Geneviève Van Maele-Fabry1, Noömi Lombaert2, Dominique Lison3. 1. Université catholique de Louvain, SSS/IREC/LTAP (Louvain Center for Toxicology and Applied Pharmacology), Avenue E. Mounier 53, bte B1.52.12, B-1200 Brussels, Belgium. Electronic address: genevieve.vanmaele@uclouvain.be. 2. International Zinc/Cadmium Association, Avenue de Tervueren 168/Box 4, B-1150 Brussels, Belgium. Electronic address: nlombaert@zinc.org. 3. Université catholique de Louvain, SSS/IREC/LTAP (Louvain Center for Toxicology and Applied Pharmacology), Avenue E. Mounier 53, bte B1.52.12, B-1200 Brussels, Belgium. Electronic address: dominique.lison@uclouvain.be.
Abstract
BACKGROUND: With tobacco smoking, diet is the main source of cadmium (Cd) exposure in the general population. The carcinogenic and estrogenic activities of Cd make it a contaminant of potential concern for hormone-dependent cancers including breast cancer. Postmenopausal women represent the most appropriate population to investigate the possible impact of exogenous factors with potential estrogenic activity on breast cancer as, after menopause, their estrogenic influence is predominant. OBJECTIVES: We systematically reviewed available studies on the association between dietary exposure to Cd and breast cancer focusing on postmenopausal women. A meta-analysis combining the risk estimators was performed and potential sources of between studies heterogeneity were traced. METHODS: Studies were searched from MEDLINE through 31 January 2015 and from the reference lists of relevant publications. Six eligible studies published between 2012 and 2014 were identified and relative risk estimates were extracted. Meta-rate ratio estimates (mRR) were calculated according to fixed and random-effect models. Meta-analyses were performed on the whole set of data and separate analyses were conducted after stratification for study design, geographic location, use of hormone replacement therapy (HRT), tumor estrogen receptor status (ER+ or ER-), progesterone receptor status (PGR+ or PGR-), body mass index (BMI), smoker status, zinc or iron intake. RESULTS: No statistically significant increased risk of breast cancer was observed when all studies were combined (mRR=1.03; 95% confidence interval [CI]: 0.89-1.19). Several sources of heterogeneity and inconsistency were identified, including smoker status, HRT use, BMI, zinc and iron intake. Inconsistency was also strongly reduced when only considering ER-, PGR-, tumors subgroups from USA and from Japan. The risks were, however, not substantially modified after stratifications. No evidence of publication bias was found. CONCLUSION: The present study does not provide support for the hypothesis that dietary exposure to Cd increases the risk of breast cancer in postmenopausal women. Misclassification in dietary Cd assessment in primary studies could have biased the results towards a finding of no association.
BACKGROUND: With tobacco smoking, diet is the main source of cadmium (Cd) exposure in the general population. The carcinogenic and estrogenic activities of Cd make it a contaminant of potential concern for hormone-dependent cancers including breast cancer. Postmenopausal women represent the most appropriate population to investigate the possible impact of exogenous factors with potential estrogenic activity on breast cancer as, after menopause, their estrogenic influence is predominant. OBJECTIVES: We systematically reviewed available studies on the association between dietary exposure to Cd and breast cancer focusing on postmenopausal women. A meta-analysis combining the risk estimators was performed and potential sources of between studies heterogeneity were traced. METHODS: Studies were searched from MEDLINE through 31 January 2015 and from the reference lists of relevant publications. Six eligible studies published between 2012 and 2014 were identified and relative risk estimates were extracted. Meta-rate ratio estimates (mRR) were calculated according to fixed and random-effect models. Meta-analyses were performed on the whole set of data and separate analyses were conducted after stratification for study design, geographic location, use of hormone replacement therapy (HRT), tumor estrogen receptor status (ER+ or ER-), progesterone receptor status (PGR+ or PGR-), body mass index (BMI), smoker status, zinc or iron intake. RESULTS: No statistically significant increased risk of breast cancer was observed when all studies were combined (mRR=1.03; 95% confidence interval [CI]: 0.89-1.19). Several sources of heterogeneity and inconsistency were identified, including smoker status, HRT use, BMI, zinc and iron intake. Inconsistency was also strongly reduced when only considering ER-, PGR-, tumors subgroups from USA and from Japan. The risks were, however, not substantially modified after stratifications. No evidence of publication bias was found. CONCLUSION: The present study does not provide support for the hypothesis that dietary exposure to Cd increases the risk of breast cancer in postmenopausal women. Misclassification in dietary Cd assessment in primary studies could have biased the results towards a finding of no association.
Authors: Aleksandra Repić; Petar Bulat; Biljana Antonijević; Marko Antunović; Jelena Džudović; Aleksandra Buha; Zorica Bulat Journal: Environ Sci Pollut Res Int Date: 2019-12-06 Impact factor: 4.223
Authors: Aleksandra Buha; David Wallace; Vesna Matovic; Amie Schweitzer; Branislav Oluic; Dusan Micic; Vladimir Djordjevic Journal: Biomed Res Int Date: 2017-11-16 Impact factor: 3.411