Nadia Vilahur

Bio: Nadia Vilahur is an academic researcher from International Agency for Research on Cancer. The author has contributed to research in topics: Cancer & MEDLINE. The author has an hindex of 6, co-authored 8 publications receiving 345 citations. Previous affiliations of Nadia Vilahur include European Commission.

The IARC Perspective on Colorectal Cancer Screening.

Abstract: IARC View on Colorectal Screening The International Agency for Research on Cancer concluded that screening for colorectal cancer with stool-based tests and with lower endoscopy (either colonoscopy or sigmoidoscopy) saves lives. Comparative effectiveness data were inconclusive.

Carcinogenicity of welding, molybdenum trioxide, and indium tin oxide.

Abstract: In March 2017, 17 scientists from ten countries met at the International Agency for Research on Cancer (IARC; Lyon, France) to evaluate the carcinogenicity of welding, molybdenum trioxide, and indium tin oxide. These assessments will be published in volume 118 of the IARC Monographs. Worldwide, an estimated 11 million workers have a job title of welder, and around 110 million additional workers probably incur weldingrelated exposures. Welding can involve exposures to fumes, gases, radiation (ultraviolet [UV] radiation and electromagnetic fields) and coexposures to asbestos and solvents. Welding involves several processes (eg, oxyfuel [gas], arc, and resistance welding) and materials (eg, mild and stainless steel). Exposure determinants include the process, material welded, ventilation, degree of enclosure, and use of personal protection. The carcinogenicity of welding fumes was assessed by IARC in 1989 and classified as “possibly carcinogenic to humans” (Group 2B), based on ‘‘limited evidence in human beings’’ and ‘‘inadequate evidence’’ in experimental animals. UV radiation was classified in Group 1 in volume 100D of the IARC Monographs. Substantial new evidence has since accumulated from observational and experimental studies. In the present evaluation, welding fumes and UV radiation from welding were classified as “carcinogenic to humans” (Group 1). Arc welding generates UV radiation, a risk factor for the rare cancer ocular melanoma. Various ocular disorders (eg, cataracts or keratoconjunctivis) occur in both welders and nearby workers. Sufficient evidence for the carcinogenicity of UV radiation from welding came from eight partly overlapping case–control studies and two census-based cohort studies that reported on ocular melanoma. Most case–control studies showed positive associations, with risks of developing ocular melanoma generally increased by between two-fold and ten-fold. Two of three studies that assessed risk by duration of employment as a welder showed positive trends. These studies also showed increased ocular melanoma risk associated with eye burns—a proxy for UV exposure— and one reported a positive exposure– response association for cumulative occupational exposure to artificial UV radiation, including welding. Risks persisted after adjustment for sun exposure, sun bed use, or both. Welding fumes are produced when metals heated above their melting point vaporise and condense to fine particles (mostly <1 μm in size). Most studies, including more than 20 case–control studies and nearly 30 occupational or population-based cohort studies, reported increased risks of lung cancer in welders or other workers exposed to welding fumes. Exposure–response associations with indices of longer or greater cumulative exposure to welding fumes were also reported in several studies, some of which were large, high-quality studies. Exposure to fumes was assessed indirectly through welding process or material, branch of industry, job title, expert assessment, or self-report. Asbestos exposure and tobacco smoking, which are important potential confounders, could not explain the observed excess lung cancer risk in welders. Positive associations persisted after adjusting directly or indirectly for smoking, asbestos co-exposure, or both; restricting to non-smokers or lowlevel smokers; and in cohorts with low or minimal asbestos exposure. Positive associations for occupation as a welder and kidney cancer were reported in nearly all relevant cohort and case–control studies. However, few studies adjusted for solvents used for cleaning metal in tandem with welding, such as trichloroethylene (a risk factor for kidney cancer). Increased risks were consistently reported across countries, occupational settings, and study designs. However, chance, bias, and confounding could not be reasonably ruled out because some findings were not statistically significant, several studies had few exposed cases, and there was little evidence of an exposure–response association. For all other cancers, the evidence for carcinogenicity was inadequate because of inconsistent findings across studies, insufficient numbers of studies, or the potential for confounding or selection bias. The Working Group concluded that there is ‘‘sufficient evidence in humans’’ that welding fumes cause lung cancer and limited evidence for kidney cancer. There is limited evidence in experimental animals for the carcinogenicity of gas metal arc–stainless steel welding fumes. In one oropharyngeal aspiration study and one inhalation study in male A/J mice, gas metal arc–stainless steel welding fumes promoted 3-methylcholanthreneinduced lung tumours. Absorption and excretion of metals (chromium, nickel, and manganese) was shown in people exposed to welding fumes, but data for particle deposition and clearance in welders were scarce. Strong evidence suggests that welding fumes induce chronic inflammation and are immunosuppressive. Lung and systemic inflammation biomarkers were increased in many panel studies (of cross-sectional and cohort design) of various arc welding fumes. Risk for infection (pneumonia) was increased Published Online April 10, 2017 http://dx.doi.org/10.1016/ S1470-2045(17)30255-3

Reducing Social Inequalities in Cancer: Setting Priorities for Research

Abstract: Social inequalities in cancer are a global problem, as has been well documented in the World Health Organization (WHO)/International Agency for Research on Cancer (IARC) publication Social Inequalities and Cancer. Inequalities in income, wealth, education, and power disproportionally impact the most disadvantaged individuals, communities, and countries to produce a social gradient in the incidence, survival, and mortality of many cancers both within and between countries. From April 16 to 18, 2018, the IARC convened a workshop to examine the current evidence and identify research priorities for reducing social inequalities in cancer. International and WHO/IARC experts drawn from many different disciplines presented a series of articles to be published in an IARC scientific publication; extensive discussion in subgroups and plenary sessions resulted in participants identifying 3 research priorities.

Welding fumes and lung cancer: a meta-analysis of case-control and cohort studies

Abstract: Background An estimated 110 million workers are exposed to welding fumes worldwide. Welding fumes are classified by the International Agency for Research on Cancer as carcinogenic to humans (group 1), based on sufficient evidence of lung cancer from epidemiological studies. Objective To conduct a meta-analysis of case-control and cohort studies on welding or exposure to welding fumes and risk of lung cancer, accounting for confounding by exposure to asbestos and tobacco smoking. Methods The literature was searched comprehensively in PubMed, reference lists of relevant publications and additional databases. Overlapping populations were removed. Meta-relative risks (mRRs) were calculated using random effects models. Publication bias was assessed using funnel plot, Eggers’s test and Begg’s test. Results Forty-five studies met the inclusion criteria (20 case-control, 25 cohort/nested case-control), which reduced to 37 when overlapping study populations were removed. For ‘ever’ compared with ‘never’ being a welder or exposed to welding fumes, mRRs and 95% CIs were 1.29 (1.20 to 1.39; I2=26.4%; 22 studies) for cohort studies, 1.87 (1.53 to 2.29; I2=44.1%; 15 studies) for case-control studies and 1.17 (1.04 to 1.38; I2=41.2%) for 8 case-control studies that adjusted for smoking and asbestos exposure. The mRRs were 1.32 (95% CI 1.20 to 1.45; I2=6.3%; 15 studies) among ‘shipyard welders’, 1.44 (95% CI 1.07 to 1.95; I2=35.8%; 3 studies) for ‘mild steel welders’ and 1.38 (95% CI 0.89 to 2.13; I2=68.1%; 5 studies) among ‘stainless steel welders’. Increased risks persisted regardless of time period, geographic location, study design, occupational setting, exposure assessment method and histological subtype. Conclusions These results support the conclusion that exposure to welding fumes increases the risk of lung cancer, regardless of the type of steel welded, the welding method (arc vs gas welding) and independent of exposure to asbestos or tobacco smoking.

Gut microbiota in colorectal cancer: mechanisms of action and clinical applications

Abstract: Colorectal cancer (CRC) accounts for about 10% of all new cancer cases globally. Located at close proximity to the colorectal epithelium, the gut microbiota comprises a large population of microorganisms that interact with host cells to regulate many physiological processes, such as energy harvest, metabolism and immune response. Sequencing studies have revealed microbial compositional and ecological changes in patients with CRC, whereas functional studies in animal models have pinpointed the roles of several bacteria in colorectal carcinogenesis, including Fusobacterium nucleatum and certain strains of Escherichia coli and Bacteroides fragilis. These findings give new opportunities to take advantage of our knowledge on the gut microbiota for clinical applications, such as gut microbiota analysis as screening, prognostic or predictive biomarkers, or modulating microorganisms to prevent cancer, augment therapies and reduce adverse effects of treatment. This Review aims to provide an overview and discussion of the gut microbiota in colorectal neoplasia, including relevant mechanisms in microbiota-related carcinogenesis, the potential of utilizing the microbiota as CRC biomarkers, and the prospect for modulating the microbiota for CRC prevention or treatment. These scientific findings will pave the way to clinically translate the use of gut microbiota for CRC in the near future.

The Navigation Guide: Evidence-Based Medicine Meets Environmental Health

Abstract: Background: The Navigation Guide methodology was developed to meet the need for a robust method of systematic and transparent research synthesis in environmental health science. We conducted a case study systematic review to support proof of concept of the method. Objective: We applied the Navigation Guide systematic review methodology to determine whether developmental exposure to perfluorooctanoic acid (PFOA) affects fetal growth in humans. Methods: We applied the first 3 steps of the Navigation Guide methodology to human epidemiological data: 1) specify the study question, 2) select the evidence, and 3) rate the quality and strength of the evidence. We developed a protocol, conducted a comprehensive search of the literature, and identified relevant studies using prespecified criteria. We evaluated each study for risk of bias and conducted meta-analyses on a subset of studies. We rated quality and strength of the entire body of human evidence. Results: We identified 18 human studies that met our inclusion criteria, and 9 of these were combined through meta-analysis. Through meta-analysis, we estimated that a 1-ng/mL increase in serum or plasma PFOA was associated with a –18.9 g (95% CI: –29.8, –7.9) difference in birth weight. We concluded that the risk of bias across studies was low, and we assigned a “moderate” quality rating to the overall body of human evidence. Conclusion: On the basis of this first application of the Navigation Guide systematic review methodology, we concluded that there is “sufficient” human evidence that developmental exposure to PFOA reduces fetal growth. Citation: Johnson PI, Sutton P, Atchley DS, Koustas E, Lam J, Sen S, Robinson KA, Axelrad DA, Woodruff TJ. 2014. The Navigation Guide—evidence-based medicine meets environmental health: systematic review of human evidence for PFOA effects on fetal growth. Environ Health Perspect 122:1028–1039; http://dx.doi.org/10.1289/ehp.1307893