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Biomedical subjects

Paolo Boffetta

Publications and source records attributed to Paolo Boffetta.

152 records · Page 9Linked to original sources

Cancer incidence of dry cleaning, laundry and ironing workers in Sweden.

OBJECTIVES: This study investigated the risk of cancer among dry cleaners, launderers, and pressers in a large record-linkage study in Sweden. METHODS: The Swedish Cancer Register III contains nationwide data on cancer incidence between 1971 and 1989, by occupation and industry of employment, as reported in the 1960 and 1970 censuses. Dry cleaners, launderers, and pressers were compared with the remaining part of the employed population using multivariable Poisson regression models and standardized incidence ratios. RESULTS: Dry cleaners, launderers, and pressers employed in the laundry, ironing, or dyeing industry in both censuses showed an increased risk of Hodgkin's disease [relative risk (RR) 2.69,95% confidence interval (95% CI) 1.01-7.19], an elevated risk of leukemia among women (RR 2.53,95% CI 1.44-4.46), and increased risks of stomach (RR 1.80,95% CI 1.05-3.11) and laryngeal (RR 2.42, 95% CI 0.91-6.45) cancers among men. The results of the analyses of launderers and dry cleaners as a separate occupational group reflected those of the whole exposure group, while pressers showed an elevated lung cancer risk (RR 1.67, 95% CI 0.75-3.72). CONCLUSIONS: If they are not due to chance or confounding, the results of this study reflect either the potentiation of other carcinogens by solvents or direct effects. The results are limited by the use of job and industry titles as proxies for occupational exposures.

Adult↗

Involuntary smoking and lung cancer.

Involuntary smoking contains human carcinogens. Exposure prevalence among adults is on the order of 40%. A meta-analysis of epidemiologic studies on lung cancer and exposure to involuntary smoking from the spouse included 51 studies. The overall relative risk (RR), based on 7369 cases of lung cancer, was 1.25 [95% confidence interval (95% CI) 1.15-1.37]. No evidence existed of an RR difference between the two genders, and study design had no influence on the results. The summary RR was lower for adenocarcinoma than for other histological types. In the largest studies cumulative exposure suggested a dose-response relationship with a unit risk of similar magnitude. The summary RR was 1.17 (95% CI 1.04-1.32) for workplace exposure. Several sources of bias may lead to both overestimation and underestimation of true association, and the most plausible interpretation favors a causal association. Even if excess risk from exposure to involuntary smoking is small, its large prevalence makes it an important environmental carcinogen.

Adenocarcinoma↗

Molecular epidemiology: a tool for understanding mechanisms of disease.

The use of biomarkers in medicine, and in epidemiology in particular, is not new but recent developments in molecular biology and genetics have increased the opportunities for their use. Epidemiological studies based on biomarkers, which belong to the discipline defined as 'molecular epidemiology', offer new avenues to investigate associations between genetic and environmental factors, diseases, and medical interventions. Important recent contributions of molecular epidemiology to cancer research include the definitive evidence of the carcinogenicity of aflatoxin in humans, and the elucidation of the mechanisms of tobacco-related carcinogenesis. However, molecular epidemiology studies are subject to problems of design and analysis similar to those of 'traditional' epidemiological studies. If biomarkers offer new opportunities to overcome some of the limitations of epidemiology, their added value over traditional approaches should be systematically assessed. Biomarkers should be validated though transitional studies; consideration to sources of bias and confounding in molecular epidemiology studies should be no less stringent than in traditional studies.

Biomarkers↗

Effect of cruciferous vegetables on lung cancer in patients stratified by genetic status: a mendelian randomisation approach.

Whether consumption of cruciferous vegetables protects against lung cancer is unclear, largely because of potential confounding factors. We therefore studied the role of cruciferous vegetables in lung cancer after stratifying by GSTM1 and GSTT1 status, two genes implicated in the elimination of isothiocyanates, the likely chemopreventative compound. In 2141 cases and 2168 controls, weekly consumption of cruciferous vegetables protected against lung cancer in those who were GSTM1 null (odds ratio=0.67, 95% CI 0.49-0.91), GSTT1 null (0.63, 0.37-1.07), or both (0.28, 0.11-0.67). No protective effect was seen in people who were both GSTM1 and GSTT1 positive (0.88, 0.65-1.21). Similar protective results were noted for consumption of cabbage and a combination of broccoli and brussels sprouts. These data provide strong evidence for a substantial protective effect of cruciferous vegetable consumption on lung cancer.

Case-Control Studies↗

Microsomal epoxide hydrolase polymorphisms and lung cancer risk: a quantitative review.

To investigate the role of microsomal epoxide hydrolase (mEH) polymorphisms in the aetiology of lung cancer and to assess the interaction between mEH polymorphisms and smoking, we performed a meta-analysis of seven published studies, which included 2078 cases and 3081 controls, and a pooled analysis of eight studies (four published and four unpublished at that time) with a total of 986 cases and 1633 controls. The combined meta-analysis odds ratios (ORs) were 0.98 (95% confidence interval [CI] = 0.72-1.35) for polymorphism at amino acid 113 in exon 3 (His/His versus Tyr/Tyr genotype) and 1.00 (95% CI = 0.71-1.41) for polymorphism at amino acid 139 in exon 4 (Arg/Arg versus His/His genotype). In the pooled analysis, we observed a significant decrease in lung cancer risk (OR = 0.70, 95% CI = 0.51-0.96) for exon 3 His/His genotype after adjustment for age, sex, smoking and centre. The protective effect of exon 3 polymorphism seems stronger for adenocarcinoma of the lung than for other histological types. The OR for high predicted mEH activity, compared with low activity, was 1.54 (95% CI = 0.77-3.07) in the meta analysis and 1.18 (95% CI = 0.92-1.52) in the pooled analysis. We did not find a consistent modification of the carcinogenic effect of smoking according to mEH polymorphism, although the risk of lung cancer decreased among never smokers with high mEH activity and among heavy smokers with the exon 3 His/His genotype. In conclusion, this study suggests a possible effect of mEH polymorphisms at exon 3 in modulating lung cancer. If present, this effect may vary among different populations, possibly because of interaction with genetic or environmental factors.

Adult↗

Assessment of exposure in an international study on cancer risks among pulp, paper, and paper product workers.

A data management system and a department-exposure matrix (PAPDEM) was designed and constructed to facilitate exposure assessment for a large multinational study on cancer risks among pulp, paper, and paper product workers. Exposure to 25 major agents was described by prevalence, P (i.e., proportion of the exposed, classified %-range), and level, L (i.e., annual mean concentration at work, classified). Some agents could be assessed only in qualitative terms. The assessment was specific to mill, work department, agent, and time period. The results of industrial hygiene measurements, information from detailed company questionnaires, and the professional judgments of the assessment team were the cornerstones of the assessment. Validity and consistency of the assessment were aimed at by setting default values for P and L prior to the assessment, accurately defining agents and exposure classes, dividing assessment work by subindustry, working in pairs, testing interrater agreement, and finalizing the estimates in a meeting. In spite of these precautions, good agreement between different assessors was difficult to reach. Exposure to chemical agents turned out to be widespread and complex with frequent multiple exposures. A computer-assisted exposure assessment system such as PAPDEM may save time and facilitate assessment in large epidemiological studies requiring complicated exposure assessment procedures. It also provides a good documentation of exposure assignments, which may be useful in the interpretation of the results and in future updates of the study.

Epidemiologic Studies↗

High exposure to polycyclic aromatic hydrocarbons may contribute to high risk of esophageal cancer in northeastern Iran.

BACKGROUND: The northeastern region of Iran has some of the highest rates of esophageal squamous cell carcinoma (ESCC) in the world. MATERIALS AND METHODS: To investigate the role of polycyclic aromatic hydrocarbons (PAHs) in the etiology of ESCC in northeastern Iran, we measured urine 1-hydroxypyrene glucuronide (1-OHPG), a stable PAH metabolite, in 99 inhabitants of this area. RESULTS: The median urine 1-OHPG in participants of this study was 4.2 pmol/ml. Forty-two subjects (42%) had levels ranging from 1 to 5 pmol/ml, indicative of moderate PAH exposure, and 41 (41%) had levels above 5 pmol/ml, indicative of very high exposure. Further analysis showed that 1-OHPG levels were high in all subgroups of our study subjects, including both sexes, rural and urban dwellers, and smokers and non-smokers. Only 15% of the variance in 1-OHPG was explained by age, sex, residence, smoking, nass, or opium consumption. This pattern of PAH exposure parallels the ESCC incidence pattern seen in this area. CONCLUSION: We conclude that people in northeastern Iran are exposed to widespread and very high levels of PAH, largely from unknown sources, and this may contribute to the high rates of ESCC observed in this area.

Adult↗