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Digestive and Liver Disease : Official... Sep 2012It has been proposed that vinyl chloride exposure is associated with increased risk of death from cirrhosis, although epidemiologic evidence is limited. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
It has been proposed that vinyl chloride exposure is associated with increased risk of death from cirrhosis, although epidemiologic evidence is limited.
METHODS
We analyzed the risk of death from cirrhosis by occupational vinyl chloride exposure by conducting a meta-analysis on seven available studies, including more than 40,000 workers exposed to vinyl chloride mostly in North America and Europe, with a total of 203 deaths from cirrhosis.
RESULTS
All epidemiological studies on vinyl chloride exposure and risk of death from cirrhosis resulted in an overall relative risk of 0.73 (95% confidence interval 0.61-0.87). Thus, the epidemiologic evidence does not suggest an excess mortality from cirrhosis in vinyl chloride-exposed workers; this is consistent with histopathological observations in livers of angiosarcoma patients and of vinyl chloride-exposed rodents revealing no signs of cirrhosis.
CONCLUSION
Overall, our findings indicate the absence of increased risk of death from cirrhosis in vinyl chloride-exposed workers.
Topics: Humans; Liver Cirrhosis; Occupational Diseases; Occupational Exposure; Vinyl Chloride
PubMed: 22440240
DOI: 10.1016/j.dld.2012.02.007 -
Mutation Research. Reviews in Mutation... Oct 2017Vinyl chloride (VC) is widely used in industry in the production of polyvinyl chloride (PVC), which is used to manufacture a large variety of materials. VC was... (Meta-Analysis)
Meta-Analysis Review
Vinyl chloride (VC) is widely used in industry in the production of polyvinyl chloride (PVC), which is used to manufacture a large variety of materials. VC was classified as a known (Group 1) human carcinogen by IARC on the basis of increased risk for liver angiosarcoma and hepatocellular cancer, and the carcinogenicity of VC was shown to be mediated by a genotoxic mechanism. Following inhalation, the compound is rapidly absorbed and metabolized in the liver to the electrophilic metabolites chloroethylene-oxide and chloroacetaldehyde, which form DNA adducts that can be processed into point mutations in cancer-related genes detected in humans and rats exposed to VC. A number of genotoxicity biomarkers were applied in workers exposed to VC to detect early biological responses associated with the carcinogenesis process. The present systematic review analyzed the published studies in which the cytokinesis-block micronucleus assay in peripheral lymphocytes (L-CBMN) was applied in VC-exposed subjects. Thirteen out of fifteen retrieved studies performed in China showed increased MN frequencies (FR 1.92-3.98) associated with increased cumulative exposure or employment time. Twofold and more than threefold increases were detected in PVC-exposed workers exposed to a mean of 50ppm of VC in the former Yugoslavia and in South India, respectively. The meta-analysis of MN frequency from six eligible studies confirmed this tendency (pooled MR 2.32 - 95% CI 1.64-3.27). The benchmark dose lower limit for 10% excess risk (BMDL 10) calculated from three studies resulted in an estimated exposure limit of 0.03-0.07mg/m. Overall the results of this review showed the need for further studies, especially because PVC products from China may contain high levels of uncoupled VCM that could represent a source of exposure to workers and consumers. Moreover, the results underline the importance of re-evaluating the recommended exposure limits using new biomonitoring methods in addition to MN.
Topics: Biomarkers; Cytokinesis; Environmental Monitoring; Humans; Lymphocytes; Micronucleus Tests; Occupational Exposure; Vinyl Chloride
PubMed: 29173494
DOI: 10.1016/j.mrrev.2017.07.003 -
Systematic Reviews Aug 2021Sarcomas are a rare and heterogeneous group of tumors originating from mesenchymal or connective tissue. They represent less than 1% of all adult cancers. The etiology... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sarcomas are a rare and heterogeneous group of tumors originating from mesenchymal or connective tissue. They represent less than 1% of all adult cancers. The etiology and epidemiology of sarcomas remain understudied and poorly understood. The main objective of our study was to systematically assess the association between various occupational exposures and risk of sarcomas.
METHODS
We performed a systematic literature search using the PubMed, Scopus, EMBASE and Cochrane databases to identify relevant cohort and case-control studies. A meta-analysis method was applied on the incidence and mortality outcomes where the estimate with 95% confidence interval (CI) was obtained.
RESULTS
We included a total of 50 publications in our systematic review and 35 in meta-analysis. For exposures to phenoxy herbicides and chlorophenols, the pooled odds ratio (OR) for sarcoma was 1.85 (95% CI: 1.22, 2.82), based on 16 studies with 2254 participants, while the pooled standardized mortality ratio was 40.93 (95% CI 2.19, 765.90), based on 4 cohort studies with 59,289 participants. For exposure to vinyl chloride monomers the pooled risk ratios for angiosarcoma of the liver and other STS were 19.23 (95% CI 2.03, 182.46) and 2.23 (95 CI 1.55, 3.22) respectively based on 3 cohort studies with 12,816 participants. Exposure to dioxins was associated with an increased STS mortality; the pooled standardized mortality ratio was 2.56 (95% CI 1.60, 4.10) based on 4 cohort studies with 30,797 participants. Finally, woodworking occupation was associated with an increased risk of STS with the pooled OR of 2.16 (95% CI 1.39, 3.36).
CONCLUSIONS
Our findings suggest a positive association between higher exposure to dioxins and increased mortality from STS, between cumulative exposure to vinyl chloride monomers and increased mortality from angiosarcoma of the liver and STS, and between woodworking occupation and STS incidence. These findings were all statistically significant.
Topics: Adult; Cohort Studies; Humans; Incidence; Occupational Diseases; Occupational Exposure; Sarcoma
PubMed: 34389054
DOI: 10.1186/s13643-021-01769-4 -
Mutation Research. Reviews in Mutation... 2016Accumulating evidence suggests that epigenetic alterations play an important role in chemically-induced carcinogenesis. Although the epigenome and genome may be equally... (Review)
Review
Accumulating evidence suggests that epigenetic alterations play an important role in chemically-induced carcinogenesis. Although the epigenome and genome may be equally important in carcinogenicity, the genotoxicity of chemical agents and exposure-related transcriptomic responses have been more thoroughly studied and characterized. To better understand the evidence for epigenetic alterations of human carcinogens, and the potential association with genotoxic endpoints, we conducted a systematic review of published studies of genotoxic carcinogens that reported epigenetic endpoints. Specifically, we searched for publications reporting epigenetic effects for the 28 agents and occupations included in Monograph Volume 100F of the International Agency for the Research on Cancer (IARC) that were classified as "carcinogenic to humans" (Group 1) with strong evidence of genotoxic mechanisms of carcinogenesis. We identified a total of 158 studies that evaluated epigenetic alterations for 12 of these 28 carcinogenic agents and occupations (1,3-butadiene, 4-aminobiphenyl, aflatoxins, benzene, benzidine, benzo[a]pyrene, coke production, formaldehyde, occupational exposure as a painter, sulfur mustard, and vinyl chloride). Aberrant DNA methylation was most commonly studied, followed by altered expression of non-coding RNAs and histone changes (totaling 85, 59 and 25 studies, respectively). For 3 carcinogens (aflatoxins, benzene and benzo[a]pyrene), 10 or more studies reported epigenetic effects. However, epigenetic studies were sparse for the remaining 9 carcinogens; for 4 agents, only 1 or 2 published reports were identified. While further research is needed to better identify carcinogenesis-associated epigenetic perturbations for many potential carcinogens, published reports on specific epigenetic endpoints can be systematically identified and increasingly incorporated in cancer hazard assessments.
Topics: Animals; Carcinogenicity Tests; Carcinogens; Environmental Exposure; Epigenesis, Genetic; Gene Expression Regulation; Genetic Association Studies; Genetic Predisposition to Disease; Genetic Variation; Humans; Mutagenicity Tests; Mutagens; Occupational Exposure
PubMed: 27234561
DOI: 10.1016/j.mrrev.2016.03.004 -
Oral Health & Preventive Dentistry 2004To assess the evidence on the effectiveness of commercially available anticalculus dentifrices. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To assess the evidence on the effectiveness of commercially available anticalculus dentifrices.
MATERIALS AND METHODS
Systematic search for published and unpublished epidemiological data in 7 electronic databases, 5 journals, and the bibliographies of retrieved papers and by making contact with subject experts in this field. Thirty-two reports were identified containing comparisons of one or more active agents with a placebo dentifrice and calculus measured using the Volpe-Manhold Index (VMI).
RESULTS
Random effect model for 3-month studies showed an effect size of -0.6 for all comparisons. The effect sizes varied from -0.3 for dentifrices with zinc chloride 0.5% to -1.1 for pyrophosphate 1.3% and copolymer 1.5% dentifrices. Meta-analysis of all the studies with 6-month follow-up gave an effect size of -1.1 (-1.5 to -0.8) and for 12-month follow-up the effect size was -13.6 (-21.4 to -5.8).
CONCLUSIONS
Anticalculus dentifrices containing pyrophosphates, zinc compounds and/or co-polymers were effective in significantly reducing calculus scores (VMI).
Topics: Dental Calculus; Dentifrices; Diphosphates; Humans; Maleates; Polyethylenes; Toothbrushing; Treatment Outcome
PubMed: 15641765
DOI: No ID Found -
Anales de Pediatria (Barcelona, Spain :... Apr 2008Pediatric Hepatic Malignancies (PHMs) are the result of the interaction between constitutional and environmental risk factors (RFs). We review the evidence on the main... (Review)
Review
OBJECTIVE
Pediatric Hepatic Malignancies (PHMs) are the result of the interaction between constitutional and environmental risk factors (RFs). We review the evidence on the main RFs associated to PHMs.
METHOD
Systematic review of the literature published in the last 25 years on Medline, Embase, Cancerlit, Lilacs and SciElo using the following key words: "etiology/risk factor/epidemiology" and "malignant liver tumors/hepatic cancer" or "hepatoblastoma/hepatocarcionoma".
RESULTS
PHMs account for 1 % of all pediatric malignancies. The main types, hepatoblastoma (HB) and hepatocarcionma (HCC) make up 98-99 % of PHM. The main constitutional RFs are: a) Beckwith-Wiedemann (BW) syndrome; b) isolated hemihyperplasia syndrome (IHS); c) adenomatous polyps of the colon; d) hemochromatosis; e) Hereditary Tyrosinemia Type 1; f) a -1-antitrypsin deficiency; g) porphyrias; h) cirrhosis; i) nonalcoholic steatosis; and j) primary sclerosing cholangitis. The main environmental RFs are: a) hepatitis B virus (HBV) and C virus (HCV); b) B1 aflatoxin (B1AF); c) ionizing radiation; d) alcohol; e) hormonal treatments; f) occupational exposure to pesticides, solvents, vinyl chloride and metals; g) smoking; h) arsenic; i) prematury and very low birth weight; and j) trematodes.
CONCLUSIONS
The clinical, analytical and ultrasound screening facilitate the early diagnosis of HB in the previously mentioned genetic syndromes, particularly BW and IHS during the first years of life. HBV universal vaccination of newborns provides the biggest opportunity to prevent a substantial proportion of PHMs. Also systematic monitoring of HBV and HCV in blood, hemoderivates, donated organs and drug addicts, are very useful. Other effective measures are: the reduction/elimination of B(1)AF in food, zero alcohol intake during childhood and adolescence as well decreasing prenatal exposure to the tobacco, solvents, pesticides, vinyl chloride, metals, ionizing radiation and hormonal treatments.
Topics: Child; Hepatoblastoma; Humans; Liver Neoplasms; Risk Factors
PubMed: 18394385
DOI: 10.1157/13117711 -
The Cochrane Database of Systematic... May 2016Breast cancer is the most common cancer in women worldwide, and is a leading cause of cancer death among women. Prophylactic or curative mastectomy is often followed by... (Review)
Review
BACKGROUND
Breast cancer is the most common cancer in women worldwide, and is a leading cause of cancer death among women. Prophylactic or curative mastectomy is often followed by breast reconstruction for which there are several surgical approaches that use breast implants with which surgeons can restore the natural feel, size and shape of the breast.
OBJECTIVES
To assess the effects of different types of breast implants on capsular contracture, surgical short- and long-term complications, postoperative satisfaction level and quality of life in women who have undergone reconstructive breast surgery after mastectomy.
SEARCH METHODS
We searched the Cochrane Breast Cancer Group's Specialised Register on 20 July 2015, MEDLINE (1985 to 20 July 2015), EMBASE (1985 to 20 July 2015) and the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 8, 2015). We also searched the World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov on 16 July 2015.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) and quasi-RCTs that compared different types of breast implants for reconstructive surgery. We considered the following types of intervention: implant envelope surfaces - texturised versus smooth; implant filler material - silicone versus saline, PVP-Hydrogel versus saline; implant shape - anatomical versus round; implant volume - variable versus fixed; brands - different implant manufacturing companies and implant generation (fifth versus previous generations).
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed methodological quality and extracted data. We used standard Cochrane methodological procedures. The quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.
MAIN RESULTS
Five RCTs with 202 participants met the inclusion criteria. The women participants were typically in their 50s, and the majority of them (about 82%) received reconstructive surgery following breast cancer, while the others had reconstructive surgery after prophylactic mastectomy. The studies were heterogenous in terms of implant comparisons, which prevented us from pooling the data.The studies were judged as being at an unclear risk of bias for most risk of bias items owing to poor quality of reporting in the trial publications. Three of the five RCTs were judged to be at high risk of attrition bias, and one at high risk of detection bias.Textured silicone versus smooth silicone implants: textured implants were associated with worse outcomes when compared to smooth implants (capsular contracture: risk ratio (RR) 0.82, 95% CI 0.14 to 4.71; 1 study, 20 participants; very low quality evidence; reintervention: RR 0.82, 95% CI 0.14 to 4.71; 1 study, 20 participants; very low quality evidence). No results in this comparison were statistically significant.Silicone versus saline implants: saline-filled implants performed better than silicone-filled implants for some outcomes; specifically, they produced less severe capsular contracture (RR 3.25, 95% CI 1.24 to 8.51; 1 study, 60 participants; very low quality evidence) and increased patient satisfaction (RR 0.60, 95% CI 0.41 to 0.88; 1 study, 58 participants; very low quality evidence). However reintervention was significantly more frequent in the saline-filled implant group than in the silicone-filled group (OR 0.08, 95% CI 0.01 to 0.43; 1 study, 60 participants; very low quality evidence).Poly(N-vinyl-2-pyrrolidone) hydrogel-filled (PVP-hydrogel) versus saline-filled implants: PVP-hydrogel-filled implants were associated with worse outcomes when compared to saline-filled implants (capsular contracture: RR 3.50, 95% CI 0.83 to 14.83; 1 study, 40 participants; very low quality evidence; short-term complications: RR 2.10, 95% CI 0.21 to 21.39; 1 study, 41 participants; very low quality evidence).Anatomical versus round implants: anatomical implants were associated with worse outcomes than round implants (capsular contracture: RR 2.00, 95% CI 0.20 to 20.15; 1 study, 36 participants; very low quality evidence; short-term complications: RR 2.00, 95% CI 0.42 to 9.58; 1 study, 36 participants; very low quality evidence; reintervention: RR 1.50, 95% CI 0.51 to 4.43; 1 study, 36 participants; very low quality evidence). No results in this comparison were statistically significant.Variable-volume versus fixed-volume implants: data about one-stage reconstruction using variable-volume implants were compared with data about fixed-volume implants positioned during the second surgical procedure of two-stage reconstructions. Fixed-volume implant reconstructions were possibly associated with a greater number of women reporting that their reconstruction corresponded with expected results (RR 0.25, 95% CI 0.10 to 0.62; 1 study, 40 participants; very low quality evidence) and fewer reinterventions (RR 7.00, 95% CI 1.82 to 26.89; 1 study, 40 participants; very low quality evidence) when compared to variable-volume implants. A higher patient satisfaction level (rated from 1 to 6, with 1 being very bad and 6 being very good) was found with the fixed-volume implants for overall aesthetic result (mean difference (MD) -1.10, 95% CI -1.59 to -0.61; 1 study, 40 participants; very low quality evidence).There were no studies that examined the effects of recent (fifth) generation silicone implants versus previous generations or different implant manufacturing companies.
AUTHORS' CONCLUSIONS
Despite the central role of breast reconstruction in women with breast cancer, the best implants to use in reconstructive surgery have been studied rarely in the context of RCTs. Furthermore the quality of these studies and the overall evidence they provide is largely unsatisfactory. Some of our results can be interpreted as early evidence of potentially large differences between different surgical approaches, which should be confirmed in new high-quality RCTs that include a larger number of women. These days - even after a few million women have had breasts reconstructed - surgeons cannot inform women about the risks and complications of different implant-based breast reconstructive options on the basis of results derived from RCTs.
Topics: Breast Implants; Breast Neoplasms; Female; Humans; Hydrogels; Mammaplasty; Mastectomy; Middle Aged; Patient Satisfaction; Prophylactic Surgical Procedures; Prosthesis Failure; Randomized Controlled Trials as Topic; Silicone Gels; Sodium Chloride
PubMed: 27182693
DOI: 10.1002/14651858.CD010895.pub2