Biomedical subjects

Adrian Cassidy

Publications and source records attributed to Adrian Cassidy.

9 recordsLinked to original sources

PubMed2007

Lung cancer risk prediction: a tool for early detection.

Although 45% of men and 39% of women will be diagnosed with cancer in their lifetime, it is difficult to predict which individuals will be affected. For some cancers, substantial progress in individual risk estimation has already been made. However, relatively few models have been developed to predict lung cancer risk beyond effects of age and smoking. This paper reviews published models for lung cancer risk prediction, discusses their potential contribution to clinical and research settings and suggests improvements to the risk modeling strategy for lung cancer. The sensitivity and specificity of existing cancer risk models is less than optimal. Improvement in individual risk prediction is important for selection of individuals for prevention or early detection interventions. In addition to smoking, factors related to occupational exposure, personal medical history and family history of cancer can add to the predictive power. A good risk prediction model is one that can identify a small fraction of the population in which a large proportion of the disease cases will occur. In the future, genetic and other biological markers are likely to be useful, although they will require rigorous evaluation. Validation is essential to establish the predictive effect and for ongoing monitoring of the model's continued relevance.

Early Diagnosis↗

PubMed2007

Occupational exposure to crystalline silica and risk of lung cancer: a multicenter case-control study in Europe.

BACKGROUND: The role of crystalline silica dust as a possible cause of lung cancer has been controversial. Relatively few large community-based studies have been conducted to investigate the lung cancer risk from exposure to silica at low levels, taking into account potential confounding factors. METHODS: Detailed lifestyle and occupational information were collected from 2852 newly diagnosed cases of lung cancer and 3104 controls between 1998 and 2002 in 7 European countries. For each job held, local experts assessed the probability, intensity, and duration of silica exposure. RESULTS: Occupational exposure to crystalline silica was associated with an increased risk of lung cancer (odds ratio = 1.37; 95% confidence interval = 1.14-1.65). This risk was most apparent for the upper tertile of cumulative exposure (OR = 2.08; 95% CI = 1.49-2.90; P for trend <0.0001), duration of exposure (1.73; 1.26-2.39; P for trend = 0.0001) and weighted duration of exposure (1.88; 1.35-2.61; P for trend <0.0001). We did not observe any interaction beyond a multiplicative model between tobacco smoking and silica exposure. CONCLUSIONS: Our results support the hypothesis that silica is an important risk factor for lung cancer. This risk could not be explained by exposure to other occupational carcinogens or smoking, and it was present for the main histologic types of lung cancer, different sources of silica exposure, and different industrial settings.

Adenocarcinoma↗

PubMed2006

Occupational exposure to asbestos and man-made vitreous fibres and risk of lung cancer: a multicentre case-control study in Europe.

OBJECTIVES: To investigate the contribution of occupational exposure to asbestos and man-made vitreous fibres (MMVF) to lung cancer in high-risk populations in Europe. METHODS: A multicentre case-control study was conducted in six Central and Eastern European countries and the UK, during the period 1998-2002. Comprehensive occupational and sociodemographic information was collected from 2205 newly diagnosed male lung cancer cases and 2305 frequency matched controls. Odds ratios (OR) of lung cancer were calculated after adjusting for other relevant occupational exposures and tobacco smoking. RESULTS: The OR for asbestos exposure was 0.92 (95% CI 0.73 to 1.15) in Central and Eastern Europe and 1.85 (95% CI 1.07 to 3.21) in the UK. Similar ORs were found for exposure to amphibole asbestos. The OR for MMVF exposure was 1.23 (95% CI 0.88 to 1.71) with no evidence of heterogeneity by country. No synergistic effect either between asbestos and MMVF or between any of them and smoking was found. CONCLUSION: In this large community-based study occupational exposure to asbestos and MMVF does not appear to contribute to the lung cancer burden in men in Central and Eastern Europe. In contrast, in the UK the authors found an increased risk of lung cancer following exposure to asbestos. Differences in fibre type and circumstances of exposure may explain these results.

Asbestos↗

PubMed2006

Lung cancer risk and occupational exposure to meat and live animals.

An increased risk of lung cancer has been reported for butchers and meat workers in several cohort studies, although confounding from tobacco smoking could not be ruled out in any of these studies. These exposures, as well as a potential risk associated with contact with live animals, are addressed here in a large case-control study with full adjustment for smoking. More than 5,900 subjects were included in a case-control study conducted in 7 European countries. For each job they employed local experts who assessed the exposure to a number of occupational agents, including (i) meat aerosols and (ii) live animals, on the basis of detailed occupational questionnaires. Information on tobacco consumption and other risk factors was also collected. A small increased risk of lung cancer was observed with exposure to meat aerosols, after adjusting for smoking, (odds ratio (OR)=1.27, 95% confidence interval (CI): 0.92, 1.75), which was most apparent for the upper tertile of cumulative exposure (OR=1.73, 95% CI: 1.03, 2.92). A similar overall effect was observed for exposure to live animals, with an increased risk observed for a high frequency of exposure, (OR=1.69, 95% CI: 1.21, 2.36) and a high intensity of exposure, (OR=1.85, 95% CI: 1.16, 2.94), with significant trends for increasing frequency (p=0.012), intensity (p=0.015) and cumulative exposure (p=0.024). In conclusion, this study provides evidence for an association between exposure to meat aerosols and lung cancer apparent in the highest tertile of exposure. The authors identified a more consistent association with exposure to live animals.

Adult↗

PubMed2006

Lung cancer and occupation in nonsmokers: a multicenter case-control study in Europe.

BACKGROUND: Tobacco smoking is the main cause for lung cancer worldwide, making it difficult to examine the carcinogenic role of other risk factors because of possible confounding by smoking. Therefore, the present study aimed to investigate the association between lung cancer and occupation independent of smoking. METHODS: A case-control study of lung cancer was carried out between March 1998 and January 2002 in 16 centers from 7 European countries, including 223 never-smoking cases and 1039 controls. Information on lifestyle and occupation was obtained through detailed questionnaires. Job and industries were classified as entailing exposure to known or suspected carcinogens; in addition, expert assessment provided exposure estimates to specific agents. RESULTS: The odds ratio of lung cancer among women employed for more than 12 years in suspected high-risk occupations was 1.75 (95% confidence interval = 0.63-4.85). A comparable increase in risk was not detected for employment in established high-risk occupations or among men. Increased risk of lung cancer was suggested among individuals exposed to nonferrous metal dust and fumes, crystalline silica, and organic solvents. CONCLUSION: Occupations were found to play a limited role in lung cancer risk among never-smokers. Jobs entailing exposure to suspected lung carcinogens should receive priority in future studies among women. Nonferrous metal dust and fumes and silica may exert a carcinogenic effect independently from smoking.

Case-Control Studies↗

PubMed2006

Defining high-risk individuals in a population-based molecular-epidemiological study of lung cancer.

Within the framework of the Liverpool Lung Project (LLP), population-based case-control and prospective cohort studies are in progress to identify molecular and epidemiological risk factors and define populations and individuals most at risk of developing lung cancer. This report describes a strategy for selection of a high-risk population and further provides support for the inclusion of occupational and genetic risk factors in future models. Data from the case-control study (256 incident cases and 314 population controls) were analysed to define a high-risk population. Detailed lifestyle and occupational information were collected during structured interviews. Models were constructed using conditional logistic regression and included terms for age, tobacco consumption and previous respiratory disease. Smoking duration was chosen as the most important predictor of lung cancer risk [>50 years (OR 15.65, 95% CI 6.10-40.15)]. However, such a model would preclude younger individuals. Several combinations of previous respiratory disease were also considered, of which a history of bronchitis, emphysema or pneumonia (BEP) was the most significant (OR 1.86, 95% CI 1.28-2.69). A high-risk subset (based on combinations of smoking duration and BEP) was identified, which have a 4.5-fold greater risk of developing lung cancer (OR 4.5, 95% CI 2.33-8.68). Future refinement of the risk model to include individuals occupationally exposed to asbestos and with the p21 genotypes is discussed. There is real potential for environmental and genetic factors to improve on risk prediction and targeting of susceptible individuals beyond the traditional models based only on smoking and age. The development of a molecular-epidemiological model will inform the development of effective surveillance, early detection and chemoprevention strategies.

Aged↗

PubMed2005

Lung cancer and indoor pollution from heating and cooking with solid fuels: the IARC international multicentre case-control study in Eastern/Central Europe and the United Kingdom.

Exposure to fuel from cooking and heating has not been studied in Europe, where lung cancer rates are high and many residents have had a long tradition of burning coal and unprocessed biomass. Study subjects included 2,861 cases and 3,118 controls recruited during 1998-2002 in the Czech Republic, Hungary, Poland, Romania, Russia, Slovakia, and the United Kingdom. The odds ratio of lung cancer associated with solid fuel use was 1.22 (95% confidence interval (CI): 1.04, 1.44) for cooking or heating, 1.37 (95% CI: 0.90, 2.09) for solid fuel only for cooking, and 1.24 (95% CI: 1.05, 1.47) for solid fuels used for both cooking and heating. Risk increased relative to the percentage of time that solid fuel was used for cooking (p(trend) < 0.0001), while no risk increase was detected for solid fuel used for heating. The odds ratio of lung cancer in whole-life users of solid cooking fuel was 1.80 (95% CI: 1.35, 2.40). Switching to nonsolid fuels resulted in a decrease in risk. The odds ratio for the longest duration of time since switching was 0.76 (95% CI: 0.63, 0.92). The data suggest a modest increased risk of lung cancer related to solid-fuel use for cooking rather than heating.

Adult↗

PubMed2004

Occupational exposure to vinyl chloride, acrylonitrile and styrene and lung cancer risk (europe).

Several industry-based cohort studies have addressed the risk of lung cancer following exposure to vinyl chloride, acrylonitrile and styrene, with inconsistent results and usually without smoking adjustment. These exposures are addressed here in a large case-control study with full adjustment for smoking. Almost 6000 subjects were included in a case-control study conducted in seven European countries. For each job they held, local experts assessed the exposure to a number of occupational agents, including vinyl chloride, acrylonitrile and styrene, on the basis of detailed occupational questionnaires. Information on tobacco consumption and other risk factors was also collected. The odds ratio (OR) for ever exposure to vinyl chloride was 1.05 (95% confidence interval, CI: 0.68-1.62) and a modest, non-significant increase in the risk of lung cancer was found in the highest exposed subgroup. The OR for ever exposure to acrylonitrile was 2.20 (95% CI: 1.11-4.36) with a positive dose-response relationship between estimated cumulative exposure and lung cancer risk. No association between exposure to styrene and lung cancer risk was found. In conclusion, we cannot exclude a weak association between occupational exposure to vinyl chloride and lung cancer risk. Exposure to acrylonitrile was associated in our study with risk of lung cancer. Exposure to styrene does not seem to increase lung cancer risk.

Acrylonitrile↗

PubMed2003

Assessing exposure misclassification by expert assessment in multicenter occupational studies.

BACKGROUND: In a multicenter case-control study of lung cancer in central and eastern Europe and in Liverpool, exposure to occupational agents was assessed by teams of local experts. We performed an interteam agreement study to estimate the levels of exposure misclassification and the expected attenuation of the risk estimate. METHODS: Eight teams of experts and a reference rater assessed exposure to 70 putative lung carcinogens for 19 jobs. Agreement among teams was calculated through Cohen's kappa, sensitivity, and specificity. RESULTS: Each team showed an overall fair to good agreement with the reference (kappa between 0.53 and 0.64). The agreement among teams in the presence of exposure was excellent for 9 agents, fair to good for 16, and poor for 29. For all agents the specificity was high (average 0.94), although sensitivity varied considerably. CONCLUSIONS: This study of expert exposure assessment showed a small range in reliability among teams of experts, but large differences among agents. This paper presents the range in levels of misclassification that can be expected using experts for assessing occupational exposure to different agents, and the attenuation of the odds ratio that can be expected to result from this misclassification.

Carcinogens, Environmental↗