Michael K. Felten

Is it useful to combine sputum cytology and low-dose spiral computed tomography for early detection of lung cancer in formerly asbestos-exposed power industry workers?

BackgroundLow-dose spiral computed tomography (LDSCT) in comparison to conventional chest X-ray proved to be a highly sensitive method of diagnosing early stage lung cancer. However, centrally located early stage lung tumours remain a diagnostic challenge. We determined the practicability and efficacy of early detection of lung cancer when combining LDSCT and sputum cytology.MethodsOf a cohort of 4446 formerly asbestos exposed power industry workers, we examined a subgroup of 187 (4.2%) high risk participants for lung cancer at least once with both LDSCT and sputum cytology. After the examination period the participants were followed-up for more than three years.ResultsThe examinations resulted in the diagnosis of lung cancer in 12 participants (6.4%). Six were in clinical stage I. We found 10 non-small cell lung carcinomas and one small cell lung carcinoma. Sputum specimens showed suspicious pathological findings in seven cases and in 11 cases the results of LDSCT indicated malignancies. The overall sensitivity and specificity of sputum cytology was 58.0% and 98% with positive (PPV) and negative (NPV) predictive values of 70% and 97%. For LDSCT we calculated the sensitivity and specificity of 92% and 97%. The PPV and NPV were 65% and 99% respectively.ConclusionsOur results confirmed that in surveillance programmes a combination of sputum cytology and LDSCT is well feasible and accepted by the participants. Sputum examination alone is not effective enough for the detection of lung cancer, especially at early stage. Even in well- defined risk groups highly exposed to asbestos, we cannot recommend the use of combined LDSCT and sputum cytology examinations as long as no survival benefit has been proved for the combination of both methods. For ensuring low rates of false-positive and false-negative results, programme planners must closely cooperate with experienced medical practitioners and pathologists in a well-functioning interdisciplinary network.

Non-response Bias in a Surveillance Program for Asbestos-related Lung Cancer

Non‐response Bias in a Surveillance Program for Asbestos‐related Lung Cancer: Lars Knoll, et al. Institute of Occupational Medicine, RWTH Aachen University, Germany—

Lung function not affected by asbestos exposure in workers with normal Computed Tomography scan

BACKGROUND It has been suggested that asbestos exposure affects lung function, even in the absence of asbestos-related pulmonary interstitial or pleural changes or emphysema. METHODS We analyzed associations between well-known asbestos-related risk factors, such as individual cumulative asbestos exposure, and key lung function parameters in formerly asbestos-exposed power industry workers (N = 207) with normal CT scans. For this, we excluded participants with emphysema, fibrosis, pleural changes, or any combination of these. RESULTS The lung function parameters of FVC, FEV1, DLCO/VA, and airway resistance were significantly associated with the burden of smoking, BMI and years since end of exposure (only DLCO/VA). However, they were not affected by factors directly related to amount (eg, cumulative exposure) or duration of asbestos exposure. CONCLUSIONS Our results confirm the well-known correlation between lung function, smoking habits, and BMI. However, we found no significant association between lung function and asbestos exposure.

Association of plasma PCB levels and HbA1c concentration in Iran

BackgroundThe rapid increase in prevalence of diabetes mellitus over the last decades warrants more attention to the effects of environmental and occupational exposures on glucose metabolism. Our study aimed to assess the association between the plasma levels of various congeners of polychlorinated biphenyls (PCBs) and the serum concentration of glycated haemoglobin (HbA1c).MethodsOur study population consisted of 140 Iranian adults from seven different occupational groups and a group of non-occupationally exposed female participants. The plasma concentration of PCBs were determined at the laboratory of occupational toxicology at RWTH Aachen University, Germany. We considered an HbA1c concentration of 5.7% and more as indicating a disturbed glucose metabolism. Logistic regression was used to assess the association between quartiles of concentrations of PCB congeners and serum HbA1c.ResultsParticipants with an increased HbA1c value had higher plasma levels of PCB 138, 153, 180 and the PCB sum, although this association was statistically not significant. There was no significant difference between the levels of PCB 138, 153, 180, the sum of these congeners, and PCB 118 in their quartiles when comparing with HbA1c concentrations.ConclusionsFor our cohort, we could not demonstrate a significant association between PCB and HbA1c concentrations indicating a disturbance of glucose metabolism.

Risk factors associated with asbestos-related lung diseases among different sub-cohorts of formerly asbestos exposed workers in Germany

Objectives To examine the association between work-place exposure to asbestos and risk factors for developing asbestos related diseases using the analysis of a cross-sectional cohort of 8582 formerly asbestos exposed workers followed between March 2002 until the end of the year 2009. To assess the value of the three risk categories used for focused health surveillance programmes among formerly asbestos exposed power industry. Methods The work started with a descriptive analysis of three asbestos exposed sub-cohorts of workers from different types of the power industry then assessed the difference between the three sub-cohorts with regard to their corresponding level of risk. Further, we investigated how well the risk categories could predict the risk of asbestos related disease in comparison to applying a single risk factor such as age or asbestos exposure. Results The smokers over 65 age of years and those who had an exposure duration over 10 years were more likely to have lung cancer in this cohort. Hence the results showed that the age of participants (over 65 years, OR=11.47), smoking habits (OR=9.48 (current smoker), were associated significantly with lung cancer. The results showed that the risk of having lung cancer in group A was 1.87 times. Conclusions There was a strong association between both duration of exposure and age, and the risk of developing lung cancer. The use of risk categories based on a combination of risk factors may be an advantage for planning focused health surveillance programmes.

Serial measurements of mesothelin and osteopontin in formerly asbestos exposed power industry workers

Objectives For the proposed tumour markers mesothelin and osteopontin we determined the influence of gender, age and former asbestos exposure on blood concentrations, assessed the changes over time and investigated characteristics of marker concentrations in prediagnosis samples of patients with malignant pleural mesothelioma (MPM) and lung cancer (LC). Methods We analysed multiple blood samples of 2262 volunteers of three groups: 1894 formerly asbestos exposed power industry workers, 266 mostly asbestos exposed patients suffering from chronic respiratory diseases and 102 not occupationally exposed controls. Marker concentrations were determined using commercial ELISA kits. For statistical analysis we used the t-test and multiple regression models. Results We measured 3273 and 3218 concentrations of mesothelin and osteopontin respectively. Second, third and fourth samples were obtained in 691, 304 and 72 participants. 16 patients suffering from newly developed MPM or LC could be identified, seven of them had multiple prediagnosis samples. While marker concentrations were associated with age (mesothelin p=0.006, osteopontin p<0.001), gender and exposure duration had no influence. Asbestos exposed power industry workers with an overall increase of marker concentrations (mesothelin 53%, osteopontin 18%) showed mean annual increases of 0.176 nmol/l for mesothelin and 86 ng/ml for osteopontin. Conclusions The concentrations of mesothelin and osteopontin in asbestos exposed healthy individuals are strongly influenced by age. Fixed cut-off values for deciding between clinical work up and continued surveillance appear inadequate. Results would be consistent with an increase of the mesothelin concentration between 6 and 18 months before specific clinical symptoms develop.