OCCUPATIONAL LUNG CANCER

CDK1 and HSP90AA1 Appear as the Novel Regulatory Genes in Non-Small Cell Lung Cancer: A Bioinformatics Approach

Lung cancer is one of the most invasive cancers affecting over a million of the population. Non-small cell lung cancer (NSCLC) constitutes up to 85% of all lung cancer cases, and therefore, it is essential to identify predictive biomarkers of NSCLC for therapeutic purposes. Here we use a network theoretical approach to investigate the complex behavior of the NSCLC gene-regulatory interactions. We have used eight NSCLC microarray datasets GSE19188, GSE118370, GSE10072, GSE101929, GSE7670, GSE33532, GSE31547, and GSE31210 and meta-analyzed them to find differentially expressed genes (DEGs) and further constructed a protein–protein interaction (PPI) network. We analyzed its topological properties and identified significant modules of the PPI network using cytoscape network analyzer and MCODE plug-in. From the PPI network, top ten genes of each of the six topological properties like closeness centrality, maximal clique centrality (MCC), Maximum Neighborhood Component (MNC), radiality, EPC (Edge Percolated Component) and bottleneck were considered for key regulator identification. We further compared them with top ten hub genes (those with the highest degrees) to find key regulator (KR) genes. We found that two genes, CDK1 and HSP90AA1, were common in the analysis suggesting a significant regulatory role of CDK1 and HSP90AA1 in non-small cell lung cancer. Our study using a network theoretical approach, as a summary, suggests CDK1 and HSP90AA1 as key regulator genes in complex NSCLC network.

Trends in the lung cancer incidence and mortality in the Slovak and Czech Republics in the contexts of an international comparison

INTRODUCTION

Lung cancer represents the most frequent cause of cancer-related deaths in the industrialized countries. The aim of this study was to analyze the lung cancer incidence and mortality and the possible reasons for any differences discovered in two neighboring Central European countries-the Slovak Republic.

METHODS

We used linear regression model when analyzing incidence and mortality; the trends are presented with corresponding 95% confidence intervals (CI) and p-value with null hypothesis being constant with time.

RESULTS

Statistically significant increase of age-standardized incidence (0.707/100,000/year, 95% CI 0.107-1.307, p = 0,025) and mortality (1.339/100,000/year, 95% CI 1.050-1.629, p < 0.0001) of the lung cancer was revealed in males in the Slovak Republic (1980-1991). On the contrary, values of both indicators were stabilized in the Czech Republic. Since year 1991-2005 a statistically highly significant decrease of both incidence and mortality values was observed in males, which was greater in the Slovak Republic. Peak of the curve was not reached in women population, while incidence and mortality values have significantly continuous growth in both countries.

CONCLUSIONS

According to the lung cancer incidence and mortality trends in both countries (in correlation with smoking prevalence) we consider the support of efforts to change the attitude towards smoking predominantly in women and younger generation to be the most accurate action to reduce these trends.

Occupational lung cancer in US women, 1984-1998

BACKGROUND

Lung cancer is the leading cause of cancer death in US women, accounting for 72,130 deaths in 2006. In addition to smoking cessation, further reduction of the burden of lung cancer mortality can be made by preventing exposure to occupational lung carcinogens. Data for occupational exposures and health outcomes of US working women are limited.

METHODS

Population-based mortality data for 4,570,711 women who died between 1984 and 1998 in 27 US States were used to evaluate lung cancer proportionate mortality over time by the usual occupation and industry reported on death certificates. Lung cancer proportionate mortality ratios were adjusted for smoking, using data from the National Health Interview Survey (NHIS) and the American Cancer Society's Cancer Prevention Study II.

RESULTS

Analyses revealed that 194,382 white, 18,225 Black and 1,515 Hispanic women died 1984-1998 with lung cancer reported as the underlying cause of death. Following adjustment for smoking, significant excess proportionate lung cancer mortality was observed among US women working in the US manufacturing; transportation; retail trade; agriculture, forestry, and fishing; and nursing/personal care industries. Women employed in precision production, technical, managerial, professional specialty, and administrative occupations experienced some of the highest significantly excess proportionate lung cancer mortality during 1984-1998.

CONCLUSIONS

The results of our study point to significantly elevated risks for lung cancer after adjustment for smoking among women in several occupations and industries. Because 6-17% of lung cancer in US males is attributable to known exposures to occupational carcinogens, and since synergistic interactions between cigarette smoke and other occupational lung carcinogens have been noted, it is important to continue research into the effects of occupational exposures on working men and women.

Epidemiology of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

BACKGROUND

The objective of this study was to summarize the published literature concerning the epidemiology of lung cancer.

METHODS

A narrative review of published evidence was conducted, identifying and summarizing key reports that describe the occurrence of lung cancer in populations and factors that affect lung cancer risk.

RESULTS

In the United States, lung cancer remains the leading cause of cancer death in both men and women, even though an extensive list of modifiable risk factors has long been identified. The predominant cause of lung cancer is exposure to tobacco smoke, with active smoking causing most cases but passive smoking also contributing to the lung cancer burden.

CONCLUSIONS

The reductions in smoking prevalence in men that occurred in the late 1960s through the 1980s will continue to drive lung cancer mortality rates downward in men during the first portion of this century, but rates in women have not yet begun to decrease. Fortunately, exposures to major occupational respiratory carcinogens have largely been controlled, but the population is still exposed to environmental causes of lung cancer, including radon, the second leading cause of lung cancer death.

Factores etiológicos del cáncer de pulmón: fumador activo, fumador pasivo, carcinógenos medioambientales y factores genéticos

Every year, in Spain 18,000 new cases of lung cancer (LC) are diagnosed. Approximately, 80-90% LC in men and women are directly attributable to tobacco abuse. Cigarette smoke contains over 300 chemicals, 40 of which are known to be potent carcinogens. In the last decade, as in Spain, prevalence of smoking in women has generally increased in the European Union. LC risk can be substantially reduced after smoking cessation, yet never reaches baseline. On the other hand, environmental tobacco smoke exposure (passive smoking) in nonsmokers appears to have a significantly increased risk of LC. An updated of etiology factors of LC, risk related to duration as well as intensity of smoking, relationship between environmental tobacco smoke exposure and LC risk, genetic predisposition and a variety of occupational and environmental exposures implicated as potential risk factors for the development of LC will be reviewed here.

[Lung cancer risk in shoe manufacturing]

OBJECTIVE

Workers in shoe manufacturing have been reported to be at a greater relative risk for bronchogenic carcinoma. Given the implications for our practice setting, we carried out a study to a) clarify whether working in shoe manufacturing is a risk factor for lung cancer and b) detect histological differences between lung cancers in shoe manufacturers and in other lung cancer patients.

PATIENTS AND METHODS

This case-control study compared all lung cancer patients diagnosed in Hospital Elda, Alicante, Spain, between January 1994 and December 1999, with a control group composed of patients admitted to the same hospital for accidental fractures. Information on occupational history and tobacco dependency was collected from all patients by telephone questionnaire.

RESULTS

One hundred and ninety-one case patients and 192 control patients were included in the study; 52 of the cases (27.2%) and 48 controls (25%) worked in shoe manufacturing. No statistically significant differences were found between the 2 groups, not even when we limited the cases and controls to only those who had worked more than 30 years in shoe manufacturing or when we analyzed only subjects who had had especially high risk occupations. No differences in tumor histology were found between cancer patients who worked in shoe manufacture and those who did not.

CONCLUSIONS

Working in shoe manufacturing has not proven to be a risk factor for bronchogenic carcinoma.

Screening for lung cancer

BACKGROUND

While population based screening for lung cancer has not been adopted by most countries, it is not clear whether sputum examinations, chest radiography or newer methods such as computed tomography are effective in reducing mortality from lung cancer.

OBJECTIVES

To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality.

SEARCH STRATEGY

Electronic databases (the Cochrane Central Register of Controlled Trials, MEDLINE, PREMEDLINE and EMBASE; 1966 to July 2000) ), bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials.

SELECTION CRITERIA

Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest.

DATA COLLECTION AND ANALYSIS

Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effects model, but for other outcomes the fixed effect model was used.

MAIN RESULTS

Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT.

REVIEWER'S CONCLUSIONS

The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.

Epidemiology, etiology, and prevention of lung cancer

Over the past century, lung cancer has gone from an obscure disease to the leading cause of cancer death worldwide. Initially an epidemic disease among men in industrialized nations, lung cancer now has become the leading cancer killer in both sexes in the United States and an increasingly common disease of both sexes in developing countries. Lung cancer incidence largely mirrors smoking prevalence, with a latency period of several decades. Other important risk factors for the development of lung cancer include environmental exposure to tobacco smoke, radon, occupational carcinogens, and pre-existing nonmalignant lung disease. Studies in molecular biology have elucidated the role that genetic factors play in modifying an individual's risk for lung cancer. Although chemopreventive agents may be developed to prevent lung cancer, prevention of smoking initiation and promotion of smoking cessation are currently the best weapons to fight lung cancer. No other malignancy has been shown to have such a strong epidemiologic relation between a preventable behavior and incidence of disease. Despite this knowledge, more than 20% of all Americans smoke, and tobacco use is exploding in developing countries. Based on current and projected smoking patterns, it is anticipated that lung cancer will remain the leading cause of cancer death in the world for decades to come.

Cooking oil fume-induced cytokine expression and oxidative stress in human lung epithelial cells

Epidemiological studies have shown an association between exposure to indoor air pollution from Chinese-style cooking and risk of lung cancer among Chinese females. Several toxic substances have been identified in cooking oil fumes (COF) collected from heated rapeseed oil. In this study, we examined the biological effects of COF on CL3 human lung epithelial cells. Exposure to 200 microg/ml COF significantly reduced cell growth within 4 days. In addition, we examined the effect of COF on TGFbeta1, TGFbeta2, IL-6, IL-8, and IFN-gamma gene expressions with the RT-PCR method. We found that TGFbeta1 mRNA levels increased after exposure to 200 microg/ml COF for 24 h. Similarly, exposure to 10 microM benzo[a]pyrene or 100 nM 12-O-tetradecanoylphorbol-13-acetate increased TGFbeta1 mRNA levels at 24 h. The mRNA levels of TGFbeta2, IL-6, IL-8, and IFN-gamma did not increase after treatment with COF, benzo[a]pyrene, or 12-O-tetradecanoylphorbol-13-acetate. COF-induced TGFbeta1 production was confirmed by quantification of TGFbeta1 in conditioned medium with enzyme-linked immunosorbent assay. Exposure to 200 microg/ml COF significantly increased TGFbeta1 secretion in a time-dependent and dose-dependent manner. It has been demonstrated that reactive oxygen intermediates induce TGFbeta1 gene expression. When CL3 cells were exposed to 200 microg/ml COF for 15 min, there was an increase in intracellular peroxide formation with the dichlorofluorescein method. Furthermore, treatment with 200 microg/ml COF for 12 h also significantly induced lipid peroxidation in CL3 cells. Our results show that exposure to COF inhibits cell growth, increases TGFbeta1 secretion, and induces oxidative stress in CL3 lung epithelial cells. This suggests that TGFbeta1 and oxidative stress play a role in the biological effects of COF on lung epithelial cells.

Screening for lung cancer

BACKGROUND

The effectiveness of screening for lung cancer with chest radiography, sputum cytology or spiral CT has not been established.

OBJECTIVES

To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality.

SEARCH STRATEGY

Electronic databases, bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials.

SELECTION CRITERIA

Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest.

DATA COLLECTION AND ANALYSIS

Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effect model, but for other outcomes the fixed effect model was used.

MAIN RESULTS

Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT.

REVIEWER'S CONCLUSIONS

The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.

Investigation and management of patients at high risk of developing cancer

Recent developments in cancer genetics have revealed genes that render individuals susceptible to cancer. These families have a unique set of new problems and benefits that must be thought through for the potential good to be accrued from these discoveries. Individual patients seek early diagnosis and prevention strategies that challenge the limits of current knowledge. Some available methods have not yet been evaluated. There is a need for the evidence to support plans of care, and consistency is required from one centre to the next in the advice given. These familial cancers are often different from the more common sporadic cases, and so traditional treatments need to be tested again in the context of the new genetic knowledge. Three groups of cancers, breast, ovary and colon, have been used to illustrate the issues surrounding these high risk families, their investigation and care. In applying new strategies to these patients, ethical issues arise that are new to the medical world, and must be considered by the lay public. It is up to the medical profession, patients and society to use this knowledge to give benefit to a vulnerable group, and not to give unaffordable hopes and unnecessary anxieties.

Socioeconomic status and lung cancer incidence in men in The Netherlands: is there a role for occupational exposure?

STUDY OBJECTIVE

To evaluate the influence of occupational exposure to carcinogens in explaining the association between socioeconomic status and lung cancer.

DESIGN

A prospective cohort study. Data on diet, other lifestyle factors, sociodemographic characteristics and job history were collected by means of a self administered questionnaire. Follow up for incident cancer was established by record linkage with a national pathology register and with regional cancer registries.

SETTING

Population originating from 204 municipalities in The Netherlands.

PARTICIPANTS

These comprised 58 279 men aged 55-69 years in September 1986. After 4.3 years of follow up there were 470 microscopically confirmed incident lung cancer cases with complete data on dietary habits and job history.

MEASUREMENTS AND MAIN RESULTS

Estimation of occupational exposure to asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes was carried out by two experts, using information on job history from the baseline questionnaire. Socioeconomic status was measured by means of highest attained level of education and two indicators based on occupation. In the initial multivariate analyses of socioeconomic status and lung cancer, adjustment was made for age, smoking habits, intake of vitamin C, beta-carotene and retinol, and history of chronic obstructive pulmonary disease or asthma. Additional adjustment for occupational exposure to the four carcinogens mentioned above did not change the inverse association between the level of education and lung cancer risk (initial model: RR highest/lowest level of education = 0.53; 95% CI 0.34, 0.82; additional model: RR highest/lowest level of education = 0.53; 95% CI 0.34, 0.84). Nor was the association between the two occupation based indicators of socioeconomic status and lung cancer risk influenced by occupational exposure to carcinogens. The effect of occupational exposure on the association between the level of education and lung cancer risk did not differ between ex-smokers and current smokers.

CONCLUSIONS

Occupational exposure to asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes could not explain the inverse association between socioeconomic status and lung cancer risk. More research which explicitly addresses possible explanations for the association between socioeconomic status and lung cancer risk is needed.

Epidemiology of lung cancer: a worldwide epidemic

OBJECTIVES

To examine patterns and trends in lung cancer and the risk factors associated with development of this disease.

DATA SOURCES

Epidemiologic studies, research studies, review articles, and government reports pertaining to epidemiology of lung cancer.

CONCLUSION

Epidemiological evidence documents that most lung cancer cases could be prevented. With 3 million persons worldwide dying annually from lung cancer attributable to smoking, cigarette smoking remains the number one target for public health action to reduce cancer risk in the general population.

IMPLICATIONS FOR NURSING PRACTICE

A useful resource for nurses is the descriptive epidemiology of lung cancer, a knowledge base that identifies who is at risk. Linking this risk information with knowledge of strategies for reducing these risks provides a basis for planning and implementing interventions to prevent lung cancer.

Obtaining information about susceptibility from the epidemiological literature

Whether people become ill after encountering environmental pollutants depends on the magnitude of their exposure and their capacity to respond. Exposure and intrinsic response capabilities vary within the population. Those that become ill when the general population remains largely unaffected are considered to be highly susceptible. The U.S. Environmental Protection Agency (USEPA), responsible for protecting the public from environmental pollutants, has developed risk assessment procedures to assist in evaluating the likelihood of health effects. However, the Agency's ability to evaluate the risk faced by highly susceptible populations is often hindered by the paucity of adequate health effects data. Response variability can be assessed with animal models and human epidemiological studies. Although animal models are useful when evaluating the effect of gender and developmental stage on susceptibility, inbred rodent strains underestimate the genetic and lifestyle-induced variability in susceptibility found in human populations. Epidemiological approaches are the preferred source of information on variability. This paper reviews the epidemiological literature from the perspective of a risk assessor seeking data suitable for estimating the risk to highly susceptible populations. Epidemiological approaches do not measure the full range of population response variability. Rather, "susceptibility factors" are evaluated either as risk factors or by focusing on the susceptible population, e.g. children. Susceptibility factors due to genetics, developmental stage, gender, ethnicity, disease state and lifestyle are most frequently encountered. Often, the information describing the health impact of the susceptibility factor is incomplete due to, (1) a failure to consider factors modifying susceptibility; (2) inadequate exposure data; (3) a failure to evaluate the health impact of the susceptibility factor. In addition, for a given exposure agent, several susceptibility factors may be relevant. While incomplete data describing susceptibility factors limits the opportunity for quantitative estimations of risk, available information can supplement qualitative evaluations and risk management.

Bronchogenic cancer in patients under 40 years old. The experience of a Latin American country

Lung cancer in young patients is increasing in frequency, as documented by data from the United States, Canada, Japan, and European countries. However, to date and to our knowledge, there have not been any reports from Latin America on this topic. The published reports show that lung cancer in young patients is associated with smoking habit and family history of lung cancer. Its clinical course seems to be more aggressive than in older patients and the histologic type is less often squamous type. We describe 48 patients, aged 40 years or younger, who were diagnosed as having lung cancer in the Instituto Nacional de Cancerología from 1980 to 1990. The patients were equally divided between men and women. Smoking was documented for only 46 percent of the cases. The histologic type most frequently diagnosed was adenocarcinoma (N = 26) followed by squamous cell carcinoma (N = 12). Almost all the cases (46 cases) were staged IV according to the TNM classification. A group of 33 patients older than 40 years (56 to 82 years) were used for comparison. The differences in sex ratio that were higher for men in the elder (m/f, 2.7:1) were family history for cancer in six patients elder; positive smoking habit in all the aged patients (100 percent) compared with only 43.7 percent in the younger group; histologic type (26 adenocarcinomas and 4 squamous in the younger compared with 14 and 12, respectively, in the elder).

Occupational lung cancer

Exposure to certain industrial agents has been thought to have carcinogenic potential, both for employees who work closely with such agents and for the general population that comes in contact with them. Although case reports, laboratory studies, and epidemiologic analyses help to determine the carcinogenicity of implicated agents, each of these types of investigation has limitations and deficiencies in distinguishing causal from noncausal associations. Asbestos has been linked with bronchogenic carcinoma, but several controversial factors--the degree of risk relative to exposure dose, the synergistic effect of cocarcinogens, and the question of existence of a threshold dose--complicate the understanding of the magnitude of the risk for exposed persons. Several other physical and chemical agents (such as chromium, nickel, and radon) have also been associated with an increased incidence of lung cancer in epidemiologic and animal studies. As with asbestos, the specific type of the agent and exposure conditions are important in determining the degree of carcinogenicity. In studies of exposure to man-made mineral fibers, formaldehyde, and silica, the findings have been inconsistent. Because the degree of health hazard attributable to asbestos and other known and suspected lung carcinogens is controversial, a wide range of opinions exists about the importance of occupational exposures to the overall incidence of lung cancers. Nevertheless, attempting to prevent lung cancers by minimizing or eliminating exposure to carcinogens is preferable to treating existent cases.