Trace elements and heavy metals in hair of stage III breast cancer patients

Serum and urinary cadmium and zinc profiles in breast cancer patients and their association with estrogen and HER-2 receptors, and redox status

BACKGROUND

Cadmium, a metal implicated in environmental toxicity, is linked to tumor growth and cancer. On the other hand, zinc plays an essential function in oxidative stress and can counteract cadmium toxicity and carcinogenicity. This research aims to evaluate the urine and serum values of cadmium and zinc in breast cancer (BC) patients and their association with estrogen (ER) and HER-2 receptors, and redox status.

METHODS

Forty BC patients and thirty healthy subjects participated in this study. Cadmium and zinc levels were measured in serum and urine samples by atomic absorption spectrophotometer. Redox status markers were determined by colorimetric methods.

RESULTS

The amount of cadmium in the BC patients was substantially greater than in the healthy subjects. Zinc levels were significantly lower in patients with BC compared to controls. Breast cancer patients with ER-positive tumors had significantly higher urinary cadmium concentrations (U-Cd) compared to patients with ER-negative tumors. There was no significant difference between the parameters of redox status and the value of cadmium and zinc between patients with BC in the HER-2 subgroup. Malondialdehyde levels in the serum were substantially greater in BC patients than in healthy subjects. Total thiol level and catalase and superoxide dismutase activity in serum were considerably lower in BC patients than in healthy subjects.

CONCLUSIONS

The etiology of BC may be due to a disturbance in redox status and levels of elements. Increasing U-Cd and lowering zinc levels in the serum could be the risk factors for BC.

Heavy metals in biological samples of cancer patients: a systematic literature review

The majority of the so-called heavy metals are suspected to be involved in a number of pathologies and play a role in human carcinogenesis. Some of them (i.e. arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg) and nickel (Ni)) have been defined as carcinogens, increasing the susceptibility of tumor development and progression in humans. Moreover, Ni, Cr, Cd, Hg, and Pb together with zinc (Zn) and iron (Fe), may be capable of stimulating the progression of breast cancer and reducing a patient's sensitivity to treatment through alterations to DNA methylation. In patients with gastric cancers, levels of various heavy metals are augmented and hypothesized to amplify the expression of the human epidermal growth factor receptor type 2 gene. Cd may increase the risk of lung cancer development and have a negative impact on the overall survival of lung cancer patients. To investigate the relation between heavy metals in biological samples and risk, occurrence and survival cancer individuals, a comprehensive review work was performed, with a focus on breast, lung, prostate and gastric cancers. An extensive search strategy was devised to ensure relevant literature could be identified, with the PECO framework being adopted to facilitate this and identify key search terms. As evidenced in this review, there is substantial data to support the hypothesis that heavy metals influence tumor development and progression. Unluckily the number of papers dealing with the determination of metals directly in samples from cancer tissues is still rather limited, so we decided to expand the scope of this review also to analyses carried out on other biological samples, as urine, plasma, hair, nail, etc. The studies reviewed showed that several limitations and current knowledge gaps are present in the literature that require further investigation to improve our comprehension of the impact of different heavy metals on tumorigenesis.

Blood Lead Level as Marker of Increased Risk of Ovarian Cancer in BRCA1 Carriers

BRCA1 mutations substantially elevate the risks of breast and ovarian cancer. Various modifiers, including environmental factors, can influence cancer risk. Lead, a known carcinogen, has been associated with various cancers, but its impact on BRCA1 carriers remains unexplored. A cohort of 989 BRCA1 mutation carriers underwent genetic testing at the Pomeranian Medical University, Poland. Blood lead levels were measured using inductively coupled plasma mass spectrometry. Each subject was assigned to a category based on their tertile of blood lead. Cox regression analysis was used to assess cancer risk associations. Elevated blood lead levels (>13.6 μg/L) were associated with an increased risk of ovarian cancer (univariable: HR = 3.33; 95% CI: 1.23-9.00; p = 0.02; multivariable: HR = 2.10; 95% CI: 0.73-6.01; p = 0.17). No significant correlation was found with breast cancer risk. High blood lead levels are associated with increased risk of ovarian cancer in BRCA1 carriers, suggesting priority for preventive salpingo-oophorectomy. Potential risk reduction strategies include detoxification. Validation in diverse populations and exploration of detoxification methods for lowering lead levels are required.

Relationship Between Arsenic in Biological Media and Breast Cancer: A Systematic Review and Meta-Analysis

Arsenic (As) is an environmental pollutant with carcinogenic effects and breast cancer (BC) is a prevalent malignant tumor in women. The goal of this meta-analysis was to establish a connection between biological sample As levels and the risk of developing BC. Pub Med, Web of Science, Scopus, and Elsevier were used to systematically screen the literature published between 1990 and 2023. The Newcastle-Ottawa scale was also used in assessing the quality of publications. A random-effects model was used to assess the pertinent data that was gleaned from these articles. Using the I2 index the heterogeneity of studies was performed. Egger's test and funnel plots were used to look at publication bias. We identified 16 epidemiologic studies that included 2713 women with BC and 5347 healthy individuals. The results showed that the difference between the case group and the control group was 0.72 [95% confidence interval (CI) 0.30 to 1.14]. According to subgroup analysis, the value for blood was 0.18 [95% CI 0.01 to 0.35], whereas the value for hair was 3.08 [95% CI 0.19 to 5.97]. The present meta-analysis suggested that As levels were significantly higher in BC patients than in controls. This systematic review and meta-analysis provide evidence supporting a positive relationship between arsenic levels in biological media and BC risk. These findings highlight the importance of further research to investigate the mechanisms of this association and explore potential preventive strategies to reduce the adverse effects of arsenic exposure on BC.

Serum Levels of Copper and Zinc and Survival in Breast Cancer Patients

There is emerging interest in the relationship between several serum micronutrients and the prognosis of patients with breast cancer. The relationship between serum zinc and copper levels and breast cancer prognosis is unclear. In our study, we included 583 patients with breast cancer diagnosed between 2008 and 2015 in the region of Szczecin, Poland. In a blood sample obtained before treatment, serum zinc and copper levels were quantified by mass spectroscopy. Each patient was assigned to one of four categories (quartiles) based on the distribution of the elements in the entire cohort. Patients were followed from diagnosis to death over a mean of 10.0 years. The 10-year overall survival was 58.3% for women in the highest and 82.1% for those in the lowest quartile of serum copper/zinc ratio (p < 0.001). The multivariate hazard ratio (HR) for breast cancer death was 2.07 (95% CI 1.17-3.63; p = 0.01) for patients in the highest quartile of serum copper/zinc ratio compared to those in the lowest. There is evidence that the serum zinc level and copper/zinc ratio provide an independent predictive value for overall survival and breast cancer-specific survival after breast cancer diagnosis.

Differences of genomic alterations and heavy metals in non-small cell lung cancer with different histological subtypes

PURPOSE

This study aimed to explore the correlations among heavy metals concentration, histologic subtypes and molecular characteristics in patients with non-small cell lung cancer (NSCLC).

METHODS

In this study, an NGS panel of 82 tumor-associated genes was used to identify genomic alternations in 180 newly diagnosed patients with NSCLC. The concentrations of 18 heavy metals in the serum samples were detected by inductively coupled plasma emission spectrometry (ICP-MS).

RESULTS

A total of 243 somatic mutations of 25 mutant genes were identified in 115 of 148 patients with LUAD and 45 somatic mutations of 15 mutant genes were found in 24 of 32 patients with LUSC. The genomic alternations, somatic interactions, traditional serum biomarkers, and heavy metals were markedly different between patients with LUAD and LUSC. Moreover, patients with LUSC were significantly positively correlated with Ba, but not LUAD. Lastly, patients with EGFR mutations presented significant negative correlations with Cd and Sr, whereas patients with TP53 mutations showed a significant positive correlation with Pb.

CONCLUSION

The genomic alternations, somatic interactions, traditional serum biomarkers, and heavy metals were different between patients with LUAC and LUSC, and heavy metals (e.g., Ba, Pb, and Cd) may contribute to the tumorigenesis of NSCLC with different histological and molecular subtypes.

Survey to identify the metal accumulation pathway in humans using hair and nail as biomarkers from fisherfolk population

Human hair and nail samples from Cuddalore fisherfolk populations were used as biomarkers for assessing metal concentrations in humans. Hair samples from 80 participants (47 men and 33 women) and nail samples from 40 participants (21 men and 19 women) were collected, and the concentrations of Cd, Cu, Pb, and Zn were assessed using an atomic absorption spectrophotometer (AAS). Metal data from AAS were compared with the survey questionnaire's personal and dietary parameters. Results indicate that both personal and dietary parameters may influence metal exposure; however, majority of the sources may have originated from metal-contaminated seafood. Higher metal accumulation in communities, especially those which consume seafood on a daily basis, may increase the possibility for them to get affected by metal-related diseases. Based on environmental parameters, people who live ≤500 m from industrial zones accumulate more metals. Further extensive studies with more individuals and more questionnaire parameters are needed to identify the metal accumulation pathway in humans.

Potentially toxic elements exposure biomonitoring in the elderly around the largest polymetallic rare earth ore mining and smelting area in China

Potentially toxic elements (PTEs) can be released during mining operations and ore processing. The pollution and health risk related to PTEs in total suspended particulates (TSPs) around the largest polymetallic rare earth mining area (Bayan Obo) and smelting area (Baotou) in Inner Mongolia, China, were evaluated. PTEs in the hair of the elderly living in these two areas and a reference area (Hohhot) were also examined. Relationships between PTEs in TSPs and hair with categorical factors (location, gender, etc.) were also modeled. Multivariate statistical analyses were carried out to analyze the possible sources of the PTEs in TSPs. The bubble maps of the concentrations of PTEs indicated that high concentrations of PTEs were near the industrial area where smelting plants and power plants were located. In addition, health risks were assessed for adults in the mining and smelting area. The carcinogenic risk of Cr was high for residents in the study areas. Also, the residents were exposed to a non-carcinogenic risk of Ni. Significant mean value differences were observed between PTEs in the hair of the elderly in Baotou and Hohhot. Results of the linear regression model indicated that around 31 % of the Pb in hair could be explained by the linear regression model, it could be affected by Ni and Zn in TSPs, but location, gender, and sampling time showed no significant contribution. Age was not significantly associated with the PTEs levels in hair in Baotou and Bayan Obo. The results provide important scientific evidence for a better understanding of the effects of PTEs in TSPs in polymetallic ore mining and smelting areas.

Dietary Trace Element Intake and Risk of Breast Cancer: A Mini Review

Trace elements are essentially required for various physiological and metabolic functions, and any disturbance in the trace elements homeostasis may result in the development of chronic diseases including breast cancer. Breast cancer is the most prevalent cancer type reported in women equally affecting both the high-income and low-income countries. This review therefore aimed to evaluate the impact of dietary trace element intake in relation to the incidence of breast cancer. We focused on five trace elements, thus emphasizing dietary selenium, zinc, iron, copper, and cadmium intake and risk of breast cancer. A systematic approach was applied to perform this review through entering a search term in PubMed and Scopus databases. A total of 24 articles were included after meeting the inclusion and exclusion criteria. Most of the studies regarding dietary iron intake showed a detrimental effect of increased dietary heme iron on breast cancer incidence risk. In addition, there is a limited evidence of high dietary intake of selenium and zinc to reduce the risk of breast cancer. Also, a few studies showed a relationship between high cadmium consumption and risk of breast cancer. More studies related to cadmium and copper exposure are needed to confirm this relationship. As a result, the findings of this review suggested that high dietary heme iron is a potential risk factor for breast cancer.

Relationships Between Biological Heavy Metals and Breast Cancer: A Systematic Review and Meta-Analysis

Introduction

Heavy metals were classified as essential, probably essential, and potentially toxic in the general population. Until now, it has been reported inconsistently on the association between heavy metals and BC. In this meta-analysis, we aimed to assess the association between heavy metals and BC and review the potential mechanisms systematically.

Methods

We searched for epidemiological studies in English about the association between heavy metals and BC published before September 2020 in PubMed, Web of Science, and Embase databases. In total 36 studies, comprising 4,151 individuals from five continents around the world were identified and included.

Results

In all biological specimens, Cu, Cd, and Pb concentrations were higher, but Zn and Mn concentrations were lower in patients with BC than in non-BC participants [SMD (95% CIs): 0.62 (0.12, 1.12); 1.64 (0.76, 2.52); 2.03 (0.11, 3.95); −1.40 (−1.96, −0.85); −2.26 (−3.39, −1.13); p = 0.01, 0.0003, 0.04, <0.0001, <0.0001]. Specifically, higher plasma or serum Cu and Cd, as well as lower Zn and Mn, were found in cases [SMD (95% CIs): 0.98 (0.36, 1.60); 2.55 (1.16, 3.94); −1.53 (−2.28, −0.78); −2.40 (−3.69, −1.10); p = 0.002, 0.0003, <0.0001, 0.0003]; in hair, only lower Zn was observed [SMD (95% CIs): −2.12 (−3.55, −0.68); p = 0.0004]. Furthermore, the status of trace elements probably needs to be re-explored, particularly in BC. More prospective studies, randomized clinical trials, and specific pathogenic studies are needed to prevent BC. The main mechanisms underlying above-mentioned findings are comprehensively reviewed.

Conclusion

For BC, this review identified the current knowledge gaps which we currently have in understanding the impact of different heavy metals on BC.

Systematic Review Registration

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020176934, identifier: CRD42020176934.

Recent advances in the application of metallomics in diagnosis and prognosis of human cancer

Metals play a critical role in human health and diseases. In recent years, metallomics has been introduced and extensively applied to investigate the distribution, regulation, function, and crosstalk of metal(loid) ions in various physiological and pathological processes. Based on high-throughput multielemental analytical techniques and bioinformatics methods, it is possible to elucidate the correlation between the metabolism and homeostasis of diverse metals and complex diseases, in particular for cancer. This review aims to provide an overview of recent progress made in the application of metallomics in cancer research. We mainly focuses on the studies about metallomic profiling of different human biological samples for several major types of cancer, which reveal distinct and dynamic patterns of metal ion contents and the potential benefits of using such information in the detection and prognosis of these malignancies. Elevated levels of copper appear to be a significant risk factor for various cancers, and each type of cancer has a unique distribution of metals in biofluids, hair/nails, and tumor-affected tissues. Furthermore, associations between genetic variations in representative metalloprotein genes and cancer susceptibility have also been demonstrated. Overall, metallomics not only offers a better understanding of the relationship between metal dyshomeostasis and the development of cancer but also facilitates the discovery of new diagnostic and prognostic markers for cancer translational medicine.

Association between trace elements in cancerous and non-cancerous tissues with the risk of breast cancers in western Iran

This study aimed to assess the tissue content of essential and toxic metals including lead (Pb), cadmium (Cd), arsenic (As), silver (Ag), aluminum (Al), chromium (Cr), copper (Cu), iron (Fe), selenium (Se), and zinc (Zn) in the breast cancerous tissues compared to the non-cancerous tissue. The biopsy specimens of 63 breast cancers along with 63 adjacent healthy tissues in Kurdistan Province, Iran, were collected from 2019 to 2020 and assayed using ICP-MS (Agilent 7900). The results of the Mann-Whitney test illustrated that the concentration of Pb, Cd, As, Cr, Cu, and Se were significantly elevated in cancerous tissue (p < 0.05), while Zn was the only trace element with higher levels in healthy subjects (p < 0.05). Moreover, weak to moderate correlations between elements were observed in the cancerous group including Al-Cr (r=0.60), As-Cu (r=0.52), and Cu-Se (r=0.56). In contrast, no correlation over 0.50 was found between trace elements in the non-cancerous group. Raw risk differences (RDs) accounted for a significant effect for Pb, Cd, As, Ag, Cr, Se, and Zn on the development of breast cancer. In conclusion, elevated levels of As, Cd, Cu, Pb, and Se may contribute to enhancing the risk of breast cancer.

Relationship Between Selenium in Human Tissues and Breast Cancer: a Meta-analysis Based on Case-Control Studies

Breast cancer is a common malignant tumor in women, and the anti-cancer effect of selenium (Se) is recognized. This meta-analysis was designed to determine the relationship between selenium levels in human tissue and breast cancer risk. Literatures published before August 2020 were systematically screened through PubMed, Web of Science, Scopus, and Elsevier. The related publication quality was evaluated by the Newcastle-Ottawa scale. We used random effect models for calculation and conducted sensitivity analysis and evaluation of publication bias. We identified 18 case-control studies, including 3374 women diagnosed with breast cancer and 3582 healthy controls. The results showed that the difference between the case group and the control group was - 0.53 μg/l [95%CI - 0.72 to - 0.34] (P < 0.001). Subgroup analysis showed a serum difference of - 1.14 μg/l [95%CI - 1.70 to - 0.58] (P < 0.001). The value of plasma was - 0.21 μg/l [95% CI - 0.37 to - 0.04] (P = 0.014). The value of toenail was - 0.21 μg/l [95% CI - 0.38 to - 0.03] (P = 0.021). In contrast, selenium levels in hair were not significantly associated with breast cancer risk. In the case-control studies, it was observed that selenium level in human tissues was negatively correlated with the risk of breast cancer, which may improve the understanding of the effects of selenium on human health.

Low Blood-As Levels and Selected Genotypes Appears to Be Promising Biomarkers for Occurrence of Colorectal Cancer in Women

In following study we examined whether blood arsenic (As) levels combined with specific polymorphisms in MT1B, GSTP1, ABCB1, NQO1, CRTC3, GPX1, SOD2, CAT, XRCC1, ERCC2 can be used as a marker for the detection of colorectal cancer (CRC) among Polish women. A retrospective case-control study of CRC included 83 CRC cases and 78 healthy controls. From each study participant pre-treatment peripheral blood was collected for As level measurement by inductively coupled–plasma mass spectrometry (ICP-MS). We estimated the odds ratio (OR) of the association between blood-As levels and CRC using multivariable unconditional logistic regression models. A low blood-As level (0.27–0.67 µg/L) was associated with an increased frequency of CRC (OR: 3.69; p = 0.005). This correlation was significantly greater when participants carried particular gene variants: CAT, rs1001179-nonCC (OR: 19.4; p = 0.001); ABCB1 rs2032582–CC (OR: 14.8; p = 0.024); GPX1 rs1050450-CC (OR: 11.6; p = 0.002) and CRTC3 rs12915189-nonGG (OR: 10.3; p = 0.003). Our study provides strong evidence that low blood-As levels are significantly associated with increased CRC occurrence and that particular gene variants significantly enhanced this correlation however, due to the novelty of these findings, we suggest further validation before a definitive statement that the combined effect of low blood-As levels with specific gene polymorphisms is a suitable CRC biomarker.

Human Hair as a Possible Surrogate Marker of Retained Tissue Gadolinium: A Pilot Autopsy Study Correlating Gadolinium Concentrations in Hair With Brain and Other Tissues Among Decedents Who Received Gadolinium-Based Contrast Agents

OBJECTIVES

We used laser ablation inductively coupled plasma mass spectrometry to quantify gadolinium in hair samples from autopsy cases with gadolinium-based contrast agent (GBCA) exposure. Hair gadolinium data were correlated with gadolinium concentrations in brain, skin, and bone tissues from the same case to investigate a potential noninvasive method for gadolinium quantification and monitoring.

MATERIALS AND METHODS

Medical records from autopsy cases at our institution were screened for history of GBCA exposure. Cases with exposure to a single type of GBCA with the most recent injection occurring within 1 year were identified and included in the study. The concentration of gadolinium in hair samples was analyzed by laser ablation inductively coupled plasma mass spectrometry, and brain (globus pallidus, dentate nucleus, white matter), bone, and skin tissues were analyzed by bulk inductively coupled plasma mass spectrometry. The mean of the maximum value in the hair samples was used to generate a representative measurement of the hair gadolinium concentration for each case. A linear regression analysis between each tissue type and hair was conducted to assess for possible correlation.

RESULTS

Tissue and hair samples from 18 autopsies (16 cases with exposure to GBCA, 2 controls) were included in the study. Comparing the different tissues revealed good correlation between some tissue types. The best model fit occurred between white matter and hair (R = 0.83; P < 0.0001) followed by the comparison between dentate nucleus and hair (R = 0.72; P < 0.0001) and dentate nucleus and skin (R = 0.70; P < 0.0001).

CONCLUSIONS

A significant correlation in this study between hair gadolinium concentrations and brain and skin gadolinium concentrations suggests that hair may serve as a safe and effective biomonitoring tissue for patients who receive GBCA injections.

Micronutrients and Breast Cancer Progression: A Systematic Review

Epidemiological studies on micronutrient consumption have reported protective associations in the incidence and/or progression of various cancer types. Supplementation with some of these micronutrients has been analyzed, showing chemoprotection, low toxicity, antiproliferation, and the ability to modify epigenetic signatures in various cancer models. This review investigates the reported effects of micronutrient intake or supplementation in breast cancer progression. A PubMed search was conducted with the keywords "micronutrients breast cancer progression", and the results were analyzed. The selected micronutrients were vitamins (C, D, and E), folic acid, metals (Cu, Fe, Se, and Zn), fatty acids, polyphenols, and iodine. The majority of in vitro models showed antiproliferative, cell-cycle arrest, and antimetastatic effects for almost all the micronutrients analyzed, but these effects do not reflect animal or human studies. Only one clinical trial with vitamin D and one pilot study with molecular iodine showed favorable overall survival and disease-free interval.

Arsenic Exposure and Breast Cancer Risk: A Re-Evaluation of the Literature

Arsenic is a widespread environmental contaminant and recognized carcinogen for the skin, bladder and lungs. In recent years, there has been an increasing number of studies that have investigated the effects of arsenic exposure and cancer risk at other sites, including the breast. However, to date, the association between arsenic exposure and breast cancer risk remains unclear. This article will provide an overview of arsenic metabolism, the clinically important biomarkers commonly used to assess arsenic exposure, and review the epidemiologic studies examining the role of arsenic exposure on breast cancer risk. Given the large burden of disease associated with breast cancer, it is of the upmost importance to identify risk factors and preventative strategies that could reduce cancer incidence. Limiting exposure to endemic environmental toxins, such as arsenic, represents one such strategy. More studies are required to better ascertain this relationship and to develop the public policy necessary to significantly reduce breast cancer incidence.

Arsenite and cadmium promote the development of mammary tumors

Previous studies demonstrate that the heavy metal cadmium and the metalloid arsenite activate estrogen receptor-alpha in breast cancer cells by forming a high-affinity complex with the ligand-binding domain of the receptor and that environmentally relevant doses of cadmium have estrogen-like activity in vivo. The present study showed that in estrogen-receptor positive cells, arsenite and cadmium increased the global expression of estrogen-responsive genes and that an environmentally relevant dose of arsenite also had estrogen-like activity in vivo. Similar to estrogens, exposure of ovariectomized animals to arsenite induced the expression of the progesterone receptor, GREB1, and c-fos in the mammary gland and the expression of complement C3, c-fos, and cyclin D1 in the uterus and the increase was blocked by the antiestrogen ICI-182,780. When virgin female animals were fed a diet, that mimics exposure to either arsenite or cadmium, and challenged with the chemical carcinogen dimethylbenzanthracene, there was an increase in the incidence of mammary tumors and a decrease in the time to tumor onset, but no difference in the total number of tumors, tumor multiplicity, or total tumor volume. Together with published results, these data showed that environmentally relevant amounts of arsenite and cadmium had estrogen-like activity in vivo and promoted mammary tumorigenesis.

Elemental bioimaging shows mercury and other toxic metals in normal breast tissue and in breast cancers

OBJECTIVE

Exposure to toxic metals such as mercury has been proposed to be a risk factor for the development of breast cancer since some metals can promote genetic mutations and epigenetic changes. We sought to find what toxic metals are present in normal breast tissue and in the tumours of women who had mastectomies for invasive ductal breast carcinoma.

MATERIALS AND METHODS

Formalin-fixed paraffin-embedded blocks from mastectomies for breast carcinoma were examined from 50 women aged 34-69 years. Paraffin blocks selected for elemental analysis were from breast tissue not involved by carcinoma and from the carcinoma itself. Seven micrometer-thick sections were stained with autometallography to demonstrate the presence of mercury, and subjected to laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to confirm the presence of mercury and to detect other toxic metals.

RESULTS

Autometallography-detected mercury was seen in intraductal secretions and some luminal epithelial cells of normal breast lobules in 26 (55%) of the 47 samples where lobules were present, and in 10 (23%) of carcinomas from the 44 samples where carcinoma was present. In eight samples ductal carcinoma in situ was present and one of these contained mercury. LA-ICP-MS confirmed the presence of mercury in samples that stained with autometallography, and detected lead, iron, nickel, aluminium, chromium and cadmium in some samples.

CONCLUSIONS

Mercury was present in normal breast lobules in more than half of mastectomy samples that contained an invasive carcinoma, and in a smaller proportion of carcinomas and ductal carcinomas in situ. Other toxic metals that may interact synergistically with mercury could be detected in some samples. These findings do not provide direct evidence that toxic metals such as mercury play a role in the pathogenesis of breast cancer, but suggest that future molecular biological investigations on the role of toxic metals in breast cancer are warranted.

Diagnostic potential of ionomic profile in the plasma of cervical cancer patients receiving neoadjuvant chemoradiotherapy

BACKGROUND AND AIM

Major and trace elements play an important role in human body, and it has been reported that ionomic distribution differ greatly in tumor patients. The aim of the present study was to investigate the effects of cisplatin-based neoadjuvant chemoradiotherapy on the ionomic profile in human plasma as a potential biomarker for the therapeutic effects of cervical cancer.

METHOD

Thirty-seven patients with cervical cancer receiving neoadjuvant chemoradiotherapy were included in this study, pretherapy and post-treatment blood samples were collected and concentrations of 24 ions were analyzed by inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

The results showed that after cisplatin chemotherapy and radiotherapy, patients' plasma Pt level significantly increased, Na, Mg, P, K, Ca, Se, Cu, Zn, Se, Sr, Ba levels significantly decreased (P < 0.01), and Al, Cu ions were significantly correlated with the treatment effect (P < 0.05). In addition, the pattern of elemental correlations changed dramatically after the neoadjuvant chemoradiotherapy.

CONCLUSION

The results indicated that the plasma ionomic profile may serve as a quick and convenient tool to reflect the therapeutic effect of cisplatin-based chemoradiotherapy in cervical cancer patients, and supplement of certain essential elements may be of great importance for the maintenance of ion homeostasis in human body and for the reduction of adverse effect of chemotherapy and radiotherapy.

A meta-analysis of zinc levels in breast cancer

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.

Metallic air pollutants and breast cancer heterogeneity

BACKGROUND

Emerging evidence suggests airborne metals may be associated with breast cancer risk. However, breast cancer is heterogenous and associations with heavy metals vary by subtype. Heavy metals possess both carcinogenic and xenoestrogenic properties which may be related to different tumor etiologies. Therefore, we tested for etiologic heterogeneity, using a case-series approach, to determine whether associations between residential airborne metal concentrations and breast cancer differed by tumor subtype.

METHODS

Between 2005 and 2008, we enrolled incident breast cancer cases into the Breast Cancer Care in Chicago study. Tumor estrogen and progesterone receptors status was determined by medical record abstraction and confirmed immunohistochemically (N = 696; 147 ER/PR-negative). The 2002 USEPA's National Air Toxics Assessment census-tract estimates of metal concentrations (antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel and selenium) were matched to participants' residences of the same year. Adjusted logistic regression models were used to examine whether the airborne heavy metal associations differed by tumor ER/PR status. Principal component analysis was performed to assess associations by metal co-exposures.

RESULTS

Comparing the highest and lowest quintiles, higher concentrations of antimony (odds ratio[OR]: 1.8, 95% confidence interval[CI]: 0.9, 3.7, P-trend: 0.05), cadmium (OR: 2.3, 95% CI: 1.2, 4.4, P-trend: 0.04) and cobalt (OR: 2.0, 95% CI: 0.9, 4.4, P-trend: 0.04) were associated with ER/PR-negative breast cancer. Mixture analysis using principal components suggested co-exposures to multiple airborne heavy metals may drive associations with tumor receptor status.

CONCLUSIONS

Among women diagnosed with breast cancer, metallic air pollutants were associated with increased odds of developing ER/PR-negative breast cancer.

Blood arsenic levels and the risk of familial breast cancer in Poland

Arsenic is recognized as a potent carcinogen at high concentrations, but the relationship between environmental arsenic and breast cancer risk has not well been studied. Most research has focused on the effect of arsenic in populations with high endemic exposure, and not in populations with arsenic levels within normal limits. We sought to determine if blood arsenic levels predict the risk of breast and other cancers risk among women in northern Poland. The cohort consisted of 1,702 healthy women, aged 40 and above, identified between 2010 and 2017. Blood arsenic level was determined by inductively coupled plasma mass spectrometry. After an average of 4.5 years of follow‐up (range 0.7–7.3 years), there were 110 incident cases of cancer diagnosed in the cohort, including 68 cases of breast cancer. Women in the highest quartile of arsenic had a highly significant 13‐fold increased risk of developing breast cancer, compared to women in the lowest quartile (hazard ratio [HR] = 13.2; 95% confidence interval [CI] 4.02–43.0). Results were similar for arsenic and all incident cancers (HR quartile 4 vs. quartile 1 = 13.3; 95% CI 4.78–37.0). If confirmed, our study suggests that the blood arsenic level may be a useful predictive marker of cancer risk in women.

What's new?

Arsenic has long been recognized as a potent carcinogen at high concentrations. But can it affect cancer risk at “normal,” environmental concentrations? In this Polish study, the authors found that women whose blood levels of arsenic were in the highest quartile had a 13‐fold increased risk of developing breast cancer, compared to women in the lowest quartile. If confirmed in further studies, these results suggests that blood arsenic level may be a useful predictive marker of cancer risk in women.

Boron's neurophysiological effects and tumoricidal activity on glioblastoma cells with implications for clinical treatment

Purpose: To define the actions of boron on normal neurophysiology and glioblastoma growth. Materials and Methods: PubMed and other relevant databases were searched. Results: Discovery of novel boron compounds in treatment of glioblastoma is being actively investigated, but the majority of such studies is focused on the synthesis of boron compounds as sensitizers to Boron Neutron Capture Therapy (BNCT). Nonetheless, the translational functionality of boron compounds is not limited to BNCT as many boron compounds possess direct tumoricidal activity and there is substantial evidence that certain boron compounds can cross the blood-brain barrier. Moreover, boron-containing compounds interfere with several tumorigenic pathways including intratumoral IGF-I levels, molybdenum Fe-S containing flavin hydroxylases, glycolysis, Transient Receptor Potential (TRP) and Store Operated Calcium Entry (SOCE) channels. Conclusions: Boron compounds deserve to be studied further in treatment of systemic cancers and glioblastoma due to their versatile antineoplastic functions.

Serum Trace Elements and Their Associations with Breast Cancer Subgroups in Korean Breast Cancer Patients

The relationships between serum levels of trace elements and breast cancer remain relatively unknown. In this study, we investigate serum levels of seven trace elements in Korean breast cancer patients compared to controls without breast cancer. Serum trace element levels were determined using inductively coupled plasma mass spectrometry in Korean breast cancer patients before initiation of breast cancer treatment. Korean females without breast cancer served as a control group. Trace element levels were measured in the discovery cohort (n = 287) and were validated in an independent cohort (n = 142). We further investigated possible associations between trace element levels and the presence of lymph node metastasis, distant metastasis, or triple-negative breast cancer among breast cancer patients in subgroup analyses. Serum manganese and molybdenum levels were significantly higher (p < 0.05) in breast cancer patients than in controls. Serum copper levels were significantly higher in breast cancer patients with distant metastasis, while selenium levels were significantly lower. Other trace elements were neither significantly different between breast cancer patients and controls nor between subgroups of breast cancer patients. Our study provides insights about the potential roles and impacts of trace elements through an assessment of the associations between trace elements and breast cancer.

Occurrence of selected elements (Ti, Sr, Ba, V, Ga, Sn, Tl, and Sb) in deposited dust and human hair samples: implications for human health in Pakistan

The current study determined, for the first time, the levels of titanium (Ti), strontium (Sr), barium (Ba), vanadium (V), gallium (Ga), tin (Sn), thallium (Tl), and antinomy (Sb), in deposited dust, and human hair collected from general population of different geographical areas of Pakistan. All the samples were prepared by microwave digestion and measured by ICP-MS. The results showed that on deposited dust samples, the detected elements followed the descending trend as: Ti > Sr > Ba > V > Ga > Sn > Tl > Sb similar to the upper continental crust. The deposited dust samples from low elevation areas exhibited highest levels of all studied elements (except antimony which was higher in soil samples from mountainous areas), followed by rive plains, mountainous areas, and highland valleys. In contrast, on human hair samples, the elements followed the descending trend as: Sr > Ba > Ti > Ga > V > Sn > Sb > Tl respectively. Ba, Ga, and V concentrations were higher in soil samples from lower elevation Indus plain, and Sr, Tl, Sb, and Ti were higher in samples from mountainous areas. The bioaccumulation trend of all studied elements was in descending order as follows: Sb, Ga, Sn, Ba, Sr, Ti, V, Tl, respectively. Principal component analysis (PCA) and correlation matrix evidenced both geological influences and anthropogenic activities as potential sources of these studied elements. On the other hand, the risk estimation (HI > 1) concluded that population were at higher health risk (non-carcinogenic) for Ga and Ti. All other studied rare elements were within safe limit for humans from all zones.

Toxic elements as biomarkers for breast cancer: a meta-analysis study

AIMS AND BACKGROUND

Breast cancer (BC) is responsible for a large proportion of incidence of cancer in the world. Identifying the risk factors contributing to the incidence of BC is crucial to find efficient preventive and management strategies for this disease. Several studies have examined Arsenic (As), Cadmium (Cd), and Nickel (Ni) as risk factors for BC. The present study aimed at studying the link between As, Cd, and Ni concentrations and BC by using a meta-analysis.

MATERIALS AND METHODS

All case-control studies addressing the relationship between As, Cd, and Ni concentrations with BC were identified through electronic search databases (Scopus, ISI Web of Science, PubMed, EmBase, and Cochrane Library). The relevant data obtained from these papers were analyzed by a random-effects model. The heterogeneity of studies was secured by using I2 index. Funnel plots and Egger's test were used to examine publication bias.

RESULTS

In the present study, due to different measurement methods used for measuring As, Cd, and Ni, the concentration of these elements was measured in various subgroups (1: plasma, 2: breast tissue, and 3: scalp hair and nail) of individuals with BC and healthy subjects. The overall integration of data from the 3 groups led to the conclusion that there was a significant difference in Cd and Ni statuses between healthy and BC patients; the standard mean difference was 2.65 (95% CI: 1.57-3.73; P=0.000) and 2.06 (95% CI: 1.20-3.32; P=0.000), respectively. Whereas, there was no significant statistical difference in As status between healthy subjects and BC patients; the standard mean difference between them being 0.52 (95% CI: -0.12-1.16; P=0.114).

CONCLUSION

The present study indicates that there is a direct and positive association between Cd and Ni concentrations and BC risk. It is a warning to health care providers and policy makers to find viable solutions and take requisite measures to reduce BC risk in the society.

Recent advances on the stimulatory effects of metals in breast cancer

Certain environmental chemicals may accumulate in human serum and tissues eliciting estrogenic and/or carcinogenic effects. Therefore, there is heightened interest in determining whether environmental chemicals may increase the risk for endocrine-related tumors like breast cancer. For instance, metals as cadmium, zinc, copper, iron, nickel and aluminum have been shown to mimic estrogen action. Moreover, the exposure to these chemicals has been reported to stimulate diverse malignancies including breast cancer, which is the most common tumor in women worldwide. In this review, we summarize the epidemiologic and experimental evidence regarding the association between the exposure to some trace elements and breast cancer risk. We also address recent insights on the molecular mechanisms involved by metals in breast tumorigenesis.

Serum and Hair Nickel Levels and Breast Cancer: Systematic Review and Meta-Analysis

Several studies have investigated the relationship between serum and hair nickel (Ni) concentration and breast cancer, but the results were inconsistent. Thus, we conducted a systematic review and meta-analysis to evaluate the association between serum and hair nickel levels and breast cancer. Nine studies determining the serum nickel levels and six studies evaluating the hair nickel levels were identified in a systematic search of PubMed, China Knowledge Resource Integrated Database, Wanfang, and China Biomedical Literature Service System databases. Based on a random-effects model, standard mean differences (SMD) and the corresponding 95% confidence intervals (CI) were pooled to compare the nickel levels between different groups. Compared with healthy controls, the serum nickel levels in breast cancer were significantly higher (SMD (95% CI) 1.76 (0.82, 2.70)), as well as in those post-treated cases (SMD (95% CI) 2.56 (1.18, 3.94)). For breast cancer cases, the treatment made no significant decrease in serum nickel levels (SMD (95% CI) -0.29 (-1.17, 0.59)). In hair, the nickel levels in breast cancer were slightly higher than in controls, but not significant (SMD (95% CI) 0.16 (-1.08, 1.40)). In conclusion, high serum nickel levels were associated with breast cancer, and nickel exposure might be a risk factor for breast cancer.

Association between YAP expression in neoplastic and non-neoplastic breast tissue with arsenic urinary levels

The Hippo pathway regulates cell proliferation and apoptosis and it has been noted that loss of critical components of this pathway can lead to uncontrolled cell growth. Yes-associated protein (YAP) is an important component of this Hippo pathway because YAP is the nuclear effector of the Hippo tumor suppressor pathway and it is crucial for the response to oxidative stress induced by cellular process and by different xenobiotics, including arsenic. It has been proposed that YAP dysregulation can contribute to a malignant cellular phenotype acting as both a tumor suppressor and an oncogene. The aim of the study was to assess and compare the expression of YAP in neoplastic and non-neoplastic breast tissue of women chronically exposed to arsenic through drinking water. YAP expression was assessed by immunohistochemistry in 120 breast biopsies from women with breast cancer and from women with other non-neoplastic breast pathologies. Arsenic concentration was quantified in urine. The results disclosed a significant lower percentage of cytoplasm YAP expression in cases and that YAP high-intensity staining in the cytoplasm but not in the nucleus decreases the risk for breast cancer. In conclusion, our overall data suggest that YAP may act as a tumor suppressor protein because their reduced expression in cases, which can induce an environment favorable for inhibition of apoptosis and promoting cellular proliferation by increasing genetic instability of cells, which might contribute to the pathogenesis of cancer. Copyright © 2017 John Wiley & Sons, Ltd.

Ameliorative Effects of Dietary Selenium Against Cadmium Toxicity Is Related to Changes in Trace Elements in Chicken Kidneys

The ameliorative effects of selenium (Se) against cadmium (Cd)-induced toxicity have been reported extensively. However, few studies have assessed the effects of multiple ions simultaneously on the variations of elements. In this study, the changes in Se, Cd, and 26 other element concentrations were investigated in chicken kidneys. One hundred and twenty-eight 31-week-old laying hens were fed a diet supplemented with either Se, Cd, or both Se and Cd for 90 days. The ion content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). We found that the Se, Cd, and combined Se and Cd treatments significantly affected the trace elements in the chicken kidneys. The Cd supplement caused ion profile disorders, including reduced concentrations of V, Cr, Mn, Mo, As, Ba, Hg, Ti, and Pb and increased Si, Cu, Li, Cd, and Sb. The Se supplement reduced the contents of Co, Mo, and Pb and increased the contents of Cr, Fe, and Se. Moreover, Se also increased the concentrations of Cr, Mn, Zn, and Se and decreased those of Li and Pb, which in contrast were induced by Cd. Complex interactions between elements were analyzed, and both positive and negative correlations among these elements are presented. The present study indicated that Se can help against the negative effects of Cd and may be related to the homeostasis of the trace elements in chicken kidneys.

Serum and hair zinc levels in breast cancer: a meta-analysis

Many studies have investigated the association between serum/hair zinc levels and breast cancer, but the results were inconsistent. To compare the serum and hair zinc levels in women with breast cancer and controls, we conducted a systematic literature search of PubMed, Web of Science, Cochrane Library and Embase to identify relevant studies with publication dates up through November 2014. Based on a random effects model, summary standard mean differences (SMDs) and the corresponding 95% confidence intervals (CIs) were used to compare the serum and hair zinc levels in women with breast cancer and controls. Fourteen studies that investigated serum zinc levels and seven studies that assessed hair zinc levels were included. Our study observed no difference in serum zinc levels between breast cancer cases and controls (SMD (95%CI): -0.65[-1.42, 0.13]). However, we determined that hair zinc levels were lower in women with breast cancer compared with those of controls (SMD (95%CI): -1.99[-3.46, -0.52]). In conclusion, this study was the first to provide evidence that hair zinc levels in female breast cancer patients are lower than in controls; however, there was no significant difference in serum zinc levels between female breast cancer patients and controls.

Levels and risk factors of antimony contamination in human hair from an electronic waste recycling area, Guiyu, China

The primitive electronic waste (e-waste) recycling has brought a series of environmental pollutants in Guiyu, China. Antimony is one of the important metal contaminants and has aroused the global concerns recently. We aimed to investigate concentrations of antimony in human hair from Guiyu and compared them with those from a control area where no e-waste recycling exists, and assessed the potential risk factors. A total of 205 human hair samples from Guiyu and 80 samples from Jinping were collected for analysis. All volunteers were asked to complete a questionnaire including socio-demographic characteristics and other possible factors related to hair antimony exposure. The concentrations of hair antimony were analyzed using atomic absorption spectrophotometer. Our results indicated that the level of hair antimony in volunteers from Guiyu (median, 160.78; range, 6.99-4412.59 ng/g) was significantly higher than those from Jinping (median, 61.74; range, 2.98-628.43 ng/g). The residents who engaged in e-waste recycling activities in Guiyu had higher hair antimony concentrations than others (P < 0.001). There was no significant difference of hair antimony concentrations among different occupation types in e-waste recycling. Multiple stepwise regression analysis indicated that hair antimony concentrations were associated with education level (β = -0.064), the time of residence in Guiyu (β = 0.112), living house also served as e-waste workshop (β = 0.099), the work related to e-waste (β = 0.169), and smoking (β = 0.018). The elevated hair antimony concentrations implied that the residents in Guiyu might be at high risk of antimony contamination, especially the e-waste recycling workers. Work related to e-waste recycling activities and long-time residence in Guiyu contributed to the high hair antimony exposure.

Analysis of serum levels of 15 trace elements in breast cancer patients in Shandong, China

Experimental and epidemiological studies suggest that serum levels of trace elements may be associated with breast cancer risk. We compared serum levels of 15 trace elements between breast cancer patients and normal controls from Shandong, China, for the first time to assess whether serum levels of trace elements were associated with breast cancer risk. Eighty-eight breast cancer patients and 84 healthy controls were enrolled in the study. A Spectraspan V direct current plasma atomic emission spectrometer was used to determine the serum levels of 15 trace elements including Zn, Mn, Al, Cd, Fe, Mg, Ca, Pb, Cu, Se, Ni, Ti, Co, Li, and Cr. Breast cancer patients had significantly higher serum levels of Cd (p = 0.000), Mg (p = 0.001), Cu (p = 0.000), Co (p = 0.006), and Li (p = 0.003) and borderline higher Cr (p = 0.052), while significantly lower Mn (p = 0.000), Al (p = 0.000), Fe (p = 0.000), and Ti (p = 0.000) compared to their matched controls. However, there were no significant differences in serum levels of Zn (p = 0.824), Ca (p = 0.711), Pb (p = 0.274), Se (p = 0.236), and Ni (p = 0.185) between the two groups. Our study showed a possible association between serum levels of trace elements and breast cancer risk in eastern China, though it warrants further investigations to confirm the association. If confirmed, modulation of trace elements may help reduce breast cancer risk.

Classification models based on the level of metals in hair and nails of laryngeal cancer patients: diagnosis support or rather speculation?

Several larynx cancer prediction models were built and each was weighted according to their performance.

Screening of trace elements in hair of the female population with different types of cancers in Wielkopolska region of Poland

Background. Cancer constitutes a major health problem worldwide. Thus, search for reliable and practical markers of the disease process remains the key issue of the diagnostic process. Objectives. The study aims at linking the trace element status of an organism, assessed by hair analysis, with the occurrence of cancer diseases. Material and Methods. Hair samples were collected from 299 patients with cancer diseases confirmed by a histopathological test and from 100 controls. Cancer patients were divided into three groups, depending on cancer type: hormone-dependent cancer, cancer of the alimentary tract, and cancer with high glycolytic activity. Mineral element analysis of hair was performed using an atomic emission spectrophotometer with inductively coupled plasma (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Results. Statistically significantly lower concentrations of selenium, zinc, copper, germanium and boron, iron, and magnesium were observed in the three groups of cancer patients. Disturbance in the axis glucose-insulin and changes in concentrations of heavy metals and toxic elements were also noted. Conclusions. It seems safe to conclude that our results confirmed usefulness of hair element analysis in screening tests for the assessment of the biomarker of various cancer diseases in a female population.

[Detection of metal ions in hair after metal-metal hip arthroplasty]

OBJECTIVE

There is an increase in the levels of metals in the serum and urine after the implantation of some models of metal-metal hip prosthesis. It has recently been demonstrated that there is an association between these levels and the levels found in hair. The aim of this study is to determine the presence of metals in hair, and to find out whether these change over time or with the removal of the implant.

MATERIAL AND METHOD

The levels of chromium, cobalt and molybdenum were determined in the hair of 45 patients at 3, 4, 5, and 6 years after a hip surface replacement. The mean age was 57.5 years, and two were female. Further surgery was required to remove the replacement and implant a new model with metal-polyethylene friction in 11 patients, 5 of them due to metallosis and a periarticular cyst.

RESULTS

The mean levels of metals in hair were chromium 163.27 ppm, cobalt 61.98 ppm, and molybdenum 31.36 ppm, much higher than the levels found in the general population. A decrease in the levels of chromium (43.8%), molybdenum (51.1%), and cobalt (91.1%) was observed at one year in the patients who had further surgery to remove the prosthesis.

CONCLUSIONS

High concentrations of metals in the hair are observed in hip replacements with metal-metal friction, which decrease when that implant is removed. The determination of metal ions in hair could be a good marker of the metal poisoning that occurs in these arthroplasty models.

Arsenic-induced cancer cell phenotype in human breast epithelia is estrogen receptor-independent but involves aromatase activation

Accumulating data suggest arsenic may be an endocrine disruptor and tentatively linked to breast cancer by some studies. Therefore, we tested the effects of chronic inorganic arsenic exposure on the normal estrogen receptor (ER)-negative breast epithelial cell line, MCF-10A. Cells were chronically exposed to a low-level arsenite (500 nM) for up to 24 weeks. Markers of cancer cell phenotype and the expression of critical genes relevant to breast cancer or stem cells (SCs) were examined. After 24 weeks, chronic arsenic-exposed breast epithelial (CABE) cells showed increases in secreted MMP activity, colony formation, invasion, and proliferation rate, indicating an acquired cancer cell phenotype. These CABE cells presented with basal-like breast cancer characteristics, including ER-α, HER-2, and progesterone receptor negativity, and overexpression of K5 and p63. Putative CD44(+)/CD24(-/low) breast SCs were increased to 80 % over control in CABE cells. CABE cells also formed multilayer cell mounds, indicative of loss of contact inhibition. These mounds showed high levels of K5 and p63, indicating the potential presence of cancer stem cells (CSCs). Epithelial-to-mesenchymal transition occurred during arsenic exposure. Overexpression of aromatase, a key rate-limiting enzyme in estrogen synthesis, occurred with arsenic starting early on in exposure. Levels of 17β-estradiol increased in CABE cells and their conditioned medium. The aromatase inhibitor letrozole abolished arsenic-induced increases in 17β-estradiol production and reversed cancer cell phenotype. Thus, chronic arsenic exposure drives human breast epithelia into a cancer cell phenotype with an apparent overabundance of putative CSCs. Arsenic appears to transform breast epithelia through overexpression of aromatase, thereby activating oncogenic processes independent of ER.

Dietary selenium supplementation modifies breast tumor growth and metastasis

The survival rate for breast cancer drops dramatically once the disease progresses to the metastatic stage. Selenium (Se) is an essential micronutrient credited with having high anticancer and chemopreventive properties. In our study, we investigated if dietary Se supplementation modified breast cancer development in vivo. Three diets supplemented with sodium selenite, methylseleninic acid (MSA) or selenomethionine (SeMet), as well as a Se-deficient and a Se-adequate diet were fed to mice before mammary gland inoculation of 4T1.2 cells. The primary tumor growth, the numbers of cancer cells present in lungs, hearts, livers, kidneys and femurs and several proinflammatory cytokines were measured. We found that inorganic selenite supplementation provided only short-term delay of tumor growth, whereas the two organic SeMet and MSA supplements provided more potent growth inhibition. These diets also affected cancer metastasis differently. Mice fed selenite developed the most extensive metastasis and had an increased incidence of kidney and bone metastasis. On the other hand, mice fed the SeMet diet showed the least amount of cancer growth at metastatic sites. The MSA diet also provided some protection against breast cancer metastasis although the effects were less significant than those of SeMet. The cytokine profiles indicated that serum levels of interlukin-2, interleukin-6, interferon γ and vascular endothelial growth factor were elevated in SeMet-supplemented mice. There was no significant difference in tumor growth and the patterns of metastasis between the Se-deficient and Se-adequate groups. Our data suggest that organic Se supplementation may reduce/delay breast cancer metastasis, while selenite may exacerbate it.

Feasibility of breast cancer screening by PIXE analysis of hair

To reveal the role of key elements present in the hair of breast cancer patients on cancer development, the levels of a number of elements in scalp hair samples of 82 people including healthy individuals, people suffering from benign breast disease, and breast cancer patients were measured by PIXE analysis. Pellets of hair samples were prepared and bombarded by 2.2 MeV proton beam of a 3-MV Van de Graaff accelerator. The number of incident ions hitting the sample was indirectly measured using the RBS spectrum of a thin Ag film placed in the beam path. The concentrations of S, Cl, K, Ca, Fe, and Cu in the hair of healthy individuals were in agreement with those observed in the hair of hyperplasia and cancer patients within standard deviations. However, a lower average level of zinc was found in samples from hyperplasia and breast cancer patients. Strong positive correlations were found between iron and potassium as well as between calcium and potassium in the cancer patients. These results could be of significance in the screening for breast cancer.

Hair analysis in health assessment

BACKGROUND

Hair analysis is used for estimation of the nutritional status of individuals. In the present work, a systematic review on the relation between the mineral composition of hair and the physical or mental disorders is discussed. Detailed information of examined populations, methods of sample preparations and analytical techniques are presented.

METHODS

A systematic literature search in four electronic databases Scopus, PubMed, Web of Science and Medline (from 1997 to 2012/01/31) for English language articles was performed. In addition, a reference list and manual search was undertaken.

RESULTS

The following number of studies was included: 66. Most of the authors reported that there exists a correlation between deficiency or excess of some elements in hair and occurrence of some diseases, such as: autism, cancer, hypertension, myocardial infarction, kidney disease and diabetes mellitus. However, not all results were consistent.

CONCLUSIONS

Most of the authors concluded that the profile of hair mineral imbalance might be useful as a diagnostic tool for the early diagnosis of many diseases. However, it seems that there is a need to standardize sample preparation procedures, in particular washing and mineralization methods.

Lead, cadmium and other metals in serum of pet dogs from an urban area of NW Poland

This study was designed to evaluate the degree of exposure of pet dogs from an urban area of NW Poland to selected metals, including toxic Cd and Pb. The study was conducted on a group of 48 healthy dogs. The serum concentration of the analysed elements followed the order Fe > Al > Zn > Cu > Mn > As > Sr > Pb > Cd > Cr > Ni > V. The presence of cadmium and lead was found in all the serum samples tested. The average contents of these elements were 0.309 and 0.489 μg/mL. The factors that played the greatest role in the intake of the analysed elements were diet and breed-dependent size of dogs. Small-sized dogs had higher concentrations of all elements compared with large dogs, with statistically significant differences noted for Cu, Pb, Cd and Sr. It was also found that dogs receiving commercial and mixed food had more metals in serum compared with dogs on homemade food (except strontium). The present study showed elevated concentrations of some heavy metals (Pb, Cd, Fe and Cu) in serum of pet dogs, which is probably due to the excess elemental load of this area. Given that no information is available on the concentrations of strontium, vanadium and aluminium in dogs, further research is necessary to determine certain reference values which would allow for an easier interpretation of results and evaluation of exposure to these elements.

Exposure to nickel by hair mineral analysis

The aim of the present work was to investigate the exposure to nickel from various sources by investigation of mineral composition of human scalp hair. The research was carried out on hair sampled from subjects, including 87 males and 178 females (22 ± 2 years). The samples of hair were analyzed by ICP-OES. The effect of several factors on nickel content in hair was examined: lifestyle habits (e.g. hair coloring, hair spray, hair straighteners, hair drier, drugs); dietary factors (e.g. yoghurts, blue cheese, lettuce, lemon, mushroom, egg, butter); other (e.g. solarium, cigarette smoking, tap water pipes, tinned food, PVC foil, photocopier, amalgam filling). These outcomes were reached by linking the results of nickel level in hair with the results of questionnaire survey. Basing on the results it can be concluded that exposure to nickel ions can occur from different sources: lifestyle, eating habits and environmental exposure.