 g (≥2 drinks) per day (stroma β=-0.08, 95% CI -0.13;-0.02; fibroglandular: β=-0.09, 95% CI -0.14;-0.04). Recent and cumulative average use of ≥22 g/day were also positively associated with % of fat (β=0.30, 95% CI 0.03; 0.57 for recent and β=0.32, 95% CI 0.04; 0.61 for cumulative average). In stratified analysis by menopausal status, recent and cumulative average alcohol use were inversely associated with % of stroma and fibroglandular tissue and positively associated with % of fat in postmenopausal women. The strongest associations were observed for recent alcohol use of ≥22 g/day (stroma: β=-0.12, 95% CI -0.21;-0.04; fat: β=0.67, 95% CI 0.23;1.12; fibroglandular: β=-0.15, 95% CI -0.23;-0.07) and cumulative average use of ≥22 g/day (stroma β=-0.14, 95% CI -0.23;-0.04; fat: β=0.53, 95% CI 0.03;1.03; fibroglandular: β=-0.16, 95% CI -0.25;-0.07). We found no associations of alcohol use with any of the tissue measures in premenopausal women. Conclusion: Our findings suggest that both recent and cumulative average alcohol consumption are associated with smaller proportion of stroma and fibroglandular tissue and a greater proportion of fat in postmenopausal women. Future studies are warranted to confirm our findings and to elucidate the underlying biological mechanisms. Citation Format: Lusine Yaghjyan, Rebecca Austin-Datta, Yujing J Heng, Gabrielle Baker, Bernard Rosner, Rulla Tamimi. Associations of alcohol consumption with benign breast tissue composition [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-12-19.

Associations of reproductive breast cancer risk factors with breast tissue composition

BackgroundWe investigated the associations of reproductive factors with the percentage of epithelium, stroma, and fat tissue in benign breast biopsy samples.MethodsThis study included 983 cancer-free women with biopsy-confirmed benign breast disease (BBD) within the Nurses’ Health Study and Nurses’ Health Study II cohorts. The percentage of each tissue type (epithelium, stroma, and fat) was measured on whole-section images with a deep-learning technique. All tissue measures were log-transformed in all the analyses to improve normality. The data on reproductive variables and other breast cancer risk factors were obtained from biennial questionnaires. Generalized linear regression was used to examine the associations of reproductive factors with the percentage of tissue types, while adjusting for known breast cancer risk factors.ResultsAs compared to parous women, nulliparous women had a smaller percentage of epithelium (β = − 0.26, 95% confidence interval [CI] − 0.41, − 0.11) and fat (β = − 0.34, 95% CI − 0.54, − 0.13) and a greater percentage of stroma (β = 0.04, 95% CI 0.01, 0.08). Among parous women, the number of children was inversely associated with the percentage of stroma (β per child = − 0.01, 95% CI − 0.02, − 0.00). The duration of breastfeeding of ≥ 24 months was associated with a reduced proportion of fat (β = − 0.30, 95% CI − 0.54, − 0.06; p-trend = 0.04). In a separate analysis restricted to premenopausal women, older age at first birth was associated with a greater proportion of epithelium and a smaller proportion of stroma.ConclusionsOur findings suggest that being nulliparous as well as having a fewer number of children (both positively associated with breast cancer risk) is associated with a smaller proportion of epithelium and a greater proportion of stroma, potentially suggesting the importance of epithelial-stromal interactions. Future studies are warranted to confirm our findings and to elucidate the underlying biological mechanisms.

Abstract PS7-90: Reproductive breast cancer risk factors and breast tissue composition on benign breast biopsies

Abstract Background: Reproductive factors related to childbearing are recognized as breast cancer risk factors. Whether any of these factors could influence adult breast tissue composition is unclear. We investigated the associations of reproductive factors with percentage of epithelium, stroma, and fat tissue in benign breast biopsy samples. Methods: This study included 983 cancer-free women with biopsy-confirmed benign breast disease (BBD) within the Nurses’ Health Study and Nurses’ Health Study II cohorts. Percentage of each tissue type (epithelium stroma, and fat) was measured on whole section images with a deep-learning technique. All tissue measures were log-transformed in all the analyses to improve normality. The data on reproductive variables and other breast cancer risk factors were obtained from biennial questionnaires. Generalized linear regression was used to examine the associations of reproductive factors (parity, age at first birth, breastfeeding, age at menarche and the duration of the interval between menarche and age at first birth) with percentage of tissue types, while adjusting for known breast cancer risk factors.Results: In this study of 983 cancer-free women, 299 (30.4%) had non-proliferative disease, 559 (56.9%) had proliferative disease without atypia, and 125 (12.7%) had atypical hyperplasia, consistent with previously reported distributions of these BBD subtypes. The average proportion of epithelium, stroma, and fat in our study sample was 9.1% (range 0.5-52.2%), 72.4% (range 23.6-99.0%), and 18.5% (range 0-71.3%), respectively. As compared to parous women, nulliparous women had a smaller percentage of epithelium (β= -0.26, 95% confidence interval [CI] -0.41, -0.11) and fat (β= -0.34, 95% CI -0.54, -0.13) and a greater percentage of stroma (β=0.04, 95% CI 0.01, 0.08). Among parous women, number of children was inversely associated with percentage of stroma (β per child= -0.01 (-0.02, -0.00). Duration of breastfeeding of ≥24 months was associated with a reduced proportion of fat (β= -0.30, 95% CI -0.54, -0.06; p-trend=0.04). In a separate analysis restricted to premenopausal women, being nulliparous was associated with a greater proportion of stroma (β=0.06, 95% CI 0.02, 0.10) and smaller proportion of epithelium (β= -0.22, 95% CI -0.38, -0.06) and fat (β= -0.32, 95% CI -0.56, -0.08). Greater parity and older age at first birth were both associated with a greater proportion of epithelium (and a smaller proportion of stroma. The age at menarche and the duration of the interval between age at menarche and first birth were not associated with the proportion of any of the tissue types. Conclusions: Our findings suggest that reproductive factors with a protective effect on breast cancer risk may be associated with a greater proportion of epithelium and a smaller proportion of stroma, potentially suggesting importance of epithelial-stromal interactions. Future studies are warranted to confirm our findings and to elucidate the underlying biological mechanisms. Citation Format: Lusine Yaghjyan, Rebecca J Austin-Datta, Hannah Oh, Yujing J Heng, Adithya D Vellal, Korsuk Sirinukunwattana, Gabrielle M Baker, Laura Collins, Divya Murthy, Bernard Rosner, Rulla M Tamimi. Reproductive breast cancer risk factors and breast tissue composition on benign breast biopsies [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-90.

Adolescent alcohol, nuts, and fiber: combined effects on benign breast disease risk in young women

Adolescent drinking is associated with higher risks of proliferative benign breast disease (BBD) and invasive breast cancer (BC). Furthermore, adolescent nut and fiber consumptions are associated with lower risks of benign lesions and premenopausal BC. We hypothesize that diet (nuts, fiber) may mitigate the elevated BBD risk associated with alcohol. A prospective cohort of 9031 females, 9–15 years at baseline, completed questionnaires in 1996–2001, 2003, 2005, 2007, 2010, 2013, and 2014. Participants completed food frequency questionnaires in 1996–2001. In 2005, participants (>=18 years) began reporting biopsy-confirmed BBD (N = 173 cases). Multivariable logistic regression estimated associations between BBD and cross-classified intakes (14–17 years) of alcohol and peanut butter/nuts (separately, total dietary fiber). Only 19% of participants drank in high school; drinking was associated with elevated BBD risk (OR = 1.75, 95% CI: 1.20–2.56; p = 0.004) compared to nondrinkers. Participants consuming any nuts/butter had lower BBD risk (OR = 0.64, 95% CI: 0.45–0.90; p = 0.01) compared to those consuming none. Participants in top 75% fiber intake had lower risk (OR = 0.57, 95% CI: 0.40–0.81; p = 0.002) compared to bottom quartile. Testing our hypothesis that consuming nuts/butter mitigates the elevated alcohol risk, analyzing alcohol and nuts combined found that those who consumed both had lower risk (RR = 0.47, 95% CI: 0.24–0.89; p = 0.02) compared to drinkers eating no nuts. Our analysis of alcohol and fiber together did not demonstrate risk mitigation by fiber. For high school females who drink, their BBD risk may be attenuated by consuming nuts. Due to modest numbers, future studies need to replicate our findings in adolescent/adult females. However, high school students may be encouraged to eat nuts and fiber, and to avoid alcohol, to reduce risk of BBD and for general health benefits.

Somatic mutations in benign breast disease tissue and risk of subsequent invasive breast cancer

BackgroundInsights into the molecular pathogenesis of breast cancer might come from molecular analysis of tissue from early stages of the disease.MethodsWe conducted a case–control study nested in a cohort of women who had biopsy-confirmed benign breast disease (BBD) diagnosed between 1971 and 2006 at Kaiser Permanente Northwest and who were followed to mid-2015 to ascertain subsequent invasive breast cancer (IBC); cases (n = 218) were women with BBD who developed subsequent IBC and controls, individually matched (1:1) to cases, were women with BBD who did not develop IBC in the same follow-up interval as that for the corresponding case. Targeted sequence capture and sequencing were performed for 83 genes of importance in breast cancer.ResultsThere were no significant case–control differences in mutation burden overall, for non-silent mutations, for individual genes, or with respect either to the nature of the gene mutations or to mutational enrichment at the pathway level. For seven subjects with DNA from the BBD and ipsilateral IBC, virtually no mutations were shared.ConclusionsThis study, the first to use a targeted multi-gene sequencing approach on early breast cancer precursor lesions to investigate the genomic basis of the disease, showed that somatic mutations detected in BBD tissue were not associated with breast cancer risk.

Body size from birth through adolescence in relation to risk of benign breast disease in young women.

Body size, from birth throughout adulthood, is associated with breast cancer risk, but few studies have investigated early-life body size and benign breast disease (BBD), a well-established breast cancer risk factor. We consider whether prenatal factors and size at birth, 10, 18year, and intervening growth, are related to BBD risk. The Growing Up Today Study includes 9032 females who completed questionnaires annually from 1996 to 2001, then 2003, 2005, 2007, 2010, and 2013. In 1996, their mothers provided pregnancy-related data. From 2005 to 2013, participants (18year+) reported whether they had ever been diagnosed with biopsy-confirmed BBD (N=142 cases). Girls had greater adiposity (BMI; kg/m2) at 10year if they were larger at birth, if mother's pre-pregnancy BMI was higher, or if gestational weight gain was greater (all p<.01). Maternal height was (positively) associated (p<.05) with adolescent peak height growth velocity (PHV; in./year). Greater 10year adiposity was associated with lower PHV and less height growth 10-18year (both p<.01). Adiposity at 10year was inversely associated with BBD (OR 0.83/(kg/m2), p<.01) as was increasing adiposity 10-18year (OR 0.85/(kg/m2), p=.01). In a separate model, 10year height (OR 1.13/in., p=.02) and height growth 10-18year (OR 1.19/in.; p<.01) were positively associated. PHV was similarly positively associated (OR 2.58, p=.01, fastest versus slowest growth quartiles). In a multivariable model of BBD risk, gestational weight gain (daughters at highest risk if <20lb gained), PHV (slowest growing girls at lowest risk), age 10year height (positive), and BMI (inverse) were the most critical childhood risk factors (each p<.05). Body size factors from pregnancy through adolescence were independently associated with BBD risk in young women.

Mammographic density and breast cancer risk: a mediation analysis.

BackgroundHigh mammographic density (MD) is a strong risk factor for breast cancer. However, it is unclear whether high MD is an intermediate phenotype or whether breast cancer risk factors influence breast cancer risk and MD independently.MethodsOur study population included 1290 invasive breast cancer cases and 3422 controls from the Nurses’ Health Studies. We estimated the percent of the total association between the risk factor and breast cancer that was mediated by MD.ResultsIn both pre- and postmenopausal women, the association between history of biopsy-confirmed benign breast disease and risk was partially mediated by percent MD (percent mediated (PM) = 17 %, p < 0.01 and PM = 33 %, p = 0.04, respectively). In premenopausal women, the associations between early life body size (adolescent somatotype and BMI at age 18) and breast cancer risk were substantially mediated by percent MD (PM = 73 %, p = 0.05 and PM = 82 %, p = 0.04, respectively). In postmenopausal women, the proportion of the associations of childhood somatotype and adolescent somatotype that were mediated by percent MD were lower (PM = 26 %, p = 0.01 for both measures). Hormone therapy use at mammogram was significantly mediated by percent MD in postmenopausal women (PM = 22 %, p < 0.01). Associations with other risk factors, such as age at menarche or family history of breast cancer, were not mediated by percent MD.ConclusionsPercent MD partially mediated some of the associations between risk factors and breast cancer, though the magnitude varied by risk factor and menopausal status. These findings suggest that high MD may be an intermediate in some biological pathways for breast cancer development.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-016-0750-0) contains supplementary material, which is available to authorized users.

A prospective study of endometriosis and risk of benign breast disease.

Given the altered hormonal and inflammatory environment of women with endometriosis, several studies have suggested a positive association between endometriosis and breast cancer, although findings have been mixed. This study investigates the relationship between endometriosis and benign breast disease (BBD), benign lesions that are associated with an increased risk of breast cancer. Among women in the Nurses' Health Study II followed from 1991-2003 (n=76,393), we investigated the association between laparoscopically confirmed endometriosis and biopsy-confirmed BBD. Cox proportional hazard models, adjusted for a priori potential confounding factors, were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). Across follow-up, 2011 BBD biopsies were collected and centrally reviewed by study pathologists (nonproliferative=675, proliferative=1336). Effect modification by infertility history and use of screening mammography was investigated. Endometriosis was associated with a modest increased risk of biopsy-confirmed BBD in crude and multivariable adjusted models (HR 1.20, 95% CI 1.00-1.43). When evaluating subtypes of BBD, we did not see different associations for nonproliferative or proliferative BBD lesions, as endometriosis was associated with a modest increased risk for both (HR nonproliferative 1.15, 95% CI 0.84-1.57; HR proliferative 1.22, 95% CI 0.98-1.52). The association between endometriosis and proliferative BBD appeared strongest among women who had ever experienced infertility (HR 1.50, 95% CI 1.12-2.03; P value, test for heterogeneity=0.05). Sensitivity analyses investigating screening behaviors between those with and without endometriosis did not significantly alter results. Endometriosis was associated with a modest increased risk of both proliferative and nonproliferative BBD, although future work should replicate this novel finding.

Prenatal factors and infant feeding in relation to risk of benign breast disease in young women.

Benign breast disease (BBD) is a well-established risk factor for breast cancer, but little work has considered a girl's early life and her risk for BBD in adulthood. We investigated factors, from pre-conception through infant feeding practices, in relation to subsequent BBD risk in young women. The Growing Up Today Study (GUTS) includes 9032 females, born 1980-1987, who completed questionnaires annually from 1996 through 2001, then 2003, 2005, 2007, 2010, and 2013. In 1996, their mothers provided each participant's birth weight and length, gestational age, biological father's height, and infant feeding factors (e.g., breast-fed, type of formula). In 1999, their mothers reported maternal pre-pregnancy weight and weight gain during index pregnancy. Beginning in 2005, daughters (18 years+) reported whether they had ever been diagnosed with biopsy-confirmed BBD (n = 142 cases, through 2013). Logistic regression estimated associations between early life factors and biopsy-confirmed BBD. Girls whose mother's BMI prior to pregnancy was 20-25 kg/m(2) were at lower risk of BBD as young women (OR = 0.66, p = 0.04, vs. maternal pre-pregnancy BMI < 20). Girls whose mothers gained 20 + pounds (vs. <20 pounds) during pregnancy were at lower risk (among full-term singleton births: OR = 0.48, p = 0.007, if mother gained 20-35 pounds). However, neither birth weight nor BMI at birth were associated with subsequent BBD risk. We found no evidence that infant feeding practices were linked to BBD. A healthy maternal BMI before pregnancy and sufficient weight gain during pregnancy may produce daughters at lower risk for BBD as young women. Further examination of these findings is needed.

Adolescent dietary vitamin D and sun exposure in relation to benign breast disease.

Vitamin D may reduce cell proliferation and tumor growth in breast tissue, and exposure may be most important during adolescence when breast tissue is developing. In the Nurses' Health Study II, higher recalled adolescent vitamin D intake was associated with a lower risk of benign breast disease (BBD). Our study aimed to assess adolescent vitamin D exposure in relation to BBD in young women. Vitamin D was assessed in 6,593 adolescent girls (9-15years of age at baseline) in the prospective Growing Up Today Study cohort using the mean energy-adjusted intakes from food frequency questionnaires in 1996, 1997, and 1998. In 1999, 5,286 girls reported skin color, sunscreen use, tanning bed use, and number of sunburns in the past year, and we used state of residence to assess low versus high ultraviolet index. Biopsy-confirmed BBD was reported on questionnaires in 2005, 2007, and 2010 (n=122). Dietary vitamin D, tanning behaviors, and other sun exposure variables were not significantly associated with BBD in logistic regression models adjusted for age, family history of breast cancer or BBD, age at menarche, nulliparity, alcohol intake, body mass index, and physical activity. The relative risk for the top (>467IU/day) versus bottom (<243IU/day) quartile of vitamin D intake was 0.76 (95% CI 0.47, 1.23). Sun exposure was not significantly associated with BBD in this prospective cohort. However, a suggestive inverse association between dietary vitamin D and BBD was observed that merits further study.

Adolescent physical activity and inactivity: a prospective study of risk of benign breast disease in young women.

In previous investigations of adolescent activity recalled in adulthood, modest reductions in risk of benign breast disease (BBD) and premenopausal breast cancer were seen with moderate-strenuous activity during high school. We therefore investigated physical activity, walking, and recreational inactivity (watching TV-videos, playing computer-videogames) reported by adolescent girls in relation to their subsequent risk for BBD as young women. The Growing Up Today Study includes 9,039 females, 9-15years at study initiation (1996), who completed questionnaires annually through 2001, then in2003, 2005, 2007, 2010 and 2013. Annual surveys (1996-2001) obtained data on physical and sedentary activities during the past year. Beginning in 2005, women (≥18years) reported whether they hadever been diagnosed with BBD confirmed by breast biopsy (n=133 cases, to 11/01/2013). Logistic regression (adjusted for baseline adiposity and age; additional factors in multivariable-adjusted models) estimated associations between adolescent activities (moderate-vigorous, walking, METS, inactivity) and biopsy-confirmed BBD in young women. Girls who walked the most had significantly lower risk of BBD (multivariable-adjusted OR=0.61, ≥30 vs ≤15min/day;p = .049). We observed no evidence that inactivity (≥3 vs <2h/day OR=1.02, p=.92) or METS (top vs bottom tertile OR=1.19, p=.42) were associated with BBD. Accounting for factors including family history, childhood adiposity,and other activities and inactivities, adolescent girls who walked the most were at lower risk for BBD. We found no evidence that high moderate-vigorous activity might reduce risk, nor did we observe any association with inactivity. Continued follow-up will re-evaluate these findings as more BBD cases, and ultimately breast cancer, are diagnosed.

Association between melanocytic nevi and risk of breast diseases: The French E3N prospective cohort.

While melanocytic nevi have been associated with genetic factors and childhood sun exposure, several observations also suggest a potential hormonal influence on nevi. To test the hypothesis that nevi are associated with breast tumor risk, we explored the relationships between number of nevi and benign and malignant breast disease risk. We prospectively analyzed data from E3N, a cohort of French women aged 40-65 y at inclusion in 1990. Number of nevi was collected at inclusion. Hazard ratios (HRs) for breast cancer and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models. Associations of number of nevi with personal history of benign breast disease (BBD) and family history of breast cancer were estimated using logistic regression. Over the period 15 June 1990-15 June 2008, 5,956 incident breast cancer cases (including 5,245 invasive tumors) were ascertained among 89,902 women. In models adjusted for age, education, and known breast cancer risk factors, women with "very many" nevi had a significantly higher breast cancer risk (HR = 1.13, 95% CI = 1.01-1.27 versus "none"; ptrend = 0.04), although significance was lost after adjustment for personal history of BBD or family history of breast cancer. The 10-y absolute risk of invasive breast cancer increased from 3,749 per 100,000 women without nevi to 4,124 (95% CI = 3,674-4,649) per 100,000 women with "very many" nevi. The association was restricted to premenopausal women (HR = 1.40, ptrend = 0.01), even after full adjustment (HR = 1.34, ptrend = 0.03; phomogeneity = 0.04), but did not differ according to breast cancer type or hormone receptor status. In addition, we observed significantly positive dose-response relationships between number of nevi and history of biopsy-confirmed BBD (n = 5,169; ptrend<0.0001) and family history of breast cancer in first-degree relatives (n = 7,472; ptrend = 0.0003). The main limitations of our study include self-report of number of nevi using a qualitative scale, and self-reported history of biopsied BBD. Our findings suggest associations between number of nevi and the risk of premenopausal breast cancer, BBD, and family history of breast cancer. More research is warranted to elucidate these relationships and to understand their underlying mechanisms.

Adolescent Carotenoid Intake and Benign Breast Disease

Carotenoids may reduce risk of benign breast disease (BBD), an independent risk factor for breast cancer, through antioxidative or antiproliferative mechanisms. Exposure to carotenoids may be most important during adolescence when breast tissue is still developing. We examined adolescent carotenoid intake in relation to BBD in young women. In 6593 adolescent girls in the prospective Growing Up Today Study cohort, intakes of α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and lycopene were assessed by using the means from food-frequency questionnaires in 1996, 1997, and 1998. Girls reported biopsy-confirmed BBD on questionnaires in 2005, 2007, and 2010 (n = 122). We conducted logistic regression of energy-adjusted carotenoid intakes in relation to BBD, adjusted for age, family history of breast cancer or BBD, age at menarche, nulliparity, alcohol intake, BMI, and physical activity. Mean (SD) age at baseline was 12.0 (1.6) years. β-Carotene intake was inversely associated with BBD; comparing the highest to lowest quartile, the multivariate-adjusted odds ratio was 0.58 (95% confidence interval: 0.34-1.00; P-trend = .03). α-Carotene and lutein/zeaxanthin were also inversely associated with BBD, but the associations were not statistically significant. Adolescent carotenoid intake may be associated with lower BBD risk; these findings warrant further study.

Vegetable protein and vegetable fat intakes in pre-adolescent and adolescent girls, and risk for benign breast disease in young women

Previous investigations, of adolescent diet recalled in adulthood, found lower risk for benign breast disease (BBD) with higher intakes of vegetable fat and nuts during high school. We investigate whether vegetable protein and fat, derived from diets reported during pre-adolescence and adolescence, are associated with subsequent risk for BBD in young women. The Growing Up Today Study includes 9,039 females, 9-15 years in 1996, who completed questionnaires annually through 2001, and then in 2003, 2005, 2007, and 2010. Food frequency questionnaires (1996-2001) obtained intake data on a variety of foods. Beginning in 2005, women (18-30 years) reported whether they had ever been diagnosed with BBD that was confirmed by breast biopsy (n = 112 cases). Logistic regression estimated associations between intakes of vegetable protein and fat and biopsy-confirmed BBD. Those individual foods that were the largest contributors of protein and fat in this cohort were also investigated. In analyses of intakes from 1996 through 1998, when our cohort was youngest, vegetable fat (OR = 0.72/(10 gm/day), 95 % CI 0.53-0.98; p = 0.04) was inversely associated with BBD risk. The greatest sources of vegetable fat and protein in these girls were peanut butter, peanuts, nuts, beans (beans, lentils, and soybeans), and corn. A daily serving of any one of these was associated with lower risk (OR = 0.32/(serv/day), 95 % CI 0.13-0.79; p = 0.01). Peanut butter (and nuts) at age 11 years was inversely associated with risk (p = 0.01). In analyses of intakes at age 14 years, vegetable protein was associated with lower BBD risk (OR = 0.64/(10 gm/day), 95 % CI 0.43-0.95; p = 0.03). A daily serving at 14 years of any one of the foods was associated with lower risk (OR = 0.34, 95 % CI 0.16-0.75; p = 0.01), as was peanut butter (and nuts) (p = 0.02). Girls with a family history of breast cancer had significantly lower risk if they consumed these foods or vegetable fat. In conclusion, consumption of vegetable protein, fat, peanut butter, or nuts by older girls may help reduce their risk of BBD as young women.

Insulin-like growth factor-1, insulin-like growth factor binding protein-3 and lobule type in the Nurses' Health Study II

IntroductionPrevious research in the Nurses' Health Study (NHS) and the NHSII observed that, among women diagnosed with benign breast disease (BBD), those with predominant type 1/no type 3 lobules (a marker of complete involution) versus other lobule types were at lower risk of subsequent breast cancer. Studies in animal models suggest that insulin-like growth factor-1 (IGF-1) may inhibit involution of lobules in the breast; however, this has not been studied in humans.MethodsWe conducted a cross-sectional study among 472 women in the NHSII who were diagnosed with biopsy-confirmed proliferative BBD between 1991 and 2002 and provided blood samples between 1996 and 1999. A pathologist, blinded to exposure status, classified lobule type in normal adjacent tissue on available biopsy slides according to the number of acini per lobule. For each participant, the pathologist determined the predominant lobule type (that is, type 1, type 2, or type 3) and whether any type 1 or any type 3 lobules were present. Lobule type was then classified as: predominant type 1/no type 3 lobules, which is suggestive of complete involution; or other lobule types. Multivariate logistic models were used to assess the associations between plasma IGF-1, insulin-like growth factor binding protein-3 (IGFBP-3), and the ratio of IGF-1:IGFBP-3 levels with lobule type.ResultsIn univariate analyses, greater age, higher body mass index, postmenopausal status, nulliparity, and lower IGF-1 levels were associated with predominant type 1/no type 3 lobules (P < 0.05). In multivariate models adjusting for age and assay batch, higher IGF-1 levels were associated with decreased odds of predominant type 1/no type 3 lobules (odds ratio quartile 4 vs. quartile 1 = 0.37, 95% confidence interval = 0.15 to 0.89). Greater ratios of IGF-1:IGFBP-3 levels were also associated with decreased odds of predominant type 1/no type 3 lobules (odds ratio quartile 4 vs. quartile 1 = 0.26, 95% confidence interval = 0.11 to 0.64). These results were slightly attenuated after adjustment for other potential predictors of lobule type.ConclusionsHigher IGF-1 levels and a greater IGF-1:IGFBP-3 ratio were associated with decreased odds of having predominant type 1 lobules/no type 3 lobules among women with proliferative BBD in the NHSII. This study provides further evidence for the role of insulin-like growth factors in the structure of breast lobules and lobular involution.

P4-11-02: Insulin-Like Growth Factor-1 (IGF-1), Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3) and Lobule Type among Women in the Nurses' Health Study II (NHS II).

Abstract In a previous analysis of women enrolled in NHSII, we found that among women diagnosed with benign breast disease (BBD), those with predominant type 1/no type 3 lobules were at lower risk of subsequent breast cancer compared to women with other lobule types. Additionally, studies in animal models suggest that higher levels of IGF-1, a polypeptide hormone involved in the proliferation/differentiation of normal mammary epithelium, may inhibit involution of breast lobules. However, the interaction between IGF-1 levels and lobule types in determining breast cancer risk has not been previously evaluated. Therefore, we examined the association between IGF-1 levels and lobule type among women with BBD. Methods: We conducted a cross-sectional study among 484 women in NHSII with biopsy-confirmed BBD between 1993–2001 who had blood samples available for determining levels of IGF-1 and IGFBP-3. A pathologist, blinded to exposure status, classified lobule type on biopsy slides according to the number of acini per lobule (type 1 &amp;lt; 12; type 2∼50; type 3∼80 acini). Lobule type was classified into (1) predominant type 1/no type 3 lobules or (2) other lobule types. Multivariate logistic models were used to assess the associations between plasma IGF-1, IGFBP-3, and IGF-1/IGFBP-3 levels with lobule type. Models were adjusted for age, IGF-1 batch and additional potential confounders in secondary analyses. Results: In univariate analyses, older age at biopsy, higher body mass index, postmenopausal status, nulliparity, and lower IGF-1 levels were associated with predominant type1/no type 3 lobules (p&amp;lt;0.05). In multivariate logistic models adjusting for age, higher IGF-1 levels were associated with a decreased risk of predominant type 1/no type 3 lobules (OR quartile 4 vs. quartile 1 = 0.35, 95%CI: 0.15−0.81). Greater IGF-1/IGFBP-3 ratio was also associated with a decreased risk of predominant type1/no type 3 lobules (OR quartile 4 vs. quartile 1 = 0.24, 95%CI: 0.10−0.57). These associations persisted, though were slightly attenuated, in models adjusting for additional potential confounders. Conclusion: Higher IGF-1 levels and greater IGF-1/IGFBP-3 ratios are associated with a decreased risk of predominant type 1 lobules/no type 3 lobules among women with BBD in the NHSII. Whether this association contributes to the mechanism by which IGF-1 confers an elevated breast cancer risk requires further investigation. Acknowledgements: This work was supported by T32 CA09001-35 CA124865, R01 CA050385, and the Breast Cancer Research Foundation Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-02.