Epidemiology of lung cancer: smoking, secondhand smoke, and genetics

Cancer cases attributable to modifiable lifestyle risk factors in Switzerland between 2015 and 2019

Several modifiable lifestyle risk factors have been linked to higher cancer risk in the literature. Determining the proportion and number of cancer cases attributable to these risk factors is pivotal in informing effective cancer prevention and control plans that have the greatest effect on reducing cancer incidence. We aimed to estimate the proportion and number of incident cancer cases that were attributable to modifiable lifestyle risk factors (ie, tobacco smoking, high alcohol consumption, excess body weight, physical inactivity and unhealthy diet) in Switzerland between 2015 and 2019. The exposure prevalence of selected risk factors was estimated based on the representative national nutrition survey menuCH, the associated relative risks were obtained from systematic literature reviews and the numbers of incident cancer cases were provided by the National Institute for Cancer Epidemiology and Registration. The fractions and numbers of attributable cases were calculated overall, by sex and by the three major language regions of Switzerland. The investigated modifiable risk factors combined were linked to 25.2% of potentially preventable incident cancer cases in Switzerland between 2015 and 2019. The proportion and numbers were slightly larger in males (28.4%, 6945 cases per year) than in females (21.9%, 4493 cases per year), and variations were observed between language regions. Tobacco smoking, excess body weight and high alcohol consumption were the leading contributors to lifestyle-attributable cancer cases. The observed differences in the leading risk factors both within Switzerland and compared to other countries underline the need for regionally and nationally tailored cancer prevention and education strategies.

Educational disparities in cancer incidence, stage, and survival in Oslo

OBJECTIVES

This study aimed to examine disparities in cancer incidence, stage at diagnosis, and survival rates across districts with differences in education levels in Oslo, Norway.

METHODS

Aggregated data from the Cancer Registry of Norway in the period 2013-2021 were used to describe the distribution of cancer incidence and survival across Oslo's 15 administrative districts, subsequently grouped into three areas based on the population's level of education. Age-standardised incidence rates and five-year relative survival were calculated for colon, rectal, lung, melanoma, breast, and prostate cancer. The stage at the time of diagnosis was categorised as localised, regional, distant, and unknown for all cancer types except breast cancer, which was categorised into stage I-IV and unknown.

RESULTS

Mid- and high-education areas had higher incidences of breast, melanoma, and prostate cancer, while the low-education area had higher incidence rates for lung cancer. The low-education area had a higher proportion diagnosed at a distant stage than the other groups for all cancer types studied, except breast cancer. The mid- and high-education areas had higher five-year relative survival rates overall.

CONCLUSIONS

Incidence, stage at diagnosis, and survival varied between education areas. The variation indicates disparities in healthcare access, quality of care, and health behaviours. Addressing these disparities can help improve overall health outcomes and promote health equity.

Long non-coding RNAs in non-small cell lung cancer: implications for preventing therapeutic resistance

Lung cancer has the highest mortality and morbidity rates among all cancers worldwide. Despite many complex treatment options, including radiotherapy, chemotherapy, targeted drugs, immunotherapy, and combinations of these treatments, efficacy is low in cases of resistance to therapy, metastasis, and advanced disease, contributing to low overall survival. There is a pressing need for the discovery of novel biomarkers and therapeutic targets for the early diagnosis of lung cancer and to determine the efficacy and outcomes of drug treatments. There is now substantial evidence for the diagnostic and prognostic value of long noncoding RNAs (lncRNAs). This review briefly discusses recent findings on the roles and mechanisms of action of lncRNAs in the responses to therapy in non-small cell lung cancer.

Drainless Thoracoscopic Lobectomy for Lung Cancer

OBJECTIVES: Drainless video-assisted thoracoscopic (VATS) wedge resection has been demonstrated as feasible in treating various lung diseases. However, it remains unknown whether this surgical technique can be effectively applied to lobectomy. In the current study, we evaluated the perioperative outcome of drainless, minimally invasive lobectomy in patients with lung cancer. METHODS: A total of 26 lung cancer patients who received surgery-performed pulmonary lobectomy were enrolled. The perioperative outcomes were analyzed based on a propensity score matching a comparison with those who had chest drainage. RESULTS: No major surgical morbidity and mortality was noted during the perioperative period. The mean of postoperative hospital stay was 5.08 ± 2.48 days. There was no significant difference in postoperative hospital stay between the two groups of patients. However, the presence of significant postoperative pain (VAS score > 30) on the first day after surgery was less in the drainless group (34.6% vs. 3.8%; p = 0.005). CONCLUSIONS: Our results demonstrated that drainless, minimally invasive lobectomy for selected lung cancer patients is feasible. Further evaluation of its impact on short- and long-term surgical outcomes is required in the future.

A prolonged exposure of human lung carcinoma epithelial cells to benzo[a]pyrene induces p21-dependent epithelial-to-mesenchymal transition (EMT)-like phenotype

Deciphering the role of the aryl hydrocarbon receptor (AhR) in lung cancer cells may help us to better understand the role of toxic AhR ligands in lung carcinogenesis, including cancer progression. We employed human lung carcinoma A549 cells to investigate their fate after continuous two-week exposure to model AhR agonists, genotoxic benzo[a]pyrene (BaP; 1 μM) and non-genotoxic 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 10 nM). While TCDD increased proliferative rate of A549 cells, exposure to BaP decreased cell proliferation and induced epithelial-to-mesenchymal transition (EMT)-like phenotype, which was associated with enhanced cell migration, invasion, and altered cell morphology. Although TCDD also suppressed expression of E-cadherin and activated some genes linked to EMT, it did not induce the EMT-like phenotype. The results of transcriptomic analysis, and the opposite effects of BaP and TCDD on cell proliferation, indicated that a delay in cell cycle progression, together with a slight increase of senescence (when coupled with AhR activation), favors the induction of EMT-like phenotype. The shift towards EMT-like phenotype observed after simultaneous treatment with TCDD and mitomycin C (an inhibitor of cell proliferation) confirmed the hypothesis. Since BaP decreased cell proliferative rate via induction of p21 expression, we generated the A549 cell model with reduced p21 expression and exposed it to BaP for two weeks. The p21 knockdown suppressed the BaP-mediated EMT-like phenotype in A549 cells, thus confirming that a delayed cell cycle progression, together with p21-dependent induction of senescence-related chemokine CCL2, may contribute to induction of EMT-like cell phenotype in lung cells exposed to genotoxic AhR ligands.

A comparison of the burden of lung cancer attributable to tobacco exposure in China and the USA

Background

Tobacco exposure (TE) is the major contributor to lung cancer mortality worldwide. This study aims to clarify the possible reasons underlying the long-term trends and differences in lung cancer mortality attributable to TE in China and the United States of America (USA).

Methods

Lung cancer mortality data from China and the USA were obtained from the Global Burden of Disease (GBD) Study 2017. Joinpoint regression analysis was used to assess the magnitude and direction of trends from 1990 to 2017, and the age-period-cohort model (APCM) was used to analyze the temporal trends of lung cancer mortality by age, period, and cohort.

Results

For lung cancer attributable to smoking, the age-standardized mortality rates (ASMRs) exhibited an upward trend in China and a downward trend in the USA. The overall net drifts per year were 0.72% for China and -3.03% for the USA, and the local drift values in China and the USA increased by age group. All cohort/period relative risks (RRs) increased in China but decreased in the USA. The longitudinal age curves increased rapidly in China, whereas those in the USA were rose gradually. For lung cancer attributable to secondhand smoke, the ASMRs showed a downward trend in both China and the USA. The overall net drifts per year were -0.48% for China and -3.97% for the USA, and the local drift values in China and the USA also increased by age group. Cohort/period RRs decreased in the USA, and fluctuated in China. The longitudinal age curve trends in China and the USA were similar to those of smoking.

Conclusions

The dangers of TE in China remain serious. The rates of lung cancer mortality attributable to TE have increased, especially in older individuals. We recommend that China strengthens the implementation of effective targeted tobacco control policies and other interventions to reduce the burden of lung cancer.

Bayesian Profile Regression to Deal With Multiple Highly Correlated Exposures and a Censored Survival Outcome. First Application in Ionizing Radiation Epidemiology

As multifactorial and chronic diseases, cancers are among these pathologies for which the exposome concept is essential to gain more insight into the associated etiology and, ultimately, lead to better primary prevention strategies for public health. Indeed, cancers result from the combined influence of many genetic, environmental and behavioral stressors that may occur simultaneously and interact. It is thus important to properly account for multifactorial exposure patterns when estimating specific cancer risks at individual or population level. Nevertheless, the risk factors, especially environmental, are still too often considered in isolation in epidemiological studies. Moreover, major statistical difficulties occur when exposures to several factors are highly correlated due, for instance, to common sources shared by several pollutants. Suitable statistical methods must then be used to deal with these multicollinearity issues. In this work, we focused on the specific problem of estimating a disease risk from highly correlated environmental exposure covariates and a censored survival outcome. We extended Bayesian profile regression mixture (PRM) models to this context by assuming an instantaneous excess hazard ratio disease sub-model. The proposed hierarchical model incorporates an underlying truncated Dirichlet process mixture as an attribution sub-model. A specific adaptive Metropolis-Within-Gibbs algorithm-including label switching moves-was implemented to infer the model. This allows simultaneously clustering individuals with similar risks and similar exposure characteristics and estimating the associated risk for each group. Our Bayesian PRM model was applied to the estimation of the risk of death by lung cancer in a cohort of French uranium miners who were chronically and occupationally exposed to multiple and correlated sources of ionizing radiation. Several groups of uranium miners with high risk and low risk of death by lung cancer were identified and characterized by specific exposure profiles. Interestingly, our case study illustrates a limit of MCMC algorithms to fit full Bayesian PRM models even if the updating schemes for the cluster labels incorporate label-switching moves. Then, although this paper shows that Bayesian PRM models are promising tools for exposome research, it also opens new avenues for methodological research in this class of probabilistic models.

TP53 Arg72Pro and XPD Lys751Gln Gene Polymorphisms and Risk of Lung Cancer in Bangladeshi Patients

Background:

Tumor suppressor gene (TP53) is considered as the most frequently mutated gene in almost all forms of human cancer. Moreover, genetic variations in the XPD gene affect the DNA repair capacity increasing cancer susceptibility. Polymorphisms within these genes can play a major role in determining individual lung cancer susceptibility. However, several studies have investigated this possibility; but reported conflicting results. Therefore, the objective of this study was to investigate the role of TP53 Arg72Pro and XPD Lys751Gln gene polymorphisms on lung cancer susceptibility in the Bangladeshi population.

Materials and Methods:

Study subjects comprised of 180 lung cancer patients and 200 healthy volunteers. Genetic polymorphism of TP53 was determined by multiplex PCR-based method, while XPD genotypes were analyzed using Polymerase Chain Reaction-based Restriction Fragment Length Polymorphism (PCR-RFLP) method. Lung cancer risk was estimated as odds ratio (OR) and 95% confidence interval (CI).

Results:

From the results, no significant association between TP53 Arg72Pro polymorphism and lung cancer risk was observed. Whereas, patients with homozygous mutant variants (Gln/Gln) of XPD at codon 751 were found significantly associated with lung cancer risk when compared to the control (OR=3.58; 95% CI=1.58-8.09; p=0.002). Lung cancer risk was found significantly higher with Gln/Gln variants of XPD among smokers (OR=4.03; 95% CI=1.11-14.63; p=0.026). Significant increased risk of lung cancer was found with Arg/Pro genotypes of TP53, Lys/Gln and Gln/Gln variants of XPD in individuals with family history of cancer (OR=3.44; 95% CI=1.36-8.72; p=0.011; OR=3.17; 95% CI=1.20-8.39; p=0.024; OR=16.35; 95% CI=0.92-289.5; p=0.007, respectively).

Conclusion:

The findings indicated that homozygous mutant variants (Gln/Gln) of XPD were associated with increased lung cancer risk, whereas TP53 Arg72Pro polymorphism was not associated with risk of lung cancer among Bangladeshi patients.

LncRNA MIR17HG inhibits non-small cell lung cancer by upregulating miR-142-3p to downregulate Bach-1

Background

This study aimed to investigate the role of MIR17HG in non-small cell lung cancer (NSCLC).

Methods

Differential expression of MIR17HG in NSCLC was first detected by exploring the TCGA dataset. Expression levels of miR-142-3p in both NSCLC and non-tumor tissues were determined by qPCR. The effects of overexpressing MIR17HG on the methylation of miR-142 were assessed by MSP. The effects of overexpressing MIR17HG, miR-142-3p and Bach-1 on the invasion and migration of NSCLC cells were assessed by Trasnwell invasion or migration assay.

Results

Analysis of TCGA dataset revealed slightly downregulated expression of MIR17HG in NSCLC. This downregulation was further confirmed by measuring the expression levels of MIR17HG in NSCLC and non-tumor tissues from NSCLC patients. MIR17HG was found to decrease the methylation of miR-142-3p, and overexpression of MIR17HG led to upregulated miR-142-3p. Moreover, overexpression of MIR17HG also led to downregulated Bach-1, the downstream target of miR-142-3p. Cell invasion and migration analysis showed that overexpression of MIR17HG and miR-142-3p led to inhibited cancer cell invasion and migration. In contrast, overexpression of Bach-1 played an opposite role and attenuated the effects of overexpressing MIR17HG and miR-142-3p.

Conclusion

MIR17HG inhibits NSCLC by upregulating miR-142-3p to downregulate Bach-1.

Trial registration

TJ-MU-2012-0148594, registered January 2, 2012

Epidemiology of lung cancer in Northern Greece: An 18-year hospital-based cohort study focused on the differences between smokers and non-smokers

INTRODUCTION

Lung cancer remains a leading cause of cancer incidence, yet, in Greece, country-level registry-based data are limited. We have thus investigated the epidemiology of lung cancer and its trends in the George Papanikolaou Hospital, Northern Greece over 18 years (2000–2018).

METHODS

We analyzed all the cases reported in the Bronchoscopy Unit of the Hospital for the period 2000–2018. In total, 15131 subjects (12300 males and 2831 females) that presented with a mass in the imaging, were submitted to bronchoscopy. Characteristics of patients such as age, sex, smoking history and occupation were collected. Statistical analysis was performed with SPSS 21.0 software package.

RESULTS

Among all subjects, a total of 5628 (37.2%; mean age: 65.85 ± 9.6 years) cases of primary lung cancer were identified with a male to female ratio of 2:1 (41.1% to 20.4%) (p<0.001). Squamous cell lung cancer was the most common type of lung cancer identified in this population (44%) with a higher proportion in males compared to females (p<0.001). Furthermore, adenocarcinoma was mostly observed in female non-smokers compared to males (p<0.001). The majority of lung cancer cases were identified in patients occupied with agriculture and livestock breeding (41.1%). The mean age at lung cancer diagnosis was 66.13 ± 9.19 years for the whole study population. Lung cancer cases observed with a higher mean of 43.93 ± 10.84 years of smoking compared to cancer-free patients with 39.64 ± 13.23 years of smoking (p<0.001).

CONCLUSIONS

Apart from smoking, demographic characteristics including age, sex and occupation appear to have an impact on lung cancer development in this population. Smoking history alone could not predict the development of lung cancer in the studied northern Greek population.

Effect of trail C1595T variant and gene expression on the pathogenesis of non-small cell lung cancer

It is known that disorders in apoptosis function play an important role in the pathogenesis of many types of cancer, including lung cancer. Tumor necrosis factor related apoptosis inducing ligand (TRAIL), a type II transmembrane protein, is a death ligand capable of inducing apoptosis by activating distinctive death receptor. Our purpose in this study is to investigate the gene polymorphisms in TRAIL molecular pathway and TRAIL gene expression levels in non-small cell lung cancer (NSCLC) patients in terms of pathogenesis and prognosis of the disease. In this study, TRAIL C1595T polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis in 158 patients with NSCLC and 98 healthy individuals. Surgically resected tissues were examined and classified histopathologically. In addition, TRAIL gene expression levels in tumor tissue and tumor surrounding tissue samples of 48 patients with NSCLC were determined using real-time polymerase chain reaction. TRAIL gene expression levels of NSCLC patients were detected significantly 28.8 fold decrease in the tumor tissue group compared to the control group (p=0.026). When patients were compared to tumor stage, expression of TRAIL gene in advanced tumor stage was found to be significantly 7.86 fold higher than early tumor stage [p=0.028]. No significant relationship was found between NSCLC predisposition and prognostic parameters of NSCLC with TRAIL genotypes, but the frequency of TRAIL gene 1595 CT genotype was observed to be lower in the patients compared to the other genotypes, and the difference was found to be very close to statistical significance (p=0.07). It can be suggested that TRAIL may play an important role in the development of NSCLC and may be an effective prognostic factor in tumor progression.: It is known that disorders in apoptosis function play an important role in the pathogenesis of many types of cancer, including lung cancer. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a type II transmembrane protein, is a death ligand capable of inducing apoptosis by activating distinctive death receptor. Our purpose in this study is to investigate the gene polymorphisms in TRAIL molecular pathway and TRAIL gene expression levels in non-small cell lung cancer (NSCLC) patients in terms of pathogenesis and prognosis of the disease.

MiR-326/Sp1/KLF3: A novel regulatory axis in lung cancer progression

OBJECTIVES

To investigate the function and regulatory mechanism of Krüppel-like factor 3 (KLF3) in lung cancer.

MATERIALS AND METHODS

KLF3 expression was analysed by qRT-PCR and Western blot assays. The proliferation, migration, invasion, cycle and apoptosis were measured by CCK-8 and EdU, wound-healing and Transwell, and flow cytometry assays. The tumour growth was detected by nude mouse tumorigenesis assay. In addition, the interaction between KLF3 and Sp1 was accessed by luciferase reporter, EMSA and ChIP assay. JAK2, STAT3, PI3K and p-AKT levels were evaluated by Western blot and IHC assays.

RESULTS

The results indicated that KLF3 expression was elevated in lung cancer tissues. Knockdown of KLF3 inhibited lung cancer cell proliferation, migration and invasion, and induced cell cycle arrest and apoptosis. In addition, the downregulation of KLF3 suppressed tumour growth in vivo. KLF3 was transcriptionally activated by Sp1. miR-326 could bind to 3'UTR of Sp1 but not KLF3 and decreased the accumulation of Sp1, which further indirectly reduced KLF3 expression and inactivated JAK2/STAT3 and PI3K/AKT signaling pathways in vitro and in vivo.

CONCLUSIONS

Our data demonstrate that miR-326/Sp1/KLF3 regulatory axis is involved in the development of lung cancer, which hints the potential target for the further therapeutic strategy against lung cancer.

Interaction Between Environmental Risk Factors and Catechol-O-Methyltransferase (COMT) and X-Ray Repair Cross-Complementing Protein 1 (XRCC1) Gene Polymorphisms in Risk of Lung Cancer Among Non-Smoking Chinese Women: A Case-Control Study

Backgrpound

Various studies have highlighted the link between polymorphisms in the XRCC1 gene (encoding X-ray repair cross-complementing group 1) with the incidence of decreased DNA repair capacity and an increased predisposition to cancer. Catechol-O-methyltransferase (COMT) plays a crucial role in estrogen-induced cancers. In the present study was analyzed the potential influence of XRCC1 and COMT gene polymorphisms as predisposing factors from a lung cancer perspective, in addition to conducting an investigation into their interaction with environmental risk factors in relation to lung cancer among non-smoking Chinese women.

Material/Methods

The XRCC1 gene T-77C, Arg194Trp, Arg280His, Arg399Gln, COMT gene 186C>T, and Val158Met mutations were evaluated in peripheral blood collected from 261 non-smoking female patients diagnosed with primary lung cancer and 265 female patients with benign lung disease.

Result

The results obtained from this study demonstrated that XRCC1–77TC + CC, XRCC1 399Gln/Gln, COMT 186CT + TT, COMT 158Val/Met genotypes, type of occupation, cooking-oil fumes, and soot exposures were all independent risk factors involved with the occurrence of lung cancer among non-smoking women. Moreover, interactions between environmental exposure factors as well as XRCC1 and COMT gene polymorphisms were determined to play significant contributory roles regarding susceptibility of non-smoking females to lung cancer.

Conclusions

Taken together, T-77C and Arg399Gln polymorphisms of the XRCC1 gene, as well as the 186C>T and Val158Met polymorphisms of the COMT gene, increased the risk of lung cancer in non-smoking women, with the factors of occupation type, cooking-oil fumes, and soot exposures representing key contributing factors.

Pomegranate Juice Prevents the Formation of Lung Nodules Secondary to Chronic Cigarette Smoke Exposure in an Animal Model

BACKGROUND

Cigarette smoke (CS) induces an oxidative stress, DNA damage, and lung cancer. Pomegranate juice (PJ) possess potent antioxidant activity attributed to its polyphenols. We investigated whether PJ supplementation would prevent the formation of lung nodules, attenuate mitotic activity, and reduce hypoxia-inducible factor-1α (HIF-1α) expression secondary to CS exposure in an animal model.

METHODS

Mice were divided into: Control group, CS group, CS + PJ group, and PJ-only group. CS and CS + PJ were exposed to CS, 5 days per week, for a total of 5 months. Animals were then housed for additional four months. CS + PJ and PJ groups received PJ throughout the experiment period while others received placebo. At the end of the experiment, the incidence of lung nodules was assessed by (1) histological analysis, (2) mitotic activity [measurement of PHH3 antibodies], and (3) measurement of HIF-1α expression.

RESULTS

The incidence of lung nodules was significantly increased in CS. CS exposure significantly increased PHH3 and HIF-1α expression. PJ supplementation attenuated the formation of lung nodules and reduced PHH3 and HIF-1α expression.

CONCLUSION

PJ supplementation significantly decreased the incidence of lung cancer, secondary to CS, prevented the formation of lung nodules, and reduced mitotic activity and HIF-1α expression in an animal model.

Role of LASP-1, a novel SOX9 transcriptional target, in the progression of lung cancer

Lung cancer accounts for most cancer-related deaths worldwide. However, the underlying mechanism by which it mediates the progression of lung cancer remains unclear. Expression of LASP-1 (LIM and SH3 protein 1) was evaluated in lung cancer tissues and tumor-adjacent normal tissues using immunohistochemistry and western blotting. Functional studies have shown that siRNA-mediated silencing of LASP-1 in human lung cancer cells and reduced cell proliferation, migration, and invasion. Flow cytometry and immunofluorescence staining also revealed that rate of cell apoptosis was increased after knockdown of expression of LASP-1, thereby suggesting that LASP-1 may function as an oncogene during lung cancer progression. SOX9 is an important transcription factor, which is involved in the development of several types of human cancer. Further analysis has showed the presence of a consensus-binding site of SOX9 in the promoter region of LASP-1. Mechanistic investigations showed that LASP-1 was transcriptionally activated by SOX9. Through luciferase reporter and ChIP assays, we demonstrated that LASP-1 was a direct target gene of sex determining region Y-box 9 (SOX9). Knockdown of SOX9 expression by RNA interference reduces cell proliferation and induces apoptosis of lung cancer cells, which was consistent with the results obtained from silencing the expression of LASP-1 in NCI‑H1650 cells. Together, these findings indicated that LASP-1, as a downstream target of SOX9, may act as a novel biomarker for lung cancer and plays an important role in cell proliferation, migration, and invasion.

Increased incidence trend of low-grade and high-grade neuroendocrine neoplasms

PURPOSE

The incidence of neuroendocrine neoplasms is increasing. This work aimed at: (i) establishing worldwide incidence trend of low-grade neuroendocrine neoplasms; (ii) defining the incidence and temporal trend of high-grade neuroendocrine neoplasms in USA utilizing the Surveillance Epidemiology and End Results database; (iii) comparing trends for low-grade vs. high-grade neuroendocrine neoplasms.

METHODS

We conducted a literature search on MEDLINE and Scopus databases and incidence trends were plotted for 1973-2012. The Surveillance Epidemiology and End Results database was used to identify incidence rates in USA for 1973-2012. Incidence rates were stratified according to histological grade, gender and ethnicity. Trends were summarized as annual percent change and corresponding 95% confidence interval.

RESULTS

11 studies were identified involving 72,048 cases; neuroendocrine neoplasm incidence rates increased over time in all countries for all sites, except for appendix. In Surveillance Epidemiology and End Results low-grade neuroendocrine neoplasm incidence rate increased from 1.09 in 1973 to 3.51 per 100,000 in 2012. During this interval, high-grade neuroendocrine neoplasm incidence rate increased from 2.54 to 10.52 per 100,000. African Americans had the highest rates of digestive neuroendocrine neoplasms with male prevalence in high-grade.

CONCLUSIONS

Our data indicate an increase in the incidence of neuroendocrine neoplasms as a worldwide phenomenon, affecting most anatomical sites and involving both low-grade and high-grade neoplasms.

Interferon induced transmembrane protein 3 regulates the growth and invasion of human lung adenocarcinoma

Background

Interferon induced transmembrane protein 3 (IFITM3) plays an important role in the tumorigenesis and progression of multiple cancers. This study investigated the expression and function of IFITM3 in human lung adenocarcinoma.

Methods

Fifty human lung adenocarcinoma tissues were collected. IFITM3 expression was assessed by immunohistochemical staining. The clinicopathologic characteristics of all patients were analyzed.

Results

IFITM3 was mainly detected in the cytoplasm of advanced cancer tissues and its expression was correlated with tumor malignancy grade. Knockdown of IFITM3 in vitro markedly inhibited the proliferation and invasion of lung adenocarcinoma cells.

Conclusion

IFITM3 represents a potential therapeutic target for the treatment of lung adenocarcinoma.

Lung cancer and tobacco smoking in Crete, Greece: reflections from a population-based cancer registry from 1992 to 2013

Background

The Cancer Registry of Crete is a regional population database that collects cancer morbidity/mortality data along with several risk factors. The current study assessed the geographical variation of lung cancer among ever and never smokers in Crete during the last 20 years.

Method

Lung cancer patient records (1992–2013) including information on medical history and smoking habits were obtained from the Cancer Registry of Crete. Age-Adjusted Incidence Rates (AAIR), prevalence of smoking among lung cancer patients and the Population-Attributable Fraction (PAF%) of tobacco smoking were estimated. Kaplan-Meier curves, grouped per smoking status were constructed, and spatio-temporal analyses were carried out to assess the geographical variations of lung cancer and smoking (a = 0.05).

Results

New lung cancer cases in Crete accounted for 9% of all cancers (AAIR_{both genders} = 40.2/100,000/year, AAIR_males = 73.1/100,000/year, AAIR_females = 11.8/100,000/year). Ever smokers presented significantly higher incidence compared to ex-smokers (p = 0.02) and never smokers (p < 0.001). The highest increase was observed in ever smokers (AAIR₁₉₉₂ = 19.2/100,000/year, AAIR₂₀₁₃ = 25.4/100,000/year, p = 0.03), while never smokers presented the lowest increase from 1992 to 2013 (AAIR₁₉₉₂ = 5.3/100,000/year, AAIR₂₀₁₃ = 6.8/100,000/year, p = 0.2). The PAF% of lung cancer mortality is 86% for both genders (males: 89%, females: 78%). AAIRs ranged from 25 to 50/100,000/year, while significant geographical differences were observed among the municipalities of Crete (p = 0.02). Smokers living in the south-east urban regions presented higher risk of dying from lung cancer (RR = 2.2; 95%CI = 1.3–3.5).

Conclusions

The constant increase of lung cancer rates among both genders, especially in females, outlines the need for targeted, geographically-oriented, life-style preventive measures. Design of population-based screening programs, tobacco awareness campaigns and smoking cessation programs in lung cancer hot spots could be guide by these findings.

Viral colonization in exhaled breath condensate of lung cancer patients: Possible role of EBV and CMV

INTRODUCTION

Today, an increasing interest is being addressed to the viral etiology of lung tumors. As a consequence, research efforts are currently being directed to the identification of the new viruses involved in lung carcinogenesis toward which the screening programs could be directed.

OBJECTIVES

The aim of this study was to investigate the airways colonization by the Epstein-Barr virus (EBV) and Citomegalovirus (CMV) in patients affected by lung cancer using, as a respiratory non-invasive sample, the exhaled breath condensate (EBC).

METHODS

About 70 lung-cancer patients and 40 controls were enrolled. All subjects underwent bronchial brushing and EBC collection. EBV-DNA and CMV-DNA were evaluated in both samples by real-time PCR assay.

RESULTS

They were able to detect EBV and CMV in the EBC. An increase of the EBV positivity in non-small cell lung cancer (NSCLC) patients compared with controls and of the CMV in advanced stages of lung cancer were observed. The association of the positivity of the cytology and the CMV test (in EBC or brushing) slightly increased the sensitivity of malignant diagnosis.

CONCLUSION

EBV and CMV resulted detectable in the EBC. In consideration of the potential involvement of these viruses in lung cancer, which was confirmed in this study, future studies in this direction were supported.

Oncogenic roles and drug target of CXCR4/CXCL12 axis in lung cancer and cancer stem cell

Although the great progress has been made in diagnosis and therapeutic in lung cancer, it induces the most cancer death worldwide in both males and females. Chemokines, which have chemotactic abilities, contain up to 50 family members. By binding to G protein-coupled receptors (GPCR), holding seven-transmembrane domain, they function in immune cell trafficking and regulation of cell proliferation, differentiation, activation, and migration, homing under both physiologic and pathologic conditions. The alpha-chemokine receptor CXCR4 for the alpha-chemokine stromal cell-derived-factor-1 (SDF-1) is most widely expressed by tumors. In addition to human tissues of the bone marrow, liver, adrenal glands, and brain, the CXC chemokine SDF-1 or CXCL12 is also highly expressed in lung cancer tissues and is associated with lung metastasis. Lung cancer cells have the capabilities to utilize and manipulate the CXCL12/CXCR system to benefit growth and distant spread. CXCL12/CXCR4 axis is a major culprit for lung cancer and has a crucial role in lung cancer initiation and progression by activating cancer stem cell. This review provides an evaluation of CXCL12/CXCR4 as the potential therapeutic target for lung cancers; it also focuses on the synergistic effects of inhibition of CXCL12/CXCR4 axis and immunotherapy as well as chemotherapy. Together, CXCL12/CXCR4 axis can be a potential therapeutic target for lung cancers and has additive effects with immunotherapy.

Secondhand tobacco smoke exposure and susceptibility to smoking, perceived addiction, and psychobehavioral symptoms among college students

OBJECTIVE

To examine the association of secondhand smoke (SHS) exposure with susceptibility to smoking, perceived addiction, and psychobehavioral effects of exposure among never- and ever-smoking college students.

PARTICIPANTS

Participants were 665 college students at a large, southeastern university in the United States.

METHODS

This study is a secondary analysis of online cross-sectional survey data from randomly selected students in April 2013.

RESULTS

Thirty-eight percent of the sample had moderate to high SHS exposure. Among never-smokers, SHS exposure was associated with increased susceptibility to initiating smoking. Among ever-smokers, SHS exposure was not associated with their perceived addiction to tobacco. In the total sample, SHS exposure was associated with greater psychobehavioral symptoms of exposure.

CONCLUSIONS

SHS exposure may the increase risk of smoking, especially among never-smoking college students. This study strengthens the need for prevention strategies that limit SHS exposure in college environments.

Geographic trends of tobacco-related cancers in Cyprus

BACKGROUND

Causal relationships have been previously established between smoking and various cancers. In Cyprus, 39 % of men and 14 % of women reported daily smoking in 2008. The objective of this study was to compare the incidence of tobacco-related cancers to all other cancers by district and rural-urban classification to understand the impact of tobacco in Cyprus.

METHODS

Data on lung, urinary bladder, oral, pharyngeal, head/neck, and laryngeal cancers were obtained from the Cyprus Cancer Registry (1998-2008). There were 3,635 patients with tobacco-related cancers and 18,780 with non-tobacco cancers. Univariate analysis comparing tobacco-related cancers and all other cancers were conducted with regards to age at diagnosis, age groups, sex, smoking status, disease stage, and rural/urban status, with a p-value of 0.05 considered significant. Smoking prevalence, lung cancer, and bladder cancer rates of Cyprus were also compared to a number of other European countries.

RESULTS

Patients with tobacco-related cancers were older than those with non-tobacco cancers (mean age 67.2 ± 12.4 vs. 62.4 ± 17.1, p < 0.0001). Among those with tobacco-related cancers, 80.1 % were male compared to 45.4 % males with other cancer types. The proportion of ever smokers was higher among males compared to females in urban and rural districts. Sub-districts 41 (Age Adjusted Rate (AAR) 41.9, 95 % CI: 35.7-48.1), 60 (AAR 40.3, 95 % CI: 35.2-45.3), and 50 (AAR 36.3, 95 % CI: 33.8-38.7) had the highest rates of tobacco-related cancers. The overall tobacco-related cancer rate was the highest among males in urban districts (AAR 60.8, 95 % CI: 58.2-63.5). Among tobacco-related cancers, lung cancer had the highest overall AAR (17.9 per 100,000) while head and neck cancer had the lowest overall AAR (5.3 per 100,000). Additionally, even though Cypriot males aged 65-69 years old exhibited higher smoking prevalence than other European countries, the overall lung and bladder cancer rates were lower in Cyprus.

CONCLUSION

Despite the high proportion of smokers in Cyprus, cancer rates are low compared to other countries. Future in-depth measurements of relevant risk factors and smoking exposure can help understand this phenomenon and provide insights for cancer prevention.

Synergistic impaired effect between smoking and manganese dust exposure on pulmonary ventilation function in Guangxi manganese-exposed workers healthy cohort (GXMEWHC)

Purpose

The aims of this study were to investigate the effects of manganese (Mn) dust exposure on lung functions and evaluate the potential synergistic effect between smoking and Mn dust exposure among refinery workers.

Methods

A retrospective study including 1658 workers in a ferromanganese refinery was conducted, with subjects who were from the Guangxi manganese-exposed workers healthy cohort (GXMEWHC). Based on the Mn manganese cumulative exposure index (Mn-CEI), all subjects were divided into the low exposure group (n = 682) and the high exposure group (n = 976). A pulmonary function test was performed using an electronic spirometer, including the values and percentages of FVC, FEV₁, FEV₁/FVC, MMEF, PEFR, MVV, respectively.

Results

No significant effect of Mn dust exposure on the pulmonary function was found in the female workers (all p>0.05). However, there was an obvious decrease in the male workers in the high exposure group compared with those in the low exposure group (FVC -60 ml, FEV₁ -120 ml, MMEF -260 ml/s, MVV -5.06 L, all p<0.05). In the high exposure group, the reduction in FVC% predicted, MMEF and MMEF% predicted was 1.0%, 210 mL/s, and 4.9%, respectively. In particular, among the exposed subjects smokers had a statistically significant decrease in lung function compared with non-smokers and the reduction in FVC% predicted, MMEF and MMEF% predicted was 1.0%, 210 mL/s, and 4.9%, respectively (p<0.05). Partial correlation analysis showed that there was also negative correlation between Mn-CEI and decreased changes in MMEF (r = -0.159, p = 0.018) and also MMEF% predicted (r = -0.163, p = 0.015).

Conclusions

Mn dust can impair the pulmonary ventilation function of male workers but not females, and individual smoking habits and manganese exposure had a synergistic effect on the lung function decrease.

Single-nucleotide polymorphism (c.309T>G) in the MDM2 gene and lung cancer risk

Murine double minute 2 (MDM2) is a negative regulator of p53. A single-nucleotide polymorphism (SNP) (rs2279744: c.309T>G) in the promoter region of the MDM2 gene has been shown to result in higher levels of MDM2 RNA and protein. Regarding the contribution of c.309T>G in the MDM2 gene to the lung cancer risk, previous studies are conflicting. In order to evaluate the association between c.309T>G and the lung cancer risk, a case-control study was performed. The MDM2 genotypes were determined in 762 lung cancer patients and in 700 cancer-free control subjects using the Smart Amplification Process. Statistical adjustment was performed for gender, age and pack-years of smoking. The distributions of c.309T>G (T/T, T/G, G/G) were 20.1, 49.7, 30.2% in the case group and 21.7, 47.9, 30.4% in the healthy-control group. There were no overall associations between the MDM2 genotypes and the risk of lung cancer [T/G genotype: Adjusted odds ratio (AOR), 1.30; 95% confidence interval (CI), 0.88-1.93; and G/G genotype: AOR, 1.18; 95% CI, 0.78-1.80]. The subgroup analysis of gender, histology, smoking status and epidermal growth factor receptor mutation status also indicated that there was no association with lung cancer. Additionally, the genotypes did not have an effect on the age at the time of diagnosis of lung cancer (P=0.25). In conclusion, the G allele frequency in the lung cancer cases was 0.551, which was similar to other studies. The results of the present study suggest that the c.309T>G is not significantly associated with lung cancer.

Polymorphisms in DNA repair genes of XRCC1, XPA, XPC, XPD and associations with lung cancer risk in Chinese people

BACKGROUND

The carcinogenic chemicals and reactive oxygen species in tobacco can result in DNA damage. DNA repair genes play an important role in maintaining genome integrity. Genetic polymorphisms of DNA repair genes and smoking may contribute to susceptibility of lung cancer.

METHODS

In this hospital-based case-control study, we investigated the relationship between 13 tagging single nucleotide polymorphisms (SNPs) in base excision repair pathway and nucleotide excision repair pathway genes, smoking, and lung cancer susceptibility. Thirteen tag SNPs were genotyped in 265 lung cancer patients and 301 healthy controls. Logistic regression and multifactor dimensionality reduction method were applied to explore the association and high-order gene-gene and gene-smoking interaction.

RESULTS

In single tag SNP analysis, XPA rs2808668, XPC rs2733533, and XPD rs1799787 were significantly associated with lung cancer susceptibility. Joint effects analysis of XPA rs2808668, XPC rs2733533 and XPD rs1799787 showed that there was an increased risk of lung cancer with increasing numbers of risk alleles. Haplotype analysis showed that XRCC1 (rs25487, rs1799782, rs3213334) GCC had a positive association with lung cancer. Analysis of gene-gene and gene-smoking interaction by multifactor dimensionality reduction showed that a positive interaction existed between the four genes and smoking. The two-factor model, including XPC rs2755333 and smoking, had the best prediction ability for lung cancer. Compared with the C/C genotype of XPC rs2733533 and no smoking, the combination of genotype A carriers with XPC rs2733533 and heavy smokers (≥30 pack-year) had a 13.32-fold risk of lung cancer.

CONCLUSION

Our results suggest multiple genetic variants in multiple DNA repair genes may jointly contribute to lung cancer risk through gene-gene and gene-smoking interactions.

Prenatal tobacco exposure and brain morphology: a prospective study in young children

It is well known that smoking during pregnancy can affect offspring health. Prenatal tobacco exposure has been associated with negative behavioral and cognitive outcomes in childhood, adolescence, and young adulthood. These associations between prenatal tobacco exposure and psychopathology in offspring could possibly be explained by the influence of prenatal tobacco exposure on brain development. In this prospective study, we investigated the association between prenatal tobacco exposure, behavioral and emotional functioning and brain morphology in young children. On the basis of age and gender, we matched 113 children prenatally exposed to tobacco with 113 unexposed controls. These children were part of a population-based study in the Netherlands, the Generation R Study, and were followed from pregnancy onward. Behavioral and emotional functioning was assessed at age 6 with the Child Behavior Checklist. We assessed brain morphology using magnetic resonance imaging techniques in children aged 6-8 years. Children exposed to tobacco throughout pregnancy have smaller total brain volumes and smaller cortical gray matter volumes. Continued prenatal tobacco exposure was associated with cortical thinning, primarily in the superior frontal, superior parietal, and precentral cortices. These children also demonstrated increased scores of affective problems. In addition, thickness of the precentral and superior frontal cortices was associated with affective problems. Importantly, brain development in offspring of mothers who quit smoking during pregnancy resembled that of nonexposed controls (no smaller brain volumes and no thinning of the cortex). Our findings suggest an association between continued prenatal tobacco exposure and brain structure and function in school-aged children.

Polymorphisms in the vitamin D receptor gene and the lung cancer risk

The relationship between the vitamin D receptor (VDR) polymorphisms and the susceptibility to lung cancer remains unclear. The present meta-analysis was performed to estimate the polymorphisms of VDR and lung cancer risk. The pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated. Subgroup analysis by smoking status was carried out for further elucidation. The VDR BsmI polymorphism seemed to be negatively associated with the lung cancer risk (A vs. G, OR = 0.71, 95 % CI, 0.52-0.96; GA vs. GG, OR = 0.54, 95 % CI, 0.35-0.83; AA + GA vs. GG, OR = 0.55, 95 % CI, 0.36-0.84), particularly among the smokers (AA + GA vs. GG, OR = 0.39, 95 % CI, 0.21-0.72). The VDR ApaI variant genotypes did not alter the risk of lung cancer under all gene models in overall analysis. However, smokers carrying the variant G allele were more susceptible to lung cancer (G vs. T, OR = 1.60, 95 % CI, 1.14-2.25). The polymorphism of VDR TaqI was related to a decreased risk of lung cancer (C vs. T, OR = 0.62, 95 % CI, 0.26-1.46; CC vs. TT, OR = 0.44, 95 % CI, 0.21-0.91; TC vs. TT, OR = 0.58, 95 % CI, 0.38-0.90; CC + TC vs. TT, OR = 0.55, 95 % CI, 0.36-0.84). Besides, the CC + TC carriers in the smokers were at a significantly reduced risk of lung cancer (CC + TC vs. TT, OR = 0.48, 95 % CI, 0.16-1.44). The study supports that the polymorphisms of VDR BsmI and TaqI play protective roles in the lung carcinogenesis, particularly among the smokers. The association of VDR ApaI polymorphism with the lung cancer risk needs to be further elucidated.

P53 codon 72 Arg/Pro polymorphism and lung cancer risk in Asians: an updated meta-analysis

The polymorphism of p53 codon 72, a transversion of G to C (Arg to Pro), has been demonstrated to be associated with the risk for lung cancer. However, individual studies conducted in Asians have provided conflicting and inconclusive findings. Thus, we performed a meta-analysis by pooling all currently available case–control studies to estimate the effect of p53 codon 72 Arg/Pro polymorphism on the development of lung cancer. The pooled odds ratios (ORs) with the corresponding 95 % confidence intervals (95 %CIs) were calculated to assess this effect. A total of 14 individual studies involving 7,929 cases and 5,924 controls were included into this meta-analysis according to the inclusion criteria. The overall OR for the dominant genetic model indicated that the p53 codon 72 Arg/Pro variant was positively correlated with lung cancer risk (OR_{Arg/Pro + Pro/Pro vs. Arg/Arg} = 1.14, 95 %CI 1.07–1.23, P_OR < 0.001). Similar results were found in the stratified analysis of population-based studies. The histological types of lung cancer and smoking status seemed to exert no effect on the lung cancer risk. Sensitivity analysis confirmed the stability of the above findings. The updated meta-analysis suggests that the p53 codon 72 Arg/Pro polymorphism is a risk factor for lung cancer in the Asian population. However, the potential role of gene–environment interaction in lung cancer susceptibility needs further investigation in future studies with high quality.

Association between the XRCC3 C241T polymorphism and lung cancer risk in the Asian population

X-ray repair cross-complementing group 3 (XRCC3) plays a vital role in maintaining the stability of genome by homologous recombination repair for DNA double-strand breaks. The genetic polymorphism of XRCC3 C241T has been implicated in lung cancer risk, but the findings across published studies in Asians are inconsistent and inconclusive. To estimate the precise association of XRCC3 C241T polymorphism with lung cancer risk, a meta-analysis of all currently available studies in Asians was performed. A comprehensive search of the PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases was conducted for eligible studies based on the inclusion criteria. The pooled odds ratios (ORs) with corresponding 95 % confidence intervals (CIs) were calculated to assess the association. Besides, subgroup analysis and sensitivity analysis were also performed for further estimation. Seven available studies with a total of 7,398 subjects were finally included into this meta-analysis. The overall ORs indicated that the XRCC3 C241T polymorphism was not associated with a lung cancer risk among Asians in all genetic contrast modes (ORT allele vs. C allele = 1.08, 95 % CI 0.95-1.24, P OR = 0.252; ORTT vs. CC = 1.30, 95 % CI 0.69-2.45, P OR = 0.426; ORCT vs. CC = 1.07, 95 % CI 0.93-1.24, P OR = 0.363; ORTT + CT vs. CC = 1.08, 95 % CI 0.94-1.24, P OR = 0.300; ORTT vs. CC + CT = 1.29, 95 % CI 0.68-2.43, P OR = 0.439). We failed to identify significant association between the XRCC3 C241T polymorphism and risk of lung cancer in Chinese and population-based studies. Interestingly, the pooled ORs in hospital-based studies indicated that the XRCC3 C241T variant carriers were more susceptible to lung cancer (ORT allele vs. C allele = 1.27, 95 % CI 1.04-1.56, P OR = 0.019; ORCT vs. CC = 1.26, 95 % CI 1.01-1.57, P OR = 0.045; ORTT + CT vs. CC = 1.28, 95 % CI 1.03-1.59, P OR = 0.027). Sensitivity analysis confirmed the stability and liability of all results. This meta-analysis suggests that the XRCC3 C241T polymorphism may not exert a risk effect on the lung cancer risk in Asians, although a statistically significant association was observed among the hospital-based studies. Thus, the precise relationship between the XRCC3 C241T variant and lung cancer risk needs further confirmation in future studies with large available data.

A change in the number of CCSP(pos)/SPC(pos) cells in mouse lung during development, growth, and repair

BACKGROUND

Putative resident stem/progenitor cells have been identified in the bronchoalveolar duct junction (BADJ) of the murine lung. However, the contribution of stem cells expressing both Clara cell secretory protein (CCSP) and pro-surfactant protein C (SP-C) to the repair and maintenance of normal homeostasis is still unclear. In this study, we identified and then quantified CD45(neg)/CCSP(pos)/SP-C(pos) cell numbers in normal and lung-injured mice.

METHODS

Normal lung tissues of fetal, newborn, and adult mice were used to evaluate lung progenitor cells during development and growth. Mice treated with naphthalene were used for the bronchiolar epithelium injury model, and mice treated with bleomycin were used for the alveolar epithelium injury model. These lung tissues were stained with CD45, CCSP, and SP-C antibodies by immunofluorescence. The number of lung progenitor cells was counted as CD45(neg)/CCSP(pos)/SP-C(pos) cells by flow cytometry.

RESULTS

CCSP(pos)/SP-C(pos) epithelial cells in the BADJ were identified from E18 to 7 months after birth. The percentage of CD45(neg)/CCSP(pos)/SP-C(pos) cells was relatively stable to 7 months (between 0.3±0.04% and 1.28±0.11%). When lungs were treated with naphthalene, the proliferation of CCSP(pos)/SP-C(pos) cells was observed as patches of double-positive cells and preceded the recovery of bronchioles. In contrast, when lungs were treated with bleomycin, the proliferation of CCSP(pos)/SP-C(pos) cells was observed, but the type II alveolar epithelial cells never recovered to baseline.

CONCLUSIONS

CCSP(pos)/SP-C(pos) lung cells were stable until 7 months after birth. These cells in the BADJ primarily regenerate bronchiolar epithelial cells and not alveolar epithelial cells.

Dust is in the air: effects of occupational exposure to mineral dust on lung function in a 9-year study

BACKGROUND

Occupational mineral dust exposure is a well-known risk factor for numerous respiratory and systemic diseases. The aim of the present longitudinal study was to assess the influence of work-associated dust exposure on spirometric results. Furthermore, the impact of implementation of stricter limit values for occupational contact with quartz dust on lung function was evaluated.

METHODS

Anthropometric data (age, gender, BMI), smoking behavior, and lung function parameters (FVC, FEV1, MEF50) from 7,204 medical examinations of 3,229 female and male workers during the years 2002-2010 were examined following Austrian standards for occupational medicine and the guidelines of the European Respiratory Society. Analysis of data was performed using models of multiple linear regression.

RESULTS

Lung function decrease over time was associated with smoking habits and duration of occupational dust exposure. Specifically, occupational quartz exposure negatively influenced the annual lung function parameters (FVC, -6.68 ml; FEV1, -6.71 ml; and MEF50, -16.15 ml/s, all p < 0.001). Thus, an overadditive effect of smoking and work-related contact with quartz was found regarding decline in MEF50 (p < 0.05). Implementation of stricter occupational limit values for dust exposure resulted in a highly significant deceleration of the annual decrease in respiratory function (p = 0.001).

CONCLUSIONS

Individual smoking habits and occupational dust exposure had a negative impact on lung function. To reduce the risk of loss of respiratory capacity, smoking cessation is especially recommended to workers exposed to quartz dust. Moreover, stricter limit values could prevent chronic occupational damage to the respiratory system.

Adenomatous polyposis coli-mediated accumulation of abasic DNA lesions lead to cigarette smoke condensate-induced neoplastic transformation of normal breast epithelial cells

Adenomatous polyposis coli (APC) is a multifunctional protein having diverse cellular functions including cell migration, cell-cell adhesion, cell cycle control, chromosomal segregation, and apoptosis. Recently, we found a new role of APC in base excision repair (BER) and showed that it interacts with DNA polymerase β and 5'-flap endonuclease 1 and interferes in BER. Previously, we have also reported that cigarette smoke condensate (CSC) increases expression of APC and enhances the growth of normal human breast epithelial (MCF10A) cells in vitro. In the present study, using APC overexpression and knockdown systems, we have examined the molecular mechanisms by which CSC and its major component, Benzo[α]pyrene, enhances APC-mediated accumulation of abasic DNA lesions, which is cytotoxic and mutagenic in nature, leading to enhanced neoplastic transformation of MCF10A cells in an orthotopic xenograft model.

Surgery for lung adenocarcinoma with smokers' polycythemia: a case report

Background

Smoking is a cause of cancer and polycythemia. Therefore, surgeons who treat patients with cancer may also encounter patients with polycythemia. However, few cases of surgical patients with polycythemia have been reported; in particular, a surgical case involving smokers’ polycythemia has never been reported. We herein report a patient with lung cancer and smokers’ polycythemia who successfully underwent lobectomy with control of hematocrit based on a modified formula in the perioperative period.

Case presentation

A 67-year-old man underwent abdominoperineal resection for rectal carcinoma in June 2008. A ground glass opacity had been identified in the upper lobe of the right lung and was gradually enlarging. In March 2012, bronchoscopic cytology for investigation of the mass revealed non-small cell lung cancer, suggesting primary lung non-small cell carcinoma (T1bN0M0, Stage IA). When he was referred to our hospital for surgery, his complete blood count showed a red blood cell level of 6.50×10⁶/μL, hemoglobin of 21.0 g/dL, and hematocrit of 60.1%. The hematologists’ diagnosis was secondary polycythemia due to heavy smoking (smokers’ polycythemia) because the white blood cell and platelet counts were within normal limits and the erythropoietin was not increased. We calculated the appropriate phlebotomy and infusion volumes based on a formula that we modified. After 550 g of blood was phlebotomized to reduce the hematocrit to approximately 55%, video-assisted right lung upper lobectomy with lymph node dissection was performed in April 2012. The hematocrit was maintained at <50% postoperatively, and the patient was uneventfully discharged on postoperative day 7. The predictive hematocrit and measured hematocrit were very closely approximated in this case.

Conclusion

We experienced a patient with smokers’ polycythemia who underwent right upper lobectomy for adenocarcinoma. The findings in this case report are meaningful for surgeons treating cancer patients because there are few reports discussing the perioperative care of surgical patients with polycythemia.

CXCR4/CXCL12 in non-small-cell lung cancer metastasis to the brain

Lung cancer represents the leading cause of cancer-related mortality throughout the world. Patients die of local progression, disseminated disease, or both. At least one third of the people with lung cancer develop brain metastases at some point during their disease, even often before the diagnosis of lung cancer is made. The high rate of brain metastasis makes lung cancer the most common type of tumor to spread to the brain. It is critical to understand the biologic basis of brain metastases to develop novel diagnostic and therapeutic approaches. This review will focus on the emerging data supporting the involvement of the chemokine CXCL12 and its receptor CXCR4 in the brain metastatic evolution of non-small-cell lung cancer (NSCLC) and the pharmacological tools that may be used to interfere with this signaling axis.

MMP1-1607 1G/2G polymorphism and lung cancer risk: a meta-analysis

Matrix metalloproteinase-1 (MMP-1) plays an important role in the breakdown of extracellular matrix and mediates pathways of apoptosis, angiogenesis, and immunity. It has been demonstrated that MMP-1 overexpression is associated with tumor initiation, invasion, and metastasis. Many studies have investigated the association between MMP1-1607 1G/2G polymorphism and lung cancer risk, but the impact of MMP1-1607 1G/2G polymorphism on lung cancer is unclear owing to the obvious inconsistence among those studies. This study aimed to quantify the strength of the association between MMP1-1607 1G/2G polymorphism and lung cancer risk. We searched the PubMed, Embase, and Wanfang databases for studies on the association between MMP1-1607 1G/2G polymorphism and risk of lung cancer. We estimated summary odds ratio (OR) with its corresponding 95 % confidence interval (95%CI) to assess the association. Overall, MMP1-1607 1G/2G polymorphism was associated with increased risk of lung cancer under four genetic models (OR(2G versus 1G) = 1.21, 95 %CI 1.06-1.37; OR(2G2G versus 1G1G) = 1.36, 95%CI 1.09-1.70; OR(2G2G versus 2G1G+1G1G) = 1.33, 95 %CI 1.10-1.61; and OR(2G2G+2G1G versus 1G1G) = 1.15, 95 %CI 1.04-1.27). Meta-analyses of studies with high quality showed that MMP1-1607 1G/2G polymorphism was still associated with lung cancer risk under those four genetic models. Subgroup analyses by ethnicity and sensitivity analyses further identified the significant association in East Asians. No evidence of publication bias was observed. Meta-analyses of available data show a significant association between MMP1-1607 1G/2G polymorphism and lung cancer risk.

Association of MDM2 SNP309 variation with lung cancer risk: evidence from 7196 cases and 8456 controls

Background

Evidence suggests that MDM2 T309G polymorphism may be a risk factor for several cancers. Increasing investigations have been conducted on the association of MDM2 T309G polymorphisms with lung cancer risk and have yielded conflicting results. Previous meta-analyses on this issue have reported inconclusive data. The aim of the present study was to derive a more precise estimation of the relationship.

Methods and Findings

Updated meta-analyses examining the association between MDM2 T309G polymorphism and lung cancer risk were performed. Separate analyses on ethnicity, smoking status, histological types and gender as well as source of controls were also implemented. Eligible studies were identified for the period up to Feb 2012. Lastly, ten publications including eleven case-control studies were selected for analysis. The overall data failed to indicate a significant association between MDM2 T309G polymorphism and lung cancer risk (GG vs TT OR = 1.14; 95%CI = 0.95−1.37; dominant model: OR = 1.05; 95%CI = 0.92−1.19; recessive model: OR = 1.12; 95%CI = 0.99−1.27). In a subgroup analysis by smoking status, increased lung cancer risk was shown among never-smokers (GG vs TT: OR = 1.76; 95%CI = 1.36−2.29; dominant model: OR = 1.48; 95%CI = 1.22−1.81; recessive model: OR = 1.37; 95%CI = 1.11−1.69). In subgroup analysis by gender, elevated risk was presented among women under a recessive model (OR = 1.29; 95%CI = 1.04−1.59). In the subgroup analysis by ethnicity, histological types and source of controls, no marked associations were observed.

Conclusions

Compared to the previous meta-analyses, the results of this study confirmed that MDM2 T309G polymorphism might be a risk factor for lung cancer among never-smokers. However, the data failed to suggest a marked association between the G allele of MDM2 T309G and lung cancer risk among Asians. More interestingly, subgroup analysis by gender indicated that homozygous GG alleles might raise lung cancer risk among females.