Lung cancer and exposure to tobacco smoke in the household

Health effects associated with exposure to secondhand smoke: a Burden of Proof study

Despite a gradual decline in smoking rates over time, exposure to secondhand smoke (SHS) continues to cause harm to nonsmokers, who are disproportionately children and women living in low- and middle-income countries. We comprehensively reviewed the literature published by July 2022 concerning the adverse impacts of SHS exposure on nine health outcomes. Following, we quantified each exposure-response association accounting for various sources of uncertainty and evaluated the strength of the evidence supporting our analyses using the Burden of Proof Risk Function methodology. We found all nine health outcomes to be associated with SHS exposure. We conservatively estimated that SHS increases the risk of ischemic heart disease, stroke, type 2 diabetes and lung cancer by at least around 8%, 5%, 1% and 1%, respectively, with the evidence supporting these harmful associations rated as weak (two stars). The evidence supporting the harmful associations between SHS and otitis media, asthma, lower respiratory infections, breast cancer and chronic obstructive pulmonary disease was weaker (one star). Despite the weak underlying evidence for these associations, our results reinforce the harmful effects of SHS on health and the need to prioritize advancing efforts to reduce active and passive smoking through a combination of public health policies and education initiatives.

Unravelling hub genes as potential therapeutic targets in lung cancer using integrated transcriptomic meta-analysis and in silico approach

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. Smoking has been identified as the main contributing cause of the disease's development. The study aimed to identify the key genes in small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), the two major types of LC. Meta-analysis was performed with two datasets GSE74706 and GSE149507 obtained from Gene Expression Omnibus (GEO). Both the datasets comprised samples from cancerous and adjacent non-cancerous tissues. Initially, 633 differentially expressed genes (DEGs) were identified. To understand the underlying molecular mechanism of the identified genes, pathway enrichment, gene ontology (GO) and protein-protein interaction (PPI) analyses were done. A total of 9 hub genes were identified which were subjected to mutation study analysis in LC patients using cBioPortal. These   9 genes (i.e. AURKA, AURKB, KIF23, RACGAP1, KIF2C, KIF20A, CENPE, TPX2 and PRC1) have shown overexpression in LC patients and can be explored as potential candidates for prognostic biomarkers. TPX2 reported a maximum mutation of 4 % . This was followed with high throughput screening and docking analysis to identify the potential drug candidates following competitive inhibition of the AURKA-TPX2 complex. Four compounds, CHEMBL431482, CHEMBL2263042, CHEMBL2385714, and CHEMBL1206617 were identified. The results signify that the selected 9 genes can be explored as biomarkers in disease prognosis and targeted therapy. Also, the identified 4 compounds can be further analyzed as promising therapeutic candidates.Communicated by Ramaswamy H. Sarma.

Changing Pattern of Common Cancers in the Last Five Years in Kashmir, India: A Retrospective Observational Study

Introduction Cancer is emerging as a major health problem worldwide. Profile and pattern of cancers vary as per the geographic, ethnic, and sociocultural background of the population. It is imperative to know the change in the pattern of cancer in the population to formulate an effective strategy for its control and management.

Objective To study the changing trends and epidemiological distribution of common cancer types in an ethnic population of Northern India.

Materials and Methods In this retrospective observational study, we audited records of 22,188 patients with histologically documented cancer registered between January 2014 and December 2018 in the regional cancer center of a tertiary care institute in North India. For all identified patients, medical records were reviewed for demographic information (age of diagnosis, sex, type of cancer, and select risk factors). The data analysis was done using IBM SPSS Statistics for Windows from IBM Corp. Data were expressed as frequencies with percentages. The incidence and trends were depicted through tables, and line diagrams were used to show the changes (if any) over the last 5 years.

Results The most common cancer reported in the last 5 years was lung cancer, overall (10.6%; 95% confidence interval [CI], 10.2–11.0) as well as in men (14.8%; 95% CI, 14.2–15.4) and breast cancer in females (13.5%; 95% CI, 12.8–14.2). The top five cancers reported at our center were lung (10.6%), esophagus (9.1%), stomach (9.0%), breast (6.0%), and colon (3.8%). Compared with that, the top five cancers reported from our center in 2012 were esophagus and gastroesophageal junction (17.2%), lung (11.9%), stomach (9.7%), colorectal (7.1%), and breast (6.5%). Prostate cancer was reported in 3.4% of cases, which was much higher than that reported in 2012 (1.7%). Surprisingly, thyroid cancer (6.4%) was the fourth commonest cancer reported in females, while it did not figure in the top 10 cancers in the 2012 report. Expectantly, cervix cancer did not figure among the top 10 cancers in women.

Conclusion There is a change in the pattern of cancers. Lung and breast have emerged as the most commonly occurring cancers in men and women, respectively, whereas there was a slight downward trend in the incidence of esophageal cancer.

Progress on pivotal role and application of exosome in lung cancer carcinogenesis, diagnosis, therapy and prognosis

Lung cancer is often diagnosed at an advanced stage and has a poor prognosis. Conventional treatments are not effective for metastatic lung cancer therapy. Although some of molecular targets have been identified with favorable response, those targets cannot be exploited due to the lack of suitable drug carriers. Lung cancer cell-derived exosomes (LCCDEs) receive recent interest in its role in carcinogenesis, diagnosis, therapy, and prognosis of lung cancer due to its biological functions and natural ability to carry donor cell biomolecules. LCCDEs can promote cell proliferation and metastasis, affect angiogenesis, modulate antitumor immune responses during lung cancer carcinogenesis, regulate drug resistance in lung cancer therapy, and be now considered an important component in liquid biopsy assessments for detecting lung cancer. Therapeutic deliverable exosomes are emerging as promising drug delivery agents specifically to tumor high precision medicine because of their natural intercellular communication role, excellent biocompatibility, low immunogenicity, low toxicity, long blood circulation ability, biodegradable characteristics, and their ability to cross various biological barriers. Several studies are currently underway to develop novel diagnostic and prognostic modalities using LCCDEs, and to develop methods of exploiting exosomes for use as efficient drug delivery vehicles. Current status of lung cancer and extensive applicability of LCCDEs are illustrated in this review. The promising data and technologies indicate that the approach on LCCDEs implies the potential application of LCCDEs to clinical management of lung cancer patients.

Female reproductive factors and the risk of lung cancer in postmenopausal women: a nationwide cohort study

Background

Reproductive factors and hormone use in postmenopausal women have been hypothesised to affect the risk of developing lung cancer, but the epidemiological evidence is inconsistent.

Methods

Using the Korean National Health Insurance System database, we identified 4,775,398 postmenopausal women older than 40 years who had undergone both cardiovascular health- and cancer screening between 1 January 2009 and 31 December 2014. Information about reproductive factors was obtained from a self-administered questionnaire. The risk of lung cancer was estimated using Cox proportional hazard regression models.

Results

During a median follow-up of 4.4 years, 16,556 women (15,223 non-smokers) were diagnosed with lung cancer. The risk of lung cancer was not significantly influenced by early menarche age (adjusted hazard ratio [aHR] 1.03 for menarche ≥18 vs. ≤14; 95% confidence interval [CI], 0.98–1.09) or late age at menopause (aHR 1.02 for menopause ≥55 vs. <40; 95% CI, 0.91–1.14). Furthermore, the number of children, duration of breastfeeding and use of hormone replacement therapy were not associated with the risk of lung cancer.

Conclusions

No statistically significant association was found between reproductive factors and the risk of lung cancer in postmenopausal Korean women.

Workplace smoking restrictions and support for smoking cessation in the USA: state, region, and overall trends from 2010-11 to 2014-15

We discuss the most recent changes in smoking policies and support for smoking cessation offered to smokers at US workplaces. We used reports of employed adults (n = 112,008) regarding smoking restrictions and support for smoking cessation offered at their indoor workplaces from the 2010–11 and 2014–15 Tobacco Use Supplement-Current Population Survey. The percentage of adults who reported having workplace smoking restrictions was 94% in 2010–11 and 93% in 2014–15 (P = 0.001). There was a decrease in the Northeastern region (P < 0.001) and no significant changes in the other three US regions. The percentages decreased in Hawaii, New York, Oregon, Pennsylvania, and Tennessee and increased in Indiana, Nebraska, and Wyoming. The percentage of employees who reported having workplace support for smoking cessation increased from 24% to 29% (P < 0.001), which was uniform across all US regions but differed across the US states. The percentages decreased in Hawaii and increased in the majority of states. Analysis of smokers’ reports (versus all reports) resulted in lower percentages of workplaces with smoking restrictions and support for smoking cessation. It is essential to further enhance support for smoking cessation offered to smokers at US workplaces.

A review of the effects of tobacco smoking on cancer treatment: smoking cessation intervention should be integrated into the cancer care continuum

Background:

The adverse health effects associated with smoking tobacco have been well investigated, and its detrimental effects on cancer treatment outcomes, efficacy and quality of life (QOL) for cancer patients have also been well documented. Tobacco smoke contains many thousands of chemicals, including a plethora of carcinogens, and the exposure of human cells to these carcinogens, and their metabolic activation, is the main mechanism by which smoking-related cancer is initiated.

Materials and Methods:

This paper reports on a narrative review of recent studies in the field of effects of tobacco smoking on cancer treatment, including the effects of carcinogens in smoke on carcinogenesis, cell mutations and the immune system. The health effects of smokeless tobacco, effects of tobacco smoking on cancer treatment, and its impact on surgery, radiation therapy and chemotherapy are reported. The potential risks of second primary cancers or recurrence from tobacco use, the effects of second-hand smoking and cancer treatment, the impact of smoking on the QOL after cancer treatment and the need to integrate smoking cessation programs into the cancer care continuum are also reported.

Conclusions:

Tobacco use has a direct impact on cellular function by inhibiting apoptosis, stimulating proliferation and decreasing the efficacy of cancer treatment; therefore, quitting its use has the potential to improve treatment response rates and survival, as well as reduces the risk of developing second cancers and potentially improves the QOL after treatment. Smoking cessation is one of the most important interventions to prevent cancer and is also essential after the diagnosis of cancer to improve clinical outcomes. Due to the numerous benefits of smoking cessation, it should become a critical component of the cancer care continuum in all oncology programs – from prevention of cancer through diagnosis, treatment, survivorship and palliative care. Evidence-based smoking cessation intervention should be sustainably integrated into any comprehensive cancer program, and the information should be targeted to the specific benefits of cessation in cancer patients.

Exposure to Secondhand Smoke and Risk of Cancer in Never Smokers: A Meta-Analysis of Epidemiologic Studies

This is first meta-analysis to evaluate cancer risk associated with secondhand smoking across all cancers. A literature search was conducted for articles published before June 2014 on Pubmed, SCOPUS, Cochrane library, and CINAHL, and 40 articles on secondhand smoke and the prevalence of cancer among never smokers were selected for final analysis as per the inclusion criteria. Of the 40 articles, 27 were case-control studies and 13 were prospective cohort studies. With respect to overall cancer risk, odds ratio (OR) involving never smokers with significant exposure to secondhand smoke compared to never smokers without such exposure was 1.163 (95%CI 1.058–1.279). Subgroup meta-analyses by study design showed significant positive associations for both case-control studies and prospective cohort studies (OR 1.165, 95%CI 1.029–1.320; and OR 1.160, 95%CI 1.002–1.343, respectively). The association was stronger in the case of females (OR 1.253, 95%CI 1.142–1.374), lung cancer (OR 1.245, 95%CI 1.026–1.511), and breast cancer (OR 1.235, 95%CI 1.102–1.385). Secondhand smoking may increase the overall risk of cancer for never smokers, particularly lung and breast cancer, and especially in women. Strict implementation of smoking cessation programs should be encouraged, not only to reduce active smoking but also to limit exposure to secondhand smoke.

Epidemiological profile and prognostic factors in patients with lung cancer

OBJECTIVE

To describe the epidemiological profile of patients with lung cancer treated at a public tertiary referral hospital specializing in oncology, and to explore variables that may be related to the overall survival (OS) of these patients.

METHOD

Data from the medical records of all patients with invasive lung cancer consecutively seen at the Oncology Department of Hospital Estadual Mário Covas between August 2008 and December 2013 were extracted. The information obtained was submitted to statistical analysis.

RESULTS

Of the total 210 patients, 39 were excluded from analysis due to lack of information in the medical record. The most common histological type was adenocarcinoma, representing 39.41% of the sample, followed by squamous cell carcinoma with 25.29% and small-cell carcinoma with 13.53%. Other histological types were responsible for the remaining 21.76%. There was a statistically significant association between Karnofsky performance status (KPS) ≤ 70%, palliative chemotherapy lines performed and stage at diagnosis, and OS. Additionally, administration of target therapy to patients with EGFR mutation was associated with significantly better overall survival. However, analysis of laboratory variables (hemoglobin, albumin and LDH) as possible prognostic factors for survival showed no statistically significant relationship. Among patients with stage III and IV, the median OS was 10.1 months.

CONCLUSION

The risk factors for shorter OS were KPS score ≤ 70%, less than two lines of palliative chemotherapy, and stage III and IV at diagnosis. The implementation of CT screening for risk patients may allow earlier diagnosis of cases and improve these results.

Differences in Dietary Patterns of Nonsmoking Adults Married to Smokers vs. Nonsmokers

Purpose.

To compare dietary intakes of nonsmoking adults married to smokers or non-smokers.

Design.

Respondents to the U.S. Department of Agriculture's Continuing Survey of Food Intakes by Individuals (CSFII), 1994 to 1996 (response rate = 76.1% for 2 days of dietary intake). Nonsmoking adults aged 18 and older were grouped according to the smoking status of their spouse.

Setting.

In-home interviews in all 50 states and Washington, D.C.

Subjects.

The selected sample included 757 men and 754 women who were married to nonsmokers, and 197 men and 262 women who were married to smokers.

Measures.

Selected demographic variables, food group servings, food energy, and densities of selected nutrients were compared using χ2 and analysis of covariance.

Results.

Men and women married to smokers had greater (p ⩽ .025) energy-adjusted intakes of total and saturated fat but significantly lower (p ⩽ .05) energy-adjusted intakes of fiber and vitamin A. Men married to smokers consumed significantly more (p < .025) energy-adjusted cholesterol and ethanol but significantly less calcium (p = .026); women married to smokers consumed significantly less (p = .014) energy-adjusted folate. Men married to smokers consumed significantly more (p ⩽ .05) alcoholic beverages, coffee, and soft drinks; women married to smokers consumed significantly less water (p = .014) but more cheese and table sweeteners (p ⩽ .05).

Conclusions.

Nonsmoking men and women who were married to smokers had compromised dietary intakes. Nonsmoking men whose wives smoked, in particular, had unhealthy diets due to elevated intakes of fat and cholesterol and low intakes of vitamin A, calcium, and fiber. Health professionals should continue to provide tobacco cessation instruction and dietary guidance, but also be aware of at-risk patients' immediate family members who likely share an increased risk of disease because of poor diet quality and exposure to environmental tobacco smoke.

Environmental tobacco smoke exposure and lung cancer: A systematic review

AIM: To review evidence relating passive smoking to lung cancer risk in never smokers, considering various major sources of bias.

METHODS: Epidemiological prospective or case-control studies were identified which provide estimates of relative risk (RR) and 95%CI for never smokers for one or more of seven different indices of exposure to environmental tobacco smoke (ETS): The spouse; household; workplace; childhood; travel; social and other; and total. A wide range of study details were entered into a database, and the RRs for each study, including descriptions of the comparisons made, were entered into a linked database. RRs were derived where necessary. Results were entered, where available, for all lung cancer, and for squamous cell cancer and adenocarcinoma. “Most adjusted” results were entered based on results available, adjusted for the greatest number of potential confounding variables. “Least adjusted” results were also entered, with a preference for results adjusted at least for age for prospective studies. A pre-planned series of fixed-effects and random-effects meta-analyses were conducted. Overall analyses and analyses by continent were run for each exposure index, with results for spousal smoking given by sex, and results for childhood exposure given by source of ETS exposure. For spousal exposure, more extensive analyses provide results by various aspects of study design and definition of the RR. For smoking by the husband (or nearest equivalent), additional analyses were carried out both for overall risk, and for risk per 10 cigarettes per day smoked by the husband. These adjusted for uncontrolled confounding by four factors (fruit, vegetable and dietary fat consumption, and education), and corrected for misclassification of smoking status of the wife. For the confounding adjustment, estimates for never smoking women were derived from publications on the relationship of the four factors to both lung cancer risk and at home ETS exposure, and on the correlations between the factors. The bias due to misclassification was calculated on the basis that the proportion of ever smokers denying smoking is 10% in Asian studies and 2.5% elsewhere, and that those who deny smoking have the same risk as those who admit it. This approach, justified in previous work, balances higher true denial rates and lower risk in deniers compared to non-deniers.

RESULTS: One hundred and two studies were identified for inclusion, published in 1981 onwards, 45 in Asia, 31 in North America, 21 in Europe, and five elsewhere. Eighty-five were of case-control design and 17 were prospective. Significant (P < 0.05) associations were noted, with random-effects of (RR = 1.22, 95%CI: 1.14-1.31, n = 93) for smoking by the husband (RR = 1.14, 95%CI: 1.01-1.29, n = 45) for smoking by the wife (RR = 1.22, 95%CI: 1.15-1.30, n = 47) for workplace exposure (RR = 1.15, 95%CI: 1.02-1.29, n = 41) for childhood exposure, and (RR = 1.31, 95%CI: 1.19-1.45, n = 48) for total exposure. No significant association was seen for ETS exposure in travel (RR = 1.34, 95%CI: 0.94-1.93, n = 8) or in social situations (RR = 1.01, 95%CI: 0.82-1.24, n = 15). A significant negative association (RR = 0.78, 95%CI: 0.64-0.94, n = 8) was seen for ETS exposure in childhood, specifically from the parents. Significant associations were also seen for spousal smoking for both squamous cell carcinoma (RR = 1.44, 95%CI: 1.15-1.80, n = 24) and adenocarcinoma (RR = 1.33, 95%CI: 1.17-1.51, n = 30). Results generally showed marked heterogeneity between studies. For smoking by either the husband or wife, where 119 RR estimates gave an overall estimate of (RR = 1.21, 95%CI: 1.14-1.29), the heterogeneity was highly significant (P < 0.001), with evidence that the largest RRs were seen in studies published in 1981-89, in small studies (1-49 cases), and for estimates unadjusted by age. For smoking by the husband, the additional analyses showed that adjustment for the four factors reduced the overall (RR = 1.22, 95%CI: 1.14-1.31) based on 93 estimates to (RR = 1.14, 95%CI: 1.06-1.22), implying bias due to uncontrolled confounding of 7%. Further correction for misclassification reduced the estimate to a marginally non-significant (RR = 1.08, 95%CI: 0.999-1.16). In the fully adjusted and corrected analyses, there was evidence of an increase in Asia (RR = 1.18, 95%CI: 1.07-1.30, n = 44), but not in other regions (RR = 0.96, 95%CI: 0.86-1.07, n = 49). Studies published in the 1980’s, studies providing dose-response data, and studies only providing results unadjusted for age showed elevated RRs, but later published studies, studies not providing dose-response data, and studies adjusting for age did not. The pattern of results for RRs per 10 cigs/d was similar, with no significant association in the adjusted and corrected results (RR = 1.03, 95%CI: 0.994-1.07).

CONCLUSION: Most, if not all, of the ETS/lung cancer association can be explained by confounding adjustment and misclassification correction. Any causal relationship is not convincingly demonstrated.

The association between lung cancer incidence and ambient air pollution in China: A spatiotemporal analysis

BACKGROUND

China is experiencing more and more days of serious air pollution recently, and has the highest lung cancer burden in the world.

OBJECTIVES

To examine the associations between lung cancer incidence and fine particles (PM2.5) and ozone in China.

METHODS

We used 75 communities' data of lung cancer incidence from the National Cancer Registration of China from 1990 to 2009. The annual concentrations of fine particles (PM2.5) and ozone at 0.1°×0.1° spatial resolution were generated by combing remote sensing, global chemical transport models, and improvements in coverage of surface measurements. A spatial age-period-cohort model was used to examine the relative risks of lung cancer incidence associated with the air pollutants, after adjusting for impacts of age, period, and birth cohort, sex, and community type (rural and urban) as well as the spatial variation on lung cancer incidence.

RESULTS

The relative risks of lung cancer incidence related to a 10 µg/m(3) increase in 2-year average PM2.5 were 1.055 (95% confidence interval (CI): 1.038, 1.072) for men, 1.149 (1.120, 1.178) for women, 1.060 (1.044, 1.075) for an urban communities, 1.037 (0.998, 1.078) for a rural population, 1.074 (1.052, 1.096) for people aged 30-65 years, and 1.111 (1.077, 1.146) for those aged over 75 years. Ozone also had a significant association with lung cancer incidence.

CONCLUSIONS

The increased risks of lung cancer incidence were associated with PM2.5 and ozone air pollution. Control measures to reduce air pollution would likely lower the future incidence of lung cancer.

Altered expression of histone deacetylases, inflammatory cytokines and contractile-associated factors in uterine myometrium of Long Evans rats gestationally exposed to benzo[a]pyrene

Etiology of preterm birth (PTB) is multifactorial; therefore, decreasing the incidence of PTB is a major challenge in the field of obstetrics. Epidemiological studies have reported an association between toxicants and PTB. However, there are no studies on the role of benzo[a]pyrene (BaP), an environmental toxicant, in the incidence of PTB. We first assessed the effects of BaP (150 and 300 µg kg(-1) body weight) dosed via gavage from day 14 to 17 of pregnancy on gestation length in Long Evans rats. We further assessed the histopathology of the uterus, expression of inflammatory cytokines, contractile-associated factors, histone deacetylases (HDACs) and NFқB-p65 in myometrium collected on day 22 postpartum versus vehicle-treated controls. In our study, rats exposed to BaP delivered prematurely (P < 0.05) compared to control. Hematoxylin and eosin staining of uterus showed squamous metaplasia, glandular and stromal hyperplasia in BaP-exposed rats versus control. The concentrations of BaP metabolites measured by high-pressure liquid chromatography were higher in uterine myometrium of BaP-exposed rats while they were undetectable in controls. Quantitative real-time polymerase chain reaction showed significant increases in mRNA expression of interleukin-1β and -8, tumor necrosis factor-α, connexin 43, cyclo-oxygenase-2 and prostaglandin F2α receptor as compared to controls (P < 0.05). Western blot analysis revealed that BaP exposure caused decreases in class I HDACs 1 and 3 and increases in class II HDAC 5, cyclo-oxygenase-2 and nuclear translocation of NFκB-p65 relative to controls. Our results suggest that gestational exposure to BaP increases incidence of PTB through epigenetic changes that causes increases in the expression of contractile-associated factors through the NFκB pathway. Copyright © 2015 John Wiley & Sons, Ltd.

Active and passive smoking in relation to lung cancer incidence in the Women's Health Initiative Observational Study prospective cohort

BACKGROUND

Lung cancer is the leading cause of worldwide cancer deaths. While smoking is its leading risk factor, few prospective cohort studies have reported on the association of lung cancer with both active and passive smoking. This study aimed to determine the relationship between lung cancer incidence with both active and passive smoking (childhood, adult at home, and at work).

PATIENTS AND METHODS

The Women's Health Initiative Observational Study (WHI-OS) was a prospective cohort study conducted at 40 US centers that enrolled postmenopausal women from 1993 to 1999. Among 93 676 multiethnic participants aged 50-79, 76 304 women with complete smoking and covariate data comprised the analytic cohort. Lung cancer incidence was calculated by Cox proportional hazards models, stratified by smoking status.

RESULTS

Over 10.5 mean follow-up years, 901 lung cancer cases were identified. Compared with never smokers (NS), lung cancer incidence was much higher in current [hazard ratio (HR) 13.44, 95% confidence interval (CI) 10.80-16.75] and former smokers (FS; HR 4.20, 95% CI 3.48-5.08) in a dose-dependent manner. Current and FS had significantly increased risk for all lung cancer subtypes, particularly small-cell and squamous cell carcinoma. Among NS, any passive smoking exposure did not significantly increase lung cancer risk (HR 0.88, 95% CI 0.52-1.49). However, risk tended to be increased in NS with adult home passive smoking exposure ≥30 years, compared with NS with no adult home exposure (HR 1.61, 95% CI 1.00-2.58).

CONCLUSIONS

In this prospective cohort of postmenopausal women, active smoking significantly increased risk of all lung cancer subtypes; current smokers had significantly increased risk compared with FS. Among NS, prolonged passive adult home exposure tended to increase lung cancer risk. These data support continued need for smoking prevention and cessation interventions, passive smoking research, and further study of lung cancer risk factors in addition to smoking. CLINICALTRIALS.GOV: NCT00000611.

A DRD1 polymorphism predisposes to lung cancer among those exposed to secondhand smoke during childhood

Lung cancer has a familial component which suggests a genetic contribution to its etiology. Given the strong evidence linking smoking with lung cancer, we studied miRNA-related loci in genes associated with smoking behavior. CHRNA, CHRNB gene families, CYP2A6, and DRD1 (dopamine receptor D1) were mined for SNPs that fell within the seed region of miRNA binding sites and then tested for associations with risk in a three-stage validation approach. A 3'UTR (untranslated region) SNP in DRD1 was associated with a lower risk of lung cancer among individuals exposed to secondhand smoke during childhood [OR, 0.69; 95% confidence interval (CI), 0.60-0.79; P < 0.0001]. This relationship was evident in both ever (OR, 0.74; 95% CI, 0.62-0.88; P = 0.001) and never smokers (OR, 0.61; 95% CI, 0.47-0.79; P < 0.0001), European American (OR, 0.65; 95% CI, 0.53-0.80; P < 0.0001), and African American (OR, 0.73; 95% CI, 0.62-0.88; P = 0.001) populations. Although much remains undefined about the long-term risks associated with exposure to secondhand smoke and heterogeneity between individuals in regard to their susceptibility to the effects of secondhand smoke, our data show an interaction between an SNP in the 3'UTR of DRD1 and exposure to secondhand smoke during childhood. Further work is needed to explore the mechanistic underpinnings of this SNP and the nature of the interaction between DRD1 and exposure to secondhand smoke during childhood.

Exposure to parental smoking and child growth and development: a cohort study

Background

Studies on adverse childhood health and development outcomes associated with parental smoking have shown inconsistent results. Using a cohort of Belarusian children, we examined differences in cognition, behaviors, growth, adiposity, and blood pressure at 6.5 years according to prenatal and postnatal exposure to parental smoking.

Methods

Using cluster-adjusted multivariable regression, effects of exposure to prenatal smoking were examined by comparing (1) children whose mothers smoked during pregnancy with those of mothers who smoked neither during nor after pregnancy and (2) children whose mothers smoked during and after pregnancy with those whose mothers smoked after pregnancy only; effects of postnatal smoking were examined by comparing (1) children whose mothers smoked after pregnancy only with those of mothers who smoked neither during nor after pregnancy and (2) children whose fathers smoked with those whose fathers did not smoke among children of non-smoking mothers after adjusting for a wide range of socioeconomic and family characteristics.

Results

After adjusting for confounders, children exposed vs unexposed to prenatal maternal smoking had no differences in mean IQ, teacher-rated behavioral problems, adiposity, or blood pressure. Children exposed to maternal postnatal smoking had slightly increased behavioral problems [0.9, 95% CI: 0.6, 1.2 for total difficulties], higher body mass index [0.2, 95% CI: 0.1, 0.3], greater total skinfold thickness [0.4, 95% CI: 0.04, 0.71], and higher odds of overweight or obesity [1.4, 95% CI; 1.1, 1.7]. Similar magnitudes of association were observed with postnatal paternal smoking.

Conclusions

No adverse cognitive, behavioral and developmental outcomes were associated with exposure to maternal prenatal smoking. Observed associations with postnatal smoking of both parents may reflect residual confounding by genetic and family environmental factors.

Cigarette smoke induces methylation of the tumor suppressor gene NISCH

We have previously identified a putative tumor suppressor gene, NISCH, whose promoter is methylated in lung tumor tissue as well as in plasma obtained from lung cancer patients. NISCH was observed to be more frequently methylated in smoker lung cancer patients than in non-smoker lung cancer patients. Here, we investigated the effect of tobacco smoke exposure on methylation of the NISCH gene. We tested methylation of NISCH after oral keratinocytes were exposed to mainstream and side stream cigarette smoke extract in culture. Methylation of the promoter region of the NISCH gene was also evaluated in plasma obtained from lifetime non-smokers and light smokers (<20 pack/year), with and without lung tumors, and heavy smokers (20+ pack/year) without disease. Promoter methylation of NISCH was tested by quantitative fluorogenic real-time PCR in all samples. Promoter methylation of NISCH occurred after exposure to mainstream tobacco smoke as well as to side stream tobacco smoke in normal oral keratinocyte cell lines. NISCH methylation was also detected in 68% of high-risk, heavy smokers without detectable tumors. Interestingly, in light smokers, NISCH methylation was present in 69% of patients with lung cancer and absent in those without disease. Our pilot study indicates that tobacco smoke induces methylation changes in the NISCH gene promoter before any detectable cancer. Methylation of the NISCH gene was also found in lung cancer patients' plasma samples. After confirming these findings in longitudinally collected plasma samples from high-risk populations (such as heavy smokers), examining patients for hypermethylation of the NISCH gene may aid in identifying those who should undergo additional screening for lung cancer.

Afatinib: emerging next-generation tyrosine kinase inhibitor for NSCLC

The discovery of epidermal growth-factor receptor (EGFR)-activating mutations and the introduction of oral EGFR tyrosine kinase inhibitors (EGFR-TKIs) have expanded the treatment options for patients with non-small cell lung cancer. The first two reversible EGFR-TKIs, erlotinib and gefitinib, are approved for use in the first-line setting in patients with known EGFR-activating mutations and in the second- and third-line settings for all NSCLC patients. These first-generation EGFR-TKIs improve progression-free survival when compared to chemotherapy in patients with EGFR-activating mutations in the first-line setting. However, nearly all patients develop resistance to EGFR-directed agents. There is a need for further therapy options for patients with disease progression after treatment with reversible EGFR-TKIs. Afatinib is an irreversible ErbB family blocker that inhibits EGFR, HER2, and HER4. In vitro and in vivo, afatinib have shown increased inhibition of the common EGFR-activating mutations as well as the T790M resistance mutation when compared to erlotinib and gefitinib. Clinically, afatinib has been evaluated in the LUX-Lung series of trials, with improvement in progression-free survival reported in patients with EGFR-activating mutations in both first- and second-/third-line settings when compared to chemotherapy. Further investigation is needed to determine the precise role that afatinib will play in the treatment of patients with non-small cell lung cancer and EGFR-activating mutations.

Perception of the combined effects of smoking and alcohol on cancer risks in never smokers and heavy smokers

The issue addressed in the study is: How do people perceive the combined effect of alcohol consumption and tobacco consumption on risks of cancer? The method used was an application of Information Integration Theory. Sixty-four participants of both sexes were asked to estimate the risk of cancer associated with a number of situations described by a tobacco-consumption level associated with an alcohol-consumption level. Participants were subsequently presented with a questionnaire concerning the way alcohol and tobacco consumption can cause cancer. Results showed that French adults apparently considered that indulging in only one of these two behaviours represents a maximum health risk. The two effects were seen to combine disjunctively which runs counter to current medical data. However, there was total contradiction between the participants' answers to the questionnaire concerning their knowledge and the information integration task.

Evaluation of Bronchiolar and Alveolar Cell Injuries Induced by Short- and Long-term Exposure to Sidestream Smoke

Background

We investigated effects of short- and long-term exposure to sidestream smoke on the bronchiolar and alveolar cells in Sprague-Dawley rats.

Methods

Rats were divided into five experimental groups: groups 1, 2, and 3 (1-month exposure to 3, 5, and 7 cigarettes a day, respectively), groups 4 and 5 (3- and 6 month exposure to five cigarettes a day, respectively). We examined the morphologic changes, the expressions of tumor necrosis factor α (TNF-α), tumor growth factor β1 (TGF-β1), interlekin (IL)-1α, IL-1β, Ki-67, and cytokeratin 14 and in situ apoptosis in the bronchiolar and alveolar cells on light microscopy (LM) and electron microscopic (EM) terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining.

Results

LM showed the respiratory bronchiolar dilatation and alveolar wall collapse. In groups 3, 4, and 5, EM showed loss of the cilia and Clara cells with irregular size, more prominent alveolar wall collapse and dilation of alveolar duct than those of groups 1 and 2. Bronchiolar and alveolar cells showed increased expressions of TNF-α and TGF-β in groups 4 and 5. LM and EM TUNEL stains showed increased apoptosis in groups 3, 4, and 5.

Conclusions

Sidestream smoke causes a bronchiolar and alveolar cell injury and the severity correlates strongly the volume and duration of exposure to sidestream smoke.

Lung cancer: epidemiology, etiology, and prevention

Lung cancer is the leading cause of cancer death in the United States and around the world. A vast majority of lung cancer deaths are attributable to cigarette smoking, and curbing the rates of cigarette smoking is imperative. Understanding the epidemiology and causal factors of lung cancer can provide additional foundation for disease prevention. This article focuses on modifiable risk factors, including tobacco smoking, occupational carcinogens, diet, and ionizing radiation. It also discusses briefly the molecular and genetic aspects of lung carcinogenesis.

Lung cancer: epidemiology, etiology, and prevention

Lung cancer is the leading cause of cancer death in the United States and around the world. A vast majority of lung cancer deaths are attributable to cigarette smoking, and curbing the rates of cigarette smoking is imperative. Understanding the epidemiology and causal factors of lung cancer can provide additional foundation for disease prevention. This article focuses on modifiable risk factors, including tobacco smoking, occupational carcinogens, diet, and ionizing radiation. It also discusses briefly the molecular and genetic aspects of lung carcinogenesis.

[Survey on passive smoking in children in Agadir]

INTRODUCTION

The aim of the study was to assess children's exposure to tobacco smoke at home, at school and in public places, to study its risks and to educate parents about the dangers of passive smoking.

METHODS

This is a survey conducted in October 2007 among children enrolled in pre-school and primary school in the city of Agadir, Morocco. The data was gathered by a written questionnaire completed by parents at home.

RESULTS

The survey covered 776 children. The response rate to the questionnaires was 88%. The father was a smoker in 28.9% of cases, against 0.7% for the mother. The prevalence of childhood exposure to tobacco was 34.1% at home, 36.4% in public places and 30.1% in schools. Concerning pregnant women, passive smoking and/or active was associated with a significantly increased risk of respiratory distress in newborn babies and hospitalisations in the neonatology department. In infant and child, involuntary inhalation of tobacco smoke involved an increased risk of sudden infant death syndrome and recurrent respiratory symptoms. However, its noxious effects were not found in the case of child asthma and tumour.

CONCLUSION

Passive smoking is a real public health problem and smoking is a dangerous but also a preventable source of pollution.

Exposure to mosquito coil smoke may be a risk factor for lung cancer in Taiwan

Background

About 50% of lung cancer deaths in Taiwan are not related to cigarette smoking. Environmental exposure may play a role in lung cancer risk. Taiwanese households frequently burn mosquito coil at home to repel mosquitoes. The aim of this hospital-based case-control study was to determine whether exposure to mosquito coil smoke is a risk for lung cancer.

Methods

Questionnaires were administered to 147 primary lung cancer patients and 400 potential controls to ascertain demographic data, occupation, lifestyle data, indoor environmental exposures (including habits of cigarette smoking, cooking methods, incense burning at home, and exposure to mosquito coil smoke ), as well as family history of cancer and detailed medical history.

Results

Mosquito coil smoke exposure was more frequent in lung cancer patients than controls (38.1% vs.17.8%; p<0.01). Risk of lung cancer was significantly higher in frequent burners of mosquito coils (more than 3 times [days] per week) than nonburners (adjusted odds ratio = 3.78; 95% confidence interval: 1.55-6.90). Those who seldom burned mosquito coils (less than 3 times per week) also had a significantly higher risk of lung cancer (adjusted odds ratio = 2.67; 95% confidence interval: 1.60-4.50).

Conclusion

Exposure to mosquito coil smoke may be a risk factor for development of lung cancer.

Women and lung cancer

OBJECTIVES

There is expanding evidence that lung cancer has a multitude of sex differences. This article will review these differences and discuss nursing implications for women with lung cancer.

DATA SOURCES

Research and journal articles.

CONCLUSION

Understanding the sex differences of lung cancer is essential for individualizing care for women with lung cancer.

IMPLICATIONS FOR NURSING PRACTICE

Nurses play an integral role throughout the trajectory of illness for women with lung cancer. Understanding the sex differences will help nurses to individualize the care for this population to meet their specific needs.

Effect of passive smoking on lung function and respiratory infection

OBJECTIVE

To study the effect of environmental tobacco smoke to children's health and more specifically to the development of respiratory tract infections and also its influence to their respiratory function.

METHODS

We studied 586 children from the district of west Thrace in Greece aged 5-14 years, randomly selected from 20 primary and 10 secondary schools in regards their exposure to tobacco smoke, and its possible relation with respiratory tract infections. We assessed respiratory function by spirometry. Epidemiological data were also analysed.

RESULTS

Children who were exposed to environmental tobacco smoke had higher risk for upper and lower respiratory tract infections in comparison to children who lived in a smoke free environment (3 fold and 2 fold, respectively. Their lung function was also reduced with decreased values of FEV1, FEF50, PFR (values p<0.001).

CONCLUSION

Passive smoking has an unfavorable effect in respiratory function of children and predisposes them to respiratory tract infections. Every effort should be undertaken in order to avoid exposure of children to environmental tobacco smoke.

Second hand smoke, age of exposure and lung cancer risk

BACKGROUND

Exposure to second hand smoke (SHS) has been identified as a risk factor for lung cancer for three decades. It is also known that the lung continues to grow from birth to adulthood, when lung growth stops. We hypothesize that after adjusting for active cigarette smoking, if SHS exposure took place during the period of growth, i.e. in the earlier part of life (0-25 years of age) the risk of lung cancer is greater compared to an exposure occurring after age 25.

METHOD

Second hand smoke exposure was self-reported for three different activities (leisure, work and at home) for this study population of 1669 cases and 1263 controls. We created variables that captured location of exposure and timing of first exposure with respect to a study participant's age (0-25, >25 years of age). Multiple logistic regressions were used to study the association between SHS exposure and lung cancer, adjusting for age, gender and active smoking variables.

RESULT

For study participants that were exposed to SHS at both activities (work and leisure) and compared to one or no activity, the adjusted odds ratio (AOR) for lung cancer was 1.30 (1.08-1.57) when exposure occurred between birth and age 25 and 0.66 (0.21-1.57) if exposure occurred after age 25 years. Respective results for non-smokers were 1.29 (0.82-2.02) and 0.87 (0.22-3.38), and current and ex-smokers combined 1.28 (1.04-1.58) and 0.66 (0.15-2.85).

CONCLUSION

All individuals exposed to SHS have a higher risk of lung cancer. Furthermore, this study suggests that subjects first exposed before age 25 have a higher lung cancer risk compared to those for whom first exposure occurred after age 25 years.

[The effects of tobacco on children]

INTRODUCTION

Smoking remains an important topic. It is estimated that at present half the children born in France have been, or will be, exposed to the toxic effects of passive smoking. This paper aims to review the evidence of the effects of passive smoking, both intra and extra-uterine.

STATE OF THE ART

Extra-uterine passive smoking is implicated in numerous respiratory (asthma, allergy, infections...) and non respiratory diseases (neoplastic, dental, ophthalmic, digestive, cardio-vascular and infective). Intra-uterine exposure is even more dangerous and leads to abnormalities of the pregnancy (placental abnormalities, prematurity...), of the foetus (behavioural problems, malformations) and long term problems for the unborn child. Passive smoking is responsible for pulmonary morphological abnormalities (pulmonary hypoplasia, reduction in elasticity, increased deposition of collagen and alteration of alveolar structure) and functional disorders (reduced compliance, increased airways resistance, bronchial hyperreactivity). Finally it causes a disturbance of respiratory control, promoting all the factors responsible for sudden cot death.

CONCLUSIONS

The ill effects of passive smoking fully justify efforts to inform and persuade the medical profession of its duty to fight this scourge.

Relationship between polycyclic aromatic hydrocarbon-DNA adducts, environmental tobacco smoke, and child development in the World Trade Center cohort

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs), including benzo[a]pyrene (BaP), are air pollutants released by the World Trade Center (WTC) fires and urban combustion sources. BaP-DNA adducts provide a measure of PAH-specific genetic damage, which has been associated with increased risk of adverse birth outcomes and cancer. We previously reported that levels of BaP-DNA adducts in maternal and umbilical cord blood obtained at delivery were elevated among subjects who had resided within 1 mile of the WTC site during the month after 9/11; and that elevated blood adducts in combination with in utero exposure to environmental tobacco smoke (ETS) were significantly associated with decreased fetal growth.

OBJECTIVE

Our aim was to assess possible effects of prenatal exposure to WTC pollutants on child development.

METHODS

After 11 September 2001, we enrolled a cohort of nonsmoking pregnant women who delivered at three lower Manhattan hospitals. We have followed a subset of children through their third birthdays and measured cognitive and motor development using the Bayley-II Scales of Child Development (BSID-II).

RESULTS

In multivariate analyses, we found a significant interaction between cord blood adducts and in utero exposure to ETS on mental development index score at 3 years of age (p = 0.02, n = 98) whereas neither adducts nor ETS alone was a significant predictor of (BSID-II) cognitive development.

CONCLUSION

Although limited by small numbers, these results suggest that exposure to elevated levels of PAHs in conjunction with prenatal ETS exposure may have contributed to a modest reduction in cognitive development among cohort children.

Lung cancer risk and workplace exposure to environmental tobacco smoke

OBJECTIVES

We sought to quantitatively evaluate the association between work-place environmental tobacco smoke exposure and lung cancer.

METHODS

We performed a meta-analysis in 2003 of data from 22 studies from multiple locations worldwide of workplace environmental tobacco smoke exposure and lung cancer risk. Estimates of relative risk from these studies were analyzed by fitting the data to fixed and mixed effects models. Analyses of highly exposed workers and of the relationship between duration of exposure and lung cancer were also performed.

RESULTS

The meta-analysis indicated a 24% increase in lung cancer risk (relative risk [RR]=1.24; 95% confidence interval [CI]=1.18, 1.29) among workers exposed to environmental tobacco smoke. A 2-fold increased risk (RR=2.01; 95% CI=1.33, 2.60) was observed for workers classified as being highly exposed to environmental tobacco smoke. A strong relationship was observed between lung cancer and duration of exposure to environmental tobacco smoke.

CONCLUSIONS

The findings from this investigation provide the strongest evidence to date that exposure to environmental tobacco smoke in the workplace is associated with an increased risk of lung cancer.

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.

Smoking and hormesis as confounding factors in radiation pulmonary carcinogenesis

Confounding factors in radiation pulmonary carcinogenesis are passive and active cigarette smoke exposures and radiation hormesis. Significantly increased lung cancer risk from ionizing radiation at lung doses < 1 Gy is not observed in never smokers exposed to ionizing radiations. Residential radon is not a cause of lung cancer in never smokers and may protect against lung cancer in smokers. The risk of lung cancer found in many epidemiological studies was less than the expected risk (hormetic effect) for nuclear weapons and power plant workers, shipyard workers, fluoroscopy patients, and inhabitants of high-dose background radiation. The protective effect was noted for low- and mixed high- and low-linear energy transfer (LET) radiations in both genders. Many studies showed a protection factor (PROFAC) > 0.40 (40% avoided) against the occurrence of lung cancer. The ubiquitous nature of the radiation hormesis response in cellular, animal, and epidemio-logical studies negates the healthy worker effect as an explanation for radiation hormesis. Low-dose radiation may stimulate DNA repair/apoptosis and immunity to suppress and eliminate cigarette-smoke-induced transformed cells in the lung, reducing lung cancer occurrence in smokers.

The economic impact of early life environmental tobacco smoke exposure: early intervention for developmental delay

BACKGROUND AND OBJECTIVES

Early-life exposure to environmental tobacco smoke (ETS) can result in developmental delay as well as childhood asthma and increased risk of cancer. The high cost of childhood asthma related to ETS exposure has been widely recognized; however, the economic impact of ETS-related developmental delay has been less well understood.

METHODS AND RESULTS

The Columbia Center for Children's Environmental Health (CCCEH) has reported adverse effects of prenatal ETS exposure on child development in a cohort of minority women and children in New York City (odds ratio of developmental delay = 2.36; 95% confidence interval 1.22-4.58). Using the environmentally attributable fraction (EAF) approach, we estimated the annual cost of one aspect of ETS-related developmental delay: Early Intervention Services. The estimated cost of these services per year due to ETS exposure is > Dollars 50 million per year for New York City Medicaid births and Dollars 99 million per year for all New York City births.

CONCLUSION

The high annual cost of just one aspect of developmental delay due to prenatal exposure to ETS provides further impetus for increased prevention efforts such as educational programs to promote smoke-free homes, additional cigarette taxes, and subsidizing of smoking cessation programs.

Risk factors for lung cancer in Iowa women: implications for prevention

BACKGROUND

Multiple risk factors possibly associated with lung cancer were examined as part of a large-scale residential radon case-control study conducted in Iowa between 1994 and 1997. We were particularly interested in stratifying risk factors by smoking status. Relatively little risk factor information is available for Midwestern rural women.

METHODS

Four hundred thirteen female lung cancer cases and 614 controls aged 40-84, who were residents of their current home for at least 20 years, were included. Risk factors examined included cigarette smoking, passive smoking, occupation, chemical exposure, previous lung disease, family history of cancer, and urban residence. Multiple logistic regression analysis was conducted after adjusting for age, education, and cumulative radon exposure.

RESULTS

As expected, active cigarette smoking was the major risk factor for lung cancer. While cessation of smoking was significantly associated with a reduced risk for lung cancer, the risk remained significantly elevated for 25 years. Among all cases, asbestos exposure was a significant risk. Among ex-smokers, pack-year history predominated as the major risk. Among never smokers, a family history of kidney or bladder cancer were significant risk factors (OR=7.34, 95% CI=1.91-28.18; and OR=5.02, 95% CI=1.64-15.39, respectively), as was a history of previous lung disease (OR=2.28, 95% CI=1.24-4.18) and asbestos exposure. No statistically significant increase in lung cancer risk was found for occupation or urban residence.

CONCLUSIONS

Smoking prevention activities are urgently needed in rural areas of the United States. Relatives of individuals with smoking-related cancers are potentially at increased risk. Genetic risk factors should be more fully investigated in never smokers.

A summary of recent findings on birth outcomes and developmental effects of prenatal ETS, PAH, and pesticide exposures

Inner-city minority populations are high-risk groups for adverse birth outcomes and also more likely to be exposed to environmental contaminants, including environmental tobacco smoke (ETS), benzo[a]pyrene B[a]P, other ambient polycyclic aromatic hydrocarbons (global PAHs), and residential pesticides. The Columbia Center for Children's Environmental Health (CCCEH) is conducting a prospective cohort study of 700 northern Manhattan pregnant women and newborns to examine the effects of prenatal exposure to these common toxicants on fetal growth, early neurodevelopment, and respiratory health. This paper summarizes results of three published studies demonstrating the effects of prenatal ETS, PAH, and pesticides on birth outcomes and/or neurocognitive development [Perera FP, Rauh V, Whyatt RM, Tsai WY, Bernert JT, Tu YH, et al. Molecular evidence of an interaction between prenatal environment exposures on birth outcomes in a multiethnic population. Environ Health Perspect 2004;12:630-62; Rauh VA, Whyatt RM, Garfinkel R, Andrews H, Hoepner L, Reyes A, et al. Developmental effects of exposure to environmental tobacco smoke and material hardship among inner-city children. Neurotoxicol Teratol 2004;26:373-85; Whyatt RM, Rauh V, Barr DB, Camann DE, Andrews HF, Garfinkel R, et al. Prenatal insecticide exposures, birth weight and length among an urban minority cohort. Environ Health Perspect, in press]. To evaluate the effects of prenatal exposure to ETS, PAHs, and pesticides, researchers analyzed questionnaire data, cord blood plasma (including biomarkers of ETS and pesticide exposure), and B[a]P-DNA adducts (a molecular dosimeter of PAHs). Self-reported ETS was associated with decreased head circumference (P = 0.04), and there was a significant interaction between ETS and adducts such that combined exposure had a significant multiplicative effect on birth weight (P = 0.04) and head circumference (P = 0.01) after adjusting for confounders. A second analysis examined the neurotoxic effects of prenatal ETS exposure and postpartum material hardship (unmet basic needs in the areas of food, housing, and clothing) on 2-year cognitive development. Both exposures depressed cognitive development (P < 0.05), and there was a significant interaction such that children with exposure to both ETS and material hardship exhibited the greatest cognitive deficit (7.1 points). A third analysis found that cord chlorpyrifos, and a combined measure of cord chlorpyrifos, diazinon, and propoxur-metabolite, were inversely associated with birth weight and/or length (P < 0.05). These results underscore the importance of policies that reduce exposure to ETS, air pollution, and pesticides with potentially adverse effects on fetal growth and child neurodevelopment.

Relationships among polycyclic aromatic hydrocarbon-DNA adducts, proximity to the World Trade Center, and effects on fetal growth

Polycyclic aromatic hydrocarbons (PAHs) are toxic pollutants released by the World Trade Center (WTC) fires and various urban combustion sources. Benzo[a]pyrene (BaP) is a representative member of the class of PAHs. PAH-DNA adducts, or BaP-DNA adducts as their proxy, provide a measure of chemical-specific genetic damage that has been associated with increased risk of adverse birth outcomes and cancer. To learn whether PAHs from the WTC disaster increased levels of genetic damage in pregnant women and their newborns, we analyzed BaP-DNA adducts in maternal (n = 170) and umbilical cord blood (n = 203) obtained at delivery from nonsmoking women who were pregnant on 11 September 2001 and were enrolled at delivery at three downtown Manhattan hospitals. The mean adduct levels in cord and maternal blood were highest among newborns and mothers who resided within 1 mi of the WTC site during the month after 11 September, intermediate among those who worked but did not live within this area, and lowest in those who neither worked nor lived within 1 mi (reference group). Among newborns of mothers living within 1 mi of the WTC site during this period, levels of cord blood adducts were inversely correlated with linear distance from the WTC site (p = 0.02). To learn whether PAHs from the WTC disaster may have affected birth outcomes, we analyzed the relationship between these outcomes and DNA adducts in umbilical cord blood, excluding preterm births to reduce variability. There were no independent fetal growth effects of either PAH-DNA adducts or environmental tobacco smoke (ETS), but adducts in combination with in utero exposure to ETS were associated with decreased fetal growth. Specifically, a doubling of adducts among ETS-exposed subjects corresponded to an estimated average 276-g (8%) reduction in birth weight (p = 0.03) and a 1.3-cm (3%) reduction in head circumference (p = 0.04). The findings suggest that exposure to elevated levels of PAHs, indicated by PAH-DNA adducts in cord blood, may have contributed to reduced fetal growth in women exposed to the WTC event.

Circulating tumour-derived DNA and RNA markers in blood: a tool for early detection, diagnostics, and follow-up?

BACKGROUND

Lung cancer is the most common cause of cancer death in developed countries. The prognosis is poor with only 10-15% of patients surviving 5 years after diagnosis. This dismal prognosis is attributed to the lack of efficient diagnostic methods for early detection and lack of successful treatment for metastatic disease. Within the last decade, rapid advances in molecular biology and radiology have provided a rational basis for improving early detection and patients' outcome. A non-invasive blood test effective in detecting preneoplastic changes or early lung cancer in high risk individuals has been perceived as a holy grail by cancer researchers.

METHODS

The introduction of polymerase chain reaction (PCR)-based technology in the late 1980s and its refinement over the last 10 years have allowed us to detect and quantify extremely small amounts of tumour-derived nucleic acids. This has led to an increased knowledge of the molecular pathogenesis of lung cancer and a basis for the use of DNA and RNA markers in blood for early cancer detection, diagnostics, and follow-up. Common genetic alterations in lung carcinogenesis are already well known. We reviewed published literature on DNA and RNA in plasma or serum in lung cancer patients up to 2004, with particular emphasis on reports published since 1995.

RESULTS

Twenty-two clinical studies have evaluating the role of DNA and RNA aberrations in the blood of lung cancer patients. A total of 1618 (range 10-163/study) cases and 595 (range 10-120/study) control cases were evaluated, and overall plasma/serum abnormalities were found in 43% (range 0-78%) of cases and 0.8% of healthy controls. For (1) total DNA and gene expression levels, 61% (range 53-71%) of cases and 0.9% of controls; (2) oncogene mutations, 16% (range 0-30%) and 0%; (3) microsatellite alterations, 46% (range 24-71%) and 21% (controls with non-malignant pulmonary disease); (4) promoter methylation, 42% (range 5-73%) and 0%; (5) tumour-related RNAs, 54% (range 39-78%) and 6%. In general, the studies contain small series of lung cancer patients and even smaller or missing case control groups.

CONCLUSION

The analysis of circulating DNA or RNA in plasma is a promising non-invasive diagnostic tool, requiring only a limited blood sample. Its wide applicability and potential importance will possibly lead to increasing clinical impact in the near future. However, large prospective clinical studies are needed to validate and standardise any tests for DNA or RNA alteration in plasma or serum of high risk individuals or patients with established lung cancer.

Clear the air: adolescents' perceptions of the risks associated with secondhand smoke

BACKGROUND

Despite numerous studies on adolescents' recognition of the medical risks of primary smoke, there have been surprisingly few investigations of how adolescents perceive the risks associated with exposure to secondhand smoke. This study examined whether adolescents' risk estimates when exposed to secondhand smoke differed by: (1) actual smoking experience and (2) adolescents' intentions to smoke in the near future. We also explored whether adolescents perceive different risk depending on who is producing the secondhand smoke.

METHODS

Three hundred and ninety-five 9th graders (mean age = 14.0) completed a survey concerning their perceptions of secondhand smoke, smoking experiences, and intentions.

RESULTS

On average, adolescents were aware of the serious risks posed by exposure to secondhand smoke. However, adolescents who smoke or intend to smoke were more likely to perceive the risks from exposure to secondhand smoke as lower than did adolescents who had never smoked or had no intentions to smoke.

CONCLUSIONS

The findings from this study suggest that education regarding the risks of secondhand smoke might serve as an additional deterrent against smoking and smoking intentions. Further study using longitudinal data is still needed to fully understand the relationship between such perceptions and smoking behavior.

Biomarkers in non-small cell lung cancer prevention

Identification of biomarkers is one of the most promising approaches for the detection of early malignant or even premalignant lesions with the chance of diagnosing early stages of non-small cell lung cancer that could be treated curatively. Alterations of chromosomes (3p, 5q, 9p), genes (Rb, C-myc, C-mos, hTERT), proteins (p16, p53, K-ras, hnRNP A2/B1, MCM2, EGFR, erbB-2, erbB-3, erbB-4) and others can be found in lung cancer. Some of these occur at early stages of the disease and few could serve as potential screening markers. The actual literature is reviewed and the relevance of the different biomarkers for early lung cancer detection is discussed.

Investigating cigarette-smoke indoor pollution in a controlled environment

The objective of this study was to investigate the evolution of pollutant concentrations generated by smoking in a controlled indoor environment. For this purpose, a small flat in the centre of Athens, Greece was equipped with NO(x), O(3) and SO(2) continuous measuring instruments and portable analysers for spot measurements of TVOCs and CO(2), while two volunteer smokers remained inside and smoked as normal inhabitants. The results indicated that when windows are kept closed and smoking takes place NO(x), CO(2) and TVOCs concentrations increase by an order of 3, 4 or 10 times, respectively, and decrease returning to initial levels after 1 or 2 h.

Medical comorbidity in addictive disorders

Greater risks exist for medical comorbidities in persons with addictive disorders. Clinicians should screen for early comorbidities such as hepatitis C and HIV. During acute intoxications and overdoses, patients are at greater risk for major respiratory and cardiac events. Long-term management of persons with addictions and medical disorders requires integrative care programs involving comprehensive primary and psychiatric care.