Yeunjung Kim1, Jingkai Wei2, Jessica Citronberg3, Terryl Hartman4, Veronika Fedirko4, Michael Goodman4. 1. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, U.S.A. Department of Internal Medicine, University of Maryland School of Medicine, Baltimore, MD, U.S.A. 2. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, U.S.A. Department of Epidemiology, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, U.S.A. jingkai@live.unc.edu. 3. Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, U.S.A. 4. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, U.S.A. Winship Cancer Institute, Emory University, Atlanta, GA, U.S.A.
Abstract
BACKGROUND: Epidemiological studies of selenium and vitamin E, two antioxidants hypothesized to reduce prostate cancer risk, have shown no discernible benefit. It has been proposed, however, that tobacco smoking may modify the effect of these nutrients. MATERIALS AND METHODS: We performed a meta-analysis of studies evaluating the relation of vitamin E and selenium exposure to prostate cancer risk in never smokers vs. ever smokers and, when feasible, former and current smokers. Overall and stratum-specific meta-risk ratios (meta-RRs) and 95% confidence intervals (CIs) were calculated using random-effects models. RESULTS: A total of 21 studies have met the inclusion criteria. Meta-RR (95% CI) estimates of prostate cancer associated with vitamin E use were 1.03 (0.95-1.11) in never smokers and 0.98 (0.90-1.07) in ever-smokers. For selenium, meta-RRs were 1.09 (0.78-1.52 and 0.76 (0.60-0.96) for never and ever-smokers, respectively; however, results for current smokers were weaker than those for former smokers. Sub-analyses according to different exposure assessment methods and outcome definitions produced similar results across strata. CONCLUSION: The association between vitamin E and prostate cancer is not modified by smoking. Selenium exposure is associated with lower prostate cancer risk among ever-smokers; however, the lack of an association for current smokers indicates that this finding needs to be interpreted with caution. Copyright
BACKGROUND: Epidemiological studies of selenium and vitamin E, two antioxidants hypothesized to reduce prostate cancer risk, have shown no discernible benefit. It has been proposed, however, that tobacco smoking may modify the effect of these nutrients. MATERIALS AND METHODS: We performed a meta-analysis of studies evaluating the relation of vitamin E and selenium exposure to prostate cancer risk in never smokers vs. ever smokers and, when feasible, former and current smokers. Overall and stratum-specific meta-risk ratios (meta-RRs) and 95% confidence intervals (CIs) were calculated using random-effects models. RESULTS: A total of 21 studies have met the inclusion criteria. Meta-RR (95% CI) estimates of prostate cancer associated with vitamin E use were 1.03 (0.95-1.11) in never smokers and 0.98 (0.90-1.07) in ever-smokers. For selenium, meta-RRs were 1.09 (0.78-1.52 and 0.76 (0.60-0.96) for never and ever-smokers, respectively; however, results for current smokers were weaker than those for former smokers. Sub-analyses according to different exposure assessment methods and outcome definitions produced similar results across strata. CONCLUSION: The association between vitamin E and prostate cancer is not modified by smoking. Selenium exposure is associated with lower prostate cancer risk among ever-smokers; however, the lack of an association for current smokers indicates that this finding needs to be interpreted with caution. Copyright
Authors: Domenico Ferro; Francesco Baratta; Daniele Pastori; Nicholas Cocomello; Alessandra Colantoni; Francesco Angelico; Maria Del Ben Journal: Nutrients Date: 2020-09-10 Impact factor: 5.717
Authors: Noah C Peeri; Jordan H Creed; Gabriella M Anic; Reid C Thompson; Jeffrey J Olson; Renato V LaRocca; Sajeel A Chowdhary; John D Brockman; Travis A Gerke; L Burton Nabors; Kathleen M Egan Journal: Cancer Epidemiol Date: 2018-05-25 Impact factor: 2.984