Arsenic-contaminated drinking water and cholangiocarcinoma

Arsenic's shadowy influence: A systematic review of its carcinogenic role in gallbladder cancer

INTRODUCTION

Gallbladder carcinoma (GBC) and cholangiocarcinoma are aggressive forms of cancer developed in the gallbladder and biliary tracts which are related to the liver. This systematic review aimed to highlight the significant association between gallbladder, biliary cancers, and arsenic exposure.

METHODS

An extensive search was conducted in Embase, Cochrane, Scopus, PubMed, and Web of Science. We included studies that assessed arsenic levels in gallbladder cancer patients, without restrictions on age, sex, or language. Biological samples, such blood, bile, gallbladder tissue, gallstones, and hair were obtained, and arsenic levels were measured. Also, arsenic water and soil concentrations were collected.

RESULTS

A total of 13 studies were included in our review. These studies included 2234 non-gallbladder carcinoma patients and 22 585 gallbladder carcinoma cases. The participant demographics showed a gender distribution of 862 males and 1845 females, with an age range of 20-75 years. The average body mass index (BMI) was 19.8 kg/m2 for nongallbladder carcinoma patients and 20.1 kg/m2 for gallbladder carcinoma cases. The selected studies examined arsenic concentrations across various biological samples, including blood, hair, gallstones, and bile. Blood arsenic levels ranged from 0.0002 to 0.3893 μg/g and were significantly associated with increased gallbladder carcinoma risk in several studies. Hair also demonstrated a significant correlation, with arsenic concentrations ranging from 0.0002 to 6.9801 μg/g.

CONCLUSION

There is a strong link between arsenic exposure and gallbladder cancer or cholangiocarcinoma. Even chronic exposure to low-moderate amounts could lead to gallbladder carcinoma. These findings stress the need for more comprehensive and dedicated studies, to control arsenic water/soil levels and seek other preventive measures for this high mortality disease.

Solvent Extraction with Cyanex 923 to Remove Arsenic(V) from Solutions

The removal of harmful arsenic(V) from aqueous solutions using Cyanex 923 (solvation extractant) was investigated using various experimental variables: equilibration time, the acidity of the aqueous phase, temperature, extractant and arsenic concentrations, and O/A ratio. Cyanex 923 extracted As(V) (and sulfuric acid) from acidic solutions; however, it could not be used to remove the metal from slightly acid or neutral solutions. The extraction of arsenic is exothermic and responded to the formation of H3AsO4·nL species in the organic phase (L represents the extractant, and the stoichiometric factor, n = 1 or 2, depends on the acidity of the aqueous phase). Extraction isotherms are derived from the experimental results. Both arsenic and sulfuric acid loaded onto the organic phase can be stripped with water, and stripping isotherms are also derived from the experimental results. The selectivity of the system against the presence of other metals (Cu(II), Ni(II), Bi(III), and Sb(III)) is investigated, and the ability of Cyanex 923 to extract As(V) and sulfuric acid compared to the use of other P=O-based solvation reagents, such dibutyl butylphosphonate (DBBP) and tri-butyl phosphate (TBP), is also investigated.

Carcinogenic effect of arsenic in digestive cancers: a systematic review

BACKGROUND

The carcinogenic effect of arsenic (As) has been documented in lung, bladder and skin cancers but remains unclear for digestive cancers, although metabolic pathways of As and recent data suggest that it may be an important determinant in these malignancies as well.

OBJECTIVE

This study aimed to systematically review the available literature investigating the potential association between As and digestive cancers.

METHODS

An extensive search was conducted in Medline Ovid SP, Cochrane, PubMed, Embase.com, Cochrane Library Wiley, Web of Science and Google Scholar. Studies providing original data in humans, with As measurement and analysis of association with digestive cancers including esogastric cancers (esophagus and stomach), hepato-pancreatico-biliary (HPB) cancers (including biliary tract, liver and pancreas) and colorectal cancers were eligible.

RESULTS

A total of 35 studies were identified, 17 ecological, 13 case-control and 5 cohort studies. Associations between As and digestive cancers were reported for both risks of incidence and cancer-related mortality. Overall, 43% (3/7) and 48% (10/21) studies highlighted an association between As and the incidence or the mortality of digestive cancers, respectively.

CONCLUSIONS

A substantial proportion of studies exploring the potential link between As and digestive cancers suggested an association, particularly in HPB malignancies. These findings emphasize the need to further investigate this topic with dedicated and high-quality studies, as it may have an important impact, including for prevention strategies.

Arsenic may be a carcinogenic determinant of a subset of gallbladder cancer: A pilot study

Gallbladder cancer (GBC) is one of the deadliest malignancy and treatment options are deplorably limited. Better strategies of prevention are urgently needed but knowledge on risk factors remains scarce. Recent data suggested that arsenic (As) may be involved in GBC carcinogenesis but the question remains debated. To date, there are no data on As measurement in GBC samples. This pilot study aimed to measure As concentrations in tissue samples from patients with GBC compared to non-cancerous gallbladder (NCGB). Included patients underwent cholecystectomy at Hospital Clinico Universidad de Chile, Santiago in Chile, a country with high As exposure, between 2001 and 2020. Tissue samples were preserved in formalin-fixed, paraffin-embedded blocks. Selected samples were retrieved, processed and submitted to inductively coupled plasma mass spectrometry (ICP-MS) to determine As concentrations. A total of 77 patients were included, including 35 GBC and 42 NCGB. The two groups were comparable, except for age (68 vs. 49 years, p < 0.001). Measured in 11 GBC and 38 NCGB, total As was detected in 5 GBC (14%) compared to 0 NCGB samples (p < 0.001). GBC group also showed higher median values of As compared to NCGB (p < 0.001). This pilot study provided a proof-of-concept to measure As concentrations in gallbladder samples and showed higher level of As in GBC samples compared to NCGB, paving the way for future studies aiming to investigate the impact of As on GBC, which may contribute to the prevention of this deadly disease.