Leila Jouybari1, Faezeh Kiani2, Akbar Akbari3, Akram Sanagoo4, Fatemeh Sayehmiri5, Jan Aaseth6, Max Stanley Chartrand7, Kourosh Sayehmiri8, Salvatore Chirumbolo9, Geir Bjørklund10. 1. Nursing Research Center, Golestan University of Medical Sciences, Gorgan, Iran. Electronic address: jouybari@goums.ac.ir. 2. Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran. 3. Department of Immunology, Abadan School of Medical Sciences, Abadan, Iran. 4. Nursing Research Center, Golestan University of Medical Sciences, Gorgan, Iran. Electronic address: sanagoo@goums.ac.ir. 5. Student Research Committee, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: fsayehmiri@yahoo.com. 6. Research Department, Innlandet Hospital Trust, Brumunddal, Norway; Inland Norway University of Applied Sciences, Elverum, Norway. 7. DigiCare Behavioral Research, Casa Grande, AZ, USA. 8. Prevention Center of Social Mental Injuries, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran. 9. Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Italy. 10. Council for Nutritional and Environmental Medicine, Mo i Rana, Norway. Electronic address: bjorklund@conem.org.
Abstract
BACKGROUND: Breast cancer is the most commonly occurring neoplasm in females, comprising 16% of all female cancers worldwide. Various studies indicate some discrepancies regarding zinc (Zn) levels in various samples of breast cancer patients. OBJECTIVE: The present study evaluated by meta-analysed the published data for Zn levels analyzed in breast tissue, plasma, serum, and hair samples and its relationship with breast cancer. METHODS: The present meta-analysis included 36 studies, all of which were published in the years between 1984 to 2017 and selected by searching the databases MEDLINE, EMBASE, Cochrane Library, PubMed, Scopus, and the ISI Web of Knowledge. The articles were analyzed, and I² statistics were used to examine heterogeneity. The objective analysis was performed on data from the 36 studies, with total 1699 study subjects and 2009 controls. RESULTS: Significant statistical differences overall were observed, based on a random effects model (SMD (95 % CI), -0.78[-1.40, -0.16], P = 0.014). Data from 19 of these studies indicated significant statistical differences between cancerous patients and controls with regard to serum and plasma Zn concentration (SMD [(95 %CI): -1.61(-2.43, -0.79)]. There was a significant statistical difference between the breast tissue and hair as regards Zn status (SMD (95%CI): 2.32(1.42, 3.21)) and (SMD (95v%CI): -1.80(-3.41, -0.20), respectively. Zn concentration levels typically decreased in blood and hair samples of patients with breast cancer, whereas it was elevated in tumor tissues. CONCLUSIONS: There is a significant relationship between lowered serum Zn concentrations and risk of breast cancer onset or recurrences in women, but because of high heterogeneity, we recommend other primary studies.
BACKGROUND:Breast cancer is the most commonly occurring neoplasm in females, comprising 16% of all female cancers worldwide. Various studies indicate some discrepancies regarding zinc (Zn) levels in various samples of breast cancerpatients. OBJECTIVE: The present study evaluated by meta-analysed the published data for Zn levels analyzed in breast tissue, plasma, serum, and hair samples and its relationship with breast cancer. METHODS: The present meta-analysis included 36 studies, all of which were published in the years between 1984 to 2017 and selected by searching the databases MEDLINE, EMBASE, Cochrane Library, PubMed, Scopus, and the ISI Web of Knowledge. The articles were analyzed, and I² statistics were used to examine heterogeneity. The objective analysis was performed on data from the 36 studies, with total 1699 study subjects and 2009 controls. RESULTS: Significant statistical differences overall were observed, based on a random effects model (SMD (95 % CI), -0.78[-1.40, -0.16], P = 0.014). Data from 19 of these studies indicated significant statistical differences between cancerous patients and controls with regard to serum and plasma Zn concentration (SMD [(95 %CI): -1.61(-2.43, -0.79)]. There was a significant statistical difference between the breast tissue and hair as regards Zn status (SMD (95%CI): 2.32(1.42, 3.21)) and (SMD (95v%CI): -1.80(-3.41, -0.20), respectively. Zn concentration levels typically decreased in blood and hair samples of patients with breast cancer, whereas it was elevated in tumor tissues. CONCLUSIONS: There is a significant relationship between lowered serum Zn concentrations and risk of breast cancer onset or recurrences in women, but because of high heterogeneity, we recommend other primary studies.
Authors: Nicole M Niehoff; Katie M O'Brien; Alexander P Keil; Keith E Levine; Chamindu Liyanapatirana; Laura G Haines; Suramya Waidyanatha; Clarice R Weinberg; Alexandra J White Journal: Am J Epidemiol Date: 2021-11-02 Impact factor: 4.897