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Biomedical subjects

P Boffetta

Publications and source records attributed to P Boffetta.

At least 217 records · Page 12Linked to original sources
PubMed1995

Wood dust and sino-nasal cancer: pooled reanalysis of twelve case-control studies.

In order to examine the relationship between wood dust and sino-nasal cancer, data from 12 case-control studies conducted in seven countries were pooled and reanalyzed. The relative risks associated with wood-related jobs and with exposure to wood dust, measured using a job exposure matrix based on occupation and industry titles, were examined using logistic regression. The combined data set consisted of 680 male cases, 2,349 male controls, 250 female cases, and 787 female controls. A high risk of adenocarcinoma among men was associated with employment in wood-related occupations (odds ratio [OR] = 13.5, 95% confidence interval [CI] = 9.0-20.0) and the risk was greatest among men who had been employed in jobs with the highest wood dust exposure (OR = 45.5, 95% CI = 28.3-72.9) and increased with duration of exposure. The risk of adenocarcinoma also appeared elevated among women employed in wood-related jobs (OR = 2.5, 95% CI = 0.5-12.3), but the small number of exposed cases precluded detailed analysis. Women in wood dust-exposed jobs appeared to have an excess of squamous cell carcinoma (OR = 2.1, 95% CI = 0.8-5.5) which increased with duration of exposure. An increased risk of squamous cell carcinoma in men was seen only among those employed for 30 or more years in jobs with exposure to fresh wood (OR = 2.4, 95% CI = 1.1-5.0). The results of this analysis provide strong support to the association between exposure to wood dust in a variety of occupations and the risk of sino-nasal adenocarcinoma and are consistent with the results of individual participating studies, although the magnitude of the excess risk varied. The evidence in regard to squamous cell carcinomas was ambiguous and there was a great deal of heterogeneity observed in individual study results. This may be due to differences in risk associated with exposure to hardwoods and softwoods or with other, as yet to be identified, aspects of exposure.

Adenocarcinoma↗
PubMed1995

Occupational risk factors for lung cancer in Tianjin, China.

Information about occupation and industry of cancer patients is routinely recorded in the Cancer Registry of Tianjin, People's Republic of China. Occupational risk factors of lung cancer for the period of 1981-1987 were assessed using other cancers as controls. For each occupation and industry, workers employed in it were considered exposed and were compared with all other workers. Elevated risks were found for a number of industries for both sexes, including, in particular, the textile, wood, metal, and construction industries. Results by occupation were similar to those by industry. Smoking scores were calculated for various occupations on the basis of a separate population survey in Tianjin. Smoking cannot explain the elevated odds ratios in males, while among females a strong correlation was observed between smoking scores and lung cancer odds ratios, suggesting a confounding effect.

Adult↗
PubMed1995

Sources of bias, effect of confounding in the application of biomarkers to epidemiological studies.

This article addresses some methodological aspects of the application of biomarkers of exposure, effect and susceptibility to cancer epidemiology. The application of biomarkers to cancer epidemiology should enhance the validity of exposure and outcome measurement, and strengthen the statistical association between exposure and diseases, thus reducing the possibility of random and systematic error. However, the use of biomarkers provides in turn new opportunities for bias and confounding. Small sample size is a limitation of many molecular epidemiology studies. Three major types of bias are recognized: selection bias, information bias (measurement error), and confounding. An important aspect of confounding is that biomarkers can be seen both as exposure and outcome. A second aspect of confounding lies in the role of the biological marker in the causal pathway between exposure and disease. Molecular epidemiology offers better opportunity for the elucidation of interactions between genetic and environmental factors. Genetic susceptibility studies should demonstrate the highest disease risk for exposed susceptible groups and the lowest risk for non-susceptible unexposed groups.

Bias↗
PubMed1995

Clinico-pathological features and survival of lung cancer patients in Paris, France.

We studied the clinico-pathological features of 750 lung cancers identified in Paris, France, during 1988. An internal comparison was performed between adenocarcinomas and other subtypes. Survival of 502 patients was studied. 85% of patients were males; 93% were smokers or ex-smokers. Squamous cell carcinomas, adenocarcinomas, small cell carcinomas and large cell cancers accounted for 51, 22, 15 and 12% of all cases, respectively. Differences were found for the distribution of histological subtyping according to sex (P = 0.001) and smoking status (P = 0.0001) with a greater proportion of adenocarcinomas for women and non-smokers. Median overall survival was less than one year. In multiple regression analysis, small cell lung cancer patients appeared to have a worse prognosis than other histological subtypes. This study describes patients who were treated in community practice and might be more representative of the real clinico-pathological profile of this disease in France.

Adult↗
PubMed1995

Alcohol, tobacco, diet and the risk of oral cancer: a pooled analysis of three case-control studies.

This combined analysis of data from three large case-control studies of oral cancer confirms the important effect of tobacco in the aetiology of the disease. The studies have been conducted in the United States, Italy and China and results for risks associated with tobacco smoking were generally consistent across centres, while those for alcohol were not; increased risks amongst alcohol drinkers were evident in two centres but not in the study conducted in Turin, Italy. In addition, the combined analysis had large enough numbers to analyse the risk of tobacco consumption in non-drinkers. In females these showed increased risks while in males the effect of tobacco alone was weaker. Given the popularity of tobacco smoking, and its consequent high attributable risk in terms of oral cancer it is reassuring, in terms of public health, that cessation will result in a substantial reduction in risk; a 30% reduction in risk for those stopping smoking between 1 and 9 years, and a 50% reduction for those stopping more than 9 years. Although encouraging smokers to stop should be the principal aim, decreases in risk for everyone could be achieved by encouraging high fruit and vegetable consumption.

Adult↗
PubMed1995

Cancer and occupational exposure to inorganic lead compounds: a meta-analysis of published data.

OBJECTIVES: To review and summarise the epidemiological evidence on the carcinogenicity of occupational exposure to inorganic lead. METHODS: Case-control and cohort studies were reviewed and combined for meta-analysis. Fixed and random effect methods were used to estimate the summary effects. RESULTS: The combined results show a significant excess risk of overall cancer, stomach cancer, lung cancer, and bladder cancer, with relative risk ratios (RRs) and 95% confidence intervals (95% CIs) in the meta-analysis of 1.11 (1.05-1.17), 1.33 (1.18-1.49), 1.29 (1.10-1.50), and 1.41 (1.16-1.71) respectively. The RR (95% CI) for kidney cancer was also high, but did not reach significance (1.19 (0.96-1.48)). A separate analysis of studies of heavily exposed workers provided slightly increased RRs for cancers of the stomach (1.50) and lung (1.42). CONCLUSIONS: The findings from the workers with heavy exposure to lead provided some evidence to support the hypothesis of an association between stomach and lung cancer and exposure to lead. The main limitation of the present analysis is that the excess risks do not take account of potential confounders, because little information was available for other occupational exposures, smoking, and dietary habits. To some extent, the risk of lung cancer might be explained by confounders such as tobacco smoking and exposure to other occupational carcinogens. The excess risk of stomach cancer may also be explained, at least in part, by non-occupational factors. For bladder and kidney cancers, the excess risks are only suggestive of a true effect because of possible publication bias.

Case-Control Studies↗
PubMed1995

Current Perspectives on Occupational Cancer Risks.

On the basis of the International Agency for Research on Cancer's evaluations of occupational exposures, 22 occupational agents are classified as human carcinogens and an additional 22 agents as probable human carcinogens. In addition, evidence of increased risk of cancer was associated with particular industries and occupations, although no specific agents could be identified as etiologic factors. The main problem in the construction and interpretation of such lists is the lack of detailed qualitative and quantitative knowledge about exposures to known or suspected carcinogens. The recent examples of recognized occupational carcinogens, such as cadmium, beryllium, and ethylene oxide, stress the importance of the refinement in the methods for exposure assessment and for statistical analysis on the one hand and the potential benefits from the application of biomarkers of exposure and early effect on the other hand. Other trends that may be identified include the increasing practice of multicentric studies and investigations of exposures relevant to white collar workers and women. Finally, there is a need for investigation of occupational cancer risks in developing countries.

Journal Article↗
PubMed1995

Pooled reanalysis of cancer mortality among five cohorts of workers in wood-related industries.

OBJECTIVES: To provide more information regarding the risk of cancer associated with wood dust, a pooled reanalysis of data from five cohort studies was performed. METHODS: The combined cohort consisted of 28,704 persons from five studies: British furniture workers, members of the union representing furniture workers in the United States, two cohorts of plywood workers, and one of wood model makers, among whom 7665 deaths occurred. Pooled analyses were carried out for all of the cohorts combined, the two furniture worker cohorts combined, and the two plywood workers cohorts combined. RESULTS: Significant excesses of nasal [observed 11, standardized mortality ratio (SMR) 3.1, 95% confidence interval (95% CI) 1.6-5.6] and nasopharyngeal (observed 9, SMR 2.4, 95% CI 1.1-4.5) cancer were observed. That for nasal cancer appeared to be associated with exposure to wood dust but was based solely on cases from the British furniture worker cohort, while that of nasopharyngeal cancer was observed for furniture and plywood workers and was associated with both high and low probability of wood dust exposure. Some support for an excess risk of multiple myeloma was also observed but was less clearly associated with wood dust exposure. No excesses of lung, larynx, stomach, or colon cancer were found to be associated with any surrogate indicators of wood dust exposure. CONCLUSIONS: Workers exposed to wood dust may have an excess risk of nasopharyngeal cancer and multiple myeloma in addition to sinonasal cancer. The limitations of this study would tend to obscure relationships, rather than create false positive findings.

Cause of Death↗
PubMed1995

Cancer risk for European asphalt workers.

OBJECTIVES: The feasibility of a European epidemiologic study of cancer risk among asphalt workers was examined in Western Europe. The study was motivated by occupational and public health concern about possible health risk from exposure to bitumen fumes. METHODS: Information on the accessibility and quality of epidemiologic resources, retrospective worker records, mortality and cancer incidence records, and exposures was requested from research institutes and road paving and asphalt mixing companies in 15 European countries. RESULTS: Research institutes and asphalt companies in 12 countries responded. It was found that at least 44 companies in seven countries can be included in a retrospective mortality study of a minimum of 32,000 employees with 356,000 person-years (over 100 lung cancers). Coal tar will be an important confounder for these data. The power of a cohort study of workers who have never worked with tar-containing materials remains insufficient. Even in an ambispective study extending to the year 2005, the expected lung cancer deaths in a tar-free cohort would be only four. CONCLUSIONS: The results suggest that a case-referent study of lung cancer, nested in an international cohort of asphalt workers, represents the design of choice, conditionally on the possibility of assessing relevant individual life-time exposures. A cross-sectional determination of relevant biomarkers of exposure such as adducts in lymphocytes or the presence of metabolites of polycyclic aromatic compounds in urine in a group of workers exposed to bitumen fumes will provide further relevant information.

Adult↗
PubMed1994

Cancer risk in asphalt workers and roofers: review and meta-analysis of epidemiologic studies.

Twenty epidemiologic studies have described cancer risk in asphalt workers and roofers in various countries. A current concern for these workers is the potential carcinogenicity posed by inhalation of bitumen fumes or dermal exposure to bitumens. Bitumens are chemically different from many carcinogenic coal-tar based materials. Both have been employed in road paving and waterproofing. We examined and combined the results of the epidemiologic studies conducted on asphalt workers and roofers. We examined the cancer risk separately in three broad job categories: 1) roofers (exposed to bitumen fumes and previously often to coal-tar fumes); 2) highway maintenance workers (HMWs) and road pavers (exposed to bitumen fumes as well as possibly coal-tar fumes previously); and 3) miscellaneous and unspecified bitumen/asphalt workers. In roofers, an increased risk was suggested for cancers of the lung (aggregated relative risk 1.8, 95% confidence interval 1.5-2.1), stomach (1.7, 1.1-2.5), nonmelanoma skin (4.0, 0.8-12), and leukemia (1.7, 0.9-2.9). Some of the excesses may be attributable to polycyclic aromatic hydrocarbons (PAH) from coal-tar products. The aggregated relative risks in road pavers and HMWs were consistently lower than in roofers for cancers of the lung (0.9, 0.8-1.0), stomach (1.1, 0.8-1.5), bladder (1.2, 0.7-1.8), skin (2.2, 1.2-3.7), and leukemias (1.3, 0.9-1.8). Their risk of skin cancer was significantly increased, based on one study. Miscellaneous and unspecified workers had a significant excess (1.5, 1.2-1.8) of lung cancer. The data were poorly focused to address the carcinogenicity of bitumen fumes, as contrasted with tar-derived exposures. For the prospect of shedding more light on the bitumen-cancer controversy, the feasibility of a powerful multicenter cohort is currently being studied by the International Agency for Research on Cancer (IARC).

Air Pollutants, Occupational↗
PubMed1994

Bladder cancer: epidemiology and risk factors in Bulawayo, Zimbabwe.

The incidence of bladder cancer, and the importance of some selected risk factors in its etiology, were estimated from the data collected in the cancer registry of Bulawayo, Zimbabwe, during the period 1963-77. Cancer cases were interviewed with a standard questionnaire, and more than 70 percent of these were complete. Incidence rates in the urban population of Bulawayo in the first 10-year period were relatively high, with age standardized rates of 17.9 per 100,000 in men and 9.5 in women. Risk-factor distribution was compared in 680 bladder cancer cases (494 males, 186 females) and a control group comprising other cases with non-tobacco-related cancers (8,201). Seventy-one percent of bladder cancer cases were squamous cell carcinomas. The presence of schistosomiasis, evaluated from past history of bilharzia or hematuria, was associated with a significantly increased risk of bladder cancer in both genders (odds ratio [OR] = 3.9 for men, 5.7 for women), a result reflected in the differing risk by province of residence, which correlated with the prevalence of infection among cancer cases. The proportion of bladder cancer attributable to schistosomiasis was estimated to be 28 percent. Social status, as reflected by education level, also influenced risk (ORs for literate cf illiterate males = 0.6), but tobacco smoking in men had no effect on the risk of squamous cell tumors. For transitional cell carcinomas or adenocarcinomas, there was a nonsignificant increased risk of 2.0 in the highest smoking categories (15 g of tobacco per day), compared with non smokers.

Female↗
PubMed1994

A population-based study of prognostic factors in oral and oropharyngeal cancer.

Cases of oral cavity and oropharynx cancer diagnosed among the residents of Torino, Italy, between 1982 and 1984 (n = 143) were followed up to June 1990. During this period, 97 subjects (67.8%) died, 69 from oral or oropharyngeal cancer. 10 more cases died from causes possibly related to oral cancer. The overall relative 5-year survival rate was 37.2%. Men experienced a worse survival than women. No difference was shown according to age, education or occupation. Patients with smooth lesions had a poorer prognosis than those with fissured or granular lesions; no association between survival and colour, elevation, induration or bleeding from the lesion was found. Extension of the tumour and nodal involvement were strong and independent predictors of survival, but no difference was found between T1 and T2 lesions. Patients who reported a 2-3-month interval between onset of symptoms and diagnosis experienced a better survival than those with shorter or longer interval. Oropharynx cases had a better prognosis than cancers of the oral cavity.

Adult↗
PubMed1994

A cohort study of workers compensated for mercury intoxication following employment in the fur hat industry.

This article presents the preliminary results of a follow-up study (1950-1992) of 1,146 subjects (person-years = 30,954; 23,055 for women) receiving compensation for mercury poisoning. In a province of Tuscany in central Italy, severe exposure to mercury occurred during fur hat production. A deficit in all causes of mortality was observed in both sexes, whereas mortality due to cancer was slightly higher than expected. Mortality from stomach cancer was significantly elevated for men and women. A significant excess of lung cancer was observed in women only. Whereas the excess of stomach cancer probably reflects elevated rates in the study area rather than exposure to mercury, the excess of lung cancer mortality does appear to be related to mercury exposure. Smoking habits or other exposures at work do not seem to explain the excess of lung cancer.

Adult↗
PubMed1994

Exposure to passive smoking during pregnancy and childhood, and cancer risk: the epidemiological evidence.

There are relatively few studies on the association between environmental tobacco smoke (ETS) during pregnancy and childhood, and cancer in childhood, adolescence or adulthood. The associations between maternal smoking during pregnancy and childhood cancer have been studied intensively, but there is no clear association overall, or for specific sites. The association between childhood cancer and smoking by the father in the preconceptional period, and by either parent during the child's lifetime, has been little studied. Again, no clear associations have been identified. However, evidence from studies of exposure to known carcinogens from ETS, and of genotoxic effects indicates that any effect, if present, is expected to be weak, and therefore could not have been detected by most of the studies which have been performed, due to the small number of cases included. There is some consistency of association between ETS exposure in childhood and the risk of lung cancers in adulthood. There is therefore a need for further epidemiological studies on ETS exposure during pregnancy and childhood and the occurrence of cancers.

Adolescent↗
PubMed1994

Exposure to environmental tobacco smoke and adult non-neoplastic respiratory diseases.

Exposure to environmental tobacco smoke (ETS) is widespread in European countries, the most serious exposures occurring at home and in the workplace. Epidemiological studies have, essentially, addressed the association between ETS exposure and respiratory health in children, and increased risk of lung cancer among adult nonsmokers. Relatively few studies have been reported on ETS and adult non-neoplastic respiratory diseases. On the basis of the available data, no definite conclusion (excluding the acute irritating effect of ETS on respiratory mucous membranes) can be drawn. Although biologically plausible, it remains controversial whether ETS exposure is associated with chronic respiratory symptoms and occurrence of chronic obstructive pulmonary disease, including asthma. Most of the studies that have used the most sensitive indicators of pulmonary function have suggested a negative impact of ETS exposure. However, if really present, the physiological significance of such small changes is unclear, and the relationship to long-term changes in lung function is not established. Moreover, the possibility of bias and confounding factors must be taken into account. Thus, there is a need for further epidemiological studies on ETS exposure and adult non-neoplastic respiratory disorders.

Environmental Exposure↗
PubMed1994

Exposure to environmental tobacco smoke and risk of lung cancer: the epidemiological evidence.

Exposure of nonsmokers to environmental tobacco smoke (ETS) is widespread in European countries, the most serious exposures occurring at home and in the workplace. Epidemiological studies available up to 1986 have been reviewed by several international and national authorities, which agreed in concluding that ETS exposure is causally related to lung cancer. A number of epidemiological studies have been published since then, and have confirmed this association. The possibility of positive results due to bias has been envisaged; it seems, however, that such bias could not explain the whole excess of lung cancer. Few data are available on confounders, such as diet and previous history of lung disease, that might be responsible for the association; however, there is no evidence that they play an important role. Moreover, the biological plausibility of a causal association is supported by the similarity of the composition of ETS and active smoke. The causal association between ETS exposure and lung cancer now seems well-established; however, its public health impact is still debated. Estimates are available from the United States, Canada, Australia, New Zealand and England.

Humans↗