Effect of cigarette smoking on major histological types of lung cancer: a meta-analysis

Whole Transcriptome Analysis of Pre-invasive and Invasive Early Squamous Lung Carcinoma in Archival Laser Microdissected Samples

Background

Preinvasive squamous cell cancer (PSCC) are local transformations of bronchial epithelia that are frequently observed in current or former smokers. Their different grades and sizes suggest a continuum of dysplastic change with increasing severity, which may culminate in invasive squamous cell carcinoma (ISCC). As a consequence of the difficulty in isolating cancerous cells from biopsies, the molecular pathology that underlies their histological variability remains largely unknown.

Method

To address this issue, we have employed microdissection to isolate normal bronchial epithelia and cancerous cells from low- and high-grade PSCC and ISCC, from paraffin embedded (FFPE) biopsies and determined gene expression using Affymetric Human Exon 1.0 ST arrays. Tests for differential gene expression were performed using the Bioconductor package limma followed by functional analyses of differentially expressed genes in IPA.

Results

Examination of differential gene expression showed small differences between low- and high-grade PSCC but substantial changes between PSCC and ISCC samples (184 vs 1200 p-value <0.05, fc ±1.75). However, the majority of the differentially expressed PSCC genes (142 genes: 77%) were shared with those in ISCC samples. Pathway analysis showed that these shared genes are associated with DNA damage response, DNA/RNA metabolism and inflammation as major biological themes. Cluster analysis identified 12 distinct patterns of gene expression including progressive up or down-regulation across PSCC and ISCC. Pathway analysis of incrementally up-regulated genes revealed again significant enrichment of terms related to DNA damage response, DNA/RNA metabolism, inflammation, survival and proliferation. Altered expression of selected genes was confirmed using RT-PCR, as well as immunohistochemistry in an independent set of 45 ISCCs.

Conclusions

Gene expression profiles in PSCC and ISCC differ greatly in terms of numbers of genes with altered transcriptional activity. However, altered gene expression in PSCC affects canonical pathways and cellular and biological processes, such as inflammation and DNA damage response, which are highly consistent with hallmarks of cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-016-0496-3) contains supplementary material, which is available to authorized users.

Factors associated with influenza vaccination coverage among the elderly in South Korea: the Fourth Korean National Health and Nutrition Examination Survey (KNHANES IV)

OBJECTIVE

The annual outbreak of influenza is one of the major causes of morbidity and mortality among the elderly population around the world. While there is an annual vaccine available to prevent or reduce the incidence of disease, not all older people in Korea choose to be vaccinated. There have been few previous studies to examine the factors influencing influenza vaccination in Korea. Thus, this study identifies nationwide factors that affect influenza vaccination rates in elderly Koreans.

METHODS

We obtained data from the Fourth Korean National Health and Nutrition Examination Survey 2007-2009 (KNHANES IV), a nationwide health survey in Korea. To assess influenza vaccination status, we analysed answers to a single question from the survey. From the respondents, we selected 3567 elderly population aged 65 years or older, to analyse the effects of variables including sociodemographic, health behavioural risk, health status and psychological factors on vaccination coverage. We identified factors that affect vaccination status using a multiple logistic regression analysis.

RESULTS

The rate of influenza vaccination in this elderly population was 75.8%. Overall, the most significant determinants for choosing influenza vaccination were a recent history of health screening (adjusted OR (aOR) 2.26, 95% CI 1.92 to 2.66) and smoking (aOR 0.78, 95% CI 0.62 to 0.98). Other contributing factors were age, household income, marital status, alcohol consumption, physical activity level, self-reported health status and a limitation in daily activities. In contrast, psychological factors, including self-perceived quality of life, stress and depressive mood, did not show close association with vaccination coverage.

CONCLUSIONS

To boost influenza vaccination rates in the elderly, an influenza campaign should focus on under-represented groups, especially smokers. Additionally, promoting routine health screening for the elderly may be an efficient way to help achieve higher vaccination rates. Our results highlight the need for a new strategy for the vaccination campaign.

The effects for PM2.5 exposure on non-small-cell lung cancer induced motility and proliferation

Background

Increasing urbanization and associated air pollution, including elevated levels of particulate matter (PM), are strongly correlated with the development of various respiratory diseases. In particular, PM2.5 has been implicated in promoting lung cancer initiation, growth and progression. Cell migration and proliferation are crucial for the progression of cancer. However, the molecular signatures and biological networks representing the distinct and shared features of non-small cell lung cancer (NSCLC) after PM2.5 exposure are unknown.

Results

Functional assays demonstrated higher proliferation, migration and invasion of cancer cells stimulated with PM2.5. To investigate the complicated mechanisms, we performed global transcriptome profiling of the A549 cell line. Particularly, transcriptome sequencing revealed invasive characteristics reminiscent of cancer cells. By comparing the transcriptomes, we identified distinct molecular signatures and cellular processes defining the invasive and proliferative properties of PM2.5-exposed cells, respectively. Interestingly, under the PM2.5-stimulated condition, the A549 and H1299 cells strengthened obviously properties in motility and proliferation. Based on the network model reconstructing the shared protein–protein interactions, we selected the two most up-regulated genes, interleukin-1β (IL1β) and matrix metalloprotease 1 (MMP1), as key regulators responsible for the effects of PM2.5 exposure. Notably, IL1β and MMP1 expression was elevated in independent assays, which was further enhanced by PM2.5.

Conclusion

Taken together, our systems approach to investigating PM2.5 exposure provides a basis to identify key regulators responsible for the pathological features of NSCLC.

Association between UGT1A1*28*28 genotype and lung cancer in the Japanese population

BACKGROUND

Lung cancer is the leading cause of cancer death and is closely linked to tobacco smoking. Genetic polymorphisms in genes that encode enzymes involved in metabolizing tobacco carcinogens could affect an individual's risk for lung cancer. While polymorphism of UDP-glucuronosyltransferase1A1 (UGT1A1) is involved in detoxification of benzo(a)pyrene-7,8-dihydrodiol(-), a major tobacco carcinogen, the association between UGT1A1 genotype and lung cancer has not been examined.

METHODS

We retrieved the clinical data of 5,285 patients who underwent systemic chemotherapy at Kyoto University Hospital. A total of 765 patients (194 lung cancer patients and 671 patients with other malignancies) with UGT1A1 genotyping data were included in this analysis. We used logistic regression with recessive, dominant, and additive models to identify differences in genotype frequencies between lung cancer and other malignancies.

RESULTS

In the recessive model, UGT1A1*28*28 genotype was significantly associated with lung cancer compared to other malignancies (odds ratio 5.3, P = 0.0083). Among lung cancer patients with a smoking history, squamous cell carcinoma was significantly predominant in patients with UGT1A1*28*28 compared to those with other UGT1A1 genotypes (P = 0.024).

CONCLUSION

This is the first study to demonstrate a significant association between the homozygous UGT1A1*28 genotype and lung cancer.

IL-10 -1082A/G, -592C/A, and -819T/C polymorphisms in association with lung cancer susceptibility: a meta-analysis

Numerous studies have examined the association between interleukin-10 (IL-10 -1082A/G, -592C/A, and -819T/C) gene polymorphisms and risk of lung cancer, but these have revealed inconsistent results. The aim of this study was to clarify the relationship between these polymorphisms and the risk of lung cancer by performing a meta-analysis. The published literature concerning IL-10 polymorphisms and lung cancer risk were retrieved by systematically searching PubMed, Embase, Web of Science, China National Knowledge Infrastructure, WanFang, and Database of Chinese Scientific and Technical Periodicals (VIP) database. Statistical analysis was conducted with Stata 12.0 software. A total of ten published articles comprising of 19 studies were selected, including seven studies (1,960 controls and 1,321 cases) for IL-10 -1082A/G, seven studies (2,613 controls and 1,839 cases) for IL-10 -592C/A, and five studies (1,558 controls and 926 cases) for IL-10 -819T/C. This study found that the IL-10 -1082A/G and -592C/A polymorphisms were significantly associated with the risk of lung cancer in the overall analysis. When stratified by ethnicity, significantly increased risks were observed for IL-10 -1082A/G, -592C/A, and -819T/C polymorphisms in Asians (for -1082A/G, AA vs [AG + GG]: odds ratio [OR] =1.20, confidence interval [CI] =1.05–1.39, P<0.05; for C-592A, C vs A, OR =1.36, CI =1.20–1.53, P<0.05; CC vs AA, OR =1.85, CI =1.45–2.37, P<0.05; CC vs [CA + AA], OR =1.36, CI =1.15–1.61, P<0.05; for -819T/C, T vs C: OR =1.21, CI =1.06–1.38, P<0.05; TT vs CC, OR =1.54, CI =1.18–2.01, P<0.05; [TT + TC] vs CC, OR =1.51, CI =1.17–1.95, P<0.05). Moreover, the data indicated that there was a significant association between IL-10 -819T/C polymorphism and non-small-cell lung cancer risk. No significant publication bias was detected under the four genetic models (allele model, homozygous model, dominant model, and recessive model) in this meta-analysis. On the basis of these 19 studies, this study found that the IL-10 -1082A/G and -819T/C polymorphisms might have a significant association with risk of lung cancer in Asian populations.

Clinico-Pathological Profile and Haematological Abnormalities Associated with Lung Cancer in Bangalore, India

BACKGROUND

Lung cancer is one of the most common types of cancer causing high morbidity and mortality worldwide. An increasing incidence of lung cancer has been observed in India.

OBJECTIVES

To evaluate the clinic- pathological profile and haematological abnormalities associated with lung cancer in Bangalore, India.

MATERIALS AND METHODS

This prospective study was carried out over a period of 2 years. A total of 96 newly diagnosed and histopathologically confirmed cases of lung cancer were included in the study.

RESULTS

Our lung cancer cases had a male to female ratio of 3:1. Distribution of age varied from 40 to 90 years, with a major contribution in the age group between 61 and 80 years (55.2%). Smoking was the commonest risk factor found in 69.7% of patients. The most frequent symptom was cough (86.4%) followed by loss of weight and appetite (65.6%) and dyspnea (64.5%). The most common radiological presentation was a mass lesion (55%). The most common histopathological type was squamous cell carcinoma (47.9%), followed by adenocarcinoma (28.1%) and small cell carcinoma (12.5%). Distant metastasis at presentation was seen in 53.1% patients. Among the haematological abnormalities, anaemia was seen in 61.4% of patients, leucocytosis in 36.4%, thrombocytosis in 14.5% and eosinophilia in 19.7% of patients. Haematological abnormalities were more commonly seen in non small cell lung cancer.

CONCLUSIONS

Squamous cell carcinoma was found to be the most common histopathological type and smoking still remains the major risk factor for lung cancer. Haematological abnormalities are frequently observed in lung cancer patients, anaemia being the commonest of all.

Zeitliche Entwicklungen im Substanzkonsum in der deutschen Allgemeinbevölkerung

Zusammenfassung. Ziel: Ziel der Studie ist die Analyse von Trends des (klinisch relevanten) Konsums von Tabak, Alkohol, Cannabis und anderen illegalen Drogen sowie der Einnahme von Medikamenten zwischen 1995 und 2015. Methodik: Datengrundlage bilden acht Erhebungswellen des Epidemiologischen Suchtsurveys (ESA) aus den Jahren 1995 bis 2015. Die Befragungen erfolgten schriftlich, telefonisch oder online. Eine einheitliche Darstellung zeitlicher Trends ist für den Altersbereich 18 bis 59 Jahre möglich. Ergebnisse: Der Tabakkonsum hat in den letzten 20 Jahren abgenommen. Trenddaten des Alkoholkonsums zeigen sinkende Konsumwerte für Männer und stabile Werte für Frauen. Die Prävalenz des Rauschtrinkens ist bei Frauen seit dem Jahr 2009 angestiegen. Der Cannabiskonsum hat zwischen 2012 und 2015 bei beiden Geschlechtern zugenommen. Der wöchentliche Gebrauch von Schmerzmitteln ist angestiegen, während bei Schlaf-/Beruhigungsmitteln ein Rückgang zu verzeichnen ist. Indikatoren eines klinisch relevanten Konsums zeigen für Cannabis keine Änderungen, für Tabak einen Rückgang und für Medikamente einen Anstieg. Hinweise auf klinisch relevanten Alkoholkonsum sind bei Männern konstant geblieben und bei Frauen angestiegen. Schlussfolgerungen: Die weite Verbreitung insbesondere der legalen Substanzen legt einen dringenden Handlungsbedarf für Prävention und Intervention nahe. Als besondere Zielgruppe wurden Frauen identifiziert, bei denen der klinisch relevante Konsum von Alkohol und Medikamenten zugenommen hat.

Lung Cancer in Combined Pulmonary Fibrosis and Emphysema: A Systematic Review and Meta-Analysis

Purpose

Patients with combined pulmonary fibrosis and emphysema (CPFE) have been suggested to have an increased risk of lung cancer. We conducted a systematic review of all published data and performed a meta-analysis to define the characteristics of lung cancer that develops in CPFE.

Method

We searched Pubmed, Embase, and Cochrane to find original articles about lung cancer and CPFE published prior to September 2015. All titles/abstracts were reviewed by two radiologists to identify articles that used predefined selection criteria. Summary estimates were generated using a random-effect model and odds ratios (ORs) to develop squamous cell carcinoma (SqCC) were calculated. Kaplan–Meier survival curves were obtained for the survival of patients with CPFE and non-CPFE.

Results

Nine original articles that assessed 620 patients were included in this review. In the pooled data, patients were older age (70.4 years), almost all were heavy smokers (53.5 pack years), and males were predominant (92.6%). SqCC was the most common type (42.3%), followed by adenocarcinoma (34.4%). Compared with lung cancer population with an otherwise normal lung, the OR to develop SqCC in CPFE was 9.06 (95% CI, 6.08–13.5). The ORs in CPFE compared with lung cancers that developed in lungs with fibrosis or emphysema were also higher. The median survival for CPFE patients with lung cancer (19.5 months) was significantly shorter than in non-CPFE (53.1 months).

Conclusions

Lung cancer in CPFE, most commonly SqCC, presents in elderly heavy smokers with a male predominance. The median survival for CPFE patients with lung cancer is 19.5 months.

Tuberculosis, smoking and risk for lung cancer incidence and mortality

Among the exposures associated with risk for lung cancer, a history of tuberculosis (TB) is one potentially important factor, given the high prevalence of TB worldwide. A prospective cohort study was conducted to evaluate the associations of preexisting pulmonary TB with lung cancer incidence and mortality. The cohort consisted of 1,607,710 Korean adults covered by the National Health Insurance System who had a biennial national medical examination during 1997-2000. During up to 16 years of follow-up, there were 12,819 incident cases of lung cancer and 9,562 lung cancer deaths. Using Cox proportional hazards models and controlling for age, cigarette smoking and other covariates, the presence of underlying TB was significantly associated with increased risk for lung cancer incidence (HR 1.37 in men with 95% CI 1.29-1.45; HR 1.49 in women with 95% CI 1.28-1.74) and mortality (HR 1.43 in men with 95% CI 1.34-1.52; HR 1.53 in women with 95% CI 1.28-1.83). We also observed a dose-response relationship between number of cigarettes smoked daily and lung cancer risk. There was no evidence for synergism between a history of TB and smoking. The elevation in risk is relatively modest, particularly in comparison to that from smoking, and a prior history of TB is not likely to be useful risk indicator for clinical purposes. In populations with high prevalence of TB, it can be considered for incorporation into models for lung cancer risk prediction.

Secondhand smoke exposure and risk of lung cancer in Japan: a systematic review and meta-analysis of epidemiologic studies

OBJECTIVE

Systematic evaluation of the association between secondhand smoke exposure and lung cancer in Japan has yet to be conducted. Here, we performed a systematic review and meta-analysis of the relationship between secondhand smoke and lung cancer in Japanese non-smokers.

METHODS

Relevant studies were collected from the MEDLINE and Ichushi Web databases using a combination of search terms and Medical Subject Headings. Eligible studies were identified, and relative risks or odds ratios were extracted to calculate pooled risk estimates. This procedure was performed independently by at least two authors. Stratified analyses were carried out according to study design, publication year, and whether or not potential confounding variables were accounted for. The presence of publication bias was assessed via funnel plots.

RESULTS

We identified four cohort studies and five case-control studies. Quantitative synthesis was conducted only for secondhand smoke exposure in the home during adulthood. Of the 12 populations included in meta-analysis, positive secondhand smoke exposure-lung cancer associations were observed in 11, whereas an inverse association was found in the remaining 1. The pooled relative risk of lung cancer associated with secondhand smoke exposure was 1.28 (95% confidence interval: 1.10-1.48). We found no evidence of publication bias, and a significant association remained even when potentially missing studies were included (pooled relative risk: 1.26; 95% confidence interval: 1.09-1.46). The results were stable across different subgroup analyses, including by study design, publication year, and when adjusting for confounding variables.

CONCLUSIONS

Secondhand smoke exposure in the home during adulthood results in a statistically significant increase in the risk of lung cancer.

Anthropometry and the Risk of Lung Cancer in EPIC

The associations of body mass index (BMI) and other anthropometric measurements with lung cancer were examined in 348,108 participants in the European Investigation Into Cancer and Nutrition (EPIC) between 1992 and 2010. The study population included 2,400 case patients with incident lung cancer, and the average length of follow-up was 11 years. Hazard ratios were calculated using Cox proportional hazard models in which we modeled smoking variables with cubic splines. Overall, there was a significant inverse association between BMI (weight (kg)/height (m)(2)) and the risk of lung cancer after adjustment for smoking and other confounders (for BMI of 30.0-34.9 versus 18.5-25.0, hazard ratio = 0.72, 95% confidence interval: 0.62, 0.84). The strength of the association declined with increasing follow-up time. Conversely, after adjustment for BMI, waist circumference and waist-to-height ratio were significantly positively associated with lung cancer risk (for the highest category of waist circumference vs. the lowest, hazard ratio = 1.25, 95% confidence interval: 1.05, 1.50). Given the decline of the inverse association between BMI and lung cancer over time, the association is likely at least partly due to weight loss resulting from preclinical lung cancer that was present at baseline. Residual confounding by smoking could also have influenced our findings.

Alcohol consumption and lung cancer risk in never smokers

OBJECTIVE

The main objective of this study is to analyse the role of alcohol consumption on lung cancer risk in people who have never smoked.

METHODS

We conducted a systematic review of the scientific literature following the PRISMA statement. We searched Medline, EMBASE and CINAHL using different combinations of MeSH terms and free text. We included cohort studies, pooled cohort studies and case-control studies comprising at least 25 anatomopathologically-confirmed diagnoses of lung cancer cases, a sample size larger than 100 individuals and more than five years of follow-up for cohort studies. We excluded studies that did not specifically report results for never smokers. We developed a quality score to assess the quality of the included papers and we ultimately included 14 investigations with a heterogeneous design and methodology.

RESULTS

Results for alcohol consumption and lung cancer risk in never smokers are inconclusive; however, several studies showed a dose-response pattern for total alcohol consumption and for spirits. Heterogeneous results were found for wine and beer.

CONCLUSION

No clear effect is observed for alcohol consumption. Due to the limited evidence, no conclusion can be drawn for beer or wine consumption. There is little research available on the effect of alcohol on lung cancer risk for people who have never smoked, and more studies are urgently needed on this topic.

Different dietary patterns and reduction of lung cancer risk: A large case-control study in the U.S

Reducing lung cancer risk by modifying diet is highly desirable. We investigated whether different U.S. dietary patterns were associated with lung cancer risk. Dietary patterns were derived using exploratory factor analysis for 2139 non-small cell lung cancer (NSCLC) cases and 2163 frequency-matched controls. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). Highest adherence (highest vs. lowest quintile) to the “Tex-Mex”, “fruits and vegetables”, and “American/Western” patterns was associated with a 55% reduced (OR = 0.45; 95% CI = 0.37–0.56; P < 0.001), 32% reduced (OR = 0.68; 95% CI = 0.55–0.85; P = 0.001), and 45% increased (OR = 1.45; 95% CI = 1.18–1.78; P < 0.001) risk of lung cancer, respectively. The effects were stronger for squamous cell carcinoma and ever smokers for the “fruits and vegetables” pattern, and stronger for other non-small cell lung cancer and never smokers for the “American/Western” pattern. Among six genome-wide association (GWA) studies-identified lung cancer susceptibility loci assessed, a variant (rs2808630) of the C-reactive protein gene modified the associations for the “fruits and vegetables” (P for interaction = 0.03) and “American/Western” (P for interaction = 0.02) patterns. Our study first showed that the “Tex-Mex” dietary pattern was associated with a reduced lung cancer risk. Also, the “fruits and vegetables” and “American/Western” patterns affected lung cancer risk, and the effects were further modified by host genetic background.

Associations of Insulin and IGFBP-3 with Lung Cancer Susceptibility in Current Smokers

BACKGROUND

The epidermal growth factor receptor (EGFR) signaling network is involved in lung carcinogenesis. This study examined whether ligands that activate or suppress the EGFR signaling network were associated with lung cancer risk in ever smokers.

METHODS

A nested case-control study within the Women's Health Initiative assessed baseline plasma levels of insulin, insulin-like growth factor (IGF)-1, insulin-like growth factor binding protein (IGFBP)-3, interleukin (IL)-6, hepatocyte growth factor (HGF), and nerve growth factor (NGF) in 1143 ever-smoking lung cancer cases and 1143 controls. Leptin was measured as an adiposity biomarker. Conditional logistic regression was used in data analyses.

RESULTS

Leptin was inversely associated with lung cancer risk (odds ratio [ORcontinuous] per Ln [pg/mL] = 0.85, 95% confidence interval [CI] = 0.74 to 0.98). After adjusting for adiposity and other risk factors, null associations were found for IL-6, HGF, and NGF. In current smokers, but not former smokers, high insulin levels were associated with increased lung cancer risk (OR for 4th quartile vs others [ORq4] = 2.06, 95% CI = 1.30 to 3.26) whereas IGFBP-3 had a linear inverse association (ORcontinuous per μg/mL = 0.64, 95% CI = 0.41 to 0.98). The insulin association was consistent across subgroups defined by body mass index and histological type, but the IGFBP-3 association was specific to small cell lung cancer. There was a modest positive association between IGF-1 and lung cancer risk in current smokers (ORq4 = 1.44, 95% CI = 0.90 to 2.29).

CONCLUSIONS

Independent of obesity, high insulin levels but reduced levels of IGFBP-3 were associated with increased lung cancer risk in current smokers.

Diagnosis and Molecular Classification of Lung Cancer

Lung cancer is a complex disease composed of diverse histological and molecular types with clinical relevance. The advent of large-scale molecular profiling has been helpful to identify novel molecular targets that can be applied to the treatment of particular lung cancer patients and has helped to reshape the pathological classification of lung cancer. Novel directions include the immunotherapy revolution, which has opened the door for new opportunities for cancer therapy and is also redefining the classification of multiple tumors, including lung cancer. In the present chapter, we will review the main current basis of the pathological diagnosis and classification of lung cancer incorporating the histopathological and molecular dimensions of the disease.

Hazard Ratio of Smoking on Lung Cancer in Korea According to Histological Type and Gender

PURPOSE

Using nationwide cancer incidence data, we examined whether the strength of the association of cigarette smoking with lung cancer risk differs according to major histological type and gender, taking account of other risk factors in the Korean population.

METHODS

The study population derived from government employees and teachers aged 20 years and over who participated in a national health examination program in 1998 or 1999. Total study subjects were 1,357,447. After excluding 1556 subjects who were treated with lung cancer during 1998-2000, we restricted our analysis to 1,355,891 cases. We followed up those 1,355,891 subjects who were cancer-free at baseline until December 31, 2010. The incident cancer cases were identified from the Korea Central Cancer Registry, which is a nationwide hospital-based cancer registry system that includes 94 % of the university hospitals and 96 % of the resident training hospitals of the country.

RESULTS

A higher risk for having ever smoked was observed for squamous-cell and small-cell carcinoma in both men and women. Heavy and long-term smokers were at higher risk for these carcinomas. Significant associations with quantity and duration-related factors were observed mainly among men. These findings indicate that smoking is closely related to the risk of squamous-cell and small-cell carcinoma among women as well as men. However, the magnitude of smoking-related lung cancer risk is likely to differ between men and women.

CONCLUSION

The hazard ratios for all types of lung cancer were significantly higher in male current smokers than in male never smokers. In case of women, the hazard ratios for adenocarcinoma were not different between current smokers and never smokers. The hazard ratios we found, however, were lower than those reported in Western countries and in Korea, but consistent with those reported in North-eastern Asian countries.

Cancer incidence among Minnesota taconite mining industry workers

PURPOSE

To evaluate cancer incidence among Minnesota taconite mining workers.

METHODS

We evaluated cancer incidence between 1988 and 2010 in a cohort of 40,720 Minnesota taconite mining workers used between 1937 and 1983. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were estimated by comparing numbers of incident cancers with frequencies in the Minnesota Cancer Surveillance System. SIRs for lung cancer by histologic subtypes were also estimated. We adjusted for out-of-state migration and conducted a probabilistic bias analysis for smoking-related cancers.

RESULTS

A total of 5700 cancers were identified, including 51 mesotheliomas and 973 lung cancers. The SIRs for lung cancer and mesothelioma were 1.3 (95% CI = 1.2-1.4) and 2.4 (95% CI = 1.8-3.2), respectively. Stomach, laryngeal, and bladder cancers were also elevated. However, adjusting for potential confounding by smoking attenuated the estimates for lung (SIR = 1.1, 95% CI = 1.0-1.3), laryngeal (SIR = 1.2, 95% CI = 0.8-1.6), oral (SIR = 0.9, 95% CI = 0.7-1.2), and bladder cancers (SIR = 1.0, 95% CI = 0.8-1.1).

CONCLUSIONS

Taconite workers may have an increased risk for certain cancers. Lifestyle and work-related factors may play a role in elevated morbidity. The extent to which mining-related exposures contribute to disease burden is being investigated.

Expression and DNA methylation status of the Rap2B gene in human bronchial epithelial cells treated by cigarette smoke condensate

BACKGROUND

The relationship between lung cancer and smoking has been demonstrated. The Rap2B gene is usually overexpressed in lung cancers. This study was aimed to investigate the Rap2B gene expression and its promoter methylation in human bronchial epithelial cells (16HBE) treated by cigarette smoke condensate (CSC).

METHODS

16HBE cells were treated with CSC (1/8 IC50). Soft ager assay, tumorigenicity test, chromosome aberrations analysis were used to identify the transformed cells. The expression level of mRNA and protein of Rap2B was detected using real time PCR and Western blotting, respectively. The genome DNA methylation level was detected using combined bisulfite restriction analysis (COBRA) and the methylation status of the target fragment in Rap2B gene promoter was determined by bisulfite sequencing PCR (BSP).

RESULTS

The 16HBE cells were successfully malignant transformed after the chronic exposure to CSC. The expression of Rap2B gradually increased in the process of malignant transformation. Meanwhile, global DNA was hypomethylated. However, no obvious change was observed in the methylation level of Rap2B gene promoter in transformed 16HBE cells.

CONCLUSIONS

Rap2B gene may play an important role in the process of lung cancer and global DNA hypomethylation might be an early event in tumorigenesis.

Surgical lung cancer patients' views about smoking and support to quit after diagnosis: a qualitative study

PURPOSE

Evidence suggests that quitting smoking improves symptoms as well as disease-related mortality for cancer patients. However, smoking cessation support is typically not well integrated into routine cancer care even in the case of lung cancer.. We explored surgical lung cancer patients' views about smoking and about their preferences for support to help them to quit.

METHODS

We conducted semi-structured, qualitative interviews with 22 surgical lung cancer patients with a smoking history, after treatment with surgery. Data were analysed using the framework approach.

RESULTS

Although diagnosis promoted a successful quit attempt in some, others continued smoking or relapsed after a quit attempt. Most participants wished they were a non-smoker but, in conflict with this, also felt that smoking was enjoyable, helped with psychological coping or had some health benefits. Some also demonstrated a fatalist attitude towards the potential detrimental health effects. However, all participants felt that it was important for health professionals to address smoking and some wanted cessation support although it was often not provided. Participants wanted support to start as early as possible and to continue for the first weeks after discharge.

CONCLUSIONS

Surgical lung cancer patients often stop smoking during hospitalisation, and many want to remain quit but relapse shortly after discharge. Although it is often not provided, many patients want to be offered support to help them quit.

IMPLICATIONS FOR CANCER SURVIVORS

Surveys suggest that clinicians believe that addressing smoking will be difficult and/or unwanted. However, these findings suggest that surgical lung cancer patients would tolerate, and most would prefer, integration of smoking cessation support into routine cancer care.

Coffee consumption and incidence of lung cancer in the NIH-AARP Diet and Health Study

BACKGROUND

Coffee drinkers had a higher risk of lung cancer in some previous studies, but as heavy coffee drinkers tend to also be cigarette smokers, such findings could be confounded. Therefore, we examined this association in the nearly half a million participants of the US NIH-AARP Diet and Health Study.

METHODS

Typical coffee intake and smoking history were queried at baseline. During 4 155 256 person-years of follow-up, more than 9000 incident lung cancer cases occurred. We used Cox proportional hazards regression to estimate hazard ratios (HRs)and 95% confidence intervals for coffee intake and subsequent incidence of lung cancer. We also comprehensively adjusted for tobacco smoking and examined associations by detailed strata of tobacco use.

RESULTS

Coffee drinkers were far more likely to smoke than non-drinkers. Although coffee drinking was associated with lung cancer in age- and sex- adjusted models (HR for ≥ 6 cups/day compared with none: 4.56, 4.08-5.10), this association was substantially attenuated after adjusting for smoking (HR: 1.27, 1.14-1.42). Similar findings were observed for each different histological type of lung cancer, and for participants drinking predominantly caffeinated or decaffeinated coffee. Little evidence for an association was observed in our stratified analyses, either within never smokers or in most categories of tobacco use.

CONCLUSIONS

Coffee drinking was positively associated with lung cancer in our study, although the association was substantially attenuated after adjustment for tobacco smoking. As our adjustment for lifetime tobacco use was imperfect, it is likely that the remaining association is due to residual confounding by smoking, although other explanations are possible.

Macrophages of M1 phenotype have properties that influence lung cancer cell progression

Stromal macrophages of different phenotypes can contribute to the expression of proteins that affects metastasis such as urokinase-type plasminogen activator (uPA), its receptor uPAR, and plasminogen activator inhibitor-1 (PAI-1), but knowledge of how essential their contribution is in comparison to the cancer cells in small cell lung cancer (SCLC) and lung squamous cell carcinoma (SCC) is lacking. The expression of uPA, uPAR, and PAI-1 and of the matrix metalloproteinases (MMP)-2 and MMP-9 were studied in human macrophages of M1 and M2 phenotype and compared to a lung SCC (NCI-H520) and a SCLC (NCI-H69) cell line. Effects of treatment with conditioned media (CM) from M1 and M2 macrophages on the expression of these genes in H520 and H69 cells as well as effects on the cell growth were investigated. In addition, data on the stromal macrophages immunoreactivity of uPAR, MMP-2, and MMP-9 in a few SCC and SCLC biopsies was included. uPAR, MMP-2, and MMP-9 were confirmed in stromal cells including macrophages in the SCC and SCLC biopsies. In vitro, both macrophage phenotypes expressed considerably higher mRNA levels of uPA, uPAR, PAI-1, and MMP-9 compared to the cancer cell lines, and regarding uPAR, the highest level was found in the M1 macrophage phenotype. Furthermore, M1 CM treatment not only induced an upregulation of PAI-1 in both H520 and H69 cells but also inhibited cell growth in both cell lines, giving M1 macrophages both tumor-promoting and tumor-killing potential.

F2RL3 methylation, lung cancer incidence and mortality

Smoking accounts for a large share of lung cancer. F2RL3 methylation was recently identified as a biomarker closely reflecting both current and past smoking exposure. We aimed to assess the associations of F2RL3 methylation with lung cancer incidence and mortality. In a large population-based cohort study, F2RL3 methylation was measured in baseline blood samples of 4,987 participants by MassARRAY. Associations of F2RL3 methylation and smoking with lung cancer incidence/mortality during a median follow-up of 10.9 years were assessed by Cox regression, controlling for potential confounders. The ability of F2RL3 methylation to predict lung cancer was examined by Harrell's C statistics. Hypomethylation at F2RL3 was strongly associated with both lung cancer incidence and mortality, with age- and sex-adjusted hazard ratios (HR; 95% CI) of 9.99 (5.61-17.79) and 16.86 (8.53-33.34), respectively, for participants whose methylation intensity were ≤0.54 compared with whose methylation intensity were ≥0.75. Strongly elevated HRs of 2.88 (1.42-5.84) and 5.17 (2.28-11.70) persisted even after controlling for multiple covariates including smoking status and pack-years. With fully adjusted HRs of 9.92 (2.88-34.12) and 16.48 (4.10-66.15), the associations between methylation and the two outcomes were particularly strong among participants≥65 years. Combination of F2RL3 methylation and pack-years predicted lung cancer incidence with high accuracy (optimism-corrected Harrell's C statistics = 0.86 for participants≥65 years). These findings suggested that F2RL3 methylation is a very strong predictor of lung cancer risk and mortality, particularly at older age. The potential implications of F2RL3 methylation for early detection, risk stratification and prevention of lung cancer warrant further exploration.

Role of acetylcholinesterase in lung cancer

Acetylcholinesterase (AChE) plays a key role in catalytic hydrolysis of cholinergic neurotransmitters. Intensive research has proven the involvement of this protein in novel functions, such as cell adhesion, differentiation, and proliferation. In addition, several recent studies have indicated that acetylcholinesterase is potentially a marker and regulator of apoptosis. Importantly, AChE is also a promising tumor suppressor. In this review, we briefly summarize the involvement of AChE in apoptosis and cancer, focusing on the role of AChE in lung cancer, as well as the therapeutic consideration of AChE for cancer therapy.

Smoking and mortality in a prospective cohort study of elderly Chinese in Hong Kong

BACKGROUND AND AIMS

Large cohort studies on smoking and mortality in elderly people are scarce, and few studies examined smokers aged 85+ years separately. We estimated the risks of all-cause and cause-specific mortality due to smoking in an elderly Chinese cohort in Hong Kong.

DESIGN

A population-based prospective cohort of 65,510 Chinese enrolled from 1998 to 2001 and followed until May 2012.

SETTING

All 18 Elderly Health Service centres in Hong Kong, China.

PARTICIPANTS

Elderly people aged 65+ years.

MEASUREMENTS

Self-reported smoking status was assessed at baseline interview and categorized as never, former and current smokers.

FINDINGS

Compared with never smokers, after adjustment for sex, age, education, social security assistance, housing type, monthly expenditure, alcohol use, depressive symptoms and health status, the hazard ratio (HR) for current smokers was 1.89 [95% confidence interval (CI) = 1.81-1.98] for all participants aged 65+ years at baseline, corresponding to an attributable fraction (AF) of about 50%, which is based on AF = (HR-1)/HR. As the effect of smoking varied with age (P for age interaction <0.001), subgroup analysis by age group showed that the adjusted HR for current smokers aged 65-84 years was 1.93 (95% CI = 1.84-2.03), and for 85+ years was 1.29 (95% CI = 1.05-1.58). All the risk estimates did not vary by sex (P for sex interaction ranged 0.74-0.89).

CONCLUSIONS

In Hong Kong, the risk of death from smoking appears to be the same for Chinese women as it is for men. Half of all deaths in Chinese smokers aged 65 years and older and a quarter of all deaths in Chinese smokers aged 85 years and older are caused by smoking-attributable diseases.

FAM83B is a novel biomarker for diagnosis and prognosis of lung squamous cell carcinoma

Personalized therapy for non-small cell lung cancer (NSCLC), particularly lung adenocarcinoma, has recently been significantly improved by the discovery of various molecular targets. However, this has not been the case for lung squamous cell carcinoma (SCC). In the present study, we identified the family with sequence similarity 83, member B (FAM83B) as a candidate marker for SCC through a comprehensive gene expression analysis and examined its correlations with various clinicopathological factors. The subjects of this study consisted of 215 patients with NSCLC who underwent complete resection from 2005 to 2011 at the Fukushima Medical University Hospital (Fukushima, Japan). They included 102 patients with adenocarcinoma and 113 with SCC. FAM83B expression was first examined in some of the samples by gene expression analysis and western blotting, and then all clinical specimens were evaluated by immunohistochemistry (IHC). The relationship between the quantitative values for IHC and clinicopathological factors was statistically analyzed. The results showed that FAM83B mRNA expression was significantly higher in SCC than in normal lung or adenocarcinoma (P<0.0001). Immunoblot analysis also confirmed this trend. Specimens containing >10% positive area for FAM83B were judged as ‘positive’; 94.3% (107/113) of SCC and 14.7% (15/102) of adenocarcinoma were positive. Patients were divided into two subgroups according to expression (54 high-expression and 53 low-expression patients); the high-expression group was associated with a better disease-free survival (DFS) rate (P=0.042, log-rank test). In conclusion, FAM83B may be a reliable diagnostic and prognostic biomarker for SCC. Detailed analyses of FAM83B function in lung cancer are required to understand how its expression is associated with better prognosis in SCC.

Disease risk factors identified through shared genetic architecture and electronic medical records

Genome-wide association studies have identified genetic variants for thousands of diseases and traits. We evaluated the relationships between specific risk factors (for example, blood cholesterol level) and diseases on the basis of their shared genetic architecture in a comprehensive human disease-single-nucleotide polymorphism association database (VARIMED), analyzing the findings from 8962 published association studies. Similarity between traits and diseases was statistically evaluated on the basis of their association with shared gene variants. We identified 120 disease-trait pairs that were statistically similar, and of these, we tested and validated five previously unknown disease-trait associations by searching electronic medical records (EMRs) from three independent medical centers for evidence of the trait appearing in patients within 1 year of first diagnosis of the disease. We validated that the mean corpuscular volume is elevated before diagnosis of acute lymphoblastic leukemia; both have associated variants in the gene IKZF1. Platelet count is decreased before diagnosis of alcohol dependence; both are associated with variants in the gene C12orf51. Alkaline phosphatase level is elevated in patients with venous thromboembolism; both share variants in ABO. Similarly, we found that prostate-specific antigen and serum magnesium levels were altered before the diagnosis of lung cancer and gastric cancer, respectively. Disease-trait associations identify traits that could serve as future prognostics, if validated through EMR and subsequent prospective trials.

Race, insurance type, and stage of presentation among lung cancer patients

The purpose of this study was to determine whether African-American lung cancer patients are diagnosed at a later stage than white patients, regardless of insurance type. The relationship between race and stage at diagnosis by insurance type was assessed using a Poisson regression model, with relative risk as the measure of association. The setting of the study was a large tertiary care cancer center located in the southeastern United States. Patients who were diagnosed with lung cancer between 2001 and 2010 were included in the study. A total of 717 (31%) African-American and 1,634 (69%) white lung cancer patients were treated at our facility during the study period. Adjusting for age, sex, and smoking-related histology, African-American patients were diagnosed at a statistically significant later stage (III/IV versus I/II) than whites for all insurance types, with the exception of Medicaid. Our results suggest that equivalent insurance coverage may not ensure equal presentation of stage between African-American and white lung cancer patients. Future research is needed to determine whether other factors such as treatment delays, suboptimal preventive care, inappropriate specialist referral, community segregation, and a lack of patient trust in health care providers may explain the continuing racial disparities observed in the current study.

XRCC-1 Gene Polymorphism (Arg399Gln) and Susceptibility to Development of Lung Cancer in Cohort of North Indian Population: A Pilot Study

BACKGROUND

Smoking has been considered to be the major cause of lung cancer. However, only a fraction of cigarette smokers develop this disease. This suggests the importance of genetic constitution in predicting the individual's susceptibility towards lung cancer. This genetic susceptibility may result from inherited polymorphisms in genes controlling carcinogen metabolism and repair of damaged deoxyribonucleic acid (DNA). These repair systems are fundamental to the maintenance of genomic integrity. X-ray repair cross complimenting group I (XRCC1), a major DNA repair gene in the base excision repair (BER) pathway. It is involved in repair by interacting with components of DNA at the site of damage. Inconsistent results have been reported regarding the associations between the Arg399Gln polymorphism of XRCC1. This study demonstrates the importance of recognition of this relationship of lung carcinoma and genetic constitution of the person which will help guide clinicians on the optimal screening of this disease.

AIM

To assess the role of XRCC1 gene polymorphism (Arg399Gln) directly on the variation in susceptibility to development of lung cancer in North Indian subjects.

MATERIALS AND METHODS

One hundred males with diagnosed cases of lung cancer were recruited from Delhi State Cancer Institute (DSCI). Hundred healthy volunteers were taken as controls. DNA isolation was done and Polymerase chain reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) procedure undertaken to amplify the region containing Arg/Gln substitution at codon 399 (in exon 10).

RESULTS

XRCC1 gene polymorphism is associated with increased risk of lung cancer when the Arg/Arg genotype was used as the reference group. The Arg/Gln and Gln/Gln was associated with statistically increased risk for cancer.

CONCLUSION

Arg399Gln polymorphism in XRCC1 gene polymorphism is associated with lung cancer in North Indian subjects and screening for this polymorphism will help in targeting predisposed individuals and its prevention.

Trend analysis of lung cancer incidence rates in ninawa province, Iraq, from 2000 to 2010--decrease and recent stability

BACKGROUND

Lung cancer is the most frequent malignancy of men worldwide. In Ninawa in Iraq, lung cancer ranks first among cancers diagnosed in men. Since no prior studies have been conducted on incidence trends in our population the present investigation of rates during 2000-2010 was therefore performed.

MATERIALS AND METHODS

Registy data for lung cancer cases were collected from the Directorate of Health in Ninawa-Mosul Continuing Medical Education Center. We restricted our analyses to men categorized according to the age groups of 0- 39, 40-49, 50-59, 60-69 and 70+ years. The significance of incidence rate trends during 2000-2010 was tested using Poisson regression. Age-standardized rates (ASR), and age-specific rates per 100,000 population were calculated.

RESULTS

A total of 1,206 incident lung cancer were registered among males, accounting for 15.5% of all male cancers registered during 2000-2010. It ranked first throughout the period. Median age at diagnosis was 69 (mean 66.8± 11.0) years. The incidence rate of all male lung cancers in Ninawa (all ages) decreased from 26.4 per 100,000 in 2000 to 12.7 in 2010 (APC=-6.55%, p<.0001). The incidences in age groups 40-49, 50-59, 60-69 and 70+ decreased in earlier years and recently appeared (2007-2010) stable. The incidence in age group (0-39) remained stable between 2000-2010. Squamous cell carcinoma (SCC)was the most common type of lung cancer, while adenocarcinoma was relatively rare.

CONCLUSIONS

With the data from Directorate of Health in Ninawa during the period 2000-2010, lung cancer is the most common cancer but generally declining. Among all age groups, the recent incidence of lung cancer remained stable. The SCC predominance suggests change in tobacco habits as an important factor in the trends observed.

Epidemiologic characteristics of compensated occupational lung cancers among Korean workers

An understanding of the characteristics of occupational lung cancer is important to establish policies that prevent carcinogen exposure and to compensate workers exposed to lung carcinogens. This study analyzed the characteristics of occupational lung cancers in workers who were compensated under the Industrial Accident Compensation Insurance Law between 1994 and 2011. A total of 179 occupational lung cancers were compensated. The main carcinogenic exposure was asbestos, followed by crystalline silica and hexavalent chromium. The mean exposure duration and latency were 19.8 and 23.2 yr. The most common industry was manufacturing, followed by construction and transportation. The most common occupation was maintenance and repair, followed by foundry work, welding, painting, and spinning or weaving. Although asbestos was predominant carcinogen, the proportion of these cases was relatively low compared to other developed countries. Proper surveillance system is needed to monitor occupational lung cancer and improve prevention measures.

Prospective genetic profiling of squamous cell lung cancer and adenosquamous carcinoma in Japanese patients by multitarget assays

BACKGROUND

Despite considerable recent progress in the treatment of lung adenocarcinoma, there has been little progress in the development of efficacious molecular targeted therapies for squamous cell lung cancer. In addition to the recent comprehensive genome-wide characterization of squamous cell lung cancer, it is also important to genotype this form of cancer. We therefore conducted the Shizuoka Lung Cancer Mutation Study to analyze driver mutations in patients with thoracic malignancies. Here we report the results of genotyping in patients with squamous cell lung cancer.

METHODS

Based on the biobanking system, in conjunction with the clinic and pathology lab, we developed a genotyping panel designed to assess 24 mutations in 10 genes (EGFR, KRAS, BRAF, PIK3CA, NRAS, MEK1, AKT1, PTEN, HER2 and DDR2), EGFR, MET, PIK3CA, FGFR1 and FGFR2 copy numbers, and EML4-ALK and ROS1 translocations, using pyrosequencing plus capillary electrophoresis, quantitative polymerase chain reaction (PCR) and reverse-transcription PCR, respectively.

RESULTS

A total of 129 patients with squamous cell lung cancer and adenosquamous carcinoma were enrolled in this study between July 2011 and November 2012. We detected genetic alterations in 40% of all cases. Gene alterations included: EGFR mutations, 6%; KRAS mutations, 4%; PIK3CA mutations, 13%; NRAS mutations, 1%; KIF5b-RET fusion gene, 1%; EGFR copy number gain, 5%; PIK3CA copy number gain, 15%; and FGFR1 copy number gain, 5%. Twelve patients (9%) harbored simultaneous genetic alterations. Genetic alterations were detected more frequently in surgically-resected, snap-frozen samples than in formalin-fixed, paraffin-embedded samples (50% vs. 29%). In addition, patients aged ≤70 years old and never-smokers showed high frequencies of genetic alterations.

CONCLUSIONS

This study represents one of the largest prospective tumor-genotyping studies to be performed in Asian patients with squamous cell lung cancer. These results suggest that incorporation of genetic profiling into lung cancer clinical practice may facilitate the administration of personalized cancer treatments in patients with squamous cell lung cancer.

Effect of cigarette smoke condensate on gene promoter methylation in human lung cells

BACKGROUND

In lung cancer, an association between tobacco smoking and promoter DNA hypermethylation has been demonstrated for several genes. However, underlying mechanisms for promoter hypermethylation in tobacco-induced cancer are yet to be fully established.

METHODS

Promoter methylation was evaluated in control and cigarette smoke condensate (CSC) exposed human lung cells using the Methyl-Profiler DNA Methylation PCR System. PSAE cells were exposed to 0.3 or 1.0 μg/ml CSC for 72 hours and longer term for 14 and 30 days. NL-20 cells were exposed for 30 days to 10 or 100 μg/ml CSC.

RESULTS

Promoters of several genes, including hsa-let-7a-3, CHD1, CXCL12, PAX5, RASSF2, and TCF21, were highly methylated (>90%); hsa-let-7a-3 was affected in both cell lines and under all exposure conditions. Level of methylation tended to increase with CSC concentration and exposure duration (statistical differences were not determined). Percentage methylation of TCF21, which was >98% at exposures of 10 or 100 μg/ml CSC, was found to be reduced to 28% and 42%, respectively, in the presence of the dietary agent genistein.

CONCLUSIONS

Using array techniques, several tumor suppressor genes in human lung cells were identified that undergo promoter hypermethylation, providing further evidence of their potential involvement in tobacco smoke-induced lung carcinogenesis and their use as potential biomarkers of harm in tobacco smoke exposure. Results from the study also demonstrated the potential of a dietary agent to exert chemopreventive activity in human tissue against tobacco smoke related diseases through modulation of DNA methylation. Additional studies are needed to confirm these findings.

US lung cancer trends by histologic type

BACKGROUND

Lung cancer incidence rates overall are declining in the United States. This study investigated the trends by histologic type and demographic characteristics.

METHODS

Surveillance, Epidemiology, and End Results (SEER) program rates of microscopically confirmed lung cancer overall and squamous cell, small cell, adenocarcinoma, large cell, other, and unspecified carcinomas among US whites and blacks diagnosed from 1977 to 2010 and white non-Hispanics, Asian/Pacific Islanders, and white Hispanics diagnosed from 1992 to 2010 were analyzed by sex and age.

RESULTS

Squamous and small cell carcinoma rates declined since the 1990s, although less rapidly among females than males. Adenocarcinoma rates decreased among males and only through 2005, after which they then rose during 2006 to 2010 among every racial/ethnic/sex group; rates for unspecified type declined. Male/female rate ratios declined among whites and blacks more than among other groups. Recent rates among young females were higher than among males for adenocarcinoma among all racial/ethnic groups and for other specified carcinomas among whites.

CONCLUSIONS

US lung cancer trends vary by sex, histologic type, racial/ethnic group, and age, reflecting historical cigarette smoking rates, duration, cessation, cigarette composition, and exposure to other carcinogens. Substantial excesses among males have diminished and higher rates of adenocarcinoma among young females have emerged as rates among males declined more rapidly. The recognition of EGFR mutation and ALK rearrangements that occur primarily in adenocarcinomas are the primary basis for the molecular revolution that has transformed lung cancer diagnosis and treatment over the past decade, and these changes have affected recent type-specific trends.

Polymorphism of DNA repair gene xrcc1 and lung cancer risk

The current large-scale meta-analysis was performed to reach a reliable conclusion on the association between X-ray repair cross-complementing 1 (xrcc1) rs1799782 and the development of lung cancer. Studies that investigated the association between rs1799782 and lung cancer risk were identified by searching PubMed. We calculated odds ratio (OR) with corresponding 95 % confidence interval (CI) for Trp/Trp vs Arg/Arg, Trp/Trp + Arg/Trp vs Arg/Arg, and Trp/Trp vs Arg/Trp + Arg/Arg contrast models. Combining all 25 studies, we yielded three summary ORs: 1.07 (95 % CI 0.92-1.23) for Trp/Trp vs Arg/Arg, 0.93 (95 % CI 0.87-1.00) for Trp/Trp + Arg/Trp vs Arg/Arg, and 1.08 (95 % CI 0.94-1.25) for Trp/Trp vs Arg/Trp + Arg/Arg, suggesting rs1799782 was not associated with overall risk of lung cancer. Strikingly, a significantly deceased risk was found among Caucasian populations (Trp/Trp + Arg/Trp vs Arg/Arg, OR = 0.86, 95 % CI 0.76-0.97). This study confirms that xrcc1 rs1799782 may lower the risk of lung cancer among Caucasians.

From adversity to psychosis: pathways and mechanisms from specific adversities to specific symptoms

PURPOSE

Although there is considerable evidence that adversities in childhood such as social deprivation, sexual abuse, separation from parents, neglect and exposure to deviant parental communication are associated with psychosis in later life, most studies have considered broad diagnoses as outcomes. In this review we consider evidence for pathways between specific types of adversity and specific symptoms of psychosis.

METHODS

We present theoretical arguments for expecting some degree of specificity (although by no means perfect specificity) between different kinds of adversity and different symptoms of psychosis. We review studies that have investigated social-environmental risk factors for thought disorder, auditory-verbal hallucinations and paranoid delusions, and consider how these risk factors may impact on specific psychological and biological mechanisms.

RESULTS

Communication deviance in parents has been implicated in the development of thought disorder in offspring, childhood sexual abuse has been particularly implicated in auditory-verbal hallucinations, and attachment-disrupting events (e.g. neglect, being brought up in an institution) may have particular potency for the development of paranoid symptoms. Current research on psychological mechanisms underlying these symptoms suggests a number of symptom-specific mechanisms that may explain these associations.

CONCLUSIONS

Few studies have considered symptoms, underlying mechanisms and different kinds of adversity at the same time. Future research along these lines will have the potential to elucidate the mechanisms that lead to severe mental illness, and may have considerable clinical implications.

[Advances of immunotherapy in small cell lung cancer]

小细胞肺癌（small cell lung cancer, SCLC）具有复杂的异质性，由于细胞起源、发病机制和驱动基因尚不明确，SCLC的诊治进展缓慢，鲜有突破，迫切需要新的治疗策略提高SCLC疗效。肿瘤免疫治疗可提高免疫系统识别和排除肿瘤细胞的能力，且对正常组织影响轻微。目前已经开展了肿瘤疫苗、过继细胞免疫治疗、细胞因子、checkpoint抑制剂等治疗SCLC的临床研究，ipilimumab是最有前景的药物。免疫治疗有望为SCLC治疗带来新的希望，未来还需要对SCLC的异质性、免疫治疗靶点不明确、免疫治疗耐受等影响免疫治疗疗效的问题开展进一步研究。

Pathophysiology of tobacco smoke exposure: recent insights from comparative and redox proteomics

First-hand and second-hand tobacco smoke are causally linked to a huge number of deaths and are responsible for a broad spectrum of pathologies such as cancer, cardiovascular, respiratory, and eye diseases as well as adverse effects on female reproductive function. Cigarette smoke is a complex mixture of thousands of different chemical species, which exert their negative effects on macromolecules and biochemical pathways, both directly and indirectly. Many compounds can act as oxidants, pro-inflammatory agents, carcinogens, or a combination of these. The redox behavior of cigarette smoke has many implications for smoke related diseases. Reactive oxygen and nitrogen species (both radicals and non-radicals), reactive carbonyl compounds, and other species may induce oxidative damage in almost all the biological macromolecules, compromising their structure and/or function. Different quantitative and redox proteomic approaches have been applied in vitro and in vivo to evaluate, respectively, changes in protein expression and specific oxidative protein modifications induced by exposure to cigarette smoke and are overviewed in this review. Many gel-based and gel-free proteomic techniques have already been used successfully to obtain clues about smoke effects on different proteins in cell cultures, animal models, and humans. The further implementation with other sensitive screening techniques could be useful to integrate the comprehension of cigarette smoke effects on human health. In particular, the redox proteomic approach may also help identify biomarkers of exposure to tobacco smoke useful for preventing these effects or potentially predictive of the onset and/or progression of smoking-induced diseases as well as potential targets for therapeutic strategies.

The Treg/Th17 paradigm in lung cancer

Pathogenic mechanisms underlying the development of lung cancer are very complex and not yet entirely clarified. T lymphocytes and their immune-regulatory cytokines play a pivotal role in controlling tumor growth and metastasis. Following activation by unique cytokines, CD4+ T helper cells differentiate into Th1, Th2, Th17, and regulatory T cells (Tregs). Traditionally, research in lung cancer immunity has focused almost exclusively on Th1/Th2 cell balance. Recently, Th17 cells and Tregs represent an intriguing issue to be addressed in lung cancer pathogenesis. Tregs play an important role in the preservation of self-tolerance and modulation of overall immune responses against tumor cells. Th17 cells directly or via other proinflammatory cytokines modulate antitumor immune responses. Notably, there is a close relation between Tregs and Th17 cells. However, the possible interaction between these subsets in lung cancer remains to be elucidated. In this setting, targeting Treg/Th17 balance for therapeutic purposes may represent a useful tool for lung cancer treatment in the future. The purpose of this review is to discuss recent findings of the role of these novel populations in lung cancer immunity and to highlight the pleiotropic effects of these subsets on the development and regulation of lung cancer.

XPA gene rs1800975 single nucleotide polymorphism and lung cancer risk: a meta-analysis

No clear consensus has been reached on the XPA gene rs1800975 polymorphism and lung cancer risk. We performed a meta-analysis in an effort to systematically explore the possible association. We conducted a computer retrieval of PubMed, Embase, Wanfang, China National Knowledge Infrastructure Platform, and VIP databases prior to November 2013. References of retrieved articles were also screened. The fixed- and the random-effects model were applied for dichotomous outcomes to combine the results of the individual studies. According to the inclusion criteria, 10 articles (11 studies) were finally included. In overall, statistical association could be found between rs1800975 polymorphism and lung cancer in recessive genetic model [AA vs. (AG + GG): P = 0.02, OR = 1.16, 95% CI 1.02-1.31, P heterogeneity = 0.14, fixed-effects model]. In the East Asians, significant association was found in allele comparison model (A vs. G: P = 0.03, OR = 1.13, 95% CI 1.01-1.26, P heterogeneity = 0.39, fixed-effects model), in recessive genetic model [AA vs. (AG + GG): P = 0.005, OR = 1.30, 95% CI 1.08-1.56, P heterogeneity = 0.58, fixed-effects model] and in the homozygote comparison (AA vs. GG: P = 0.02, OR = 1.30, 95% CI 1.04-1.63, P heterogeneity = 0.39, fixed-effects model). No evidence suggested that rs1800975 polymorphism might associate with lung cancer in other ethnicities. Stratification analysis performed by histologic types indicated that AA genotype might represent a risk factor for squamous cell carcinoma [AA vs. (AG + GG): P = 0.01, OR = 1.42, 95% CI 1.08-1.86, P heterogeneity = 0.27, fixed-effects model; AA vs. GG: P = 0.03, OR = 1.43, 95% CI 1.04-1.96, P heterogeneity = 0.21, fixed-effects model]. No association was observed in adenocarcinoma subgroup. Our study suggested that XPA rs1800975 polymorphism might associate with lung cancer risk in overall and in East Asians. This polymorphism might also associate with squamous cell carcinoma.

Exposure to secondhand tobacco smoke and lung cancer by histological type: a pooled analysis of the International Lung Cancer Consortium (ILCCO)

While the association between exposure to secondhand smoke and lung cancer risk is well established, few studies with sufficient power have examined the association by histological type. In this study, we evaluated the secondhand smoke-lung cancer relationship by histological type based on pooled data from 18 case-control studies in the International Lung Cancer Consortium (ILCCO), including 2,504 cases and 7,276 control who were never smokers and 10,184 cases and 7,176 controls who were ever smokers. We used multivariable logistic regression, adjusting for age, sex, race/ethnicity, smoking status, pack-years of smoking, and study. Among never smokers, the odds ratios (OR) comparing those ever exposed to secondhand smoke with those never exposed were 1.31 (95% CI: 1.17-1.45) for all histological types combined, 1.26 (95% CI: 1.10-1.44) for adenocarcinoma, 1.41 (95% CI: 0.99-1.99) for squamous cell carcinoma, 1.48 (95% CI: 0.89-2.45) for large cell lung cancer, and 3.09 (95% CI: 1.62-5.89) for small cell lung cancer. The estimated association with secondhand smoke exposure was greater for small cell lung cancer than for nonsmall cell lung cancers (OR=2.11, 95% CI: 1.11-4.04). This analysis is the largest to date investigating the relation between exposure to secondhand smoke and lung cancer. Our study provides more precise estimates of the impact of secondhand smoke on the major histological types of lung cancer, indicates the association with secondhand smoke is stronger for small cell lung cancer than for the other histological types, and suggests the importance of intervention against exposure to secondhand smoke in lung cancer prevention.

Histological subtype and smoking status, but not gender, are associated with epidermal growth factor receptor mutations in non-small-cell lung cancer

Mutations in epidermal growth factor receptor (EGFR) commonly occur in non-small-cell lung cancer (NSCLC) patients characterized by female gender, never-smoker status and adenocarcinoma histology. The aim of this study was to determine whether gender is a confounding factor for EGFR mutations in NSCLC. To elucidate the confounding effect, Pearson's χ² test and logistic regression models were used to correlate these characteristics with EGFR mutations in 426 NSCLC patients treated at our institutes. Of those 426 NSCLC patients, 47% were females, 57% were non-smokers and 84% had adenocarcinomas. The multivariate logistic regression analysis demonstrated that never-smoker status [odds ratio (OR)=3.49, 95% confidence interval (CI): 1.99-6.13; P<0.001)] and adenocarcinoma (OR=9.43, 95% CI 3.62-24.56; P<0.001) were associated with EGFR mutations; however, gender was not (OR=1.25, 95% CI: 0.73-2.15; P=0.416). Furthermore, gender was not associated with EGFR mutation subtypes (OR=1.19, 95% CI: 0.56-2.50; P=0.650). The frequency of EGFR mutations among females and males was not different in non-smokers (64.8 vs. 55.8%, P=0.204) or ever-smokers (27.8 vs. 24.2%, P=0.775). Therefore, if the assessment for EGFR mutation status was limited to non-smoking females with adenocarcinoma, up to 40% of the patients harboring EGFR mutations would be precluded from the benefit of EGFR inhibitor therapy. Our results indicated that gender is a confounding factor for EGFR mutations in NSCLC and suggested that gender may not be associated with tumorigenesis in NSCLC-harboring EGFR mutations.

Lung cancer in women: an overview with special focus on Spanish women

Lung cancer incidence is decreasing worldwide among men but rising among women due to recent changes in smoking patterns in both sexes. In Europe, the smoking epidemic has evolved different rates and times, and policy responses to it, vary substantially between countries. Differences in smoking prevalence are much more evident among European women reflecting the heterogeneity in cancer incidence rates. Other factors rather than smoking and linked to sex may increase women's susceptibility to lung cancer, such as genetic predisposition, exposure to sex hormones and molecular features, all of them linked to epidemiologic and clinical characteristics of lung cancer in women. However, biological bases of sex-specific differences are controversial and need further evaluation. This review focuses on the epidemiology and outcome concerning non-small cell lung cancer in women, with emphasis given to the Spanish population.

A regression model for risk difference estimation in population-based case-control studies clarifies gender differences in lung cancer risk of smokers and never smokers

BACKGROUND

Additive risk models are necessary for understanding the joint effects of exposures on individual and population disease risk. Yet technical challenges have limited the consideration of additive risk models in case-control studies.

METHODS

Using a flexible risk regression model that allows additive and multiplicative components to estimate absolute risks and risk differences, we report a new analysis of data from the population-based case-control Environment And Genetics in Lung cancer Etiology study, conducted in Northern Italy between 2002-2005. The analysis provides estimates of the gender-specific absolute risk (cumulative risk) for non-smoking- and smoking-associated lung cancer, adjusted for demographic, occupational, and smoking history variables.

RESULTS

In the multiple-variable lexpit regression, the adjusted 3-year absolute risk of lung cancer in never smokers was 4.6 per 100,000 persons higher in women than men. However, the absolute increase in 3-year risk of lung cancer for every 10 additional pack-years smoked was less for women than men, 13.6 versus 52.9 per 100,000 persons.

CONCLUSIONS

In a Northern Italian population, the absolute risk of lung cancer among never smokers is higher in women than men but among smokers is lower in women than men. Lexpit regression is a novel approach to additive-multiplicative risk modeling that can contribute to clearer interpretation of population-based case-control studies.

Association of cigarette smoking with the expression of nuclear survivin in pathological Stage IA lung adenocarcinomas

Survivin is expressed in the cytoplasm and/or nucleus of various types of malignant tumor cells. Cytoplasmic survivin functions as an apoptosis inhibitor, while nuclear survivin is indispensable for complete mitosis completion. To investigate the effect of cigarette smoking on the survivin expression in lung adenocarcinomas at the early developmental stage, we examined the expression of nuclear and cytoplasmic survivin in pathological Stage IA lung adenocarcinomas resected from 38 non-smokers and 44 smokers (current smokers and ex-smokers) using an immunohistochemical method. Labeling indices of nuclear survivin in tumors of smokers were significantly greater than those of non-smokers. The labeling index of nuclear survivin was above 3 % in only 1 (2.6 %) of the 38 tumors of the non-smokers, while the labeling indices in 19 (43.2 %) of 44 tumors of the smokers were above 3 % with a significantly greater frequency. There was no significant difference in the labeling index of nuclear survivin between current smokers and ex-smokers. There was no significant difference in the labeling index of cytoplasmic survivin between tumors of the non-smokers and the smokers. The present results show that cigarette smoking is associated with the higher nuclear surviving expression in lung adenocarcinomas at the early stage, suggesting that cigarette smoking affects the nuclear survivin expression in lung adenocarcinomas at the early developmental stage.

Targeting the epigenome in lung cancer: expanding approaches to epigenetic therapy

Epigenetic aberrations offer dynamic and reversible targets for cancer therapy; increasingly, alteration via overexpression, mutation, or rearrangement is found in genes that control the epigenome. Such alterations suggest a fundamental role in carcinogenesis. Here, we consider three epigenetic mechanisms: DNA methylation, histone tail modification and non-coding, microRNA regulation. Evidence for each of these in lung cancer origin or progression has been gathered, along with evidence that epigenetic alterations might be useful in early detection. DNA hypermethylation of tumor suppressor promoters has been observed, along with global hypomethylation and hypoacetylation, suggesting an important role for tumor suppressor gene silencing. These features have been linked as prognostic markers with poor outcome in lung cancer. Several lines of evidence have also suggested a role for miRNA in carcinogenesis and in outcome. Cigarette smoke downregulates miR-487b, which targets both RAS and MYC; RAS is also a target of miR-let-7, again downregulated in lung cancer. Together the evidence implicates epigenetic aberration in lung cancer and suggests that targeting these aberrations should be carefully explored. To date, DNA methyltransferase and histone deacetylase inhibitors have had minimal clinical activity. Explanations include the possibility that the agents are not sufficiently potent to invoke epigenetic reversion to a more normal state; that insufficient time elapses in most clinical trials to observe true epigenetic reversion; and that doses often used may provoke off-target effects such as DNA damage that prevent epigenetic reversion. Combinations of epigenetic therapies may address those problems. When epigenetic agents are used in combination with chemotherapy or targeted therapy it is hoped that downstream biological effects will provoke synergistic cytotoxicity. This review evaluates the challenges of exploiting the epigenome in the treatment of lung cancer.