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Background: Breast cancer rates in Asia are much lower than in Europe and North America. Within Asia, rates are lower in Mongolia than in neighboring countries. Variation in pregnancy exposure to endogenous hormone concentrations may explain the differences, but data are lacking., Methods: We measured maternal serum progesterone, prolactin, estradiol and estrone concentrations in the second half of pregnancy in a cross-sectional study of urban ( n = 143-194 depending on the analyte) and rural ( n = 150-193) Mongolian women, and U.S. women from Boston ( n = 66-204). Medical records provided information on maternal and perinatal factors. Geometric mean hormones were estimated from standard linear models with the log-hormone as the dependent variable and country as the independent variable adjusted for maternal and gestational age at blood draw., Results: Mean concentrations of prolactin (5722 vs. 4648 uIU/mL; p < 0.0001) and estradiol (17.7 vs. 13.6 ng/mL; p < 0.0001) were greater in Mongolian than U.S. women, while progesterone (147 vs. 201 ng/mL; p < 0.0001) was lower. Mean hormone concentrations were similar in rural and urban Mongolian women. Results were generally similar, with additional adjustment for gravidity, parity, height, body mass index at blood draw, education and alcohol use during pregnancy, and when stratified by offspring sex or parity., Conclusions: Mongolian women had greater concentrations of prolactin and estrogen and lower concentrations of progesterone than U.S. women, while hormone concentrations were similar in rural and urban Mongolian pregnancies., Impact: These data do not support the hypothesis that estrogen concentrations in pregnant women are lower in Mongolian compared with Caucasian women.

Purpose: Menopausal hormone therapy (MHT) use induces alterations in circulating estrogens/estrogen metabolites, which may contribute to the altered risk of reproductive tract cancers among current users. Thus, the current study assessed associations between circulating estrogens/estrogen metabolites and ovarian and endometrial cancer risk among MHT users., Methods: We conducted a nested case-control study among postmenopausal women using MHT at baseline in the Women's Health Initiative Observational Study (179 ovarian cancers, 396 controls; 230 endometrial cancers, 253 controls). Multivariable logistic regression was utilized to estimate odds ratios and 95% confidence intervals overall and by subtype., Results: Estrogen/estrogen metabolite levels were not associated with overall or serous ovarian cancer risk, examined separately. However, unconjugated estradiol was positively associated with non-serous ovarian cancer risk [quintile 5 vs. quintile 1: 3.01 (1.17-7.73); p-trend = 0.03; p-het < 0.01]. Endometrial cancer risk was unrelated to estrogen/estrogen metabolite levels among women who took combined estrogen/progestin therapy (EPT)., Conclusions: These findings provide novel evidence that may support a heterogeneous hormonal etiology across ovarian cancer subtypes. Circulating estrogens did not influence endometrial cancer risk among women with EPT-induced high-estrogen levels. Larger studies are needed to delineate the relationship between ovarian/endometrial cancer subtypes and estrogen levels in the context of MHT use.

Background: Alcohol consumption is associated with an increased risk of several cancers. Potential mechanisms include altered oestrogen metabolism. Parent oestrogens metabolise into alternate pathways of oestrogen metabolites that may have variable effects on cancer pathogenesis. We examined associations of alcohol consumption with circulating oestrogen/oestrogen metabolites in postmenopausal women in the Women's Health Initiative (WHI)-Observational Study (OS)., Methods: We conducted a cross-sectional analysis of prediagnosis ovarian/endometrial cancer case-control data within WHI-OS (N=1864). Alcohol consumption was measured by validated food frequency questionnaire. Fasting serum parent oestrogens/oestrogen metabolites were assayed using liquid chromatography tandem mass-spectrometry. Geometric mean analyte concentrations (GM, pmol l -1 ) were calculated by alcohol category using inverse-probability weighted linear regression, adjusting for venepuncture age/year, race, smoking, body mass index, years since menopause, oral contraceptive duration, caffeine intake, and physical activity., Results: There was evidence for a positive association between alcohol consumption and oestrone, oestradiol and 2-hydroxylation oestrogen metabolite concentrations among menopausal hormone therapy (MHT) users. We observed an association between liquor consumption and parent oestrogens among non-MHT users, who consumed larger doses of liquor than MHT users., Conclusions: Among postmenopausal women, the association between alcohol intake and parent oestrogen, but not oestrogen metabolite concentrations, may be influenced by MHT and type of alcohol.

Background: Prolonged sitting and lower levels of physical activity have been associated with increased levels of parent oestrogens (oestrone and oestradiol), the key hormones in female cancers, in postmenopausal women. However, it is unknown whether sitting and physical activity are associated with circulating oestrogen metabolite levels., Methods: Among 1804 postmenopausal women enrolled in the Women's Health Initiative Observational Study, 15 serum oestrogens/oestrogen metabolites were quantified using liquid chromatography-tandem mass spectrometry. Physical activity and sitting were self-reported via questionnaire. Using baseline, cross-sectional data, geometric means (GM) of oestrogens/oestrogen metabolites (pmol l -1 ) were estimated using inverse probability weighted linear regression, adjusting for potential confounders and stratified on menopausal hormone therapy (MHT) use., Results: Longer time spent sitting (⩾10 vs ⩽5h per day) was associated with higher levels of unconjugated oestrone, independent of moderate- to vigorous-intensity physical activity and body mass index, among both never/former (GM=70.6 vs 57.7) and current MHT users (GM=242 vs 179) (P-trend ⩽0.03). Among never/former MHT users, sitting (⩾10 vs ⩽5h per day) was positively associated with 2-methoxyestradiol (GM=16.4 vs 14.4) and 4-methoxyestradiol (GM=2.36 vs 1.98) (P-trend ⩽0.04), independent of parent oestrogens. Inverse associations between moderate- to vigorous-intensity physical activity (⩾15 vs 0 metabolic equivalent task-hours per week) and parent oestrogens were found as expected. After adjustment for parent oestrogens, physical activity was not associated with oestrogen metabolites., Conclusions: Our data suggest that prolonged sitting and lower moderate- to vigorous-intensity physical activity are associated with higher levels of postmenopausal oestrogens/oestrogen metabolites, the oestrogen metabolism patterns that have previously been associated with higher endometrial and breast cancer risk.

Higher levels of circulating estrogens and estrogen metabolites (EMs) have been associated with higher breast cancer risk. In breast tissues, reduced levels of terminal duct lobular unit (TDLU) involution, as reflected by higher numbers of TDLUs and acini per TDLU, have also been linked to elevated breast cancer risk. However, it is unknown whether reduced TDLU involution mediates the risk associated with circulating EMs. In a cross-sectional analysis of 94 premenopausal and 92 postmenopausal women referred for clinical breast biopsy at an academic facility in Vermont, we examined the associations of 15 EMs, quantified using liquid chromatography-tandem mass spectrometry, with the number of TDLUs and acini count/TDLU using zero-inflated Poisson regression with a robust variance estimator and ordinal logistic regression models, respectively. All analyses were stratified by menopausal status and adjusted for potential confounders. Among premenopausal women, comparing the highest vs. the lowest tertiles, levels of unconjugated estradiol (risk ratio (RR) = 1.74, 95 % confidence interval (CI) = 1.06-2.87, p trend = 0.03), 2-hydroxyestrone (RR = 1.74, 95 % CI = 1.01-3.01, p trend = 0.04), and 4-hydroxyestrone (RR = 1.74, 95 % CI = 0.99-3.06, p trend = 0.04) were associated with significantly higher TDLU count. Among postmenopausal women, higher levels of estradiol (RR = 2.09, 95 % CI = 1.01-4.30, p trend = 0.04) and 16α-hydroxyestrone (RR = 2.27, 95 % CI = 1.29-3.99, p trend = 0.02) were significantly associated with higher TDLU count. Among postmenopausal women, higher levels of EMs, specifically conjugated estrone and 2- and 4-pathway catechols, were also associated with higher acini count/TDLU. Our data suggest that higher levels of serum EMs are generally associated with lower levels of TDLU involution.

Background: Although endometrial cancer is clearly influenced by hormonal factors, few epidemiologic studies have investigated the role of endogenous estrogens or especially estrogen metabolites., Methods: We conducted a nested case-control study within the Women's Health Initiative Observational Study (WHI-OS), a cohort of 93,676 postmenopausal women recruited between 1993 and 1998. Using baseline serum samples from women who were non-current hormone users with intact uteri, we measured 15 estrogens/estrogen metabolites via HPLC/MS-MS among 313 incident endometrial cancer cases (271 type I, 42 type II) and 354 matched controls, deriving adjusted ORs and 95% confidence intervals (CI) for overall and subtype-specific endometrial cancer risk., Results: Parent estrogens (estrone and estradiol) were positively related to endometrial cancer risk, with the highest risk observed for unconjugated estradiol (OR 5th vs. 1st quintile = 6.19; 95% CI, 2.95-13.03, Ptrend = 0.0001). Nearly all metabolites were significantly associated with elevated risks, with some attenuation after adjustment for unconjugated estradiol (residual risks of 2- to 3-fold). Body mass index (kg/m(2), BMI) relations were somewhat reduced after adjustment for estrogen levels. The association with unconjugated estradiol was stronger for type I than type II tumors (Phet = 0.01)., Conclusions: Parent estrogens as well as individual metabolites appeared to exert generalized uterotropic activity, particularly for type I tumors. The effects of obesity on risk were only partially explained by estrogens., Impact: These findings enhance our understanding of estrogen mechanisms involved in endometrial carcinogenesis but also highlight the need for studying additional markers that may underlie the effects on risk of certain risk factors, for example, obesity. Cancer Epidemiol Biomarkers Prev; 25(7); 1081-9. ©2016 AACR., (©2016 American Association for Cancer Research.)

Background: A potential protective role for estrogen in colon carcinogenesis has been suggested based on exogenous hormone use, but it is unclear from previous studies whether endogenous estrogens are related to colorectal cancer risk. These few prior studies focused on parent estrogens; none evaluated effects of estrogen metabolism in postmenopausal women., Methods: We followed 15,595 women (ages 55-80 years) enrolled in the Breast and Bone Follow-up to the Fracture Intervention Trial (B∼FIT) who donated blood between 1992 and 1993 for cancer through December 2004. A panel of 15 estrogen metabolites (EM), including estradiol and estrone, were measured in serum from 187 colorectal cancer cases and a subcohort of 501 women not using exogenous hormones at blood draw. We examined EM individually, grouped by pathway (hydroxylation at the C-2, C-4, or C-16 position) and by ratios of the groupings using Cox proportional hazards regression models., Results: No significant associations were seen for estrone (HRQ4 vs. Q1 = 1.15; 95% CI, 0.69-1.93; Ptrend = 0.54), estradiol (HRQ4 vs. Q1 = 0.98; 95% CI, 0.58-1.64; Ptrend > 0.99), or total EM (the sum of all EM; HRQ4 vs. Q1 = 1.35; 95% CI, 0.81-2.24; Ptrend = 0.33). Most metabolites in the 2-, 4-, or 16-pathway were unrelated to risk, although a borderline trend in risk was associated with high levels of 17-epiestriol., Conclusion: Circulating estrogens and their metabolites were generally unrelated to colorectal cancer risk in postmenopausal women., Impact: Additional studies are needed to understand how exogenous estrogen may prevent colorectal cancer., (©2015 American Association for Cancer Research.)

Accurately quantifying parent estrogens (PE) estrone (E1) and estradiol (E2) and their metabolites (EM) within breast tissue and serum may permit detailed investigations of their contributions to breast carcinogenesis among BRCA1/2 mutation carriers. We conducted a study of PE/EM in serum, nipple aspirate fluid (NAF), and ductal lavage supernatant (DLS) among postmenopausal BRCA1/2 mutation carriers. PE/EM (conjugated and unconjugated) were measured in paired serum/NAF (n = 22 women) and paired serum/DLS samples (n = 24 women) using quantitative liquid chromatography-tandem mass spectrometry (LC/MS/MS). The relationships between serum and tissue-specific PE/EM were measured using Pearson's correlation coefficients. Conjugated forms of PE/EM constituted the majority of estrogen in serum (88 %), NAF (59 %) and DLS (69 %). PE/EM in NAF and serum were highly correlated [E1 (r = 0.97, p < 0.0001), E2 (r = 0.90, p < 0.0001) and estriol (E3) (r = 0.74, p < 0.0001)] as they were in DLS and serum [E1 (r = 0.92, p < 0.0001; E2 (r = 0.70, p = 0.0001; E3 (r = 0.67, p = 0.0004)]. Analyses of paired total estrogen values for NAF and serum, and DLS and serum yielded ratios of 0.22 (95 % CI 0.19-0.25) and 0.28 (95 % CI 0.24-0.32), respectively. This report is the first to employ LC/MS/MS to quantify PE/EM in novel breast tissue-derived biospecimens (i.e., NAF and DLS). We demonstrate that circulating PE and EM are strongly and positively correlated with tissue-specific PE and EM measured in NAF and DLS among postmenopausal BRCA1/2 mutation carriers. If confirmed, future etiologic studies could utilize the more readily obtainable serum hormone levels as a reliable surrogate measure of exposure at the tissue level.

BackgroundPostmenopausal pregnenolone and/or progesterone levels in relation to endometrial and ovarian cancer risks have been infrequently evaluated. To address this, we utilized a sensitive and reliable assay to quantify prediagnostic levels of seven markers related to endogenous hormone metabolism.MethodsHormones were quantified in baseline serum collected from postmenopausal women in a cohort study nested within the Breast and Bone Follow-up to the Fracture Intervention Trial (B∼FIT). Women using exogenous hormones at baseline (1992-1993) were excluded. Incident endometrial (n = 65) and ovarian (n = 67) cancers were diagnosed during 12 follow-up years and compared with a subcohort of 345 women (no hysterectomy) and 413 women (no oophorectomy), respectively. Cox models with robust variance were used to estimate cancer risk.ResultsCirculating progesterone levels were not associated with endometrial [tertile (T)3 vs. T1 HR (95% confidence interval): 1.87 (0.85-4.11); P trend = 0.17] or ovarian cancer risk [1.16 (0.58-2.33); 0.73]. Increasing levels of the progesterone-to-estradiol ratio were inversely associated with endometrial cancer risk [T3 vs. T1: 0.29 (0.09-0.95); 0.03]. Increasing levels of 17-hydroxypregnenolone were inversely associated with endometrial cancer risk [0.40 (0.18-0.91); 0.03] and positively associated with ovarian cancer risk [3.11 (1.39-6.93); 0.01].ConclusionsUsing sensitive and reliable assays, this study provides novel data that endogenous progesterone levels are not strongly associated with incident endometrial or ovarian cancer risks. 17-hydroxypregnenolone was positively associated with ovarian cancer and inversely associated with endometrial cancer.ImpactWhile our results require replication in large studies, they provide further support of the hormonal etiology of endometrial and ovarian cancers.

Background: Breast density, as estimated by mammography, is a strong risk factor for breast cancer in pre- and postmenopausal women, but the determinants of breast density have not yet been established. The aim of this study was to assess if urinary estrogens or gut microbiota alterations are associated with mammographic density in postmenopausal women. Methods: Among 54 cancer-free, postmenopausal controls in the Breast and Colon Health study, we classified low- versus high-density women with Breast Imaging Reporting and Data System (BI-RADS, 5th edition) mammographic screening data, then assessed associations with urinary estrogens and estrogen metabolites (determined by liquid chromatography/tandem mass spectrometry), and fecal microbiota alpha and beta diversity (using Illumina sequencing of 16S rRNA amplicons). Results: Multiple logistic regression revealed no significant association between breast density and fecal microbiota metrics (PD_tree P-value = 0.82; un-weighted and weighted UniFrac P = 0.92 and 0.83, respectively, both by MiRKAT). In contrast, total urinary estrogens (and all 15 estrogens/estrogen metabolites) were strongly and inversely associated with breast density (P = 0.01) after adjustment for age and body mass index. Conclusion: Mammographic density was not associated with the gut microbiota, but it was inversely associated with urinary estrogen levels. Impact: The finding of an inverse association between urinary estrogens and breast density in cancer-free women adds to the growing breast cancer literature on understanding the relationship between endogenous estrogens and mammographic density. [ABSTRACT FROM AUTHOR]

Background: Esophageal adenocarcinoma (EA) and gastric cardia adenocarcinoma (GCA) are characterized by a strong male predominance. Concentrations of sex steroid hormones have been hypothesized to explain this sex disparity. However, no prospective population-based study has examined sex steroid hormones in relation to EA/GCA risk. Thus, we investigated whether prediagnostic circulating sex steroid hormone concentrations were associated with EA/GCA in a nested case-control study drawn from participants in three prospective cohort studies.Methods: Using gas chromatography-mass spectrometry (GC-MS) and electrochemiluminescence immunoassay, we quantitated sex steroid hormones and sex hormone binding globulin, respectively, in serum from 259 EA/GCA male case participants and 259 matched male control participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, and Cancer Prevention Study II Nutrition Cohort. Multivariable conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between circulating hormones and EA/GCA risk. All statistical tests were two-sided.Results: Higher concentrations of dehydroepiandrosterone (DHEA) were associated with a 38% decreased risk of EA/GCA (OR per unit increase in log2 DHEA = 0.62, 95% CI = 0.47 to 0.82, Ptrend = .001). Higher estradiol concentrations were associated with a 34% reduced risk of EA/GCA (OR = 0.66, 95% CI = 0.45 to 0.98, Ptrend = .05), and the association with free estradiol was similar. No other associations between baseline hormone concentrations and future EA/GCA risk were observed.Conclusions: This study provides the first evidence that higher concentrations of circulating DHEA, estradiol, and free estradiol may be associated with lower risks of EA/GCA in men. [ABSTRACT FROM AUTHOR]

Background: Esophageal adenocarcinoma (EA) is characterized by a strong male predominance. Sex steroid hormones have been hypothesized to underlie this sex disparity, but no population-based study to date has examined this potential association. Methods: Using mass spectrometry and ELISA, we quantitated sex steroid hormones and sex hormone binding globulin, respectively, in plasma from males– 172 EA cases and 185 controls–within the Factors Influencing the Barrett/Adenocarcinoma Relationship (FINBAR) Study, a case-control investigation conducted in Northern Ireland and Ireland. Multivariable adjusted logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between circulating hormones and EA. Results: Higher androgen:estrogen ratio metrics were associated with increased odds of EA (e.g., testosterone:estradiol ratio ORQ4 v. Q1 = 2.58, 95%CI = 1.23–5.43; Ptrend = 0.009). All estrogens and androgens were associated with significant decreased odds of EA. When restricted to individuals with minimal to no decrease in body mass index, the size of association for the androgen:estrogen ratio was not greatly altered. Conclusions: This first study of sex steroid hormones and EA provides tentative evidence that androgen:estrogen balance may be a factor related to EA. Replication of these findings in prospective studies is needed to enhance confidence in the causality of this effect. [ABSTRACT FROM AUTHOR]

Background: Risk-reducing salpingo-oophorectomy is an effective ovarian cancer risk reduction strategy. However, bilateral oophorectomy has also been associated with increased long-term nonneoplastic sequelae, effects suggested to be mediated through reductions in systemic sex steroid hormone levels. Currently, it is unclear whether the postmenopausal ovary contributes to the systemic hormonal milieu or whether postmenopausal ovarian volume or other factors, such as body mass index and age, affect systemic hormone levels.Objective: We examined the impact of oophorectomy on sex steroid hormone levels in postmenopausal women. Furthermore, we explored how well ovarian volume measured by transvaginal ultrasound correlated with direct ovarian measures obtained during surgical pathology evaluation and investigated the association between hormone levels and ovarian volumes.Study Design: Postmenopausal women who underwent risk-reducing salpingo-oophorectomy (180 cases) or ovarian cancer screening (38 controls) enrolled in an international, prospective study of risk-reducing salpingo-oophorectomy and risk of ovarian cancer algorithm-based screening among women at increased risk of ovarian cancer (Gynecologic Oncology Group-0199) were included in this analysis. Controls were frequency matched to the cases on age at menopause, age at study entry, and time interval between blood draws. Ovarian volume was calculated using measurements obtained from transvaginal ultrasound in both cases and controls and measurements recorded in surgical pathology reports from cases. Serum hormone levels of testosterone, androstenedione, androstenediol, dihydrotestosterone, androsterone, dehydroepiandrosterone, estrone, estradiol, and sex hormone-binding globulin were measured at baseline and follow-up. Spearman correlation coefficients were used to compare ovarian volumes as measured on transvaginal ultrasound and pathology examinations. Correlations between ovarian volumes by transvaginal ultrasound and measured hormone levels were examined using linear regression models. All models were adjusted for age. Paired t tests were performed to evaluate individual differences in hormone levels before and after risk-reducing salpingo-oophorectomy.Results: Ovarian volumes measured by transvaginal ultrasound were only moderately correlated with those reported on pathology reports (Spearman rho [ρ]=0.42). The median time interval between risk-reducing salpingo-oophorectomy and follow-up for the cases was 13.3 months (range, 6.0-19.3), and the median time interval between baseline and follow-up for the controls was 12.7 months (range, 8.7-13.4). Sex steroid levels decreased with age but were not correlated with transvaginal ultrasound ovarian volume, body mass index, or time since menopause. Estradiol levels were significantly lower after risk-reducing salpingo-oophorectomy (percentage change, -61.9 post-risk-reducing salpingo-oophorectomy vs +15.2 in controls; P=.02), but no significant differences were seen for the other hormones.Conclusion: Ovarian volumes measured by transvaginal ultrasound were moderately correlated with volumes directly measured on pathology specimens and were not correlated with sex steroid hormone levels in postmenopausal women. Estradiol was the only hormone that declined significantly after risk-reducing salpingo-oophorectomy. Thus, it remains unclear whether the limited post-risk-reducing salpingo-oophorectomy changes in sex steroid hormones among postmenopausal women impact long-term adverse outcomes. [ABSTRACT FROM AUTHOR]