Chromium as a Risk Factor for Breast Cancer: A Meta-Analysis

Abstract

Background: Chromium (Cr) is a transition metal, natural element. Chromium is the 21st most abundant element in Earth's crust. Cr is found in soil, rocks and living organisms. It may have various oxidation states, from -2 to +6, but most of these states are too unstable to exist in any significant quantities. The purpose of this review and meta-analysis is to critically assess the scientific evidence on the carcinogenic effects of chromium (Cr) and to determine whether there is currently sufficient evidence to suggest that that there is a link between chromium levels in hair and blood serum and breast cancer in women. Material and methods: Research on the relationship between heavy metal chromium and the risk of developing breast cancer has been searched in PubMed, EMBASE, Web of Science, Scopus among papers published between January 2000 and September 2020. The search used the following terms (MeSH): breast cancer, women, trace elements, metals, chromium, chemically-induced, hair, serum using additional terms. Results: In the second group of comparisons of women from "ecologically clean" districts of Aktobe Region, there were significantly lower indicators of the microelements in tumor tissue. The amount of Fe ranges from 38.46 to 65.39 ug/g (average 49.56±5.81 ug/g), Cu from 2.8 to 6.69 ug/g (average 5.06±1.01 ug/g), Zn from 1.89 to 5.38 ug/g (average 3.88±0.89 ug/g), Cr from zero to 6,1 ug/g (average 2.13±1.29 ug/g), Ni from 0.11 to 0.42 ug/g (average 0.28±0.067 ug/g) и Pb from zero to 0.19 ug/g (average 0.098±0.06 ug/g). Conclusion: The article established that women who live or work in ecologically polluted areas or have problems with micronutrient exchange need in-depth screening and more frequent screening for early detection of pre-and breast cancer.

Effect of hexavalent chromium on growth performance and metabolism in broiler chicken

“…Heavy metal contamination in the environment (such as air, soil, and groundwater) has been a serious concern for animal husbandry and food safety, which affect the living organisms health by perturbing gut microbiota or metabolism ( 16 ). Hexavalent chromium is considered a hazardous metal contaminant, and there is increasing evidence that hexavalent chromium can cause cancer, tumor development, gastrointestinal disorders, and liver damage ( 3 , 16 , 17 ). The Cr (VI) promotes the formation of active oxygen forms (AFCs), followed by cellular damage ( 3 , 18 ).…”

“…The deposition and proliferation of heavy metals have seriously affected the ecosystem ( 1 , 2 ). Chromium is the most abundant and natural element present in rocks, soil and living things ( 3 ). Chromium has various oxidation states from −2 to +6 ( 3 ), of which Cr (VI) is widely used in industrial production such as pigments, metallurgy, plastics, and chromite.…”

“…Chromium is the most abundant and natural element present in rocks, soil and living things ( 3 ). Chromium has various oxidation states from −2 to +6 ( 3 ), of which Cr (VI) is widely used in industrial production such as pigments, metallurgy, plastics, and chromite. Also, Cr (VI) is often found in industrial waste, sewage, combustion exhaust gas and cigarette smoke ( 4 ).…”

“…Previous studies have shown that Cr (VI) can change gene expression and induce the production of a large number of free radicals, however, the body is unable to effectively remove accumulated free radicals in a timely manner and is in a state of oxidative stress ( 8 , 9 ). Currently, sufficient evidence demonstrated that Cr (VI) is associated with diseases in humans or animals ( 10 ), for example, Cr (VI) exposure to women resulted in breast cancer ( 3 ). Simultaneously, Cr (VI) contamination also affects aquatic systems and products, and in Ni’s study, hexavalent chromium caused severe toxic effects on the liver of marine medaka ( 11 ).…”

Adverse Human Health Effects of Chromium by Exposure Route: A Comprehensive Review Based on Toxicogenomic Approach

“…Cr is an important metal in pigment manufacturing, painting, metal plating, wood treating, and leather tanning, and it is used in metallurgy and refractory material production, among various other applications [ 5 ]. Cr is abundant in the Earth’s crust, in which it occurs at a level of 100 μg/g, and its toxicity depends on its chemical state [ 6 , 7 ]. Its two most prevalent oxidation forms are trivalent and hexavalent, but whereas trivalent Cr is largely non-toxic, hexavalent Cr is toxic and carcinogenic in living organisms.…”