Blood levels of endocrine-disrupting metals and prevalent breast cancer among US women

Blood Cadmium Level Is a Marker of Cancer Risk in Men

Cadmium (Cd) is a known carcinogen, but its impact on cancer risk at lower concentrations is poorly understood. Previous studies on Cd and cancer risk in men show inconsistent results, prompting further investigation. A prospective cohort study involving 2956 men was conducted. Blood Cd levels were measured, and participants were followed for 78 months to assess cancer incidence. Men with high blood Cd levels (>0.71 µg/L) had a significantly increased risk of cancer compared to those with low levels (<0.19 µg/L) (HR 3.42, p < 0.001), particularly among non-smokers (HR 3.74, p = 0.003), individuals aged < 60 years (HR 2.79, p = 0.017), and ≥60 (HR 4.63, p = 0.004). The influence of smoking on cancer risk based on Cd levels was not significant in this study. Blood Cd levels may influence cancer risk in men, emphasizing the importance of minimizing Cd exposure to reduce risk. Confirmation of these results in other populations is essential for effective preventive measures against Cd-related cancers.

Global epidemiology of breast cancer based on risk factors: a systematic review

Background

Numerous reviews of the epidemiology and risk factors for breast cancer have been published previously which heighted different directions of breast cancer.

Aim

The present review examined the likelihood that incidence, prevalence, and particular risk factors might vary by geographic region and possibly by food and cultural practices as well.

Methods

A systematic review (2017-2022) was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, reporting on epidemiological and risk factor reports from different world regions. Medical Subject Heading (MeSH) terms: "Breast neoplasm" "AND" country terms such as "Pakistan/epidemiology", "India/epidemiology", "North America/epidemiology", "South Africa/epidemiology" were used to retrieve 2068 articles from PubMed. After applying inclusion and exclusion terms, 49 papers were selected for systematic review.

Results

Results of selected articles were summarized based on risk factors, world regions and study type. Risk factors were classified into five categories: demographic, genetic and lifestyle risk factors varied among countries. This review article covers a variety of topics, including regions, main findings, and associated risk factors such as genetic factors, and lifestyle. Several studies revealed that lifestyle choices including diet and exercise could affect a person's chance of developing breast cancer. Breast cancer risk has also been linked to genetic variables, including DNA repair gene polymorphisms and mutations in the breast cancer gene (BRCA). It has been found that most of the genetic variability links to the population of Asia while the cause of breast cancer due to lifestyle modifications has been found in American and British people, indicating that demographic, genetic, and, lifestyle risk factors varied among countries.

Conclusion

There are many risk factors for breast cancer, which vary in their importance depending on the world region. However, further investigation is required to better comprehend the particular causes of breast cancer in these areas as well as to create efficient prevention and treatment plans that cater to the local population.

Effects of Environmental Cadmium Exposure on the Liver in Korean Adults: Cross-Sectional and Longitudinal Studies

Cadmium (Cd) is a ubiquitous environmental pollutant with an exceptionally long biological half-life. The liver is a major organ for Cd metabolism, but the toxicity of Cd is unclear. This study sought to determine whether blood Cd (BCd) level (representing recent exposure [months] to Cd) was associated with liver function in Korean adults, both cross-sectionally and longitudinally. The baseline cross-sectional study involved 2,086 adults (male: 908, female: 1,178) in 2010 - 2011, and 503 of them (male: 207, female: 296) were followed up in 2014 - 2015. BCd was measured by graphite-furnace atomic absorption spectrometry, and liver function indices (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and γ-glutamyltransferase [GGT]) were determined. Liver damage was defined as an abnormal elevation of more than one liver function index. The geometric mean of BCd (1.07 μg/L) was higher in females than in males (1.16 vs. 0.96 μg/L). Liver function indices increased significantly in a dose-dependent manner according to the BCd levels, except for ALT in males, and were higher in males than in females. BCd level was also associated with the risk of liver damage in both sexes. No significant changes in BCd were observed between baseline and follow-up. The liver function indices in 2014 - 2015 were comparable to those in 2010 - 2011 in males, while ALT and GGT were significantly increased in 2014 - 2015 compared to 2010 - 2011 in females with relatively high BCd. These findings suggest that even a low level of environmental Cd exposure, short- and long-term, may affect liver function, and females appear more susceptible than males.

Urinary Concentrations of Endocrine-Disrupting Metals and Prevalent Breast Cancer in US Women

The toxic metals cadmium, lead, and mercury are endocrine-disrupting agents that could produce estrogenic effects involving breast carcinogenesis. In this study, we further explored the relationship between exposure to these metals and prevalent breast cancer among female participants, aged 20 years or older, in the 2007-2016 National Health and Nutrition Examination Survey (NHANES). Exposure was determined by measuring urinary concentrations of metals using inductively coupled plasma mass spectrometry. Urine creatinine-corrected concentrations of metals were calculated for each study participant. Multivariate logistic regression models were constructed to examine the association between urinary metals and prevalent breast cancer, adjusting for potential confounders. Of the 3352 study participants, 106 had been diagnosed with breast cancer (weighted prevalence, 3.13%). The results show that women with breast cancer had significantly higher urinary concentrations of lead and cadmium (both p < 0.0001) than those without breast cancer. After adjusting for all the covariates included in the study, however, only urinary lead was shown to be significantly associated with increased prevalence of breast cancer, with an odds ratio of 2.95 (95% CI: 1.13, 7.70) in the highest quartile of urinary lead concentrations (≥ 0.71 µg/g creatinine) as compared with the lowest quartile. No statistically significant associations were observed between urine cadmium or mercury levels and breast cancer. This study demonstrates a potential association between lead exposure and prevalent breast cancer among US women. Prospective and mechanistic studies are warranted to further investigate this interaction and explore the role of lead in breast carcinogenesis.

Low-Level Environmental Mercury Exposure and Thyroid Cancer Risk Among Residents Living Near National Industrial Complexes in South Korea: A Population-Based Cohort Study

Background: Previous studies suggested that mercury may be linked to thyroid cancer due to its bioaccumulation in the thyroid gland, but no studies have evaluated the association between mercury exposure and thyroid cancer risk. We examined the relationship between mercury exposure and thyroid cancer risk, with the potential modification of hematological parameters. Methods: We performed a secondary analysis of a prospective cohort study among residents living near industrial complexes in South Korea (recruited from 2003 to 2011). Incident thyroid cancer cases (C73, ICD-10 code) were identified from the National Cancer Registry and Statistics Korea. Urinary mercury concentrations were measured using thermal decomposition amalgamation atomic absorption spectrometry (TDA-AAS). Cox proportional hazards regression models (adjusted for age, sex, educational level, smoking status, and employment) were used to estimate the hazard ratio (HR) and confidence interval [CI] between mercury exposure and the incidence of thyroid cancer. Results: We documented 69 cases of thyroid cancer in a total of 5213 participants during follow-up (median 8.7 years). The geometric mean of urinary mercury concentration was 1.8 μg/L for thyroid cancer cases and 1.2 μg/L for noncases (p for difference = 0.001). After adjusting for potential confounders, those in the highest tertile of urinary mercury levels had a twofold higher risk of thyroid cancer (HR = 1.97 [CI 1.03 - 3.80] in the highest tertile vs. the lowest tertile, p for trend = 0.043). This association was stronger for those with lower mean corpuscular volume and mean corpuscular hemoglobin status. Conclusions: Urinary mercury concentration was positively associated with the risk of thyroid cancer among residents living near national industrial complexes, and this association was influenced by red blood cell indices status. These results provide some evidence suggesting the adverse effects of environmental metal pollution in the development of thyroid cancer.

Breast cancer incidence in a national cohort of female workers exposed to special health hazards in Taiwan: a retrospective case-cohort study of ~ 300,000 occupational records spanning 20 years

OBJECTIVE

Breast cancer is the most common cancer among women worldwide. In Taiwan, workers exposed to any of 31 hazardous chemicals or carcinogens in the work environment are designated as especially exposed workers (EEWs) by Taiwan's Ministry of Labor. We assessed the risk of breast cancer in this nationwide female EEW cohort.

METHODS

We conducted a nationwide retrospective study of 4,774,295 workers combining data collected from Taiwan's Ministry of Labor's EEW database between 1997 and 2018 and Taiwan's Cancer Registry between 1997 and 2016. Standardized incidence ratios (SIRs) for women exposed to different hazards and breast cancer incidence rate ratios (IRRs) were calculated by Poisson regression, adjusting for age and duration of exposure.

RESULTS

3248 female workers with breast cancer and 331,967 without breast cancer were included. The SIRs and adjusted IRRs were 1.27 (95% CI 1.18-1.35) and 1.31 (95% CI 1.21-1.42) for lead, 1.74 (95% CI 1.23-2.24) and 1.52 (95% CI 1.13-2.04) for 1,1,2,2-tetrachloroethane, 1.47 (95% CI 1.12-1.82) and 1.42 (95% CI 1.12-1.81) for trichloroethylene/tetrachloroethylene), 1.40 (95% CI 1.23-1.57) and 1.38 (95% CI 1.22-1.57) for benzene, and 2.07 (95% CI 1.06-3.09) and 1.80 (95% CI 1.10-2.94) for asbestos. The results remained similar when factoring in a 2- or 5-year latency period.

CONCLUSION

This study found possible correlations between occupational exposure to lead, chlorinated solvents (such as 1,1,2,2-tetrachloroethane, trichloroethylene, and tetrachloroethylene), benzene, and asbestos with breast cancer risk among female EEW, suggesting a need for regular screening for breast cancer for employees exposed to these special workplace hazards.

Ambient air emissions of endocrine-disrupting metals and the incidence of hormone receptor- and HER2-dependent female breast cancer in USA

Limited evidence exists on the relationship between exposure to endocrine-disrupting metals in ambient air and hormone receptor- and HER2-dependent breast cancer. This study investigates the association between ambient air emissions of endocrine-disrupting metals and the incidence of female breast cancer of different receptor status. County-level data from the US national datasets were analyzed for the association between emissions of various metals including arsenic, cadmium, chromium VI, lead, and mercury, and the annual age-adjusted incidence of hormone receptor-dependent breast cancer for 1990-2016 and HER2-dependent breast cancer for 2010-2016 using adjusted linear regression models. Lead emissions showed the strongest association among the metals examined with the incidence of different receptor status breast cancers, including ER-positive, ER-negative, PR-negative, HER2-negative, and Triple-negative breast cancers, with the adjusted β ranging from 917.26 for ER-negative to 3182.37 for HER2-negative breast cancer. Arsenic and mercury showed significant associations with the incidence of ER-positive, ER-negative, PR-positive, and PR-negative breast cancers. However, cadmium emissions were only significantly associated with ER-negative breast cancer. Moreover, chromium was not associated with any subtypes of breast cancer. Among all of the metals, only lead and mercury emissions showed significant associations with HER2-negative and Triple-negative breast cancer incidence. The results from this study suggest that increased exposure to endocrine-disrupting metals, especially lead, in ambient air could be associated with an increased incidence of female breast cancers with various receptor status in the US. Prospective studies are warranted to further explore this relationship.

Health significant alarms of toxic carcinogenic risk consumption of blood meal metals contamination in poultry at a gold mining neighborhood, northern Thailand

The proposes of this study were to compare THg (total mercury), Pb(Lead), Cd(Cadmium), and Mn (Manganese) contamination in poultry blood between polluted areas (≤ 25 km) and unpolluted areas (> 25 km) adjacent to the largest gold mining in northern Thailand. The THg level in the free-grazing duck in polluted areas was significantly higher than unpolluted area. Both THg and Pb levels in free-grazing duck were also highest in polluted areas. In contrast, the level of (Mn) in chicken blood was the highest in polluted areas. Cadmium in farmed duck from polluted areas was significantly higher than unpolluted areas. The target hazard quotient (THQ) and hazard index (HI) of Hg, Pb, Cd, and Mn in all age groups in both areas did not exceed 1, meaning there is no possibility of the non-carcinogenic toxicity. Whereas, the incremental lifetime cancer risk (ILCR) of both Pb and Cd exceeded 1 × 10^-4 in all age groups and these were particularly higher in the polluted area and considered to yield significant health effects of increasing the cancer risk. The ILCR in descending order for Pb and Cd was 13-18 years old = 18-35 years old > 6-13 years old = 35-65 years old > 3-6 years old > 65 up years old, respectively. The results revealed that the human cancer risk related to consuming poultry blood contaminated with both Pb and Cd in all age groups must be of concern, especially 13-18 and 18-35 years, it must be recommended to avoid raising animals in contaminated areas, especially free-grazing duck.

The n-butanol fraction of the Xiao-Chai-Hu decoction alleviates the endocrine disturbance in the liver of mice exposed to lead

ETHNOPHARMACOLOGICAL RELEVANCE

Lead is a toxic heavy metal that causes health risks globally. However, the mechanism of endocrine poisoning and detoxification of lead poisoning, especially in the liver, still needs to be studied. Xiao-Chai-Hu decoction (XCHD) is regarded as an antidote and an anti-hepatotoxic traditional prescription that has been recorded in the pharmacopeia of the People's Republic of China.

AIM OF THE STUDY

The study aimed to probe the hepatoprotective activity of XCHD in the regulation of endocrine dysfunction in the liver and its molecular mechanism.

MATERIALS AND METHODS

The mice from the Institute of Cancer Research (ICR) were exposed to different concentrations of XCHD and lead. Then, serum biochemical indices and liver pathology were analyzed. The key differential genes were detected by qRT-PCR and Western blot.

RESULTS

According to the biochemical and histopathological analysis, XCHD-NBA was the most effective in attenuating lead-induced hepatotoxicity. From the transcriptome, we analyzed the key genes of XCHD-NBA in the regulation of lead toxicity, including Tubb2a, Stip1, Cyp4a12a, Cyp2c50, Ugt1a1, Cyp3a11, Cyp4a12b, Ahsa1, Cyp2c54, Tubb4b, Esr1, Hsp90aa1, Tuba1a, Tuba1c, and Hsph1. We also analyzed the main components of XCHD-NBA by LC-MS. Because of their extensive role in regulating the endocrine function, baicalin and glycyrrhizin were identified as the main active components of XCHD in regulating endocrine disorders caused by lead.

CONCLUSIONS

Lead can disturb the endocrine regulatory process of the liver, while XCHD-NBA alleviates lead-induced liver injury by regulating the endocrine regulatory process.

Is Cadmium a Risk Factor for Breast Cancer - Results from a Nested Case-Control Study Using Data from the Malmö Diet and Cancer Study

BACKGROUND

Some studies have shown that cadmium (Cd) is associated with breast cancer risk. One hypothesis is that Cd has estrogen-like properties. This case-control study investigated the association between breast cancer risk and blood Cd (BCd) levels.

METHODS

All breast cancers in the Malmö Diet and Cancer cohort were identified through linkage to the Swedish Cancer Registry, baseline (1991-1996) through 2014. Two controls per case were selected from the same cohort. BCd was analyzed at baseline. Associations were analyzed using logistic regression.

RESULTS

Mean BCd was 0.51 μg/L among 1,274 cases and 0.46 among 2,572 controls. There was an overall increased risk of breast cancer [OR, 1.18; 95% confidence interval (CI), 1.05-1.36] per μg/L of BCd. An increased risk was, however, only found at high BCd [OR, 1.34 (95% CI, 1.05-1.73)] for BCd more than 1.20 μg/L. The group with the highest BCd was mainly smokers. A spline indicated that at BCd less than 1.0 μg/L, the OR was not increased. The association with BCd was stronger in current smokers and at body mass index (BMI) above 25, while no modification due to receptor status was found.

CONCLUSIONS

The results indicated increased risk of breast cancer only for high Cd exposure, which occurred mainly among smokers. This made it difficult to disentangle the effects of smoking and Cd, despite inclusion of smoking habits in the models.

IMPACT

This study provides support for reducing Cd exposure through smoking cessation and dietary choice. On the population level, preventive measures against Cd pollution are warranted.

The association between fatty acid intake and breast cancer based on the NHANES and Mendelian randomization study

BACKGROUND

Observational studies have examined the association between fatty acid intake and breast cancer (BC), and the association might vary depending on menopausal status, but the results remain controversial. The objective of this study was to investigate the associations between fatty acid intake and BC.

METHODS

The National Health and Nutrition Examination Survey (NHANES) 1999-2016 was used in the study, and stratified analysis by menopausal status was performed. Logistic regression models were used to evaluate the associations between BC and intake of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs), adjusting for covariates. Three two-sample Mendelian randomization (MR) methods-inverse variance weighted (IVW), weighted median, and Mendelian randomization-Egger (MR-Egger) regression-were applied to further verify the associations between intake of fatty acids and BC.

RESULTS

Higher intake of MUFAs was associated with lower risk of BC in premenopausal women: ORs (95 %CI): 0.325 (0.110, 0.964). IVW showed that increased intake of MUFAs was associated with a reduced risk of BC: 0.997 (0.995, 1.000), p = 0.024. No associations between BC and SFAs, MUFAs or PUFAs were found in postmenopausal women or in the overall population.

CONCLUSIONS

Increasing intake of MUFAs might reduce the risk of BC in premenopausal women. The protective effect of MUFAs on BC was also supported by MR study.