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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

IMPACT

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

Background

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.

Methods

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.

Results

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).

Conclusion

Early-life reproductive factors may influence CD44 and ALDH1A1 expression in benign breast tissue.

Reproductive factors related to childbearing and a novel automated mammographic measure, V

BACKGROUND

We investigated the associations between several reproductive factors related to childbearing and the variation (V) measure (a novel, objective, single summary measure of breast image intensity) by menopausal status.

METHODS

Our study included 3,814 cancer-free women within the Nurses' Health Study (NHS) and NHSII cohorts. The data on reproductive variables and covariates were obtained from biennial questionnaires closest to the mammogram date. V-measures were obtained from mammographic images using a previously developed algorithm capturing the standard deviation of pixel values. We used multivariate linear regression to examine the associations of parity, age at first birth, time between menarche and first birth, time since last pregnancy, and lifetime breastfeeding duration with V-measure, adjusting for breast cancer risk factors, including percent mammographic density (PMD). We further examined if these associations were statistically accounted for (mediated) by PMD.

RESULTS

Among premenopausal women, none of the reproductive factors were associated with V. Among postmenopausal women, inverse associations of parity and positive associations of age at first birth with V were mediated by PMD (percent mediated: nulliparity: 66.7%, p<0.0001; parity: 50.5%, p<0.01; age at first birth 76.1%, p<0.001) and were no longer significant in PMD-adjusted models. Lifetime duration of breastfeeding was positively associated with V (>36 vs. 0-<1 months β=0.29, 95% CI 0.07; 0.52, p-trend<0.01), independent of PMD.

CONCLUSIONS

Parity, age at first birth, and breastfeeding were associated with postmenopausal V.

IMPACT

This study highlights associations of reproductive factors with mammographic image intensity.

Effect of testosterone therapy on breast tissue composition and mammographic breast density in trans masculine individuals

Objective

Determine the association between TT and breast tissue composition and breast tissue density in trans masculine individuals (TMIs).

Design

This is a cross-sectional study.

Setting

TMIs (n=444) underwent chest-contouring surgeries to treat their gender dysphoria between 2013 and 2019 at an urban medical center.

Participants

Of the 444 TMIs, 425 had pathology images analyzed by our deep-learning algorithm to extract breast tissue composition. A subset of 42/444 TMIs had mammography prior to surgery; mammography files were available for 25/42 TMIs and analyzed using a breast density software, LIBRA.

Main Outcomes and Measures

The first outcome was the association of duration of TT and breast tissue composition assessed by pathologists (categories of lobular atrophy and stromal composition) or by our algorithm (% epithelium, % fibrous stroma, and % fat). The second outcome is the association of TT and breast density as assessed by a radiologist (categorical variable) or by LIBRA (percent density, absolute dense area, and absolute non-dense area).

Results

Length of TT was associated with increasing degrees of lobular atrophy ( p <0.001) but not fibrous content ( p =0.821) when assessed by the pathologists. Every six months of TT was associated with decreased amounts of both epithelium (exp(β)=0.97, 95% CI 0.95-0.98, adj p =0.005) and stroma (exp(β)=0.99, 95% CI 0.98-1.00, adj p =0.051), but not fat (exp(β)=1.01, 95%CI 0.98-1.05, p =0.394) in fully adjusted models. There was no association between TT and radiologist's breast density assessment ( p =0.575) or LIBRA measurements ( p >0.05).

Conclusions

TT decreases breast epithelium and fibrous stroma, thus potentially reducing the breast cancer risk of TMIs. Further studies are warranted to elucidate the effect of TT on breast density and breast cancer risk.

Summary Box

Very little is known about the effect of gender-affirming testosterone therapy on cancer risks, such as breast cancer.Epidemiological studies had different conclusions about the association between testosterone and breast cancer in cisgender women (positive association) and trans masculine individuals (inverse association).More laboratory-based research are needed to understand the effect of testosterone on breast cancer risk in the understudied trans masculine population.Our study provides quantitative histological evidence to support prior epidemiological reports that testosterone may reduce breast cancer risk in trans masculine individuals.

Associations of stem cell markers in benign breast tissue with subsequent breast cancer risk

We examined associations of stem cell markers CD44, CD24, and ALDH1A1 in benign breast biopsy samples with subsequent breast cancer (BCa) risk and explored if these associations were mediated by mammographic breast density (MBD). We included 101 BCa cases/375 controls, all with previous biopsy-confirmed benign breast disease (BBD) within the Nurses' Health Study (NHS) and NHSII. The data on BCa risk factors were obtained from biennial questionnaires. MBD was assessed with computer-assisted techniques. Immunohistochemistry (IHC) was done on BBD tissue microarrays. For each core, the IHC expression was assessed using a semi-automated method, and expressed as % of cells that stained positive for a specific marker out of the total cell count. Logistic regression was used to examine the associations of each marker's expression of each (in epithelium and stroma) with BCa risk, adjusted for risk factors. Stromal CD44 expression was inversely associated with BCa risk (OR for ≥10% vs. <10%=0.58, 95% CI 0.34, 1.00). Combined stromal + epithelial CD24 expression was inversely associated with BCa risk (>50% vs. 0-10% OR=0.17, 95% CI 0.04-0.81, p-trend =0.03). Stromal CD24 and ALDH1A1 as well as epithelial expression of any of the three markers were not associated with BCa risk. In a smaller subset of women with available MBD, these observed associations did not appear to be mediated by MBD. Our findings suggest inverse associations of CD44 in stroma and combined stromal + epithelial CD24 with BCa risk. Future studies are warranted to confirm our findings and to examine these associations by BBD subtype.

Associations of gut microbiome with endogenous estrogen levels in healthy postmenopausal women

PURPOSE

The gut microbiome is a potentially important contributor to endogenous estrogen levels after menopause. In healthy postmenopausal women, we examined associations of fecal microbiome composition with levels of urinary estrogens, their metabolites, and relevant metabolic pathway ratios implicated in breast cancer risk.

METHODS

Eligible postmenopausal women (n = 164) had a body mass index (BMI) ≤ 35 kg/m2 and no history of hormone use (previous 6 months) or cancer/metabolic disorders. Estrogens were quantified in spot urine samples with liquid chromatography-high resolution mass spectrometry (corrected for creatinine). Bacterial DNA was isolated from fecal samples and the V1-V2 hypervariable regions of 16S rRNA were sequenced on the Illumina MiSeq platform. We examined associations of gut microbiome's indices of within-sample (alpha) diversity (i.e., Shannon, Chao1, and Inverse Simpson), phylogenetic diversity, and the ratio of the two main phyla (Firmicutes and Bacteroidetes; F/B ratio) with individual estrogens and metabolic ratios, adjusted for age and BMI.

RESULTS

In this sample of 164 healthy postmenopausal women, the mean age was 62.9 years (range 47.0-86.0). We found significant inverse associations of observed species with 4-pathway:total estrogens (p = 0.04) and 4-pathway:2-pathway (p = 0.01). Shannon index was positively associated with 2-catechols: methylated 2-catechols (p = 0.04). Chao1 was inversely associated with E1:total estrogens (p = 0.04), and 4-pathway:2-pathway (p = 0.02) and positively associated with 2-pathway:parent estrogens (p = 0.01). Phylogenetic diversity was inversely associated with 4-pathway:total estrogens (p = 0.02), 4-pathway:parent estrogens (p = 0.03), 4-pathway:2-pathway (p = 0.01), and 4-pathway:16-pathway (p = 0.03) and positively associated with 2-pathway:parent estrogens (p = 0.01). F/B ratio was not associated with any of the estrogen measures.

CONCLUSION

Microbial diversity was associated with several estrogen metabolism ratios implicated in breast cancer risk. Further studies are warranted to confirm these findings in a larger and more representative sample of postmenopausal women, particularly with enrichment of minority participants.

mTOR pathway candidate genes and energy intake interaction on breast cancer risk in Black women from the Women's Circle of Health Study

BACKGROUND

Excessive energy intake has been shown to affect the mammalian target of the rapamycin (mTOR) signaling pathway and breast cancer risk. It is not well understood whether there are gene-environment interactions between mTOR pathway genes and energy intake in relation to breast cancer risk.

METHODS

The study included 1642 Black women (809 incident breast cancer cases and 833 controls) from the Women's Circle of Health Study (WCHS). We examined interactions between 43 candidate single-nucleotide polymorphisms (SNPs) in 20 mTOR pathway genes and quartiles of energy intake in relation to breast cancer risk overall and by ER- defined subtypes using Wald test with a 2-way interaction term.

RESULTS

AKT1 rs10138227 (C > T) was only associated with a decreased overall breast cancer risk among women in quartile (Q)2 of energy intake, odds ratio (OR) = 0.60, 95% confidence interval (CI) 0.40, 0.91 (p-interaction = 0.042). Similar results were found in ER- tumors. AKT rs1130214 (C > A) was associated with decreased overall breast cancer risk in Q2 (OR = 0.63, 95% CI 0.44, 0.91) and Q3 (OR = 0.65, 95% CI 0.48, 0.89) (p-interaction = 0.026). HIF-1α C1772T rs11549465 (C > T) was associated with decreased overall breast cancer risk in Q4 (OR = 0.29, 95% CI 0.14, 0.59, p-interaction = 0.007); the results were similar in ER+ tumors. These interactions became non-significant after correction for multiple comparisons.

CONCLUSION

Our findings suggest that mTOR genetic variants may interact with energy intake in relation to breast cancer risk, including the ER- subtype, in Black women. Future studies should confirm these findings.

Association of air pollution with postmenopausal breast cancer risk in UK Biobank

BACKGROUND

We investigated the association of several air pollution measures with postmenopausal breast cancer (BCa) risk.

METHODS

This study included 155,235 postmenopausal women (of which 6146 with BCa) from UK Biobank. Cancer diagnoses were ascertained through the linkage to the UK National Health Service Central Registers. Annual exposure averages were available from 2005, 2006, 2007, and 2010 for NO2, from 2007 and 2010 for PM10, and from 2010 for PM2.5, NOX, PM2.5-10 and PM2.5 absorbance. Information on BCa risk factors was collected at baseline. Cox proportional hazards regression was used to evaluate the associations of year-specific and cumulative average exposures with BCa risk, overall and with 2-year exposure lag, while adjusting for BCa risk factors.

RESULTS

PM10 in 2007 and cumulative average PM10 were positively associated with BCa risk (2007 PM10: Hazard ratio [HR] per 10 µg/m3 = 1.18, 95% CI 1.08, 1.29; cumulative average PM10: HR per 10 µg/m3 = 1.99, 95% CI 1.75, 2.27). Compared to women with low exposure, women with higher 2007 PM10 and cumulative average PM10 had greater BCa risk (4th vs. 1st quartile HR = 1.15, 95% CI 1.07, 1.24, p-trend = 0.001 and HR = 1.35, 95% CI 1.25, 1.44, p-trend < 0.0001, respectively). No significant associations were found for any other exposure measures. In the analysis with 2-year exposure lag, both 2007 PM 10 and cumulative average PM10 were positively associated with BCa risk (4th vs. 1st quartile HR = 1.19, 95% CI 1.10, 1.28 and HR = 1.29, 95% CI 1.19, 1.39, respectively).

CONCLUSION

Our findings suggest a positive association of 2007 PM10 and cumulative average PM10 with postmenopausal BCa risk.

mTOR pathway candidate genes and physical activity interaction on breast cancer risk in black women from the women's circle of health study

BACKGROUND

Physical activity has been shown to affect the mammalian target of rapamycin (mTOR) signaling pathway and consequently breast carcinogenesis. Given that Black women in the USA are less physically active, it is not well understood whether there are gene-environment interactions between mTOR pathway genes and physical activity in relation to breast cancer risk in Black women.

METHODS

The study included 1398 Black women (567 incident breast cancer cases and 831 controls) from the Women's Circle of Health Study (WCHS). We examined interactions between 43 candidate single-nucleotide polymorphisms (SNPs) in 20 mTOR pathway genes with levels of vigorous physical activity in relation to breast cancer risk overall and by ER-defined subtypes using Wald test with 2-way interaction term and multivariable logistic regression.

RESULTS

AKT1 rs10138227 (C > T) and AKT1 rs1130214 (C > A) were only associated with a decreased risk of ER + breast cancer among women with vigorous physical activity (odds ratio [OR] = 0.15, 95% confidence interval (CI) 0.04, 0.56, for each copy of the T allele, p-interaction = 0.007 and OR = 0.51, 95% CI 0.27, 0.96, for each copy of the A allele, p-interaction = 0.045, respectively). MTOR rs2295080 (G > T) was only associated with an increased risk of ER + breast cancer among women with vigorous physical activity (OR = 2.24, 95% CI 1.16, 4.34, for each copy of the G allele; p-interaction = 0.043). EIF4E rs141689493 (G > A) was only associated with an increased risk of ER- breast cancer among women with vigorous physical activity (OR = 20.54, 95% CI 2.29, 184.17, for each copy of the A allele; p-interaction = 0.003). These interactions became non-significant after correction for multiple testing (FDR-adjusted p-value > 0.05).

CONCLUSION

Our findings suggest that mTOR genetic variants may interact with physical activity in relation to breast cancer risk in Black women. Future studies should confirm these findings.

mTOR pathway candidate genes and obesity interaction on breast cancer risk in black women from the Women's Circle of Health Study

BACKGROUND

Obesity is known to stimulate the mammalian target of rapamycin (mTOR) signaling pathway and both obesity and the mTOR signaling pathway are implicated in breast carcinogenesis. We investigated potential gene-environment interactions between mTOR pathway genes and obesity in relation to breast cancer risk among Black women.

METHODS

The study included 1,655 Black women (821 incident breast cancer cases and 834 controls) from the Women's Circle of Health Study (WCHS). Obesity measures including body mass index (BMI); central obesity i.e., waist circumference (WC) and waist/hip ratio (WHR); and body fat distribution (fat mass, fat mass index and percent body fat) were obtained by trained research staff. We examined the associations of 43 candidate single-nucleotide polymorphisms (SNPs) in 20 mTOR pathway genes with breast cancer risk using multivariable logistic regression. We next examined interactions between these SNPs and measures of obesity using Wald test with 2-way interaction term.

RESULTS

The variant allele of BRAF (rs114729114 C > T) was associated with an increase in overall breast cancer risk [odds ratio (OR) = 1.81, 95% confidence interval (CI) 1.10-2.99, for each copy of the T allele] and the risk of estrogen receptor (ER)-defined subtypes (ER+ tumors: OR = 1.83, 95% CI 1.04,3.29, for each copy of the T allele; ER- tumors OR = 2.14, 95% CI 1.03,4.45, for each copy of the T allele). Genetic variants in AKT, AKT1, PGF, PRKAG2, RAPTOR, TSC2 showed suggestive associations with overall breast cancer risk and the risk of, ER+ and ER- tumors (range of p-values = 0.040-0.097). We also found interactions of several of the SNPs with BMI, WHR, WC, fat mass, fat mass index and percent body fat in relation to breast cancer risk. These associations and interactions, however, became nonsignificant after correction for multiple testing (FDR-adjusted p-value > 0.05).

CONCLUSION

We found associations between mTOR genetic variants and breast cancer risk as well as gene and body fatness interactions in relation to breast cancer risk. However, these associations and interactions became nonsignificant after correction for multiple testing. Future studies with larger sample sizes are required to confirm and validate these findings.

Abstract 4216: Interactions of greenness with air pollution in relation to postmenopausal breast cancer risk in UK Biobank

Purpose: The evidence of the association between natural vegetation, or greenness, and breast cancer (BCa) remains inconsistent, with some studies reporting possible interactions with air pollution. We previously found a positive association of particulate matter with diameters than are 10 micrometers or smaller (PM10) with BCa risk among postmenopausal women in the UK Biobank. In this study, we investigated the associations of greenness with postmenopausal BCa risk, as well as whether association of PM10 with BCa differ by the level of greenness.

Methods: This study included 155,235 postmenopausal women (6,146 with BCa) from UK Biobank, a population-based prospective cohort. Cancer diagnoses were ascertained through the linkage to the UK National Health Service Central Registers. Greenness measures (Greenspace percentage [GP], Natural environment percentage [NEP], and the Normalized Difference Vegetation Index [NDVI]) were available at baseline assessment (2006 -2010). GP and NEP coverage were calculated at 300 m and 1000 m, respectively, around participant residence locations, while the mean NDVI was calculated within a 500 m residential buffer of each UK Biobank participant. Annual averages for PM10 were available from 2007 and 2010. Information on BCa risk factors was collected at baseline. We used Cox proportional hazards regression to evaluate associations between greenness (continuous as well as quartiles) and BCa risk, while adjusting for BCa risk factors. Next, we examined associations for year-specific and cumulative average PM10 exposure measures (per 5 µg/m3) within each stratum of greenness measure. Interactions between PM10 and greenness measures were assessed by including an interaction term in the main models.

Results: BCa risk increased by 29% per one unit increase in NDVI (Hazard ratio [HR]=1.29, 95% CI 1.03, 1.61). Compared to women in the lowest NDVI quartile, women with higher levels of NDVI had higher risk of BCa (HR=1.10, 95% CI 1.01, 1.21 for 2nd quartile, HR=1.10, 95% CI 1.00, 1.20 for 3rd quartile, and HR=1.13, 95% CI 1.04, 1.24 for 4th quartile, p-trend=0.012). No significant associations were found for any other greenness measure in relation to BCa risk. We found a significant interaction between NDVI and cumulative average PM10 exposure (p&lt;0.0001). The association of PM10 cumulative average with BCa risk was stronger at lower levels of NDVI (HR per 5 µg/m3=1.12, 95% CI 1.07, 1.17 for 1st quartile) compared to higher levels of NDVI (HR=1.04, 95% CI 1.02, 1.07 for 4th quartile). We found no interactions with other greenness measures.

Conclusions: We found a positive association of NDVI with BCa risk and an interaction between cumulative average PM10 and NDVI, with stronger positive association of cumulative average PM10 exposure with postmenopausal BCa risk at lower compared to higher levels of greenness.

Citation Format: Carmen Smotherman, Brian Sprague, Susmita Datta, Dejana Braithwaite, Huaizhen Qin, Lusine Yaghjyan. Interactions of greenness with air pollution in relation to postmenopausal breast cancer risk in UK Biobank. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4216.

Associations of alcohol consumption with breast tissue composition

BACKGROUND

We investigated the associations of alcohol with percentage of epithelium, stroma, fibroglandular tissue (epithelium + stroma), and fat in benign breast biopsy samples.

METHODS

We 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.

RESULTS

Alcohol 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.

CONCLUSION

Our 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

Background

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.

Methods

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).

Results

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.

Conclusion

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.

Associations of coffee/caffeine consumption with postmenopausal breast cancer risk and their interactions with postmenopausal hormone use

PURPOSE

We investigated the association of coffee and caffeine with breast cancer (BCa) risk, overall and by ER/PR status. We also examined potential interactions of coffee and caffeine with postmenopausal hormone use.

METHODS

Our study included 77,688 postmenopausal participants from the Women's Health Initiative observational study cohort without a history of any cancer at baseline (except non-melanoma skin) and with valid Food Frequency Questionnaire data and complete data on dietary caffeine. Regular coffee (none, 1, 2-3, 4-5, and ≥ 6 cups/day) and caffeine (tertiles) were assessed at baseline. Information on BCa risk factors was collected at baseline. The associations were examined using survival analysis, accounting for death as a competing risk.

RESULTS

The median follow-up time for our cohort was 18.3 years. During the follow-up, 5005 women developed invasive breast cancer. In multivariable analysis, coffee was not associated with the overall invasive BCa risk. Higher caffeine intake was mildly associated with increased BCa risk (2nd vs. 1st tertile SHR = 1.10, 95% CI 1.03-1.18, 3rd vs. 1st tertile SHR-1.05, 95% CI 0.98-1.13, overall p = 0.03). We found no interaction of coffee/caffeine with postmenopausal hormone use (p interaction = 0.44 and 0.42, respectively). In the exploratory analysis by ER/PR status, we found a positive association of caffeine with ER+ /PR+ BCa (2nd vs. 1st tertile SHR = 1.17, 95% CI 1.07-1.28, 3rd vs. 1st tertile SHR = 1.13, 95% CI 1.03-1.24, overall p = 0.002); no associations were observed for ER-/PR- tumors. Coffee was not associated with the risk of ER+ /PR+ or ER-/PR- tumors.

CONCLUSION

We found no associations of coffee with BCa risk, overall and for ER/PR-defined tumor subtypes. The higher caffeine consumption was mildly and positively associated with the overall BCa risk and with ER+ /PR+ tumors.

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

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-&lt;5, and ≥5 g/day; non-drinkers, &lt;11 g/day [&lt;1 drink/day], 11-&lt;22g/day [1-&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 aspirin and other anti-inflammatory medications with breast cancer risk by the status of COX-2 expression

BACKGROUND

We investigated the associations of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) with breast cancer risk by the status of COX-2 protein expression.

METHODS

This study included 421 cases and 3,166 controls from a nested case-control study within the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII) cohorts. Information on medication use was first collected in 1980 (NHS) and 1989 (NHSII) and was updated biennially. Medication use was defined as none, past or current; average cumulative dose and frequency were calculated for all past or current users using data collected from all biannual questionnaires preceding the reference date. Immunochemistry for COX-2 expression was performed using commercial antibody (Cayman Chemical and Thermo Fisher Scientific). We used polychotomous logistic regression to quantify associations of aspirin and NSAIDs with the risk of COX2+ and COX2- breast cancer tumors, while adjusting for known breast cancer risk factors. All tests of statistical significance were two-sided.

RESULTS

In multivariate analysis, we found no differences in associations of the aspirin exposures and NSAIDs with breast cancer risk by COX2 expression status. In stratified analyses by COX2 status, significant associations of these medications with breast cancer risk were observed for dosage of aspirin among current users in COX2- tumors (OR for > 5 tablets per week vs. none 1.71, 95% CI 1.01-2.88, p-trend 0.04). Regular aspirin use was marginally associated with the risk of COX2- tumors (p-trend = 0.06).

CONCLUSIONS

Our findings suggested no differences in associations of aspirin and other NSAIDs with COX2+ and COX2- tumors.

Associations of Oral Contraceptives with Mammographic Breast Density in Premenopausal Women

BACKGROUND

We investigated the associations of oral contraceptives (OC) with percent breast density (PD), absolute dense area (DA), nondense area (NDA), and a novel image intensity variation (V) measure in premenopausal women.

METHODS

This study included 1,233 controls from a nested case-control study within Nurses' Health Study II cohort. Information on OCs was collected in 1989 and updated biennially. OC use was defined from the questionnaire closest to the mammogram date. PD, DA, and NDA were measured from digitized film mammograms using a computer-assisted thresholding technique; the V measure was obtained with a previously developed algorithm measuring the SD of pixel values in the eroded breast region. Generalized linear regression was used to assess associations between OCs and density measures (square root-transformed PD, DA, and NDA, and -untransformed V).

RESULTS

OC use was not associated with PD [current vs. never: β = -0.06; 95% confidence interval (CI), -0.37-0.24; past vs. never: β = 0.10; 95% CI, -0.09-0.29], DA (current vs. never: β = -0.20; 95% CI -0.59-0.18; past vs. never: β = 0.13; 95% CI, -0.12-0.39), and NDA (current vs. never: β = -0.19; 95% CI, -0.56-0.18; past vs. never: β = -0.01; 95% CI, -0.28-0.25). Women with younger age at initiation had significantly greater V-measure (<20 years vs. never: β = 26.88; 95% CI, 3.18-50.58; 20-24 years vs. never: β = 20.23; 95% CI, -4.24-44.71; 25-29 years vs. never: β = 2.61; 95% CI -29.00-34.23; ≥30 years vs. never: β = 0.28; 95% CI, -34.16-34.72, P _trend = 0.03).

CONCLUSIONS

Our findings suggest that an earlier age at first OC use was associated with significantly greater V.

IMPACT

These findings could guide decisions about the age for OC initiation.

Associations of reproductive breast cancer risk factors with breast tissue composition

Background

We investigated the associations of reproductive factors with the 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. 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.

Results

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, 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.

Conclusions

Our 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01447-2.

Gut microbiome, body weight, and mammographic breast density in healthy postmenopausal women

PURPOSE

We examined gut microbiome (GM) profiles in relation to mammographic breast density (BD) and body mass index (BMI) in healthy postmenopausal women.

METHODS

Eligible women were postmenopausal, had a BMI ≤ 35 kg/m², and had not recently taken oral/IV antibiotics. All women provided a fecal sample and information on breast cancer risk factors. Mammographic BD was classified with the American College of Radiology's BI-RADS BD classification system. Bacterial DNA was isolated from fecal samples and the V1-V2 hypervariable regions of 16S rRNA were sequenced on the Illumina MiSeq platform. We examined associations of GM with indices of within-sample (alpha) diversity and the ratio of the two main phyla (Firmicutes and Bacteroidetes; F/B ratio) with BD and BMI.

RESULTS

Among 69 women with BD data, 39 had low BD (BI-RADS I/II) and 30 had high BD (BI-RADS III/IV). BMI was inversely associated with BD (mean BMI = 23.8 and 28.0 in women with high and low BD, respectively, p = 1.07 × 10^-5). Similar levels of GM diversity were found across weight groups according to Shannon (p = 0.83); Inverse Simpson (p = 0.97); and Chao1 (p = 0.31) indices. F/B ratio and microbiota diversity were suggestively greater in women with high vs. low BD (p = 0.35, 0.14, 0.15, and 0.17 for F/B ratio, Shannon, Inverse Simpson and Chao1, respectively).

CONCLUSION

Suggestive differences observed in women with high and low BD with respect to GM alpha diversity and prevalence of specific GM taxa need to be confirmed in larger studies.

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

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.

Association of Interactions Between Mammographic Density Phenotypes and Established Risk Factors With Breast Cancer Risk, by Tumor Subtype and Menopausal Status

Previous studies suggest that the association between mammographic density (MD) and breast cancer risk might be modified by other breast cancer risk factors. In this study, we assessed multiplicative interactions between MD measures and established risk factors on the risk of invasive breast cancer overall and according to menopausal and estrogen receptor status. We used data on 2,137 cases and 4,346 controls from a nested case-control study within the Nurses' Health Study (1976-2004) and Nurses' Health Study II (1989-2007), whose data on percent mammographic density (PMD) and absolute area of dense tissue and nondense tissue (NDA) were available. No interaction remained statistically significant after adjusting for number of comparisons. For breast cancer overall, we observed nominally significant interactions (P < 0.05) between nulliparity and PMD/NDA, age at menarche and area of dense tissue, and body mass index and NDA. Individual nominally significant interactions across MD measures and risk factors were also observed in analyses stratified by either menopausal or estrogen receptor status. Our findings help provide further insights into potential mechanisms underlying the association between MD and breast cancer.

Early-Life and Adult Adiposity, Adult Height, and Benign Breast Tissue Composition

BACKGROUND

Early-life and adult anthropometrics are associated with breast density and breast cancer risk. However, little is known about whether these factors also influence breast tissue composition beyond what is captured by breast density among women with benign breast disease (BBD).

METHODS

This analysis included 788 controls from a nested case-control study of breast cancer within the Nurses' Health Study BBD subcohorts. Body fatness at ages 5 and 10 years was recalled using a 9-level pictogram. Weight at age 18, current weight, and height were reported via questionnaires. A deep-learning image analysis was used to quantify the percentages of epithelial, fibrous stromal, and adipose tissue areas within BBD slides. We performed linear mixed models to estimate beta coefficients (β) and 95% confidence intervals (CI) for the relationships between anthropometrics and the log-transformed percentages of individual tissue type, adjusting for confounders.

RESULTS

Childhood body fatness (level ≥ 4.5 vs. 1), BMI at age 18 (≥23 vs. <19 kg/m²), and current adult BMI (≥30 vs. <21 kg/m²) were associated with higher proportions of adipose tissue [β (95% CI) = 0.34 (0.03, 0.65), 0.19 (-0.04-0.42), 0.40 (0.12, 0.68), respectively] and lower proportions of fibrous stromal tissue [-0.05 (-0.10, 0.002), -0.03 (-0.07, 0.003), -0.12 (-0.16, -0.07), respectively] during adulthood (all P _trend < 0.04). BMI at age 18 was also inversely associated with epithelial tissue (P _trend = 0.03). Adult height was not associated with any of the individual tissue types.

CONCLUSIONS

Our data suggest that body fatness has long-term impacts on breast tissue composition.

IMPACT

This study contributes to our understanding of the link between body fatness and breast cancer risk.See related commentary by Oskar et al., p. 590.

Association of Adipose Tissue Distribution With Type 2 Diabetes in Breast Cancer Patients

PURPOSE

We examined the association of adipose tissue distribution with type 2 diabetes (T2D) in breast cancer patients.

METHODS

Participants (N = 238) diagnosed with breast cancer at 20-75 years old who received breast cancer treatment at a major hospital from January 1, 2012, to December 31, 2017, with at least one completed and identifiable abdominal or pelvic computed tomography (CT) scan and data regarding race and ethnicity were included. Thirty-two breast cancer patients were identified as T2D patients after their breast cancer diagnoses. The adipose tissue distribution (visceral fat area [VFA], subcutaneous fat area [SFA], and the ratio of VFA to SFA [VFA/SFA]) was quantified on CT images of the third lumbar vertebra. T2D status was retrieved from patients' electronic medical records. The association of adipose tissue distribution with T2D in women with breast cancer was examined using multivariable logistic regression.

RESULTS

Participants with T2D had significantly smaller SFA compared to those without T2D (odds ratio [OR] = 0.88, 95% confidence interval [95% CI] = 0.81-0.96, per 10 cm2 SFA). A positive association of VFA/SFA ratio with T2D was observed (OR = 19.57, 95% CI = 3.26-117.42, per unit VFA/SFA), although the estimate was imprecise.

CONCLUSIONS

The amount of subcutaneous adipose tissue was inversely associated with T2D, and the ratio of the amount of visceral adipose tissue to the amount of subcutaneous adipose tissue was positively associated with T2D in breast cancer patients.

Risk factors for delayed viral suppression on first-line antiretroviral therapy among persons living with HIV in Haiti, 2013-2017

Studies of viral suppression on first-line antiretroviral therapy (ART) in persons living with human immunodeficiency virus (PLHIV) in Haiti are limited, particularly among PLHIV outside of the Ouest department, where the capital Port-au-Prince is located. This study described the prevalence and risk factors for delayed viral suppression among PLHIV in all geographic departments of Haiti between 2013 and 2017. Individuals who received viral load testing 3 to 12 months after ART initiation were included. Data on demographics and clinical care were obtained from the Haitian Active Longitudinal Tracking of HIV database. Multivariable logistic regression was performed to predict delayed viral suppression, defined as a viral load ≥1000 HIV-1 RNA copies/mL after at least 3 months on ART. Viral load test results were available for 3,368 PLHIV newly-initiated on ART. Prevalence of delayed viral suppression was 40%, which is slightly higher than previous estimates in Haiti. In the multivariable analysis, delayed viral suppression was significantly associated with younger age, receiving of care in the Ouest department, treatment with lamivudine (3TC), zidovudine (AZT), and nevirapine (NVP) combined ART regimen, and CD4 counts below 200 cells/mm³. In conclusion, this study was the first to describe and compare differences in delayed viral suppression among PLHIV by geographic department in Haiti. We identified populations to whom public health interventions, such as more frequent viral load testing, drug resistance testing, and ART adherence counseling should be targeted.

LC-HRMS of derivatized urinary estrogens and estrogen metabolites in postmenopausal women

In order to undertake an epidemiologic study relating levels of parent estrogens (estrone and estradiol) and estrogen metabolites (EMs) to other breast cancer risk factors, we have optimized methods for EM quantification with ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). A two-step approach was adopted; the first step comprised method development and evaluation of the method performance. The second step consisted of applying this method to quantify estrogens in postmenopausal women and determine if the observed patterns are consistent with the existing literature and prior knowledge of estrogen metabolism. First, 1-methylimidazole-2-sulfonyl chloride (MIS) was used to derivatize endogenous estrogens and estrogen metabolites in urine from study participants. Since C18 reversed phase columns have not been able to separate all the structurally related EMs, we used a C18-pentafluorophenyl (PFP) column. The parent estrogens and EMs were baseline resolved with distinct retention times on this C18-PFP column using a 30 min gradient. This method was used to quantify the parent estrogens and 13 EMs in urine samples collected in an initial pilot study involving males as well as pre- and peri-menopausal females to assess a range of EM levels in urine samples and enable comparison to the previous literature for assay evaluation. Detection limits ranged from 1 - 20 pg/mL depending on the EM. We evaluated matrix effects and interference as well as the intra- and inter-batch reproducibility including hydrolysis, extraction, derivatization and LC-MS analysis using charcoal-stripped human urine as a matrix. Methods were then applied to the measurement of estrogens in urine samples from 169 postmenopausal women enrolled in an epidemiological study to examine relationships between breast cancer risk, the intestinal microbiome, and urinary EMs. The results from our cohort are comparable to previous reports on urinary EMs in postmenopausal women and enabled thorough evaluation of the method.

Associations of aspirin and other anti-inflammatory medications with mammographic breast density and breast cancer risk

PURPOSE

We investigated the associations of aspirin and other non-steroid anti-inflammatory drugs with mammographic breast density (MBD) and their interactions in relation to breast cancer risk.

METHODS

This study included 3,675 cancer-free women within the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII) cohorts. Percent breast density (PD), absolute dense area (DA), and non-dense area (NDA) were measured from digitized film mammograms using a computer-assisted thresholding technique; all measures were square root-transformed. Information on medication use was collected in 1980 (NHS) and 1989 (NHSII) and updated biennially. Medication use was defined as none, past or current; average cumulative dose and frequency were calculated for all past or current users from all bi-annual questionnaires preceding the mammogram date. We used generalized linear regression to quantify associations of medications with MBD. Two-way interactions were examined in logistic regression models.

RESULTS

In multivariate analysis, none of the anti-inflammatory medications were associated with PD, DA, and NDA. We found no interactions of any of the medications with PD with respect to breast cancer risk (all p-interactions > 0.05). However, some of the aspirin variables appeared to have positive associations with breast cancer risk limited only to women with PD 10-24% (past aspirin OR 1.56, 95% CI 1.03-2.35; current aspirin with < 5 years of use OR 1.82, 95% CI 1.01-3.28; current aspirin with ≥ 5 years of use OR 1.89, 95% CI 1.26-2.82).

CONCLUSIONS

Aspirin and NSAIDs are not associated with breast density measures. We found no interactions of aspirin with MBD in relation to breast cancer risk.

Abstract B31: Microbiota composition in bilateral healthy breast tissue and breast tumors

Purpose: The purpose of this pilot study was to assess the differences in breast tissue microbiota composition by breast side (left versus right) within an individual woman and compare the microbiota of healthy and breast tumor tissue between women. We further aimed to determine whether certain bacterial taxa may be associated with breast tumors.

Methods: Bilateral healthy breast tissue samples (n=36) were collected from ten women who received routine mammoplasty procedures at the University of Florida Department of Surgery. Archived breast tumor samples (n=10) were obtained from an established biorepository. Bacterial DNA was extracted from tissues, amplified via polymerase chain reaction (PCR), and sequenced on the Illumina MiSeq platform. Microbiota data were analyzed using QIIME and RStudio.

Results: The most abundant phyla in both tumor and healthy tissues were Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. A total of 38 operational taxonomic units (OTUs) were found to be significantly different in terms of differential abundance between tumor and healthy tissues (absolute effect size range: 0.761-3.98). The OTUs with the largest absolute effect size associated with higher relative abundance in breast tumors were of Flavobacterium species (R2=3.98), Acinetobacter species (R2=3.64), [Mogibacteriaceae] family (R2=3.34), and Clostridiales order (R2=3.21). Alpha diversity (Shannon Diversity Index) was similar in healthy and tumor tissue (4.98 vs. 4.84; p=0.350). Based on unweighted UniFrac measures, breast tumor samples clustered distinctly from healthy samples (R2=0.10; p=0.001). Microbiota composition in healthy samples clustered within women (R2=0.20; p=0.012) and by breast side (left or right) within a woman (R2=0.36; p=0.001).

Conclusion: We identified significant differences in microbiota composition between women and between breasts of the same woman. These results warrant further investigation to elucidate the potential relationship between breast tissue microbiota and breast cancer.

Citation Format: Emily M. Klann, Jessica M. Williamson, Massimiliano S. Tagliamonte, Maria Ukhanova, Jaya Ruth Asirvatham, Harvey Chim, Lusine Yaghjyan, Volker Mai. Microbiota composition in bilateral healthy breast tissue and breast tumors [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr B31.

Abstract A23: Association of gut microbiome diversity with obesity and breast density in postmenopausal women

Purpose: The plausible roles of the gut microbiome (GM) in obesity as well as breast cancer have been discussed in recent reviews. The associations of GM with mammographic breast density (BD), a well-established strong breast cancer risk factor, also associated with body mass index (BMI), are poorly studied. We examined GM profiles in relation to BD and BMI in a sample of healthy postmenopausal women.

Methods: Women were recruited in mammography clinics at Moffitt Cancer Center and via recruitment announcements at the University of Florida. Eligible women were postmenopausal, had a BMI ≤35 kg/m2, and had not taken oral/IV antibiotics within 30 days and/or more than two separate antibiotic regimens within the previous three months. All women provided a fecal sample and comprehensive information on breast cancer risk factors including body weight and height. Mammographic BD was available for 69 women recruited at Moffitt and was classified according to the American College of Radiology’s BI-RADS BD classification system. For this analysis, BD was dichotomized as low (BI-RADS I or II) or high (BI-RADS III and IV). DNA was isolated from fecal samples and the V1-V2 hypervariable regions of 16S rRNA amplified using barcoded primers for sequencing on the Illumina MiSeq platform. Chao1, Inverse Simpson, and Shannon indices were used to classify within sample diversity. The two-sample Wilcoxon test was used to examine associations of GM with BD and BMI. Associations were also examined according to the ratio of the two main phyla in the human GM (Firmicutes and Bacteroidetes; F/B ratio) that has been linked to obesity in previous studies.

Results: Among 69 women with BD data, 39 had low BD and 30 had high BD. BMI was inversely associated with BD (mean BMI=23.8 in women with high BD and BMI=28.0 in women with low BD, p=1.07 × 10-5). The F/B ratio was not associated with BMI (median F/B ratio=0.90, 0.84, and 0.96 for normal weight, overweight, and obesity, respectively, p=0.57). Similar levels of diversity were found across weight groups according to the Shannon (4.05, 3.97, and 3.96, respectively, p=0.83); inverse Simpson (20.6, 20.1, and 19.3, respectively, p=0.97); and chao1 (433, 441, and 419, respectively, p=0.31) indices. F/B ratio and microbiota diversity were both suggestively greater in women with high vs. low BD (median F/B ratio=1.15 for high and 0.94 for low BD, p=0.35; Shannon index: 4.24 for high and 4.15 for low BD, p=0.14; inverse Simpson= 25.3 for high and 21.0 for low BD, p=0.15; chao1= 519 for high and 429 for low BD, p=0.17). Highest levels of alpha diversity were observed in women who had both high BD and low BMI. Taxonomic families that distinguished women with high vs. low BD included Ruminococcaceae, Mogibacteriaceae, Bacteroidaceae, Lachnospiraceae, Christensenellaceae, and Coriobacteriaceae.

Conclusion: Results suggest that women with high and low BD may differ with respect to GM alpha diversity and GM composition.

Citation Format: Lusine Yaghjyan, Xuefeng Wang, Maria Ukhanova, Yessica Martinez, Shannan Rich, Volker Mai, Kathleen Egan. Association of gut microbiome diversity with obesity and breast density in postmenopausal women [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr A23.

Uterine cancer in breast cancer survivors: a systematic review

PURPOSE

Epidemiological evidence on the risk factors for uterine/endometrial cancer in breast cancer (BCa) survivors is limited and inconsistent. Therefore, we critically reviewed and summarized available evidence related to the risk factors for uterine/endometrial cancer in BCa survivors.

METHODS

We conducted a literature search through PubMed, Web of Science Core Collection/Cited Reference Search, as well as through manual searches of the bibliographies of the articles identified in electronic searches. We included in this review studies that were published up to November 30, 2018 that were accessible in full-text format and were published in English.

RESULTS

Of the 27 eligible studies, 96% had > 700 participants, 74% were prospective cohorts, 70% originated outside of the US, 44% reported as having pre-/postmenopausal women, and 26% reported having racially heterogeneous populations. Risk factors positively associated with uterine/endometrial cancer risk among BCa survivors included age at BCa diagnosis > 50 years, African American race, greater BMI/weight gain, and Tamoxifen treatment. For other lifestyle, reproductive and clinical factors, associations were either not significant (parity) or inconsistent (HRT use, menopausal status, smoking status) or had limited evidence (alcohol intake, family history of cancer, age at first birth, oral contraceptive use, age at menopause, comorbidities).

CONCLUSION

We identified several methodological concerns and limitations across epidemiological studies on potential risk factors for uterine/endometrial cancer in BCa survivors, including lack of details on uterine/endometrial cancer case ascertainment, varying and imprecise definitions of important covariates, insufficient adjustment for potential confounders, and small numbers of uterine/endometrial cancer cases in the overall as well as stratified analyses. Based on the available evidence, older age and higher body weight measures appear to be a shared risk factor for uterine/endometrial cancer in the general population as well as in BCa survivors. In addition, there is suggestive evidence that African American BCa survivors have a higher risk of uterine/endometrial cancer as compared to their White counterparts. There is also evidence that Tamoxifen contributes to uterine/endometrial cancer in BCa survivors. Given limitations of existing studies, more thorough investigation of these associations is warranted to identify additional preventive strategies needed for BCa survivors to reduce uterine/endometrial cancer risk and improve overall survival.

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.

Abstract 592: Associations of mammographic breast density with breast stem cell marker-defined breast cancer subtypes

Background: High mammographic breast density is a strong, well-established breast cancer risk factor. A recent study found increased expression of stem cell markers in the areas of high breast density, but, whether stem cells may explain high breast cancer risk due to high breast density is unknown. We investigated the association between breast density and the risk of breast cancer by the status of stem cell markers CD44, CD24, and ALDH1A1 in the tumor.

Methods: We included 223 postmenopausal women with primary invasive or in-situ breast cancer and 399 age-matched controls from Mayo Clinic Mammography Study. Percent breast density, absolute dense area and non-dense area were assessed using computer-assisted thresholding technique. Immunohistochemical analysis of the markers was performed on tumor tissue microarrays according to a standard protocol with commercial antibodies. Cases with positive staining (≥1% positively stained cells) on one or more cores were considered marker-positive. We used polychotomous logistic regression to quantify the associations of breast density measures with breast cancer risk by the status of each of the markers. Heterogeneity tests were conducted to compare the differences in associations by marker-defined tumor subtypes.

Results: Of the 223 cancers in the study, 182 (82%) were positive for CD44, 83 (37%) for CD24 and 52 (23%) for ALDH1A1. Associations of percent density were not significantly different across any of the marker-defined subtypes (density 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 absolute dense area and inverse associations of non-dense area with breast cancer risk were similar across marker-defined subtypes. Similar associations of breast density measures with breast cancer were seen when cancer subtypes were defined using combined marker expression status (none, one positive marker, or two and more positive markers).

Conclusions: We found no evidence of differential associations of breast density measures with breast cancer risk by the status of stem cell markers. However, our power was limited and further studies in larger study populations are warranted to confirm these associations in a larger sample.

Citation Format: Lusine Yaghjyan, Ashwini Esnakula, Christopher Scott, Akemi Wijayabahu, Matthew Jensen, Celine Vachon. Associations of mammographic breast density with breast stem cell marker-defined breast cancer subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 592.

Adolescent caffeine consumption and mammographic breast density in premenopausal women

PURPOSE

Previous studies suggest that coffee and caffeine intake may be associated with reduced breast cancer risk. To date, there is limited and inconsistent epidemiologic evidence for associations of adolescent diet with mammographic breast density, a strong and consistent predictor of breast cancer. We investigated the association of adolescent caffeine intake with mammographic density in premenopausal women.

METHODS

This study included 751 cancer-free women within the Nurses' Health Study II cohort. Percent breast density (PD), absolute dense (DA) and non-dense areas (NDA) were measured from digitized film mammograms using a computer-assisted thresholding technique; all measures were square root-transformed. Energy-adjusted adolescent caffeine intake was estimated using the data from a food frequency questionnaire. Information regarding breast cancer risk factors was obtained from questionnaires closest to the mammogram date. We used generalized linear regression to quantify associations of caffeine intake with breast density measures.

RESULTS

In multivariable analyses, adolescent caffeine intake was not associated with any of the density phenotypes (caffeine 4th vs. 1st quartile: β = - 1.27, 95% CI - 4.62; 2.09, p-trend = 0.55 for percent density; β = - 0.21, 95% CI - 0.76, 0.34, p-trend = 0.65 for absolute dense area, and β = 0.23, 95% CI - 0.28, 0.74, p-trend = 0.50 for non-dense area). Additional adjustment of the models for body mass index at age 18 resulted in attenuation of the risk estimates.

CONCLUSIONS

Our findings do not support the hypothesis that adolescent caffeine intake is associated with premenopausal mammographic breast density.

Interaction between frailty and sex on mortality after elective abdominal aortic aneurysm repair

BACKGROUND

Controversy exists surrounding gender outcome disparity and abdominal aortic aneurysm (AAA) repair. Previous reports have demonstrated worse outcomes for women undergoing open aneurysm repair (OAR); however, these differences are less evident with endovascular aneurysm repair (EVAR). Epidemiologic studies have documented that women score higher on most frailty assessment scales but paradoxically have longer life expectancy compared to men. The interaction of gender/frailty and the influence on outcomes and practice patterns surrounding EVAR and OAR is poorly described. This analysis characterizes the association of frailty/sex interactions on mortality as well as patient selection surrounding elective AAA repair in the Society for Vascular Surgery Vascular Quality Initiative.

METHODS

All elective infrarenal AAA (EVAR + OAR; 2003-2017) cases were queried from the Vascular Quality Initiative database. Each patient was assigned a previously published modified frailty index (mFI) score derived from comorbidity and preoperative functional status data. Cox proportional hazard models, adjusted for statistically significant covariates, including procedural complexity, determined associations within full models and sex-stratified models.

RESULTS

A total of 20,750 elective AAA cases were analyzed (EVAR 15,893 [77%]; OAR 4857 [23%]). Thirty-day mortality for EVAR and OAR was 0.7% (n = 115) and 3.5% (n = 169), respectively. Patients who died were significantly more likely to be older (EVAR, 78 vs 73 years; OAR, 74 vs 69 years; P < .0001), have larger AAA diameters (EVAR, 59 vs 56 mm; P = .005; OAR, 62 vs 59 mm; P = .001), higher mFI scores (EVAR, 3.2 vs 2.4; OAR, 3.1 vs 2.2; P < .0001), and be of female sex (EVAR hazard ratio = 1.66 [95% confidence interval, 1.10-2.52]; P = .007; OAR-1.43 [1.02-1.99]; P = .003). Significant differences in the gender distribution of frailty scores among EVAR patients were evident (mean mFI: male 2.42 vs female 2.34; P = .02), but no difference was detected for OAR (male 2.17 vs female 2.22; P = .38). The mFI was a strong independent predictor of mortality (30 days: EVAR hazard ratio = 1.36 [1.22-1.53] and OAR 1.46 [1.32-1.60]; 1 year: EVAR 1.32 [1.25-1.39] and OAR-1.38 [1.28-1.48]). There was no interaction between mFI and gender on the association with mortality. Across frailty strata, male patients were nearly twofold more likely to undergo either elective EVAR or OAR for an AAA below recommended minimum diameter thresholds (male, <5.5 cm; female, <5.0 cm). Greater mFI score did not alter OAR selection but was associated with less frequent EVAR of small AAA.

CONCLUSIONS

Given the strong association between frailty and postoperative mortality, mFI can be used as a predictive tool to aid in surgical planning of patients undergoing elective AAA repair. While mFI can predict postoperative mortality for both men and women, it does not account for the survival disparity between sexes, and further research is warranted to explain this difference. There appear to be significant gender differences in patient selection based on current Society for Vascular Surgery-endorsed treatment thresholds that may have important implications on the appropriateness of AAA care delivery nationally.

Continuous Rural-Urban Coding for Cancer Disparity Studies: Is It Appropriate for Statistical Analysis?

Background: The dichotomization or categorization of rural-urban codes, as nominal variables, is a prevailing paradigm in cancer disparity studies. The paradigm represents continuous rural-urban transition as discrete groups, which results in a loss of ordering information and landscape continuum, and thus may contribute to mixed findings in the literature. Few studies have examined the validity of using rural-urban codes as continuous variables in the same analysis. Methods: We geocoded cancer cases in north central Florida between 2005 and 2010 collected by Florida Cancer Data System. Using a linear hierarchical model, we regressed the occurrence of late stage cancer (including breast, colorectal, hematological, lung, and prostate cancer) on the rural-urban codes as continuous variables. To validate, the results were compared to those from using a truly continuous rurality data of the same study region. Results: In term of associations with late-stage cancer risk, the regression analysis showed that the use of rural-urban codes as continuous variables produces consistent outcomes with those from the truly continuous rurality for all types of cancer. Particularly, the rural-urban codes at the census tract level yield the closest estimation and are recommended to use when the continuous rurality data is not available. Conclusions: Methodologically, it is valid to treat rural-urban codes directly as continuous variables in cancer studies, in addition to converting them into categories. This proposed continuous-variable method offers researchers more flexibility in their choice of analytic methods and preserves the information in the ordering. It can better inform how cancer risk varies, degree by degree, over a finer spectrum of rural-urban landscape.

Healthy behavioral choices and cancer screening in persons living with HIV/AIDS are different by sex and years since HIV diagnosis

PURPOSE

The prevalence of non-AIDS-related malignancies is on the rise among people aging with HIV population, but the evidence on healthy behaviors including cancer screening practices in this population subgroup is extremely limited. Therefore, we investigated the prevalence of healthy behaviors and sex-specific cancer screening among persons living with HIV, by sex and time since HIV diagnosis.

METHODS

We included 517 persons living with HIV from the Florida Cohort. Data were obtained from the baseline and follow-up questionnaires, electronic medical records, and Enhanced HIV/AIDS Reporting System. The prevalence of self-reported, age-appropriate cancer screening (anal, colorectal, prostate, breast, and cervical), and healthy behaviors (sustaining healthy body weight, refraining from smoking and alcohol and engaging in physical activity) was compared by sex and years since HIV diagnosis (≤ 13 vs. > 13 years).

RESULTS

In the analyses by sex, females were more likely to be obese than males (56.5% vs. 22.2%, p < 0.0001). Distribution of healthy behaviors did not differ by time since diagnosis among males and females. In the analysis of age-appropriate screening among males, 64.8% never had an anal Pap-smear, 36.2% never had a colonoscopy, and 38.9% never had prostate cancer screening. In the analysis of age-appropriate screening among females, 50.0% never had an anal Pap-smear, 46.5% never had a colonoscopy, 7.9% never had a cervical Pap-smear, and 12.7% never had a mammogram. The difference in anal Pap-smear by sex was statistically significant (p < 0.0001). Among males, the age-adjusted prevalence of never having a colonoscopy was higher in those who had HIV for ≤ 13 years (50.8% vs. 30.6%, p = 0.03).

CONCLUSION

The prevalence of selected healthy behaviors and cancer screening differed by sex and/or years since HIV diagnosis suggesting a need for tailored cancer prevention efforts among persons living with HIV via long-term sex-specific interventions.

Effect of Hospitalizations on Physical Activity Patterns in Mobility-Limited Older Adults

OBJECTIVES

To evaluate the effect of hospitalizations on patterns of sedentary and physical activity time in mobility-limited older adults randomized to structured physical activity or health education.

DESIGN

Secondary analysis of investigator-blinded, parallel-group, randomized trial conducted at 8 U.S. centers between February 2010 and December 2013.

PARTICIPANTS

Sedentary men and women aged 70 to 89 at baseline who wore a hip-fitted accelerometer 7 consecutive days at baseline and 6, 12, and 24 months after randomization (N=1,341).

MEASUREMENTS

Participants were randomized to a physical activity (PA; n = 669) intervention that included aerobic, resistance, and flexibility training or to a health education (HE; n = 672) intervention that consisted of workshops on older adult health and light upper-extremity stretching. Accelerometer patterns were characterized as bouts of sedentary (<100 counts/min; ≥1, ≥10, ≥30, ≥60 minute lengths) and activity (≥100 counts/min; ≥1, ≥2, ≥5, ≥10 minute lengths) time. Each participant was categorized as having 0, 1 to 3, or 4 or more cumulative hospital days before each accelerometer assessment.

RESULTS

Hospitalization increased sedentary time similarly in both intervention groups (8 min/d for 1-3 cumulative hospital days and 16 min/d for ≥4 cumulative hospital days). Hospitalization was also associated with less physical activity time across all bouts of less than 10 minutes (≥1: -7 min/d for 1-3 cumulative hospital days, -16 min/d for ≥4 cumulative hospital days; ≥2: -5 min/d for 1-3 cumulative hospital days, -11 min/d for ≥4 cumulative hospital days; ≥5: -3 min/d for 1-3 cumulative hospital days, -4 min/d for ≥4 cumulative hospital days). There was no evidence of recovery to prehospitalization levels (time effect p >.41). PA participants had less sedentary time in bouts of less than 30 minutes than HE participants (-8 to -10 min/d) and more total activity (+3 to +6 min/d), although hospital-related changes were similar between the intervention groups (interaction effect p >.26).

CONCLUSION

Participating in a PA intervention before hospitalization had expected benefits, but participants remained susceptible to hospitalization's detrimental effects on their daily activity levels. There was no evidence of better activity recovery after hospitalization. J Am Geriatr Soc 67:261-268, 2019.

Interactions of alcohol and postmenopausal hormone use in regards to mammographic breast density

PURPOSE

We investigated the association of alcohol intake with mammographic breast density in postmenopausal women by their hormone therapy (HT) status.

METHODS

This study included 2,100 cancer-free postmenopausal women within the Nurses' Health Study and Nurses' Health Study II cohorts. Percent breast density (PD), absolute dense (DA), and non-dense areas (NDA) were measured from digitized film mammograms using a computer-assisted thresholding technique; all measures were square root transformed. Alcohol consumption was assessed with a food frequency questionnaire (0, < 5, and ≥ 5 g/day). Information regarding breast cancer risk factors was obtained from baseline or biennial questionnaires closest to the mammogram date. We used generalized linear regression to examine associations between alcohol and breast density measures in women with no HT history, current, and past HT users.

RESULTS

In multivariable analyses, we found no associations of alcohol consumption with PD (p trend = 0.32) and DA (p trend = 0.53) and an inverse association with NDA (β = - 0.41, 95% CI - 0.73, - 0.09 for ≥ 5 g/day, p trend < 0.01). In the stratified analysis by HT status, alcohol was not associated with PD in any of the strata. We found a significant inverse association of alcohol with NDA among past HT users (β = - 0.79, 95% CI - 1.51, - 0.07 for ≥ 5 g/day, p trend = 0.02). There were no significant interactions between alcohol and HT in relation to PD, DA, and NDA (p interaction = 0.19, 0.42, and 0.43, respectively).

CONCLUSIONS

Our findings suggest that associations of alcohol with breast density do not vary by HT status.

Interactions between Alcohol Consumption and Adjuvant Hormone Therapy in Relation to Breast Cancer-Free Survival

Purpose

Alcohol consumption is associated with an increase in breast cancer risk, but findings on the association of alcohol with survival after breast cancer diagnosis have been inconsistent. Further, whether these associations could differ by adjuvant hormone therapy status is unknown. We examined interactions between alcohol consumption and adjuvant hormone therapy in relation to breast cancer-free survival among women with a primary breast cancer diagnosis.

Methods

Participants in this study included 1,399 women diagnosed with primary breast cancer between 2007 and 2012 at the Moffitt Cancer Center. Alcohol consumption during the year preceding diagnosis was assessed in a patient survey. Information on tumor characteristics, breast cancer treatment and outcomes was available from the Moffitt Cancer Registry. Associations were examined using Cox proportional hazards models in stratified analyses by adjuvant hormone therapy status, after adjustment for potential confounders.

Results

Overall, alcohol consumption was associated with significantly improved breast cancer-free survival (any vs. none: hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.65–0.92). Among women without adjuvant hormone therapy, alcohol consumption was associated with better survival in heavy drinkers (HR, 0.63; 95% CI, 0.43–0.93). Among women with adjuvant hormone therapy, survival was better in women consuming alcohol as compared to nondrinkers (moderate: HR, 0.69, 95% CI, 0.51–0.93; heavy: HR, 0.74, 95% CI, 0.57–0.96; any: HR, 0.71, 95% CI, 0.57–0.87). There was no significant interaction between alcohol and adjuvant hormone therapy (p-interaction=0.54 for alcohol modeled as none or any and p=0.34 for alcohol modeled as none, moderate, and heavy).

Conclusion

Associations of alcohol consumption with breast cancer-free survival are similar in women with and without adjuvant hormone therapy. Future studies are warranted to elucidate potential mechanisms underlying the observed inverse associations.

Interactions of coffee consumption and postmenopausal hormone use in relation to breast cancer risk in UK Biobank

PURPOSE

We investigated the association of coffee consumption with postmenopausal breast cancer risk, overall and by the status of postmenopausal hormone therapy (PMH).

METHODS

This study included 126,182 postmenopausal women (2,636 with breast cancer and 123,546 without) from UK Biobank. Cancer diagnoses were ascertained through the linkage to the UK National Health Service Central Registers. Information on breast cancer risk factors and coffee consumption was collected at baseline and updated during follow-up. We used Cox proportional hazards regression to evaluate associations between coffee consumption and breast cancer, overall and in stratified analyses by woman's PMH status (none, past, current).

RESULTS

In the overall analysis, coffee consumption was not associated with breast cancer risk (Hazard Ratio [HR] 1.00, 95% CI 0.91-1.11 for 2-3 cups/day, and HR 0.98, 95% CI 0.87-1.10 for ≥ 4 cups/day, p-trend = 0.69). Women with no PMH history who consumed ≥ 4 cups/day had a 16% reduced risk of breast cancer as compared to women who consumed < 7 cups/week (HR 0.84, 95% CI 0.71-1.00). Among women with past PMH, those consuming ≥ 4 cups/day had a 22% greater risk of breast cancer than women consuming < 7 cups/week (HR 1.22, 95% CI 1.01-1.47). No association was found among current PMH users. We found no significant interaction between PMH and coffee consumption (p = 0.24).

CONCLUSIONS

Coffee consumption might be associated with increased breast cancer risk in women who used hormones in the past. Further studies are warranted to confirm these findings and elucidate potential biological mechanisms underlying the observed associations.

Interactions of Family History of Breast Cancer with Radiotherapy in Relation to the Risk of Breast Cancer Recurrence

Purpose

We examined associations between a family history of breast cancer and the risk of breast cancer recurrence in women who received or did not receive radiotherapy.

Methods

Our study included 2,440 women enrolled in the Breast Cancer Registry of Greater Cincinnati. Information on breast cancer risk factors, including detailed family history of breast cancer, characteristics of the primary tumor, treatment received, and recurrence status was collected at baseline and via updates. Associations between a family history of breast cancer and the risk of breast cancer recurrence were examined separately in women treated with and without radiotherapy using survival analysis.

Results

Over an average follow-up time of 8.78 years, we found no associations between a family history of breast cancer and the risk of breast cancer recurrence among women with a history of radiotherapy (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.75–1.23). Among women who did not receive radiotherapy, the total number of relatives with breast cancer was positively associated with the risk of breast cancer recurrence (HR, 1.21; 95% CI, 1.00–1.47). We found no interactions of radiotherapy with family history (p-interaction >0.05).

Conclusion

Radiotherapy for a primary breast cancer in women with a family history of breast cancer does not increase risk of breast cancer recurrence. If these findings are replicated in future studies, the results may translate into an important health message for breast cancer survivors with a family history of breast cancer.

Interaction of mammographic breast density with menopausal status and postmenopausal hormone use in relation to the risk of aggressive breast cancer subtypes

PURPOSE

We examined the associations of mammographic breast density with breast cancer risk by tumor aggressiveness and by menopausal status and current postmenopausal hormone therapy.

METHODS

This study included 2596 invasive breast cancer cases and 4059 controls selected from participants of four nested case-control studies within four established cohorts: the Mayo Mammography Health Study, the Nurses' Health Study, Nurses' Health Study II, and San Francisco Mammography Registry. Percent breast density (PD), absolute dense (DA), and non-dense areas (NDA) were assessed from digitized film-screen mammograms using a computer-assisted threshold technique and standardized across studies. We used polytomous logistic regression to quantify the associations of breast density with breast cancer risk by tumor aggressiveness (defined as presence of at least two of the following tumor characteristics: size ≥2 cm, grade 2/3, ER-negative status, or positive nodes), stratified by menopausal status and current hormone therapy.

RESULTS

Overall, the positive association of PD and borderline inverse association of NDA with breast cancer risk was stronger in aggressive vs. non-aggressive tumors (≥51 vs. 11-25% OR 2.50, 95% CI 1.94-3.22 vs. OR 2.03, 95% CI 1.70-2.43, p-heterogeneity = 0.03; NDA 4th vs. 2nd quartile OR 0.54, 95% CI 0.41-0.70 vs. OR 0.71, 95% CI 0.59-0.85, p-heterogeneity = 0.07). However, there were no differences in the association of DA with breast cancer by aggressive status. In the stratified analysis, there was also evidence of a stronger association of PD and NDA with aggressive tumors among postmenopausal women and, in particular, current estrogen+progesterone users (≥51 vs. 11-25% OR 3.24, 95% CI 1.75-6.00 vs. OR 1.93, 95% CI 1.25-2.98, p-heterogeneity = 0.01; NDA 4th vs. 2nd quartile OR 0.43, 95% CI 0.21-0.85 vs. OR 0.56, 95% CI 0.35-0.89, p-heterogeneity = 0.01), even though the interaction was not significant.

CONCLUSION

Our findings suggest that associations of mammographic density with breast cancer risk differ by tumor aggressiveness. While there was no strong evidence that these associations differed by menopausal status or hormone therapy, they did appear more prominent among current estrogen+progesterone users.

Tissue-based associations of mammographic breast density with breast stem cell markers

Background

Mammographic breast density is a well-established, strong breast cancer risk factor but the biology underlying this association remains unclear. Breast density may reflect underlying alterations in the size and activity of the breast stem cell pool. We examined, for the first time, associations of CD44, CD24, and aldehyde dehydrogenase family 1 member A1 (ALDH1A1) breast stem cell markers with breast density.

Methods

We included in this study 64 asymptomatic healthy women who previously volunteered for a unique biopsy study of normal breast tissue at the Mayo Clinic (2006-2008). Mammographically identified dense and non-dense areas were confirmed/localized by ultrasound and biopsied. Immunohistochemical analysis of the markers was performed according to a standard protocol and the staining was assessed by a single blinded pathologist. In core biopsy samples retrieved from areas of high vs. low density within the same woman, we compared staining extent and an expression score (the product of staining intensity and extent), using the signed rank test. All tests of statistical significance were two-sided.

Results

A total of 64, 28, and 10 women were available for CD44, CD24, and ALDH1A1 staining, respectively. For all three markers, we found higher levels of staining extent in dense as compared to non-dense tissue, though for CD24 and ALDH1A1 the difference did not reach statistical significance (CD44, 6.3% vs. 2.0%, p < 0.001; CD24, 8.0% vs. 5.6%, p = 0.10; and ALDH1A1, 0.5% vs. 0.3%, p = 0.12). The expression score for CD44 was significantly greater in dense as compared to non-dense tissue (9.8 vs.3.0, p < 0.001).

Conclusions

Our findings suggest an increased presence and/or activity of stem cells in dense as compared to non-dense breast tissue.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0889-3) contains supplementary material, which is available to authorized users.

Abstract 4255: Associations of coffee consumption and caffeine intake with mammographic breast density

Purpose: Previous studies suggest that coffee consumption and caffeine intake may be associated with reduced breast cancer risk which may result from stimulating effect of coffee on estrogen metabolism enzymes and subsequent changes in bioavailable estrogen. We investigated the association of coffee consumption and caffeine intake with mammographic density by woman’s menopausal status and, in postmenopausal women, by hormone therapy (HT).

Methods: This study included 4,130 cancer-free women within the Nurses’ Health Study and Nurses’ Health Study II cohorts. Percent breast density (PD), absolute dense and non-dense areas were measured from digitized film mammograms using a computer-assisted thresholding technique; all measures were square-root transformed for the analysis to improve normality. Diet was assessed with a food frequency questionnaire; average cumulative coffee/caffeine consumption was calculated using data available from all the questionnaires preceding the mammogram date. Information regarding breast cancer risk factors was obtained from baseline or biennial questionnaires closest to the mammogram date. We used generalized linear regression to quantify associations between exposures and breast density measures, adjusted for potential confounders. Associations were examined separately for regular coffee, decaffeinated coffee, total coffee, and energy-adjusted caffeine intake.

Results: In multivariable analyses, decaffeinated coffee was positively associated with PD in premenopausal women (2+ cups/day: β=0.23, p-trend=0.03). In postmenopausal women, decaffeinated and total coffee were inversely associated with PD (decaffeinated coffee 2+ cups/day: β=-0.24, p-trend=0.04; total coffee 4+ cups/day: β=-0.17). These associations appeared to be driven by the inverse associations of these exposures with absolute dense area. Among current HT users (n=980), regular coffee and caffeine intake were inversely associated with PD (regular coffee 4+ cups/day: β=-0.29, p-trend&lt;0.01; caffeine 4th vs. 1st quartile: β=-0.32, p-trend&lt;0.01). Among past users (n=430), decaffeinated coffee was inversely associated with PD (2+ cups/day β=-0.70, p-trend=0.02).

Conclusions: Our findings suggest that among current HT users, regular coffee and caffeine are inversely associated with mammographic percent breast density.

Citation Format: Lusine Yaghjyan, Graham Colditz, Bernard Rosner, Aleksandra Gasparova, Rulla Tamimi. Associations of coffee consumption and caffeine intake with mammographic breast density [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4255. doi:10.1158/1538-7445.AM2017-4255