34 research outputs found

    2:16α-Hydroxyestrone Metabolite Ratio and Breast Cancer: A Combined Analysis

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    Estrogen metabolites may play an important role in breast carcinogenesis. Animal and in vitro studies suggest differing biological effects of the 2-hydroxyestrone (2-OHE1) and 16α-hydroxyestrone (16α-OHE1) metabolites, lending support to the use of 2:16α-OHE1 as a measure of estrogen balance. Although previous studies have evaluated the association between these specific metabolites and breast cancer among pre- and postmenopausal women, the results have been inconclusive. The sample size of individual studies is often small and lacks the statistical power to draw conclusions or to adequately assess the relationships within subgroups. Furthermore, the relationship between various lifestyle factors and personal characteristics and estrogen metabolites remains unclear. We evaluated the association between the 2-OHE1, 16α-OHE1 and 2:16α-OHE1 metabolites and breast cancer among premenopausal (183 cases/548 controls) and postmenopausal (319 cases/647 controls) women using a combined analysis of individual level data from previously published research studies. In separate study adjusted conditional logistic regression models matched on 5-year age groups, higher levels of 2:16α-OHE1 were not associated with breast cancer among pre- or postmenopausal women [Premenopausal: OR≥2.67 vs. <1.76=0.81 (95% CI: 0.49, 1.32); Postmenopausal: OR≥2.46 vs. <1.53=0.87 (95% CI: 0.58, 1.29)]. Using multivariable regression analyses adjusted for study, we evaluated various predictors of estrogen metabolites among the control populations of the participating studies (544 premenopausal/720 postmenopausal). Among premenopausal women, BMI was negatively associated with 2-OHE1 and 2:16α-OHE1 (p < 0.05). Analyses among postmenopausal women revealed significant associations (p<0.05) between age, age at menopausal status, and history of benign breast disease. In summary, this combined analysis does not support an association between urinary estrogen metabolites and breast cancer among pre- or post menopausal women. However, our results do suggest potential differences in factors related to estrogen metabolite levels among pre- and postmenopausal women. Enhancing our knowledge of estrogen metabolites among breast cancer patients and among healthy populations of women is a significant contribution to public health. By improving our understanding of estrogen metabolites we may be able to identify women at higher risk of breast cancer as well as increase our understanding of breast cancer etiology

    Epidemiologic Risk Factors for In Situ and Invasive Breast Cancers Among Postmenopausal Women in the National Institutes of Health-AARP Diet and Health Study

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    Comparing risk factor associations between invasive breast cancers and possible precursors may further our understanding of factors related to initiation versus progression. Accordingly, among 190,325 postmenopausal participants in the National Institutes of Health-AARP Diet and Health Study (1995-2011), we compared the association between risk factors and incident ductal carcinoma in situ (DCIS; n = 1,453) with that of risk factors and invasive ductal carcinomas (n = 7,525); in addition, we compared the association between risk factors and lobular carcinoma in situ (LCIS; n = 186) with that of risk factors and invasive lobular carcinomas (n = 1,191). Hazard ratios and 95% confidence intervals were estimated from multivariable Cox proportional hazards regression models. We used case-only multivariable logistic regression to test for heterogeneity in associations. Younger age at menopause was associated with a higher risk of DCIS but lower risks of LCIS and invasive ductal carcinomas (P for heterogeneity < 0.01). Prior breast biopsy was more strongly associated with the risk of LCIS than the risk of DCIS (P for heterogeneity = 0.04). Increased risks associated with use of menopausal hormone therapy were stronger for LCIS than DCIS (P for heterogeneity = 0.03) and invasive lobular carcinomas (P for heterogeneity < 0.01). Associations were similar for race, age at menarche, age at first birth, family history, alcohol consumption, and smoking status, which suggests that most risk factor associations are similar for in situ and invasive cancers and may influence early stages of tumorigenesis. The differential associations observed for various factors may provide important clues for understanding the etiology of certain breast cancers

    Reproductive and Hormonal Factors in Relation to Lung Cancer Among Nepali Women

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    Partial funding for Open Access provided by the UMD Libraries' Open Access Publishing Fund.Background: Of the 1.8 million global incident lung cancer cases estimated in 2012, approximately 60% occurred in less developed regions. Prior studies suggest sex differences in lung cancer risk and a potential role for reproductive and hormonal factors in lung cancer among women. However, the majority of these studies were conducted in developed regions. No prior study has assessed these relationships among Nepali women. Methods: Using data from a hospital-based case-control study conducted in B. P. Koirala Memorial Cancer Hospital (Nepal, 2009–2012), relationships between reproductive and hormonal factors and lung cancer were examined among women aged 23–85 years. Lung cancer cases (n = 268) were frequency-matched to controls (n = 226) based on age (±5 years), ethnicity and residential area. The main exposures in this analysis included menopausal status, age at menarche, age at menopause, menstrual duration, gravidity, and age at first live-birth. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression. Results: Among postmenopausal women, those with a younger age at menopause (<45 years; 45–49 years) had an increased odds of lung cancer compared to those with an older (≥50 years) age at menopause [OR (95%CI): 2.14 (1.09, 4.17); OR (95% CI): 1.93 (1.07, 3.51)], after adjusting for age and cumulative active smoking years. No statistically significant associations were observed with the other reproductive and hormonal factors examined. Conclusion: These results suggest that Nepali women with prolonged exposure to endogenous ovarian hormones, via later age at menopause, may have a lower odds of lung cancer

    Reproductive and Hormonal Factors in Relation to Lung Cancer Among Nepali Women

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    Background: Of the 1.8 million global incident lung cancer cases estimated in 2012, approximately 60% occurred in less developed regions. Prior studies suggest sex differences in lung cancer risk and a potential role for reproductive and hormonal factors in lung cancer among women. However, the majority of these studies were conducted in developed regions. No prior study has assessed these relationships among Nepali women.Methods: Using data from a hospital-based case-control study conducted in B. P. Koirala Memorial Cancer Hospital (Nepal, 2009–2012), relationships between reproductive and hormonal factors and lung cancer were examined among women aged 23–85 years. Lung cancer cases (n = 268) were frequency-matched to controls (n = 226) based on age (±5 years), ethnicity and residential area. The main exposures in this analysis included menopausal status, age at menarche, age at menopause, menstrual duration, gravidity, and age at first live-birth. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression.Results: Among postmenopausal women, those with a younger age at menopause (&lt;45 years; 45–49 years) had an increased odds of lung cancer compared to those with an older (≥50 years) age at menopause [OR (95%CI): 2.14 (1.09, 4.17); OR (95% CI): 1.93 (1.07, 3.51)], after adjusting for age and cumulative active smoking years. No statistically significant associations were observed with the other reproductive and hormonal factors examined.Conclusion: These results suggest that Nepali women with prolonged exposure to endogenous ovarian hormones, via later age at menopause, may have a lower odds of lung cancer

    Racial and Sex Differences between Urinary Phthalates and Metabolic Syndrome among U.S. Adults: NHANES 2005–2014

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    Partial funding for Open Access provided by the UMD Libraries' Open Access Publishing Fund.Phthalates, plasticizers ubiquitous in household and personal care products, have been associated with metabolic disturbances. Despite the noted racial differences in phthalate exposure and the prevalence of metabolic syndrome (MetS), it remains unclear whether associations between phthalate metabolites and MetS vary by race and sex. A cross-sectional analysis was conducted among 10,017 adults from the National Health and Nutritional Examination Survey (2005–2014). Prevalence odds ratios (POR) and 95% confidence intervals (CIs) were estimated for the association between 11 urinary phthalate metabolites and MetS using weighted sex and race stratified multivariable logistic regression. Higher MCOP levels were significantly associated with increased odds of MetS among women but not men, and only remained significant among White women (POR Q4 vs. Q1 = 1.68, 95% CI: 1.24, 2.29; p-trend = 0.001). Similarly, the inverse association observed with MEHP among women, persisted among White women only (POR Q4 vs. Q1 = 0.53, 95% CI: 0.35, 0.80; p-trend = 0.003). However, SDEHP metabolites were associated with increased odds of MetS only among men, and this finding was limited to White men (POR Q4 vs. Q1 = 1.54, 95% CI: 1.01, 2.35; p-trend = 0.06). Among Black men, an inverse association was observed with higher MEP levels (POR Q4 vs. Q1 = 0.43, 95% CI: 0.24, 0.77; p-trend = 0.01). The findings suggest differential associations between phthalate metabolites and MetS by sex and race/ethnicity.https://doi.org/10.3390/ijerph1813687
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