Lung cancer and diesel exhaust: a review

The evidence from animal studies indicates that organic extracts of diesel particulate are mutagenic and carcinogenic. Of four animal inhalation studies, two have been positive and two have been largely negative. The most recent data indicate that inhalation studies may be positive only with high doses of exhaust. Human studies of diesel-exposed occupations have been inconclusive. These studies have focused on truck drivers, bus drivers and garage workers, railroad workers, and heavy equipment operators. Most human studies have not been able to estimate exposure to diesel exhaust. Negative studies have frequently suffered from insufficient potential latency. Positive studies have often failed to control for smoking, and have sometimes involved confounding occupational exposures. In general, the occupational epidemiology of diesel-exposed workers is made difficult by the fact that many of the suspected toxic components of diesel-exhaust are also present in cigarette smoke and in ambient air. There are two ongoing epidemiologic studies in the United States, focusing on railway workers and truck drivers, which attempt to overcome prior difficulties. Preliminary data from the study of truck drivers indicates an excess of lung cancer among workers in the trucking industry compared to the U.S. population, but these data need to be controlled for smoking and analyzed according to diesel exposure.     

Brassica vegetables and prostate cancer risk: a review of the epidemiological evidence

Epidemiological studies have yielded conflicting results on the associations of diet with prostate cancer. We review evidence that Brassica vegetables are associated with reduced prostate cancer risk. Brassica vegetables, which include broccoli, cabbage, mustard and collard greens, and bok choy, contain glucosinolates, the metabolic breakdown products of which are potent modulators of xenobiotic-metabolizing enzymes that protect DNA from damage. Twelve published studies give some information about Brassica vegetables and prostate cancer risk; six of these studies can be clearly interpreted. Of these, three reported statistically significant reduced risks (P < 0.05) and one reported a borderline significant reduced risk (P = 0.06) with high Brassica vegetable consumption. The epidemiological literature provides modest support for the hypothesis that high intakes of Brassica vegetables reduce prostate cancer risk.     

An update of a mortality study of talc miners and millers in Italy

BACKGROUND: While talc containing asbestiform fibers is considered a human carcinogen, only limited animal and human data are available on non-asbestiform talc. To provide further evaluation on the issue, we updated the analysis of an Italian cohort of talc miners and millers in Val Chisone; talc found here is free from asbestiform fibers. METHODS: The cohort was comprised of 1,795 men who had worked for at least 1 year in the mine and/or in the factory between 1946 and 1995. Vital status and death certificates were obtained from registration offices in the municipality of death or of birth. Employment, termination of employment, and detailed job history were obtained from personnel records at the plant. RESULTS: No excess was found for total cancer mortality, nor mortality for lung cancer. No case of mesothelioma was reported. There was a significant excess mortality from non-neoplastic respiratory diseases (SMR 228.2, 95% CI 190.2-271.5). Mortality excess for non-neoplastic respiratory diseases was mainly due to silicosis. CONCLUSIONS: This study provides additional support for an association between talc in mining and milling and non-neoplastic respiratory diseases, while showing no significant excess risk for lung cancer and mesothelioma. The results also provide additional information of interest to evaluate the potential association between silica and lung cancer.     

Lung cancer and asbestos exposure: Asbestosis is not necessary

Recent commentaries on the issue of asbestos-related lung cancer have raised important points. One major question is whether lung cancer can be attributed to asbestos exposure in the absence of asbestosis. This review attempts to place the debate in the proper context for establishing causation. Relevant epidemiologic and pathologic studies are analyzed, as well as the scientific basis for each position in the debate. The assertion that asbestosis must be present in order to attribute a lung cancer to asbestos exposure does not meet accepted standards for establishing causation. In addition, some evidence has been incorrectly cited in support of this position. This discussion can benefit from clearer definitions of asbestosis, a more thorough evaluation of the available scientific information, and a proper context for determining causation. This review of the available evidence indicates that lung cancers can occur as a result of asbestos exposure, in the absence of clinical or histologic asbestosis. Causation in an individual should be assessed by considering duration of exposure, intensity of exposure, and appropriate latency. © 1996 Wiley-Liss, Inc.     

Hormonal contraceptive methods and risk of HIV acquisition in women: a systematic review of epidemiological evidence

Whether use of various types of hormonal contraception (HC) affect risk of HIV acquisition is a critical question for women's health. For this systematic review, we identified 22 studies published by January 15, 2014 which met inclusion criteria; we classified thirteen studies as having severe methodological limitations, and nine studies as “informative but with important limitations”. Overall, data do not support an association between use of oral contraceptives and increased risk of HIV acquisition. Uncertainty persists regarding whether an association exists between depot-medroxyprogesterone acetate (DMPA) use and risk of HIV acquisition. Most studies suggested no significantly increased HIV risk with norethisterone enanthate (NET-EN) use, but when assessed in the same study, point estimates for NET-EN tended to be larger than for DMPA, though 95% confidence intervals overlapped substantially. No data have suggested significantly increased risk of HIV acquisition with use of implants, though data were limited. No data are available on the relationship between use of contraceptive patches, rings, or hormonal intrauterine devices and risk of HIV acquisition. Women choosing progestin-only injectable contraceptives such as DMPA or NET-EN should be informed of the current uncertainty regarding whether use of these methods increases risk of HIV acquisition, and like all women at risk of HIV, should be empowered to access and use condoms and other HIV preventative measures. Programs, practitioners, and women urgently need guidance on how to maximize health with respect to avoiding both unintended pregnancy and HIV given inconclusive or limited data for certain HC methods.     

Lung cancer and related risk factors: an update of the literature

At the present time, lung cancer is the leading cause of cancer-related death in males. Diagnostic difficulty makes detection complicated and this, in conjunction with the low survival rate, renders the disease a serious health problem. In-depth knowledge of associated risk factors is therefore called for, in order to prevent or at least reduce the appearance of lung cancer and to open new avenues of research. Although the disease has a multicausal aetiology, tobacco accounts for 85-90% of all cases. This paper reviews the current situation, dividing the risk factors, for study purposes, into two groups; intrinsic (non-modifiable) and extrinsic (modifiable).     

中国1996—2014年肺癌经济负担研究系统评价

目的 探讨中国1996-2014年肺癌经济负担研究状况,为肺癌防控措施相关评价及卫生决策提供参考依据。方法 以癌症、经济负担、费用等为检索词,检索中国知网、万方和PubMed数据库1996年1月1日-2014年12月31日发表的关于中国肺癌经济负担的文献,再按非肺癌相关文献等标准进行排除,对最终纳入的32篇文献进行摘录,所有费用数据均按照2013年我国医疗保健消费价格指数行贴现处理,且以均值表示,同时计算年均增长率。结果 最终纳入的32篇文献中,基于住院患者和人群的研究分别有30和2篇;经济负担类型方面,关注直接经济负担、间接经济负担、直接和间接经济负担的文献分别有26、1和5篇;本研究分析结果显示,中国1996-2011年肺癌例均直接医疗费用为10 415~27 595元,年均增长率为2.2%（其中检查费、药品费和化验费用年均增长率分别为3.5%、-3.2%和2.2%）;1997-2010年肺癌次均直接医疗费用为9 463~38 209元,年均增长率为-1.7%（其中检查费、药品费和化验费年均增长率分别为16.9%、-2.2%和17.3%）;1996-2009年肺癌直接医疗日均费用为426~1 036元,年均增长率为6.3%;直接非医疗费用和间接费用因涵盖项目及方法差异,无法得出趋势数据。结论 中国肺癌经济负担研究数据的收集及分析方法不一,例均和次均费用整体趋势不明显,但细化项目多呈增长趋势且幅度不同。     

Polypropylene production and colorectal cancer: a review of the epidemiological evidence

Polypropylene has been produced for over 35 years and has awide variety of applications including industrial uses, foodpackaging and many domestic uses. As a high-molecular-weightpolymer, polypropylene is considered chemically inert with littleor no physiological or toxicological effects. Nevertheless,early epidemiological studies of polypropylene production workersand carpet manufacturing employees who use polypropylene reporteda significant excess of colorectal cancer. In one study, fiveof the seven cases were diagnosed within a five-month period,and in the other study, five cases were diagnosed within an18-month period. Recent updates of these two study populationshave found no continuation of the excess of colorectal cancer,thereby indicating that the earlier observations on these twogroups reflected the chance nature of a time-space cluster.Moreover, investigations of polypropylene production workersin the United States, Germany, Australia and the United Kingdomfound no association with colorectal cancer. When the resultsof all studies of polypropylene production workers are pooled,the summary risk ratio for colorectal cancer is 1.37 (95% confidenceinterval 0.83–2.11). Taken together, the epidemiologicalevidence and the absence of toxicological data do not supporta causal association between polypropylene and colorectal cancer.     

Lung cancer risk in past asbestos workers a few decades after exposure cessation and prospects for screening

To ascertain whether the current risk of lung cancer in former asbestos workers was higher than in the general population, 1,557 past asbestos workers were recruited during statutory health examinations (from 2000 onward) and followed up for mortality. Standardized mortality ratios (SMRs) were calculated. Poisson regression was used to adjust the rate ratios (RRs) for confounders. SMR was about 1.00 in workers with or without pleural plaques and 4.62 (95% confidence interval: 0.61–18.1) in those with asbestosis. Adjusted RRs for lung cancer were 4.70 (0.99–22.5) for asbestosis, 4.35 (0.97–19.5) for former smokers, 6.82 (1.38–34.4) for current smokers. Currently, lung cancer mortality in past asbestos workers is similar to the general population, probably because workers more exposed /more susceptible could have died from lung cancer before the beginning of follow-up.     

Lung cancer risk and welding: Results from a case-control study in Germany

In a case-control study, 839 male hospital-based cases of primary lung cancer and the same number of population-based controls—matched by sex, age, and region of residence—were personally interviewed for their job and smoking histories. The study allows to quantify occupational asbestos exposure that was thought to be a welding-associated risk: 6% of cases and 2% of controls were classified into the occupational category “welders or burners” (odds ratio [OR] = 2.65). This OR was reduced to 1.93 (95% confidence limit [CL]: 1.03–3.61) after adjustment for smoking and asbestos. In contrast, a history of welding in general for at least a half-year is 28% among cases and 23% among controls, yielding an OR of 1.25 (95% CL: 0.94–1.65) after adjustment for both confounders. The OR of welding for more than 6,000 hr is 1.45 (95% CL = 1.04–2.02), reduced to 1.10 after adjustment for smoking and asbestos. Oxyacetylene welding for more than 6,000 hr lifelong is associated with an OR of 1.86 (95% CL = 1.01–3.43) reduced to 1.46 (n.s.) after adjustment for smoking and asbestos. The risk of oxyacetylene welding seems to be highest for oat cell carcinoma with an adjusted OR for ever-exposure of 1.46 (95% CL = 0.69–3.10). Therefore, the present study supports the hypothesis that some, but not all, of the excess risk of welders observed in the literature may be due to a history of cigarette smoking and occupanional asbestos exposure. The elevated risk for the subgroup of employees in the aircraft industry reported for the midterm evaluation of the study still prevails, though no longer statistically significant. However, employees in this industry who ever welded show an OR of 2.29 (95% CL = 1.19–4.42) after adjustment for smoking and asbestos. Am. J. Ind. Med. 33:313–320, 1998. © 1998 Wiley-Liss, Inc.     

Carcinogenicity of occupational nickel exposures: an evaluation of the epidemiological evidence

The health effects documented in recent epidemiological studies of nickel-exposed workers relate to past exposures, mostly of unknown magnitude and unknown nickel speciation. Major studies have been carried out at nickel smelters and refineries. Although each study suffers from some deficiencies, as is common in such retrospective studies, the findings in concert strongly indicate that nickel emitted from the calcining and sintering operations is a potent carcinogen resulting in nasal and pulmonary cancers. Some risk appears to be present in other refinery operations, such as Orford furnace, copper and nickel sulfate, and crushing departments, and one study has suggested a risk associated with soluble nickel compounds in the electrolysis department, although this finding has not been confirmed. Only one study demonstrated an exposure-response relationship, which, however, was not statistically significant. Other studies showed a relationship between increased exposure time and augmented cancer risk. In nickel-using industries, no excess cancer related to nickel exposures has been demonstrated beyond doubt; concurrent exposures to other potential carcinogens constitute a confounding variable that makes interpretation difficult. However, the studies have not excluded that a cancer hazard may be present outside the nickel-producing facilities. Further, case-referent studies of respiratory cancers suggest that a nickel-related etiology may well exist in the nickel-using industries. As the exact identity of the carcinogenic form or forms of nickel remains unknown, exposure to all nickel compounds should be kept as low as reasonably achievable.     

Uranium exposure and cancer risk: a review of epidemiological studies

OBJECTIVE: At the end of 2000, certain diseases including leukemia were reported among soldiers who participated in the Balkan and in the Gulf wars. Depleted uranium used during these conflicts was considered as a possible cause. Its radiotoxicity is close to that of natural uranium. This paper reviews the epidemiological knowledge of uranium, the means of exposure and the associated risk of cancer. METHODS: The only available epidemiological data concerns nuclear workers exposed to uranium. A review of the international literature is proposed by distinguishing between uranium miners and other workers of the nuclear industry. French studies are described in details. RESULTS: In ionizing radiation epidemiology, contamination by uranium is often cited as a risk factor, but the dose-effect relationship is rarely studied. Retrospective assessment of individual exposure is generally insufficient. Moreover, it is difficult to distinguish between uranium radiotoxicity, its chemical toxicity and the radiotoxicity of its progeny. A causal relation between lung cancer and radon exposure, a gas derived from the decay of uranium, has been demonstrated in epidemiological studies of miners. Among other nuclear workers exposed to uranium, there is a mortality deficit from all causes (healthy worker effect). No cancer site appears systematically in excess compared to the national population; very few studies describe a dose-response relationship. CONCLUSION: Only studies with a precise reconstruction of doses and sufficient numbers of workers will allow a better assessment of risks associated with uranium exposure at levels encountered in industry or during conflicts using depleted uranium weapons.     

Cancer risk in the rubber industry: a review of the recent epidemiological evidence

OBJECTIVES: To examine the recent epidemiological evidence on cancer risk among workers in the rubber industry. METHODS: Epidemiological studies published after the last detailed review by the International Agency for Research on Cancer (IARC) in 1982 were reviewed. 12 cohort studies in nine countries that examined distinct populations of workers in the rubber industry, seven industry based nested case-control studies, 48 community based case-control studies in 16 countries, and 23 studies based on administrative data that reported risks for employment in the rubber industry were identified. RESULTS: Excess risks of bladder cancer, lung cancer, and leukaemia were found in most studies, with risks above 1.5 in about half of the studies. A moderate excess risk for laryngeal cancer was consistent across studies. Excess risks were found in a few studies for cancers of the oesophagus, stomach, colon, liver, pancreas, skin, prostate, kidney, brain, and thyroid, and for malignant lymphoma and multiple myeloma, but overall results were not consistent for these neoplasms. CONCLUSIONS: Magnitude of the observed risks varied considerably between studies, but overall the findings indicate the presence of a widespread moderate increased cancer risk among rubber workers. The most consistent results were for bladder, laryngeal, and lung cancer and for leukaemia. Excess risks were also found for other neoplasms but an evaluation of the consistency of the findings is difficult because of the possible selective reporting of results. Recent studies do not provide information associating specific exposures with cancer risk. The preventive measures taken in the rubber industry in recent years may decrease risks, but this has not been documented yet in epidemiological studies.

 

     

Recent trends in published occupational cancer epidemiology research: Results from a comprehensive review of the literature

Objective

To assess trends in occupational cancer epidemiology research through a literature review of occupational health and epidemiology journals.

Methods

Fifteen journals were reviewed from 1991 to 2009, and characteristics of articles that assessed the risk of cancer associated with an occupation, industry, or occupational exposure, were incorporated into a database.

Results

The number of occupational cancer epidemiology articles published annually declined in recent years (2003 onwards) in the journals reviewed. The number of articles presenting dose–response analyses increased over the review period, from 29% in the first 4 years of review to 49% in the last 4 years.

Conclusion

There has been a decrease in the number of occupational cancer epidemiology articles published annually during the review period. The results of these articles help determine the carcinogenicity of workplace exposures and permissible exposure limits, both of which may be hindered with a decline in research. Am. J. Ind. Med. 57:259–264, 2014. © 2013 The Authors. American Journal of Industrial Medicine Published byWiley Periodicals, Inc.     

Organizing palliative care for rural populations: a systematic review of the evidence

BACKGROUND: Palliative care services have developed mostly in urban areas. Rural areas typically are characterized by the lack of well-organized services, with primary care professionals, specifically GPs and community nurses, having to undertake most of the palliative care. Little is known, however, either of their views or of how best to organize palliative care in rural areas. OBJECTIVE: The aim of this study was to conduct a systematic literature review of studies that have examined the organization of rural palliative care and the views of professionals in rural areas. METHOD: Six electronic databases were searched for published studies between 1991 and 2001. Articles had to match against (i). MeSH or keyword terms relating to palliative, terminal or end of life care; and (ii). MeSH or keyword terms relating to rural. A data extraction framework was designed and used systematically by two reviewers to consider research question and method, sample characteristics, selection and size, study quality, summary results and implications. RESULTS: Twenty-six studies were identified. These were mostly questionnaire surveys and reports, and three qualitative studies. No randomized controlled studies or cohort studies were identified. Education and strategic issues were dominant research questions. Both the sample numbers and response rates in the surveys were variable. The qualitative studies had methodological strengths and elicited important views from nurses, carers and families. GPs were, however, unrepresented. Whilst the role of primary care emerged as an important theme, primary care professionals reported difficulties in obtaining education and training. There were also reported problems in symptom control and in the management of emotional issues such as bereavement counselling. Difficulties were also described in accessing specialist services such as hospices, and families were reported as having problems in accessing information. Developments in information technology such as telemedicine were seen as possible solutions to some of the problems. CONCLUSIONS: There is little published work on this topic. Most of the work identifies problems in the delivery of palliative care in rural areas. Whilst primary care professionals are seen as having a key role, there is a need to discover both their views and their needs in this field.