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Biomedical subjects

P Boffetta

Publications and source records attributed to P Boffetta.

At least 73 records · Page 4Linked to original sources
PubMed2001

Plant foods and risk of gastric cancer: a case-control study in Uruguay.

The association between plant foods intake and gastric cancer risk was investigated in a Uruguayan study on environmental factors and cancer. The study included 160 newly diagnosed and histologically verified cases of gastric carcinoma and 320 hospitalized controls. These controls were frequency-matched to the cases on age, sex, residence and urban/rural status. Total vegetable intake was associated with a reduction in risk (odds ratio (OR) 0.64, 95% confidence interval (CI) 0.38-1.08), which was markedly attenuated after adjustment for total fruit intake. The only group of vegetables that persisted as significantly protective after controlling for total energy and total fruit consumption were allium vegetables (OR 0.56, 95% CI 0.34-0.92). On the other hand, total fruit consumption displayed a strong inverse association after controlling for total vegetable intake (OR 0.35, 95% CI 0.21-0.59). Neither tubers nor pulses were associated with gastric cancer risk. Finally, total plant foods were strongly associated with a reduced risk of stomach cancer (OR 0.31, 95% CI 0.18-0.54). It is suggested that vitamins (vitamin C and carotenoids) and bioactive substances (diallyl sulfide) could be involved in the mechanisms of action of plant foods.

Adult↗
PubMed2001

Foods and risk of bladder cancer: a case-control study in Uruguay.

A case-control study on 144 cases of transitional cell bladder carcinoma and 576 hospitalized controls was conducted in Montevideo, Uruguay. Barbecued meat, salted meat and fried eggs were associated with significant increased risks of bladder cancer (odds ratio (OR) for high intake of salted meat 4.04, 95% confidence interval (CI) 2.24-7.27). On the other hand, all fruits, cooked vegetables, potatoes and cheese were associated with inverse associations (OR for high consumption of potatoes 0.38, 95% CI 0.23-0.64). The associations with salted and barbecued meat suggest that the way of preserving or cooking meat play a role in bladder carcinogenesis. More precisely, N-nitroso compounds and heterocyclic amines could be involved in this process.

Adult↗
PubMed2001

Mortality from cardiovascular diseases and exposure to inorganic mercury.

OBJECTIVE: To study the mortality from cardiovascular and other chronic non-neoplastic diseases after long term exposure to inorganic mercury. Limited information is available on the effect of chronic exposure to mercury on the cardiovascular system. METHODS: The mortality was studied among 6784 male and 265 female workers from four mercury mines and mills in Spain, Slovenia, Italy, and the Ukraine. Workers were employed between 1900 and 1990; the follow up period lasted from the 1950s to the 1990s. The mortality of the workers was compared with national reference rates. RESULTS: Among men, there was a slight increase in overall mortality (standardised mortality ratio (SMR) 1.08, 95% confidence interval (95% CI) 1.04 to 1.12). An increased mortality was found from hypertension (SMR 1.46, 95% CI 1.08 to 1.93), heart diseases other than ischaemic (SMR 1.36, 95% CI 1.20 to 1.53), pneumoconiosis (SMR 27.1, 95% CI 23.1 to 31.6), and nephritis and nephrosis (SMR 1.55, 95% CI 1.13 to 2.06). The increase in mortality from cardiovascular diseases was not consistent among countries. Mortality from hypertension and other heart diseases increased with estimated cumulative exposure to mercury; mortality from ischaemic heart disease and cerebrovascular diseases increased with duration of employment, but not with estimated exposure to mercury. Results among women were hampered by few deaths. CONCLUSION: Despite limited quantitative data on exposure, possible confounding, and likely misclassification of disease, the study suggests a possible association between employment in mercury mining and refining and risk in some groups of cardiovascular diseases.

Cardiovascular Diseases↗
PubMed2001

Meat consumption and risk of stomach cancer in Uruguay: a case-control study.

We previously reported an association between meat intake and stomach cancer in Uruguay: in that analysis, we did not control for total energy intake. To better study the relationship between intake of meat and meat constituents and gastric cancer, we conducted a further case-control study including 123 cases and 282 controls who were enrolled between September 1997 and August 1999. Total meat intake (highest tertile) was associated with an odds ratio (OR) of 4.6 [95% confidence interval (CI) = 2.3-9.0]. After adjustment for total energy intake and intake of proteins and total fat by the residuals method, the OR was 1.7 (95% CI = 0.7-4.0). The energy-adjusted OR for high intake of processed meat was 1.9 (95% CI = 1.1-3.5). Intake of fried, barbecued, and salted meat and 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine was not associated with risk of gastric cancer. The energy-adjusted OR of high intake of nitrosodimethylamine was 1.5 (95% CI = 0.9-2.8). These results suggest that, in a country with elevated meat consumption, total energy intake and intake of proteins and fat are powerful confounders in the relationship between meat intake and gastric cancer risk. However, a modest independent effect of meat, in particular of processed meat, is suggested.

Adult↗
PubMed2001

Chromosome aberrations in lymphocytes of persons exposed to an earthquake in Armenia.

OBJECTIVE: This study attempted to determine the level of chromosome aberrations in lymphocytes of victims of the 1988 earthquake in Armenia. METHODS: Chromosome aberrations were measured in blood samples taken from 41 victims of the earthquake that hit Armenia in 1988 and in samples of 47 reference blood donors. The victims suffered from severe psychoemotional stress but were otherwise healthy. All the samples were taken 2 to 3 weeks after the earthquake. All the subjects were lifetime nonsmokers. The cells were scored blind as to the exposure status. RESULTS: The subjects exposed to the earthquake had a higher proportion of cells with chromosome aberrations [3.1 (SD 2.1)%] than the referents [1.7 (SD 1.3)%, P-value for the difference 0.0009]. The difference persisted when the values were adjusted for age and gender [relative risk (RR) 1.9, 95% confidence interval (95% CI) 1.4-2.5]. The difference was present for double breaks (RR 4.1, 95% CI 2.6-6.4), but not for single breaks (RR 1.1, 95% CI 0.8-1.7). The exposed subjects also had a lower percentage of cells with 46 chromosomes (P=0.03) than the referents. CONCLUSIONS: This study suggests an increase in chromosome aberrations in the lymphocytes of victims of a severe earthquake as compared with the levels of referents. If not due to bias or confounding, the difference may reflect the effect of either environmental exposures related to the earthquake or severe psychogenic stress. The levels of chromosome aberrations found among the earthquake victims in this study are comparable with those found in prospective studies of long-term cancer risk.

Adolescent↗
PubMed2001

Exposure to titanium dioxide and risk of lung cancer in a population-based study from Montreal.

OBJECTIVES: This study assessed the lung cancer risk from exposure to titanium dioxide, an important pigment with limited evidence of carcinogenicity in experimental animals but sparse data for humans. METHODS: The risk of lung cancer among residents in Montreal, Canada, was analyzed, including 857 histologically confirmed cases of lung cancer diagnosed during 1979-1985 among men aged 35-70 years and a group of referents comprising 533 randomly selected, healthy residents and 533 persons with cancer in organs other than the lung. Exposure to titanium dioxide and other titanium compounds was assessed by a team of industrial hygienists on the basis of a detailed occupational questionnaire. RESULTS: Thirty-three cases and 43 referents were classified as exposed to titanium dioxide. The odds ratio was 0.9 [95% confidence interval (95% CI) 0.5-1.5]. No trend was apparent according to the estimated frequency, level, or duration of exposure. The odds ratio was 1.0 (95% CI 0.3-2.7) for medium or high exposure for at least 5 years. Few subjects were classified as exposed to titanium dioxide fumes or to other titanium compounds, but the risk of lung cancer was nonsignificantly increased for exposure to these agents. CONCLUSIONS: Although misclassification of exposure and low exposure prevalence might have resulted in false negative results, this study does not suggest that occupational exposure to titanium dioxide increases the risk of lung cancer.

Adult↗
PubMed2001

Risk factors of lung cancer in Chandigarh, India.

BACKGROUND & OBJECTIVES: There is a paucity of data from India on the risk factors for lung cancer. In the present paper results of a case-control study on lung cancer undertaken at Chandigarh, north India, are described. METHODS: Two hundred and sixty five (235 men, 30 women) histologically confirmed patients of lung cancer and 525 (435 men, 90 women) hospital controls matched for age and sex were interviewed according to a pre-designed questionnaire. Effects of individual variables defining the various aspects of tobacco smoking, indoor and outdoor air pollution and occupational exposures were assessed using unconditional logistic regression models. RESULTS: Eighty nine per cent of men and 33 per cent of women among the patients were ever-smokers as compared to 60 per cent of men and 20 per cent of women among controls. The Odds Ratio (OR) for ever-smoking was 5.0 (CI 3.11-8.04) among men and 2.47 (CI 0.79-7.75) among women. Among the patients, men were found to smoke a higher average number of cigarette-equivalents per day, for longer duration and started at an earlier age as compared to controls. Smoking of bidi and hooka as well as cigarettes had similar ORs for cumulative consumption. ORs for female smokers were lower than those for male smokers. Cumulative exposure of > 45 yr in women to indoor air pollution from use of coal or wood for cooking or heating showed an OR of 1.43 (CI 0.33-6.30). Residence in urban areas did not entail an increased risk for developing lung cancer. Very few subjects studied were employed in high-risk occupations. INTERPRETATION & CONCLUSIONS: Smoking (cigarettes or bidis) was the principle risk factor for causation of lung cancer among men. In women there could be several other risk factors besides smoking, as the association with smoking was not as strong.

Adult↗
PubMed2001

Metabolic gene polymorphism frequencies in control populations.

Using the International Project on Genetic Susceptibility to Environmental Carcinogens (GSEC) database containing information on over 15,000 control (noncancer) subjects, the allele and genotype frequencies for many of the more commonly studied metabolic genes (CYP1A1, CYP2E1, CYP2D6, GSTM1, GSTT1, NAT2, GSTP, and EPHX) in the human population were determined. Major and significant differences in these frequencies were observed between Caucasians (n = 12,525), Asians (n = 2,136), and Africans and African Americans (n = 996), and some, but much less, heterogeneity was observed within Caucasian populations from different countries. No differences in allele frequencies were seen by age, sex, or type of controls (hospital patients versus population controls). No examples of linkage disequilibrium between the different loci were detected based on comparison of observed and expected frequencies for combinations of specific alleles.

Black People↗
PubMed2001

Lack of interaction between asbestos exposure and glutathione S-transferase M1 and T1 genotypes in lung carcinogenesis.

An interaction between occupational carcinogens and genetic susceptibility factors in determining individual lung cancer risk is biologically plausible, but the interpretation of available studies are limited by the small number of exposed subjects. We selected from the international database on Genetic Susceptibility and Environmental Carcinogens the studies of lung cancer that included information on metabolic polymorphisms and occupational exposures. Adequate data were available for asbestos exposure and GSTM1 (five studies) and GSTT1 (three studies) polymorphisms. For GSTM1, the pooled analysis included 651 cases and 983 controls. The odds ratio (OR) of lung cancer was 2.0 [95% confidence interval (CI) 1.4-2.7] for asbestos exposure and 1.1 (95% CI 0.9-1.4) for GSTM1-null genotype. The OR of interaction between asbestos and GSTM1 polymorphism was 1.1 (95% CI 0.6-2.1) based on 54 cases and 53 controls who were asbestos exposed and GSTM1 null. The case-only approach, which was based on 869 lung cancer cases and had an 80% power to detect an OR of interaction of 1.56, also provided lack of evidence of interaction. The analysis of possible interaction between GSTT1 polymorphism and asbestos exposure in relation to lung cancer was based on 619 cases. The prevalence OR of GSTT1-null genotype and asbestos exposure was 1.1 (95% CI 0.6-2.0). Our results do not support the hypothesis that the risk of lung cancer after asbestos exposure differs according to GSTM1 genotype. The low statistical power of the pooled analysis for GSTT1 genotypes hampered any firm conclusion. No adequate data were available to assess other interactions between occupational exposures and metabolic polymorphisms.

Adult↗
PubMed2000

Lung cancer and cigarette smoking in women: a multicenter case-control study in Europe.

The association between cigarette smoking and lung cancer risk in women was investigated within the framework of a case-control study in 9 centres from 6 European countries. Cases were 1,556 women up to 75 years of age with histologically confirmed primary lung cancer; 2, 450 controls with age distribution similar to cases were selected. The predominant cell type was adenocarcinoma (33.5%), with similar proportions for squamous-cell type (26.4%) and small-cell carcinoma (22.3%). Overall, smoking cigarettes at any time was associated with a 5-fold increase in lung cancer risk (odds ratio 5.21, 95% confidence interval 4.49-6.04); corresponding figures for current smoking habits were 8.94, 7.54-10.6. The association showed a dose-response relationship with duration of the habit and daily and cumulative lifetime smoking. A significant excess risk of 70% was associated with every 10 pack-years smoked. After 10 years of smoking cessation, the relative risk decreased to 20% compared to current smokers. The following characteristics were associated with a higher relative risk: inhalation of smoke, smoking non-filter cigarettes, smoking dark-type cigarettes and starting at young age. The association was observed for all major histological types, being the strongest for small-cell type carcinoma, followed by squamous-cell type and the lowest for adenocarcinoma. The proportion of lung-cancer cases in the population attributable to cigarette smoking ranged from 14% to 85%. We concluded that women share most features of the association between cigarette smoking and lung cancer observed in men.

Adult↗
PubMed2000

Projections of alcohol- and tobacco-related cancer mortality in Central Europe.

Central European mortality rates for cancer sites related to tobacco and alcohol have increased rapidly in recent decades. From a public health point of view, it is of considerable interest to know whether these past increases in cancer mortality will continue into the future. Cancer mortality rates for the period 1965-1994 in Bulgaria, Czech Republic and Slovakia (analysed together), Hungary, Poland, and Romania were analysed for cancers of the larynx, oral cavity and pharynx, oesophagus, bladder, kidney, and pancreas. Using a Bayesian age-period-cohort approach, we have calculated smoothed observed rates. The effects of period and cohort were extrapolated to estimate mortality projections for 1995-99, 2004-09, and 2005-09. Mortality rates for all sites are projected to increase in most countries. Hungary has the highest projected rates for most sites, and particularly rapid increases are expected for cancers of the oral cavity and pharynx and of the larynx in Hungarian men. The smoothed 1990-94 male mortality rates for these two sites of 16. 32/100,000 and 8.70/100,000, respectively, are projected to reach 35. 17/100,000 for cancer of the oral cavity and pharynx and 14.12/100, 000 for cancer of the larynx by the period 2000-04. For kidney cancer, former Czechoslovakia has the highest observed and projected mortality rates. The smoothed 1990-94 rate of 8.37/100,000 is expected to increase 24% to 10.38/100,000 by 2000-04. Our results indicate that further increases may be expected on top of the already high cancer mortality levels in Central Europe. Policies to reduce alcohol consumption and prevent smoking in younger generations are necessary to reduce mortality as these cohorts age.

Adult↗
PubMed2000

Plant foods and risk of laryngeal cancer: A case-control study in Uruguay.

In order to examine the relationships between plant foods, defined as the grouping of vegetables, fruits, tubers and legumes, with the risk of developing laryngeal cancer, a case-control study was conducted in Uruguay between 1998-1999. The study included 148 cases with histologically verified squamous cell carcinoma of the larynx, which were frequency matched on age, residence and urban/rural status with 444 hospitalized controls, afflicted by non-neoplastic conditions. Both series of patients were face-to-face interviewed in the hospitals shortly after admittance using a detailed questionnaire. This questionnaire included 62 queries on food items, representative of the usual diet of the Uruguayan population. Food items and food groups were adjusted for tobacco smoking, alcohol drinking and total energy intake. High consumption of plant foods was associated with an OR of 0.42 (95% CI 0.21-0.84). Among subgroups of plant foods, fruits and raw vegetables were associated with a strong reduction in risk (OR for the highest quartile of raw vegetables 0.29, 95% CI 0.15-0.56). Also, legumes were associated with a protective effect (OR 0.62, 95% CI 0.33-1.19). Among individual food items, tomatoes and oranges were associated with the stronger protective effects (OR for tomato intake 0.32, 95% CI 0. 17-0.58). The joint effect of heavy smoking and the low intake of vegetables and fruits displayed an increased risk of 19.2 (95% CI 5. 7-64.9).

Adult↗
PubMed2000

p53 mutations and exposure to environmental tobacco smoke in a multicenter study on lung cancer.

Biomarker data may provide a way to strengthen the link between environmental tobacco smoke (ETS) exposure and lung cancer shown in epidemiological studies. We conducted a multicenter case-control study to investigate the association between ETS exposure and lung cancer in never-smokers using p53 mutations as a biomarker of tobacco-related carcinogenesis. Paraffin-embedded tissue or fresh tissue samples from 91 never-smokers and 66 smokers with histologically confirmed lung cancer and interview data about smoking habits and ETS exposure were analyzed for mutations in the p53 gene. Statistical analysis was performed using multivariate logistic regression. Among the lifelong nonsmokers, the overall mutation prevalence was 10% (nine cases). Among 48 never-smokers ever exposed to spousal ETS, 13% (six cases) showed mutations. Smokers exhibited 17 (26%) mutations. A 3-fold [odds ratio, 2.9; 95% confidence interval (CI), 1.2-7.2] increased risk of p53 mutation was observed for smokers as compared with all never-smokers combined (i.e., irrespective of ETS exposure). The increase was 4.4-fold (95% CI, 1.2-16.2) when compared with never-smokers without ETS exposure. Among never-smokers, the risk of mutation was doubled (odds ratio, 2.0; 95% CI, 0.5-8.7) for exposure to spousal ETS only, based on 6 exposed cases with mutation and 42 exposed cases without mutation. The risk was 1.5 (95% CI, 0.2-8.8) for those ever exposed to spousal or workplace ETS as compared with those never exposed to spousal or workplace ETS. For smokers, the most common mutation type was G:C to T:A transversion (31%), whereas G:C to A:T transitions were predominant among never smokers (57%). In conclusion, our study indicates a significant 3-4-fold increased risk of p53 mutation in smoking lung cancer cases, and it suggests that mechanisms of lung carcinogenesis in ETS-exposed never-smokers include mutations in the p53 gene, similar to that seen in smokers. However, the mutation patterns observed also suggest a difference between smokers and never-smokers. Clearly, additional investigations of the role of p53 mutation as a biomarker for tobacco-related carcinogenesis, including that related to ETS, are indicated.

Adenocarcinoma↗
PubMed2000

Cigarette smoking and bladder cancer in men: a pooled analysis of 11 case-control studies.

The primary risk factor for bladder cancer is cigarette smoking. Using a combined analysis of 11 case-control studies, we have accurately measured the relationship between cigarette smoking and bladder cancer in men. Available smoking information on 2,600 male bladder cancer cases and 5,524 male controls included duration of smoking habit, number of cigarettes smoked per day and time since cessation of smoking habit for ex-smokers. There was a linear increasing risk of bladder cancer with increasing duration of smoking, ranging from an odds ratio (OR) of 1.96 after 20 years of smoking (95% confidence interval [CI] 1.48-2.61) to 5.57 after 60 years (CI 4.18-7.44). A dose relationship was observed between number of cigarettes smoked per day and bladder cancer up to a threshold limit of 15-20 cigarettes per day, OR = 4.50 (CI 3.81-5. 33), after which no increased risk was observed. An immediate decrease in risk of bladder cancer was observed for those who gave up smoking. This decrease was over 30% after 1-4 years, OR = 0.65 (0. 53-0.79), and was over 60% after 25 years of cessation, OR = 0.37 (0. 30-0.45). However, even after 25 years, the decrease in risk did not reach the level of the never-smokers, OR = 0.20. (0.17-0.24). The proportion of bladder cancer cases attributable to ever-smoking was 0.66 (0.61-0.70) for all men and 0.73 (0.66-0.79) for men younger than 60. These estimates are higher than previously calculated.

Adult↗
PubMed2000

Classic kaposi sarcoma: epidemiology and risk factors.

BACKGROUND: Although Kaposi sarcoma (KS) initially was described over a century ago, its biology remains enigmatic and conflicting. Whereas the classic type occurs mainly in older men of Mediterranean or Eastern European backgrounds and is not linked to impairment of the host immune response, iatrogenic and human immunodeficiency virus (HIV)-associated KS are linked to such conditions. A recently discovered pathogen, KS-associated herpesvirus (KSHV) (also known as human herpesvirus 8 [HHV8]), is found in tissues from all four forms of KS (classic, iatrogenic, endemic [African], and HIV-associated). This universal detection of KSHV/HHV8 suggests a central role for the virus in the development of KS and a common etiology for all KS types. The epidemiology and risk factors of classic KS, along with the biology of KSHV/HHV8 and the prevalence of the virus among different populations, is presented. METHODS: The current review is based on multiple information sources, electronic health data in all languages from 1966 onward, and previously published scientific reports from the Americas, Europe, and Africa. RESULTS: Nearly 5000 cases of morphologically characterized classic KS have been reported in Europe, Mediterranean countries, and the Americas up to 1998. Geographic location, ethnicity, time interval, age, and gender heavily influence the incidence rate of classic KS. The rate of incidence of nonacquired immunodeficiency syndrome-associated KS correlates with the KSHV/HHV8 seroprevalence in the general population. CONCLUSIONS: Many contributory factors undoubtedly have etiologic and pathogenic significance in the development of classic KS; however, the interplay between these factors has complicated the understanding of the induction and development of the disease as well as the significance of each factor. As with other cell-transforming human DNA viruses, infection with KSHV/HHV8 alone is not sufficient for the development of KS and additional cofactors are required.

Adolescent↗