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P Boffetta

Publications and source records attributed to P Boffetta.

At least 181 records · Page 10Linked to original sources
PubMed1998

A case study comparing a meta-analysis and a pooled analysis of studies of sinonasal cancer among wood workers.

A pooled analysis of raw data from 12 case-control studies of sinonasal cancer has recently been conducted by the International Agency for Research on Cancer; the summary odds ratio for all wood-related occupations was 2.0 (95% confidence interval = 1.6-2.5). We have conducted a meta-analysis of the published results of 14 studies on the same topic, including 11 studies from the pooled analysis, and compared the results for several categories of wood workers. Usable results were available for 12 studies: male wood workers had a summary odds ratio of sinonasal cancer of 2.6 (95% confidence interval = 2.1-3.3). The corresponding value based only on the studies that were also included in the pooled analysis was 2.4 (95% confidence interval = 1.9-3.0). When our meta-analysis was based on a relatively large number of studies, results tended to be higher than those of the pooled analysis. As compared with the meta-analysis, the pooled analysis controlled the effect of publication bias by using data from studies for which no specific result was reported, and it reduced misclassification of exposure; the resources used in the pooled analysis, however, were one order of magnitude greater than those needed for the meta-analysis. Whether a pooled analysis of raw data or a meta-analysis should be carried out depends on the research question; we propose some criteria for this decision.

Case-Control Studies↗
PubMed1998

4-Hydroxy-1-(3-pyridyl)-1-butanone-hemoglobin adducts as biomarkers of exposure to tobacco smoke: validation of a method to be used in multicenter studies.

Hemoglobin (Hb) adducts of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB), a metabolite of two tobacco-specific nitrosamines [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and N'-nitrosonornicotine], were measured as biomarkers of exposure to tobacco smoke as part of a study on genetic alterations and susceptibility to lung cancer among nonsmokers. HPB-Hb adducts were measured after collection of RBCs by Ficoll gradient in six collaborating centers, release of HPB by alkaline hydrolysis from Hb, clean-up by solid-phase extraction, and analysis of an electron-capturing derivative by gas chromatography-electron capture mass spectrometry. Prior to analysis of samples from study subjects, the reproducibility of this approach was validated in blood from donors. The coefficient of variation of reproducibility of paired aliquots from five samples ranged from 7 to 25%; the within-sample reproducibilities of four and eight aliquots were 4 and 16%, respectively. The study subjects consisted of 18 smokers and 52 never-smokers. HPB-Hb adduct levels were significantly higher (P = 0.02) in smokers (26 +/- 13 fmol HPB/g Hb) than in never-smokers (20 +/- 8 fmol HPB/g Hb). There was no difference between sexes. These results suggest that the level of HPB-Hb adducts, measured using a method modified to facilitate use in multicenter studies, can be a useful biomarker of exposure to tobacco smoke.

Biomarkers↗
PubMed1997

Epidemiology of bladder cancer in Alexandria, Egypt: tobacco smoking.

The relationship between smoking and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 151 males with incident, histologically confirmed invasive cancer of the bladder, and controls were 157 males admitted to hospital for acute, non-neoplastic, non-urinary tract, non-smoking-related conditions. With reference to never smokers, ex-smokers had a multivariate odds ratio (OR) of 4.4 [95% confidence interval (CI) 1.7-11.7] and current smokers of 6.6 (95% CI 3.1-13.9). The ORs were 5.4 for < 20 and 7.6 for > or = 20 cigarettes per day. After adjustment for cigarette smoking, the ORs were 0.8 for waterpipe and 0.4 for hashish smokers. The risk was significantly related to duration of smoking (OR of 16.5 for > 40 years), and inversely related to age at starting (OR of 8.8 for starting < 20 years), and inversely related to time since quitting smoking. Compared with never smokers who did not report a clinical history of schistosomiasis, the OR was 9.4 for smokers with a history of schistosomiasis, and 10.7 for smokers ever employed in high-risk occupations compared with non-smokers not reporting such a history. Thus, our results, while not giving indications of an increased bladder cancer risk with habits other than cigarette smoking, found a remarkably strong association with various measures of cigarette smoking that could explain 75% of bladder cancer cases among males from Alexandria. The prevalence of smoking was very low among women, and consequently tobacco was not a relevant risk factor for female bladder cancer.

Adult↗
PubMed1997

Tobacco smoking and gastric cancer: review and meta-analysis.

Although declining, gastric cancer (GC) is estimated to be second in frequency worldwide. Major causes appear to be environmental rather than genetic. A relationship has been suggested between tobacco smoking and GC. A number of epidemiological studies have been performed dealing with this question. All the cohort studies showed a significantly increased risk of GC of the order of 1.5-2.5 for cigarette smokers. Evidence from case-control studies is less consistent. We have carried out a meta-analysis on the 40 studies providing a quantitative estimate of the association between GC risk and tobacco smoking. Results suggest a risk of stomach cancer among smokers of the order of 1.5-1.6 as compared to non-smokers. The summary relative risk was higher in men (1.59) than in women (1.11). Several studies examined the dose-response relationship which existed in 4 cohort studies and 6 case-control studies. We estimated the number of GC cases attributable to tobacco smoking occurring worldwide: in total, over 80,000 cases of GC (11% of all estimated cases) may be attributed to tobacco smoking each year. This figure is larger than that estimated for other cancers for which association with tobacco smoking is clearly established, such as pancreatic and renal cancers.

Aged↗
PubMed1997

Cancer mortality in workers exposed to phenoxy herbicides, chlorophenols, and dioxins. An expanded and updated international cohort study.

The authors examined cancer mortality in a historical cohort study of 21,863 male and female workers in 36 cohorts exposed to phenoxy herbicides, chlorophenols, and dioxins in 12 countries. Subjects in this updated and expanded multinational study coordinated by the International Agency for Research on Cancer were followed from 1939 to 1992. Exposure was reconstructed using job records, company exposure questionnaires, and serum and adipose tissue dioxin levels. Among workers exposed to phenoxy herbicides contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or higher chlorinated dioxins, mortality from soft-tissue sarcoma (6 deaths; standardized mortality ratio (SMR) = 2.03, 95% confidence interval (CI) 0.75-4.43) was higher than expected from national mortality rates. Mortality from all malignant neoplasms (710 deaths; SMR = 1.12, 95% CI 1.04-1.21), non-Hodgkin's lymphoma (24 deaths; SMR = 1.39, 95% CI 0.89-2.06), and lung cancer (225 deaths; SMR = 1.12, 95% CI 0.98-1.28) was slightly elevated. Risks for all neoplasms, for sarcomas, and for lymphomas increased with time since first exposure. In workers exposed to phenoxy herbicides with minimal or no contamination by TCDD and higher chlorinated dioxins, mortality from all neoplasms (398 deaths; SMR = 0.96, 95% CI 0.87-1.06), non-Hodgkin's lymphoma (9 deaths; SMR = 1.00), and lung cancer (148 deaths; SMR = 1.03) was similar to that expected, and mortality from soft-tissue sarcoma was slightly elevated (2 deaths; SMR = 1.35). In a Poisson regression analysis, workers exposed to TCDD or higher chlorinated dioxins had an increased risk for all neoplasms (rate ratio = 1.29, 95% CI 0.94-1.76) compared with workers from the same cohort exposed to phenoxy herbicides and chlorophenols but with minimal or no exposure to TCDD and higher chlorinated dioxins. These findings indicate that exposure to herbicides contaminated with TCDD and higher chlorinated dioxins may be associated with a small increase in overall cancer risk and in risk for specific cancers.

Australia↗
PubMed1997

Prognostic factors and survival of laryngeal cancer patients from Turin, Italy. A population-based study.

Little information is available on the role of risk factors for cancer of the larynx in survival. This study analyzed survival through the end of 1994 for 355 cases of laryngeal cancer diagnosed among residents of Turin, Italy, during 1979-1982. Relative survival at 5 years was 75% in women and 67% in men. The role of clinical and etiologic factors was analyzed in detail among 222 male cases. The role of nodal involvement as a strong predictor of poor survival was confirmed. Patients of low socioeconomic status experienced poorer survival than other patients, as did heavy smokers. Alcohol drinking and diet did not seem to strongly influence survival. Survival in this series of laryngeal cancer cases closely parallels that observed in other case series from Europe. While the results regarding socioeconomic status, tobacco smoking, and alcohol drinking parallel those of the few previous studies available, this investigation did not confirm a role for diet in the survival of laryngeal cancer patients, a finding that was recently seen in another study from northern Italy.

Aged↗
PubMed1997

Risk of cancer and exposure to gasoline vapors.

Until the introduction of self-service around 1970, service station workers in the Nordic countries were exposed to gasoline vapors. Based on measurements reported in the literature, the 8-hour time-weighted average benzene exposure was estimated to be in the range of 0.5-1 mg/m3. We studied the cancer incidence in a cohort of 19,000 service station workers from Denmark, Norway, Sweden, and Finland. They were identified from the 1970 censuses and followed through 20 years, where 1,300 incident cancers were observed. National incidence rates were used for comparison. The incidence was not increased for leukemia (observed = 28, standardized incidence ratio (SIR) = 0.9, 95% confidence interval (CI) 0.6-1.3) not for acute myeloid leukemia (observed = 13, SIR = 1.3, 95% CI 0.7-2.1). The incidence was slightly elevated for kidney cancer observed = 57, SIR = 1.3, 95% CI 1.0-1.7) and for pharyngeal, laryngeal, and lung cancer. A 3.5-fold risk of nasal cancer was found (observed = 12, SIR = 3.5, 95% CI 1.8-6.1). This cohort exposed to gasoline vapors with benzene levels estimated to be 0.5-1 mg/m3 showed no excess risk of leukemia or acute myeloid leukemia, a 30% elevated risk of kidney cancer, and a previously unnoticed risk of nasal cancer.

Air Pollutants, Occupational↗
PubMed1997

Sinonasal cancer and occupation. Results from the reanalysis of twelve case-control studies.

A pooled reanalysis of twelve case-control studies on sinonasal cancer and occupation from seven countries was conducted in order to study associations with occupations other than wood- and leather-related occupations. The pooled data set included a total of 930 cases (680 men and 250 women) and 3,136 controls (2,349 men and 787 women). All the studies included a detailed occupational history for cases and controls. Each job was coded using the same classifications for occupation and industry. Two approaches were used in the analysis: systematic analysis of occupations; a priori analysis using a preestablished list of occupations and industries. The results confirmed associations observed in several studies not included in this analysis. For agricultural workers, significant excesses were observed for squamous cell carcinoma among women (OR = 1.69) and men (OR = 3.72 for ten years or more of employment as an orchard worker), and adenocarcinomas among men (OR = 2.98 for ten years or more of employment). Associations with textile occupations were observed for adenocarcinoma among women (OR = 2.60) and squamous cell carcinoma among men (OR = 5.09 for fiber preparers, 3.01 for bleachers). Elevated risks for both histologic types were observed among men employed in food manufacturing (OR = 3.25, adenocarcinoma), or as food preservers (OR = 13.9, squamous cell carcinoma), and among men employed as cooks (OR = 1.99, squamous cell carcinoma). A positive association with squamous cell carcinoma was observed for male transport equipment operators (OR = 1.21), and also with adenocarcinoma for male motor-vehicle drivers (OR = 2.50). A number of other associations were observed in the systematic analysis.

Adenocarcinoma↗
PubMed1997

Mortality in employees of a Scottish paper mill.

To assess possible health risks associated with the manufacture of paper, we carried out a retrospective analysis of mortality among 4,242 men and women employed at a Scottish paper mill between 1955 and 1992. During follow-up to 1994, 959 subjects had died giving an SMR of 0.85 (95% CI 0.80-0.90) in comparison with the national population. Mortality from all cancer (SMR 0.77, 95% CI 0.68-0.88) and particularly from lung cancer (SMR 0.64, 95% CI 0.50-0.81) was lower than expected. An excess of lymphatic and hematopoietic cancer (11 deaths, SMR 2.17) was observed in the making department. These findings do not support an occupational hazard of lung cancer as suggested by several earlier studies. The excess of lymphatic and hematopoietic cancer in the making department was unexpected, and may be a chance occurrence.

Cause of Death↗
PubMed1997

Hepatitis B and C virus infection, alcohol drinking, and hepatocellular carcinoma: a case-control study in Italy. Brescia HCC Study.

We performed a case-control study to assess the association of hepatocellular carcinoma (HCC) with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and alcohol drinking. We recruited as cases 172 subjects with an initial diagnosis of HCC, who were admitted to the two major hospitals in the province of Brescia, northern Italy, and 332 subjects, sex-, age-, and hospital-matched, who were admitted to the Departments of Ophthalmology, Dermatology, Urology, Cardiology, and Internal Medicine, as controls. Of the HCC cases, 23.8% were positive for HBsAg and 37.8% for HCV RNA; among the controls, 5.4% were positive for HBsAg and 4.8% for HCV RNA. History of heavy alcohol intake (>80 g of ethanol per day for at least 5 years) was found among 58.1% of the cases and among 36.4% of the controls. The relative risks (RRs) for HBsAg, HCV RNA positivity, and heavy alcohol intake were, respectively: 11.4 (95% confidence interval: 5.7-22.8), 23.2 (95% confidence interval: 11.8-45.7), and 4.6 (95% confidence interval: 2.7-7.8). Positive interactions (synergisms) between both HBsAg positivity and HCV RNA positivity and heavy alcohol intake were found, suggesting more than additive effects of viral infections and alcohol drinking on the risk of HCC. Infection with HCV genotype 1b showed a higher risk than type 2 (RR = 2.9; 95% confidence interval: 0.9-10), suggesting a major role for the former type in causing HCC. On the basis of population attributable risks (AR), heavy alcohol intake seems to be the single most relevant cause of HCC in this area (AR: 45%), followed by HCV (AR: 36%), and HBV (AR: 22%) infection.

Adult↗
PubMed1997

Familial Hodgkin's disease: a disease of young adulthood?

Familial Hodgkin's disease (FHD) is estimated to represent approximately 4.5% of all cases of Hodgkin's disease (HD). Shared environmental factors, such as Epstein-Barr virus and other viral agents, and genetic determinants have all been proposed to explain familial aggregation of HD. In order to compare the characteristic features of FHD with those of the much more common sporadic form, we reviewed 28 articles on FHD, published between 1972 and 1995, and analyzed in further detail data from 18 papers, reporting on a total of 328 patients. The male-to-female ratio of the FHD population examined was 1.5, similar to that reported for sporadic HD, and lower than the one suggested for FHD by some authors. On the other hand, a significant difference was found between sporadic and familial HD according to age at diagnosis; that is, only one major peak between 15 and 34 years was present in the group of patients with FHD. Further investigation of FHD in young adulthood may provide insight into the hypothesis of a genetic or infectious etiology of the disease.

Family Health↗
PubMed1997

International data base of exposure measurements in the pulp, paper and paper product industries.

An international data base of exposure measurements in the pulp, paper and paper product industries was constructed to be used in exposure assessment for epidemiology studies and hazard control. Industrial hygiene and biological monitoring data were collected from countries participating in the multicentric study of the International Agency for Research on Cancer. Each measurement was characterized by country, mill type and number, department, job, agent measured, sampling method, measurement result in the standard unit, duration and date of sampling, assessment of representativeness, measurer, purpose of measurements, and remarks (e.g. on measurement sites and biases). Over 31,000 measurement results on 246 different chemical agents from 13 countries were available from pulp (45% of measurements), paper/paperboard/recycling (12%) and paper product (11%) mills or from their non-production departments (23%). Most measurements (82%) were carried out after 1980. The most frequently measured group of agents was inorganic gases (35%), followed by organic compounds (25%), solvents (18%), mineral dusts (12%), metals (6%) and bioaerosols (3%). Over 90% of the measurements were without an obvious bias, but their true representativeness is difficult to assess. Concentrations of various agents, including sulfur dioxide, chlorine dioxide, carbon monoxide, nitrogen dioxide, ozone, ammonia, formaldehyde and some solvents, often exceeded current occupational exposure limits. This data base summarizes a great deal of previously unpublished exposure data, provides a unique opportunity to study exposure patterns at the international level and identifies exposure situations that require further attention and investigation.

Bias↗
PubMed1997

Bladder cancer, tobacco smoking, coffee and alcohol drinking in Brescia, northern Italy.

The association between tobacco smoking, the consumption of coffee and alcohol and bladder cancer was investigated in a hospital-based case-control study in Brescia, northern Italy. A total of 172 incident cases (135 men and 37 women) and 578 controls (398 men and 180 women) were enrolled. As expected, cigarette smoking was strongly associated with bladder cancer. The odds ratios (OR) for coffee drinking adjusted for age, education, residence and cigarette smoking in current drinkers were 2.6 (95% confidence interval, CI: 1.1-6.1) in men and 5.2 (95% CI: 1.0-30.4) in women. A dose-response relationship was found in men, with the highest risk in the highest category of exposure: drinkers of more than 5 cups per day had an OR of 4.5 (95% CI: 1.2-16.8). The ORs for current alcohol drinkers were 2.1 (95% CI: 1.0-4.8) in men and 3.4 (95% CI: 1.2-9.7) in women; according to grams of ethanol drunk per day (grams/day, g/d) the ORs were: 1.7 (1-20 g/d), 1.6 (21-40 g/d), 4.3 (41-60 g/d) and 4.6 (61+ g/d) in men and 3.1 (1-20 g/d) and 3.9 (21+ g/d) in women. These results suggest that regular consumption of both coffee and alcohol can be independently associated with an increased bladder cancer risk.

Aged↗
PubMed1997

Cancer risk from occupational and environmental exposure to polycyclic aromatic hydrocarbons.

Epidemiologic evidence on the relationship between polycyclic aromatic hydrocarbons (PAH) and cancer is reviewed. High occupational exposure to PAHs occurs in several industries and occupations. Covered here are aluminum production, coal gasification, coke production, iron and steel foundries, tar distillation, shale oil extraction, wood impregnation, roofing, road paving, carbon black production, carbon electrode production, chimney sweeping, and calcium carbide production. In addition, workers exposed to diesel engine exhaust in the transport industry and in related occupations are exposed to PAHs and nitro-PAHs. Heavy exposure to PAHs entails a substantial risk of lung, skin, and bladder cancer, which is not likely to be due to other carcinogenic exposures present in the same industries. The lung seems to be the major target organ of PAH carcinogenicity and increased risk is present in most of the industries and occupations listed above. An increased risk of skin cancer follows high dermal exposure. An increase in bladder cancer risk is found mainly in industries with high exposure to PAHs from coal tars and pitches. Increased risks have been reported for other organs, namely the larynx and the kidney; the available evidence, however, is inconclusive. The results of studies addressing environmental PAH exposure are consistent with these conclusions.

Acetylene↗
PubMed1997

Avoided and avoidable risks of cancer.

Despite the considerable efforts and funds devoted to cancer research over several decades, cancer still remains a mainly lethal disease. Cancer incidence and mortality have not declined at the same rate as other major causes of death, indicating that primary prevention remains a most valuable approach to decrease mortality. There is general agreement that environmental exposures are variously involved in the causation of the majority of cancer cases and that at least half of all cancers could be avoided by applying existing etiologic knowledge. There is disagreement, however, regarding the proportion of cancer risks attributable to specific etiological factors, including diet, occupation and pollution. Estimates of attributable risks are largely based today on unverified assumptions and the calculation of attributable risks involves taking very unequal evidence of various types of factors and treating them equally. Effective primary prevention resulting in a reduction of cancer risk can be obtained by: (i) a reduction in the number of carcinogens to which humans are exposed; or (ii) a reduction of the exposure levels to carcinogens. Exposure levels that could be seen as sufficiently low when based on single agents, may actually not be safe in the context of the many other concomitant carcinogenic and mutagenic exposures. The list of human carcinogens and of their target organs might be quite different if: (i) epidemiological data were available for a larger proportion of human exposures for which there is experimental evidence of carcinogenicity; (ii) more attention was paid to epidemiological evidence that is suggestive of an exposure-cancer association, but is less than sufficient, particularly in identifying target organs; and (iii) experimental evidence of carcinogenicity, supported by mechanistic considerations, were more fully accepted as predictions of human risk.

Carcinogenicity Tests↗
PubMed1997

Comparison of information on occupation and lifestyle habits obtained from European man-made vitreous fibre production workers and their relatives.

BACKGROUND: Studies of the aetiology of fatal diseases often rely on data obtained from relatives, which can cause loss of precision and introduce bias. We assessed the quality of such information on demographics, occupation, smoking and alcohol habits. METHODS: We compared contemporary interviews, based on a structured questionnaire, with male workers from the man-made vitreous fibre production industry in four European countries and their relatives. The participation rate was 63% (74 pairs of workers and relatives). RESULTS: Only minor differences in the ability to answer the questions appeared among workers and relatives, except for specific occupational questions. There was moderate to excellent agreement for demographics, residential and work history (kappa or intraclass correlation range: 0.44-0.98). For smoking habits, beer and wine consumption the agreement was good to excellent (range: 0.59-0.99). In particular, number of different residential areas, jobs, industries, and duration of wine drinking were significantly underreported by the relatives. No general determinant for reduced agreement appeared. CONCLUSIONS: In general, the quality of information obtained from relatives appeared good. However, information on specific occupational exposures may be improved by supplementing the information from relatives with details obtained from colleagues, occupational hygiene experts or occupation-exposure matrices.

Adolescent↗