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Shrubsole M.J.,Vanderbilt University | Shrubsole M.J.,Vanderbilt Epidemiology Center | Shu X.O.,Vanderbilt University | Li H.-L.,Shanghai Cancer Institute | And 5 more authors.
American Journal of Epidemiology | Year: 2011

Methionine, folate, vitamin B6, vitamin B12, niacin, and riboflavin intakes may be related to breast carcinogenesis. These associations may vary by breast cancer type. Using the prospective cohort Shanghai Women's Health Study (1997-2008) including 718 Chinese breast cancer cases, the authors evaluated baseline dietary intake of these factors and breast cancer risk and whether the associations varied by menopausal status and estrogen receptor (ER) and progesterone receptor (PR) status. They estimated associations using hazard ratios and 95% confidence intervals from Cox proportional hazards regression models and stratified analyses by menopausal status and ER/PR status. Lowest quantile of intake was used as the comparison group. For postmenopausal women, dietary intakes of methionine and B vitamins were not associated with breast cancer risk. For premenopausal women, higher intake of folate was associated with decreased breast cancer risk (hazard ratio = 0.58, 95% confidence interval: 0.34, 0.99 for the highest vs. lowest quintile of intake). Only niacin intake was associated with ER+/PR+ breast cancer risk (hazard ratio = 1.62, 95% confidence interval: 1.07, 2.46; P for trend = 0.04 for the highest vs. lowest quartile of intake). Findings support the hypothesis that high folate intake may reduce breast cancer risk and that the association may vary by menopausal and ER/PR status. © The Author 2011. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. Source

Boice Jr. J.D.,International Epidemiology Institute | Boice Jr. J.D.,Vanderbilt Epidemiology Center
Health Physics | Year: 2011

Epidemiology is the study of the distribution and causes of disease in humans. Studies of human populations exposed to ionizing radiation have been conducted for nearly 100 y during the "Golden Age of Radiation Epidemiology." Radiation epidemiology is now so sophisticated that human studies are the basis for radiation protection standards and for compensation schemes in response to claims of ill health from prior exposures. The studies of exposed human populations are very broad and include not only the Japanese atomic bomb survivors, but also patients given radiotherapy for cancer, patients treated with radiation for nonmalignant disease, patients given diagnostic radiation, persons with intakes of radionuclides, workers exposed to occupational radiation, and communities exposed to environmental sources of radiation. But there is more to be learned, and future knowledge may be advanced from new and continued occupational studies of the early radiation workers, atomic veterans, medically exposed patients, and populations living in areas of high natural background radiation. The interaction between radiation and underlying genetic susceptibilities is an important emerging area of research. It is indeed an honor to be included among the Lauriston S. Taylor Lecturers. Health Phys. 100(1):59 -76; 2011 © 2010 Health Physics Society. Source

Cui Y.,Vanderbilt Epidemiology Center | Deming-Halverson S.L.,Vanderbilt Epidemiology Center | Beeghly-Fadiel A.,Vanderbilt Epidemiology Center | Lipworth L.,Vanderbilt Epidemiology Center | And 4 more authors.
Clinical Cancer Research | Year: 2014

Purpose: To examine potential modifying effects of body weight and bilateral oophorectomy on the association of hormone replacement therapy (HRT) with risk of breast cancer, overall and by subtypes according to status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2) among postmenopausal women. Experimental Design: This analysis included 2,510 postmenopausal white women recruited in the Nashville Breast Health Study, a population-based case-control study of breast cancer. Multivariable logistic regression was used to estimate ORs and 95% confidence intervals (CI) for associations between HRT use and risk of breast cancer overall and by subtypes, adjusted for age and education. Results: Among women with natural menopause and body mass index (BMI) < 25 kg/m2, ever-use of HRT was associated with increased breast cancer risk (OR, 1.95; 95% CI, 1.32-2.88). Risk was elevated with duration of HRT use (P for trend = 0.002). Similar association patterns were found for ER ̄, ER ̄PR ̄ , and luminal A cancer subtypes but not ER ̄, ER ̄ PR ̄ , and triple-negative cancer. In contrast, ever-HRT use in overweight women (BMI ≥ 25 kg/m2) showed no association with risk of breast cancer overall or by subtypes; interaction tests for modifying effect of BMI were statistically significant. Ever-HRT use was associated with decreased breast cancer risk (OR, 0.70; 95% CI, 0.38-1.31) among women with prior bilateral oophorectomy but elevated risk (OR, 1.45; 95% CI, 0.92-2.29) among those with hysterectomy without bilateral oophorectomy (P for interaction = 0.057). Similar associations were seen for virtually all breast cancer subtypes, although interaction tests were statistically significant for ER ̄ and luminal A only. Conclusion: Body weight and bilateral oophorectomy modify associations between HRT use and breast cancer risk, especially the risk of hormone receptor-positive tumors. © 2014 AACR. Source

Zheng W.,Vanderbilt Epidemiology Center | Wen W.,Vanderbilt Epidemiology Center | Gao Y.-T.,Vanderbilt University | Gao Y.-T.,Shanghai Cancer Institute | And 9 more authors.
Journal of the National Cancer Institute | Year: 2010

Background Most of the genetic variants identified from genome-wide association studies of breast cancer have not been validated in Asian women. No risk assessment model that incorporates both genetic and clinical predictors is currently available to predict breast cancer risk in this population. Methods We analyzed 12 single-nucleotide polymorphisms (SNPs) identified in recent genome-wide association studies mostly of women of European ancestry as being associated with the risk of breast cancer in 3039 case patients and 3082 control subjects who participated in the Shanghai Breast Cancer Study. All participants were interviewed in person to obtain information regarding known and suspected risk factors for breast cancer. The c statistic, a measure of discrimination ability with a value ranging from 0.5 (random classification) to 1.0 (perfect classification), was estimated to evaluate the contribution of genetic and established clinical predictors of breast cancer to a newly established risk assessment model for Chinese women. Clinical predictors included in the model were age at menarche, age at first live birth, waist-to-hip ratio, family history of breast cancer, and a previous diagnosis of benign breast disease. The utility of the models in risk stratification was evaluated by estimating the proportion of breast cancer patients in the general population that could be accounted for above a given risk threshold as predicted by the models. All statistical tests were two-sided. Results Eight SNPs (rs2046210, rs1219648, rs3817198, rs8051542, rs3803662, rs889312, rs10941679, and rs13281615), each of which reflected a genetically independent locus, were found to be associated with the risk of breast cancer. A dose-response association was observed between the risk of breast cancer and the genetic risk score, which is an aggregate measure of the effect of these eight SNPs (odds ratio for women in the highest quintile of genetic risk score vs those in the lowest = 1.85, 95% confidence interval = 1.58 to 2.18, Ptrend = 2.5 × 10-15). The genetic risk score, the waist-to-hip ratio, and a previous diagnosis of benign breast disease were the top three predictors of the risk of breast cancer, each contributing statistically significantly (P <. 001) to the full risk assessment model. The model, with a c statistic of 0.6295 after adjustment for overfitting, showed promise for stratifying women into different risk groups; women in the top 30% risk group accounted for nearly 50% of the breast cancers diagnosed in the general population. Conclusion A risk assessment model that includes both genetic markers and clinical predictors may be useful to classify Asian women into relevant risk groups for cost-efficient screening and other prevention programs. © 2010 The Author. Published by Oxford University Press. Source

Mukolo A.,Vanderbilt University | Villegas R.,Vanderbilt Epidemiology Center | Aliyu M.,Vanderbilt University | Wallston K.A.,Vanderbilt University
AIDS and Behavior | Year: 2013

Early commencement of antiretroviral treatment can be beneficial and economical in the long run. Despite global advances in access to care, a significant proportion of adults presenting at HIV/AIDS care facilities present with advanced HIV disease. Understanding factors associated with late presentation for HIV/AIDS services is critical to the development of effective programs and treatment strategies. Literature on factors associated with late presentation for an HIV diagnosis is reviewed. Highlighted is the current emphasis on socio-demographic factors, the limited exploration of psychosocial correlates, and inconsistencies in the definition of late presentation that make it difficult to compare findings across different studies. Perspectives based on experiences from resource limited settings are underreported. Greater exploration of psychosocial predictors of late HIV diagnosis is advocated for, to guide future intervention research and to inform public policy and practice targeted at 'difficult to reach' populations. © 2011 Springer Science+Business Media, LLC. Source

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