Hermann Pohlabeln

Cigarette smoking and lung cancer – relative risk estimates for the major histological types from a pooled analysis of case-control studies

Lung cancer is mainly caused by smoking, but the quantitative relations between smoking and histologic subtypes of lung cancer remain inconclusive. By using one of the largest lung cancer datasets ever assembled, we explored the impact of smoking on risks of the major cell types of lung cancer. This pooled analysis included 13,169 cases and 16,010 controls from Europe and Canada. Studies with population controls comprised 66.5% of the subjects. Adenocarcinoma (AdCa) was the most prevalent subtype in never smokers and in women. Squamous cell carcinoma (SqCC) predominated in male smokers. Age‐adjusted odds ratios (ORs) were estimated with logistic regression. ORs were elevated for all metrics of exposure to cigarette smoke and were higher for SqCC and small cell lung cancer (SCLC) than for AdCa. Current male smokers with an average daily dose of >30 cigarettes had ORs of 103.5 (95% confidence interval (CI): 74.8–143.2) for SqCC, 111.3 (95% CI: 69.8–177.5) for SCLC and 21.9 (95% CI: 16.6–29.0) for AdCa. In women, the corresponding ORs were 62.7 (95% CI: 31.5–124.6), 108.6 (95% CI: 50.7–232.8) and 16.8 (95% CI: 9.2–30.6), respectively. Although ORs started to decline soon after quitting, they did not fully return to the baseline risk of never smokers even 35 years after cessation. The major result that smoking exerted a steeper risk gradient on SqCC and SCLC than on AdCa is in line with previous population data and biological understanding of lung cancer development.

Lung cancer and cigarette smoking in Europe: An update of risk estimates and an assessment of inter-country heterogeneity

Ten case‐control studies have been carried out in 6 European countries to investigate the major risk factors for lung cancer. Carcinogenic effect from cigarette smoke was the most relevant interest in our study, which has included 7,609 cases of lung cancer and 10,431 controls, mainly population based. The results indicate elevated odds ratios (ORs; 23.9 among men and 8.7 among women) with attributable risks exceeding 90% for men and close to 60% for women. A large, and statistically significant, variability of the results across countries was detected after adjusting for the most common confounding variables, and after controlling, at least in part, for the instability of the ORs due to the small number of non‐smokers in some of the study subsets. This pattern of lung cancer risk associated with cigarettes smoke, across different European regions, reflects inherent characteristics of the studies as well as differences in smoking habits, particularly calender periods of starting, and it is likely to have been influenced by effect modifiers like indoor radon exposure, occupation, air pollution and dietary habits.

Prevalence of overweight and obesity in European children below the age of 10

Background:There is a lack of common surveillance systems providing comparable figures and temporal trends of the prevalence of overweight (OW), obesity and related risk factors among European preschool and school children. Comparability of available data is limited in terms of sampling design, methodological approaches and quality assurance. The IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS) study provides one of the largest European data sets of young children based on state-of-the-art methodology.Objective:To assess the European distribution of weight status according to different classification systems based on body mass index (BMI) in children (2.0–9.9 years). To describe the prevalence of weight categories by region, sex, age and socioeconomic position.Design:Between 2007 and 2010, 18 745 children from eight European countries participated in an extensive, highly standardised protocol including, among other measures, anthropometric examinations and parental reports on socio-demographic characteristics.Results:The combined prevalence of OW/obesity ranges from more than 40% in southern Europe to less than 10% in northern Europe. Overall, the prevalence of OW was higher in girls (21.1%) as compared with boys (18.6%). The prevalence of OW shows a negative gradient with social position, with some variation of the strength and consistency of this association across Europe. Overall, population groups with low income and/or lower education levels show the highest prevalence of obesity. The use of different reference systems to classify OW results in substantial differences in prevalence estimates and can even reverse the reported difference between boys and girls.Conclusions:There is a higher prevalence of obesity in populations from southern Europe and in population groups with lower education and income levels. Our data confirm the need to develop and reinforce European public health policies to prevent early obesity and to reduce these health inequalities and regional disparities.

Exposure to Diesel Motor Exhaust and Lung Cancer Risk in a Pooled Analysis from Case-Control Studies in Europe and Canada

RATIONALE Diesel motor exhaust is classified by the International Agency for Research on Cancer as probably carcinogenic to humans. The epidemiologic evidence is evaluated as limited because most studies lack adequate control for potential confounders and only a few studies have reported on exposure-response relationships. OBJECTIVES Investigate lung cancer risk associated with occupational exposure to diesel motor exhaust, while controlling for potential confounders. METHODS The SYNERGY project pooled information on lifetime work histories and tobacco smoking from 13,304 cases and 16,282 controls from 11 case-control studies conducted in Europe and Canada. A general population job exposure matrix based on ISCO-68 occupational codes, assigning no, low, or high exposure to diesel motor exhaust, was applied to determine level of exposure. MEASUREMENTS AND MAIN RESULTS Odds ratios of lung cancer and 95% confidence intervals were estimated by unconditional logistic regression, adjusted for age, sex, study, ever-employment in an occupation with established lung cancer risk, cigarette pack-years, and time-since-quitting smoking. Cumulative diesel exposure was associated with an increased lung cancer risk highest quartile versus unexposed (odds ratio 1.31; 95% confidence interval, 1.19-1.43), and a significant exposure-response relationship (P value < 0.01). Corresponding effect estimates were similar in workers never employed in occupations with established lung cancer risk, and in women and never-smokers, although not statistically significant. CONCLUSIONS Our results show a consistent association between occupational exposure to diesel motor exhaust and increased risk of lung cancer. This association is unlikely explained by bias or confounding, which we addressed by adjusted models and subgroup analyses.

A multicenter case-control study of diet and lung cancer among non-smokers

Objective: We have examined the role of dietary patterns and specific dietary nutrients in the etiology of lung cancer among non-smokers using a multicenter case–control study.Methods: 506 non-smoking incident lung cancer cases were identified in the eight centers along with 1045 non-smoking controls. Dietary habits were assessed using a quantitative food-frequency questionnaire administered by personal interview. Based on this information, measures of total carotenoids, beta-carotene and retinol nutrient intake were estimated.Results: Protective effects against lung cancer were observed for high consumption of tomatoes, (odds ratio (OR) = 0.5; 95% confidence interval (CI) 0.4–0.6), lettuce (OR = 0.6; 95% CI 0.3–1.2), carrots (OR = 0.8; 95% CI 0.5–1.1), margarine (OR = 0.7; 95% CI 0.5–0.8) and cheese (OR = 0.7; 95% CI 0.5–1.0). Only weak protective effects were observed for high consumption of all carotenoids (OR = 0.8; 95% CI 0.6–1.0), beta-carotene (OR=0.8; 95% CI 0.6–1.1) and retinol (OR = 0.9; 95% CI 0.7–1.1). Protective effects for high levels of fruit consumption were restricted to squamous cell carcinoma (OR = 0.7; 95% CI 0.4–1.2) and small cell carcinoma (OR = 0.7; 95% CI 0.4–1.2), and were not apparent for adenocarcinoma (OR = 0.9; 95% CI 0.6–1.3). Similarly, any excess risk associated with meat, butter and egg consumption was restricted to squamous and small cell carcinomas, but was not detected for adenocarcinomas.Conclusions: This evidence suggests that the public health significance of increasing vegetable consumption among the bottom third of the population would include a reduction in the incidence of lung cancer among lifetime non-smokers by at least 25%, and possibly more. A similar protective effect for increased fruit consumption may be present for squamous cell and small cell lung carcinomas.

Intra- and inter-observer reliability in anthropometric measurements in children

Introduction:Studies such as IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) seek to compare data across several different countries. Therefore, it is important to confirm that body composition indices, which are subject to intra- and inter-individual variation, are measured using a standardised protocol that maximises their reliability and reduces error in analyses.Objective:To describe the standardisation and reliability of anthropometric measurements. Both intra- and inter-observer variability of skinfold thickness (triceps, subscapular, biceps, suprailiac) and circumference (neck, arm, waist, hip) measurements were investigated in five different countries.Methods:Central training for fieldwork personnel was carried out, followed by local training in each centre involving the whole survey staff. All technical devices and procedures were standardised. As part of the standardisation process, at least 20 children participated in the intra- and inter-observer reliability test in each centre. A total of 125 children 2–5 years of age and 164 children 6–9 years of age took part in this study, with a mean age of 5.4 (±1.2) years.Results:The intra-observer technical error of measurement (TEM) was between 0.12 and 0.47 mm for skinfold thickness and between 0.09 and 1.24 cm for circumference measurements. Intra-observer reliability was 97.7% for skinfold thickness (triceps, subscapular, biceps, suprailiac) and 94.7% for circumferences (neck, arm, waist, hip). Inter-observer TEMs for skinfold thicknesses were between 0.13 and 0.97 mm and for circumferences between 0.18 and 1.01 cm. Inter-observer agreement as assessed by the coefficient of reliability for repeated measurements of skinfold thickness and circumferences was above 88% in all countries.Conclusion:In epidemiological surveys it is essential to standardise the methodology and train the participating staff in order to decrease measurement error. In the framework of the IDEFICS study, acceptable intra- and inter-observer agreement was achieved for all the measurements.

Assessment of diet, physical activity and biological, social and environmental factors in a multi-centre European project on diet- and lifestyle-related disorders in children (IDEFICS)

Obesity is a major public health problem in developed countries. We present a European project, called Identification and Prevention of Dietary and Lifestyle-induced Health Effects in Children and Infants (IDEFICS), that focuses on diet- and lifestyle-related diseases in children. This paper outlines methodological aspects and means of quality control in IDEFICS. IDEFICS will use a multicentre survey design of a population-based cohort of about 17,000 2- to 10-year-old children in nine European countries (Belgium, Cyprus, Estonia, Germany, Greece, Hungary, Italy, Spain and Sweden). The project will investigate the impact of dietary factors such as food intake and food preferences, lifestyle factors such as physical activity, psychosocial factors and genetic factors on the development of obesity and other selected diet- and lifestyle-related disorders. An intervention study will be set up in pre-school and primary school settings in eight of the survey centres. Standardised survey instruments will be designed during the first phase of the project and applied in the surveys by all centres. Standard operation procedures (SOPs) will be developed, as well as a plan for training the personnel involved in the surveys. These activities will be accompanied by a quality control strategy that will encompass the evaluation of process and result quality throughout the project. IDEFICS will develop comparable Europe-wide health indicators and instruments for data collection among young children. Establishment of a new European cohort within IDEFICS will provide a unique opportunity to document the development of the obesity epidemic in the current generation of young Europeans and investigate the impact of primary prevention in European children populations.

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. Int. J. Cancer 88:820–827, 2000.

Population attributable risk of tobacco and alcohol for upper aerodigestive tract cancer.

Tobacco and alcohol are major risk factors for upper aerodigestive tract (UADT) cancer and significant variation is observed in UADT cancer rates across Europe. We have estimated the proportion of UADT cancer burden explained by tobacco and alcohol and how this varies with the incidence rates across Europe, cancer sub-site, gender and age. This should help estimate the minimum residual burden of other risk factors to UADT cancer, including human papillomavirus. We analysed 1981 UADT cancer cases and 1993 controls from the ARCAGE multicentre study. We estimated the population attributable risk (PAR) of tobacco alone, alcohol alone and their joint effect. Tobacco and alcohol together explained 73% of UADT cancer burden of which nearly 29% was explained by smoking alone, less than 1% due to alcohol on its own and 44% by the joint effect of tobacco and alcohol. Tobacco and alcohol together explained a larger proportion of hypopharyngeal/laryngeal cancer (PAR=85%) than oropharyngeal (PAR=74%), esophageal (PAR=67%) and oral cancer (PAR=61%). Tobacco and alcohol together explain only about half of the total UADT cancer burden among women. Geographically, tobacco and alcohol explained a larger proportion of UADT cancer in central (PAR=84%) than southern (PAR=72%) and western Europe (PAR=67%). While the majority of the UADT cancers in Europe are due to tobacco or the joint effect of tobacco and alcohol, our results support a significant role for other risk factors in particular, for oral and oropharyngeal cancers and also for UADT cancers in southern and western Europe.

Television habits in relation to overweight, diet and taste preferences in European children: the IDEFICS study

Early television exposure has been associated with various health outcomes including childhood obesity. This paper describes associations between patterns of television viewing, on one hand, and diet, taste preference and weight status, on the other, in European preschoolers and schoolchildren. The IDEFICS baseline survey was conducted at examination centers in Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary, and Spain. 15,144 children aged 2–9 completed the basic protocol, including anthropometry and parental questionnaires on their diets and television habits. A subsample of 1,696 schoolchildren underwent further sensory testing for fat and sweet taste preferences. Three dichotomous indicators described: children’s habitual television exposure time; television viewing during meals; and having televisions in their bedrooms. Based on these variables we investigated television habits in relation to overweight (IOTF) and usual consumption of foods high in fat and sugar. A possible role of taste preference in the latter association was tested in the sensory subgroup. All television indicators were significantly associated with increased risk of overweight, with odds ratios ranging from 1.21 to 1.30, in fully adjusted models. Children’s propensities to consume high-fat and high-sugar foods were positively and, in most analyses, monotonically associated with high-risk television behaviors. The associations between television and diet propensities were not explained by preference for added fat or sugar in test foods. To summarize, in addition to being more overweight, children with high-risk television behaviors may, independent of objectively measured taste preferences for fat and sugar, passively overconsume higher-fat and particularly higher-sugar diets.