Dan Guo1, Michael Hendryx2, Xiaoyun Liang3, JoAnn E Manson4, Ka He5, Mara Z Vitolins6, Yueyao Li7, Juhua Luo8. 1. School of Social Development and Public Policy, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875, China. 2. Department of Environmental and Occupational Health, School of Public Health, Indiana University Bloomington, 1025 E 7th street, Bloomington, IN, 47405, USA. 3. School of Social Development and Public Policy, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875, China. liangxiaoyun@bnu.edu.cn. 4. Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, 900 Commonwealth Avenue, 3rd Fl, Boston, MA, 02215, USA. 5. Department of Epidemiology, Mailman School of Public Health, Columbia University Irving Medical Center, 622 W. 168th Street, New York, NY, 10032, USA. 6. Department of Epidemiology and Prevention, School of Medical, Wake Forest University, 475 Vine Street, Winston-Salem, NC, 27157, USA. 7. Department of Dermatology, Brown Alpert Medical School, 336 Eddy Street, Providence, RI, 02903, USA. 8. Department of Epidemiology and Biostatistics, School of Public Health, Indiana University Bloomington, 1025 E 7th street, Bloomington, IN, 47405, USA.
Abstract
PURPOSE: It has been hypothesized that selenium (Se) can prevent cancer, and that Se deficiency may be associated with an increased risk of breast cancer. However, findings from epidemiological studies have been inconsistent. The objective of this study was to assess the association between Se intake and risk of breast cancer in the Women's Health Initiative (WHI). METHODS: This study included 145,033 postmenopausal women 50-79 years who completed baseline questionnaires between October 1993 and December 1998, which addressed dietary and supplemental Se intake and breast cancer risk factors. The association between baseline Se intake and incident breast cancer was examined in Cox proportional hazards analysis. RESULTS: During a mean follow-up of 15.5 years, 9487 cases of invasive breast cancer were identified. Total Se (highest versus lowest quartile: HR 1.00, 95% CI 0.92-1.09, Ptrend = 0.66), dietary Se (highest versus lowest quartile: HR 0.99, 95% CI 0.89-1.08, Ptrend = 0.61), and supplemental Se (yes versus no: HR 0.99, 95% CI 0.95-1.03) were not associated with breast cancer incidence. CONCLUSIONS: This study indicates that Se intake is not associated with incident breast cancer among postmenopausal women in the United States. Further studies are needed to confirm our findings by using biomarkers such as toenail Se to reduce the potential for misclassification of Se status.
PURPOSE: It has been hypothesized that selenium (Se) can prevent cancer, and that Se deficiency may be associated with an increased risk of breast cancer. However, findings from epidemiological studies have been inconsistent. The objective of this study was to assess the association between Se intake and risk of breast cancer in the Women's Health Initiative (WHI). METHODS: This study included 145,033 postmenopausal women 50-79 years who completed baseline questionnaires between October 1993 and December 1998, which addressed dietary and supplemental Se intake and breast cancer risk factors. The association between baseline Se intake and incident breast cancer was examined in Cox proportional hazards analysis. RESULTS: During a mean follow-up of 15.5 years, 9487 cases of invasive breast cancer were identified. Total Se (highest versus lowest quartile: HR 1.00, 95% CI 0.92-1.09, Ptrend = 0.66), dietary Se (highest versus lowest quartile: HR 0.99, 95% CI 0.89-1.08, Ptrend = 0.61), and supplemental Se (yes versus no: HR 0.99, 95% CI 0.95-1.03) were not associated with breast cancer incidence. CONCLUSIONS: This study indicates that Se intake is not associated with incident breast cancer among postmenopausal women in the United States. Further studies are needed to confirm our findings by using biomarkers such as toenail Se to reduce the potential for misclassification of Se status.
Entities:
Keywords:
Breast cancer; Incidence; Postmenopausal women; Selenium intake