Active screening for lung cancer increases smoking abstinence in Australia

Background

Smoking cessation is an important screening component, but the evidence base to inform implementation is lacking. We report longitudinal smoking behavior in an Australian screening cohort and examine predictor variables associated with continued smoking.

Methods

Healthy current or former smokers (quit less than 15 years and ≥30-pack year smoking history) aged 60–74 years underwent CT screening at baseline, year 1 and year 2. Participants received brief smoking cessation advice and generic Quitline materials. Smoking status was self-reported every 6 months for 5 years. Mediators of smoking behavior, adjusted for sociodemographic, health and scan variables were explored using logistic regression modeling.

Results

Two hundred thirty-five participants were analyzed. One hundred eight (46%) were current smokers at enrolment. At baseline, current smokers’ mean Fagerström Test for Nicotine Dependence was 4.9, and they had higher levels of lung cancer-specific distress and passive smoke exposure than former smokers. At 36 months, 33% of baseline smokers achieved sustained (≥6 months) smoking abstinence. Five (4%) former smokers relapsed at any point during the study. Continued smoking was positively associated with greater nicotine dependence and smoking pack-years, and negatively associated with cardiovascular disease, stroke, and lung cancer family history.

Conclusions

This study provides the first data on smoking cessation rates in Australian lung cancer screenees and supports screening as a teachable moment. We identify several factors that identify smokers who may require more intensive smoking cessation interventions and could be used to develop effective smoking cessation as part of lung cancer screening, tailored to individual risk profiles.     

Genome-wide association study of INDELs identified four novel susceptibility loci associated with lung cancer risk

Genome-wide association studies (GWAS) have identified 45 susceptibility loci associated with lung cancer. Only less than SNPs, small insertions and deletions (INDELs) are the second most abundant genetic polymorphisms in the human genome. INDELs are highly associated with multiple human diseases, including lung cancer. However, limited studies with large-scale samples have been available to systematically evaluate the effects of INDELs on lung cancer risk. Here, we performed a large-scale meta-analysis to evaluate INDELs and their risk for lung cancer in 23,202 cases and 19,048 controls. Functional annotations were performed to further explore the potential function of lung cancer risk INDELs. Conditional analysis was used to clarify the relationship between INDELs and SNPs. Four new risk loci were identified in genome-wide INDEL analysis (1p13.2: rs5777156, Insertion, OR = 0.92, p = 9.10 × 10⁻⁸; 4q28.2: rs58404727, Deletion, OR = 1.19, p = 5.25 × 10⁻⁷; 12p13.31: rs71450133, Deletion, OR = 1.09, p = 8.83 × 10⁻⁷; and 14q22.3: rs34057993, Deletion, OR = 0.90, p = 7.64 × 10⁻⁸). The eQTL analysis and functional annotation suggested that INDELs might affect lung cancer susceptibility by regulating the expression of target genes. After conducting conditional analysis on potential causal SNPs, the INDELs in the new loci were still nominally significant. Our findings indicate that INDELs could be potentially functional genetic variants for lung cancer risk. Further functional experiments are needed to better understand INDEL mechanisms in carcinogenesis.     

Japanese genome‐wide association study identifies a significant colorectal cancer susceptibility locus at chromosome 10p14

Genome‐wide association studies are a powerful tool for searching for disease susceptibility loci. Several studies identifying single nucleotide polymorphisms (SNP) connected intimately to the onset of colorectal cancer (CRC) have been published, but there are few reports of genome‐wide association studies in Japan. To identify genetic variants that modify the risk of CRC oncogenesis, especially in the Japanese population, we performed a multi‐stage genome‐wide association study using a large number of samples: 1846 CRC cases and 2675 controls. We identified 4 SNP (rs7912831, rs4749812, rs7898455 and rs10905453) in chromosome region 10p14 associated with CRC; however, there are no coding or non‐coding genes within this region of fairly extensive linkage disequilibrium (a 500‐kb block) on 10p14. Our study revealed that the 10p14 locus is significantly correlated with susceptibility to CRC in the Japanese population, in accordance with the results of multiple studies in other races.     

CHRNA5 polymorphisms and risk of lung cancer in Chinese Han smokers

Lung cancer is the most frequent cancer among men in many countries. It is the result of interactions between genetic and environmental factors, among which tobacco smoking is a key environmental factor. CHRNA5, Cholinergic Receptor, Neuronal Nicotinic, Alpha Polypeptide-5, was previously reported to be associated with lung cancer risk. To identify the genetic susceptibility and tobacco smoking that influence lung cancer risk in Han population, we performed a case-control study in 228 patients and 301 controls. These data were compared using the χ²-test, genetic model analysis, and haplotype analysis. rs495956, rs680244, rs601079, rs555018, 588765 and rs11637635 showed an increased risk of lung cancer in both allelic model and genetic mode analysis. The genotype G/A-A/A of rs11637635 was most strongly associated with a 2.17-fold increased risk of lung cancer in dominant model (p = 0.018). One SNP, rs684513, was associated with a 0.645-fold decreased risk (p = 0.033) in allelic model analysis. By haplotype association analysis, haplotype sequences CTTATCAAAGA and GA of CHRNA5 were found to be associated with a 2.03-fold and 1.91-fold increased lung cancer risk (p < 0.05). Our results, combined with those from previous studies, suggest that genetic variation in CHRNA5 may influence susceptibility to lung cancer among Han smokers.     

控烟是预防肺癌的主要措施——记太原市肺癌病例对照流行病学调查

背景 与目的:山西省太原市空气污染常较为严重.了解各种类型肺癌的危险因素,以采取有效的预防措施.方法:2005年3月—2007年9月,山西省太原市396例肺癌新发病例和465名健康对照者纳入本研究.利用太原市肿瘤医院病理学检查确诊的肺癌病例,配以人群为基础、随机选择的对照,进行病例对照询问调查和环境监测.分析时注意排除...     

hOGG1, p53 genes, and smoking interactions are associated with the development of lung cancer

This study aimed to investigate the effects of Ser/Cys polymorphism in hOGG1 gene, Arg/Pro polymorphism in p53 gene, smoking and their interactions on the development of lung cancer. Ser/Cys polymorphism in hOGG1 and Arg/Pro polymorphism in p53 among 124 patients with lung cancer and 128 normal people were detected using PCR-RFLP. At the same time, smoking status was investigated between the two groups. Logistic regression was used to estimate the effects of Ser/Cys polymorphism and Arg/Pro polymorphisms, smoking and their interactions on the development of lung cancer. ORs (95% CI) of smoking, hOGG1 Cys/Cys and p53 Pro/ Pro genotypes were 2.34 (1.41-3.88), 2.12 (1.03-4.39), and 2.12 (1.15-3.94), respectively. The interaction model of smoking and Cys/Cys was super-multiplicative or multiplicative, and the OR (95% CI) for their interaction item was 1.67 (0.36 -7.78). The interaction model of smoking and Pro/Pro was super-multiplicative with an OR (95%CI) of their interaction item of 5.03 (1.26-20.1). The interaction model of Pro/Pro and Cys/Cys was multiplicative and the OR (95%CI) of their interaction item was 0.99 (0.19-5.28). Smoking, hOGG1 Cys/Cys, p53 Pro/Pro and their interactions may be the important factors leading to the development of lung cancer.     

Expression of nicotinic acetylcholine receptor subunit genes in non-small-cell lung cancer reveals differences between smokers and nonsmokers

Nicotine and its derivatives, by binding to nicotinic acetylcholine receptors (nAChR) on bronchial epithelial cells, can regulate cellular proliferation and apoptosis via activating the Akt pathway. Delineation of nAChR subtypes in non-small-cell lung cancers (NSCLC) may provide information for prevention or therapeutic targeting. Expression of nAChR subunit genes in 66 resected primary NSCLCs, 7 histologically non-involved lung tissues, 13 NSCLC cell lines, and 6 human bronchial epithelial cell lines (HBEC) was analyzed with quantitative PCR and microarray analysis. Five nonmalignant HBECs were exposed to nicotine in vitro to study the variation of nAChR subunit gene expression with nicotine exposure and removal. NSCLCs from nonsmokers showed higher expression of nAChR alpha6 (P < 0.001) and beta3 (P = 0.007) subunit genes than those from smokers, adjusted for gender. In addition, nAChR alpha4 (P < 0.001) and beta4 (P = 0.029) subunit gene expression showed significant difference between NSCLCs and normal lung. Using Affymetrix GeneChip U133 Sets, 65 differentially expressed genes associated with NSCLC nonsmoking nAChR alpha6beta3 phenotype were identified, which gave high sensitivity and specificity of prediction. nAChR alpha1, alpha5, and alpha7 showed significant reversible changes in expression levels in HBECs upon nicotine exposure. We conclude that between NSCLCs from smokers and nonsmokers, different nAChR subunit gene expression patterns were found, and a 65-gene expression signature was associated with nonsmoking nAChR alpha6beta3 expression. Finally, nicotine exposure in HBECs resulted in reversible differences in nAChR subunit gene expression. These results further implicate nicotine in bronchial carcinogenesis and suggest targeting nAChRs for prevention and therapy in lung cancer.     

miR-146a 多态性与非小细胞肺癌易感性的研究

目的：研究汉族人群miR-146a rs2910164 G/C基因多态性与非小细胞肺癌易感性的关系。方法：通过病例-对照研究,应用PCR-限制性片段长度多态性（PCR-RFLP）检测技术对198例非小细胞肺癌患者与218例对照组人群进行rs2910164基因型的检测,并随机抽取10%的样本进行DNA测序,进行遗传平衡检测。进一步采用Logistic回归分析该位点与非小细胞肺癌的相关性。结果：rs2910164被酶切成GG、GC、CC基因型,GG、GC、CC分型在对照组分别为103例（47.25%）、85例（38.99%）、30例（13.76%）;在病例组分别为31例（15.66%）、99例（50.00%）、68例（34.34%）。随机抽取10%的样本进行DNA测序,其结果与PCRRFLP分型结果一致,基因分型频率满足Hardy-Weinberg遗传平衡（P>0.05）。与对照组相比,Logistic回归分析发现携带C等位基因的基因型可明显增加非小细胞肺癌的发病风险[显性模型OR=5.04,95%CI为（4.72,5.39）,P<0.01;隐性模型OR=2.75,95%CI为（2.57,2.94）,P<0.01];而rs2910164基因多态性与非小细胞肺癌的临床病理特征（分级、分期、转移）之间无明显相关关系（P>0.05）,rs2910164基因多态性与吸烟之间无交互作用（P>0.05）。结论：携带miR-146a rs2910164 C等位基因的基因型可能与非小细胞肺癌的遗传易感性相关。     

Association of genetic polymorphisms in DNA repair pathway genes with non-small cell lung cancer risk

DNA repair function is believed to play an important role in cancer development and to be affected by genetic polymorphisms. Numerous epidemiological studies have examined the associations between single nucleotide polymorphisms (SNPs) in the DNA repair genes and lung cancer risk, but the results are inconsistent. The aim of this study was to investigate the associations of several SNPs in the DNA repair pathways and risk of non-small cell lung cancer (NSCLC) in a Chinese population. The study included 581 NSCLC cases and 603 healthy controls. The polymorphisms studied include XRCC1 (rs25487), hOGG1 (rs1052133), MUTYH (rs3219489) in the base excision repair (BER) pathway, XPA (rs1800975), ERCC2 (rs1799793 and rs13181) in the nucleotide excision repair (NER) pathway and XRCC3 (rs861539) in the double strand break repair (DSB) pathway. The associations between lung cancer risk and genetic polymorphisms were evaluated using the logistic regression models and subgroup analyses. Meta-analyses were conducted for the SNPs shown to be significantly associated with lung cancer risk in our study. Our findings showed that XPA −4G>A (rs1800975) had a significant association with lung cancer (OR = 1.64; 95% CI: 1.03-2.60), and the association was more evident in squamous cell carcinoma (OR = 1.69; 95% CI: 1.00-2.84). Three BER polymorphisms showed no independent effects on the risk of lung cancer. The stratified analysis showed higher lung cancer risk among the smokers carrying the variant XPA allele (OR = 1.75; 95% CI: 1.15-2.65) and among the non-smokers carrying the variant ERCC2 allele of 312Asn (OR = 2.10; 95% CI: 1.22-3.64). Meta-analysis showed that individuals with the variant AA genotype of XPA (−4G>A) had higher risk of lung cancer compared to those with the ‘G’ wild allele (OR = 1.28; 95% CI: 1.12-1.47); and those with variant alleles of ERCC2 312Asn had higher risk compared to those with wild 312Asp alleles among nonsmokers (OR = 1.58; 95% CI: 1.20-2.08). Although smoking is the dominant risk factor of lung cancer, XPA −4G>A (rs1800975) is also associated with the risk of NSCLC, especially for squamous cell carcinoma, among Asian young smokers. ERCC2 Asp/Asn (rs1799793) polymorphism may also affect lung cancer risk among nonsmokers. The NER pathway seems to have more strong influences on lung cancer than the BER pathway.     

代谢酶基因多态性与肺癌易感性

肺癌的易感性存在个体差异,参与解毒及生物转化的代谢酶的基因多态性被认为与肺癌易感性相关.催化致癌物质代谢过程的酶主要有Ⅰ相代谢酶和Ⅱ相代谢酶,包括细胞色素P450酶系及由N-乙酰转移酶、微粒体环氧化物酶、醌氧化还原酶1(NQO1)等构成的Ⅱ相代谢酶系,均为预测肺癌易感的候选基因.通过研究代谢酶基因多态性与肺癌易感性的关系,发现有意义的肺癌标志物,筛选肺癌易感人群并提前进行干预,有利于降低肺癌的发病风险.     

Fine mapping of chromosome 5p15.33 identifies novel lung cancer susceptibility loci in Han Chinese

Genome‐wide association studies in European and Asian populations have consistently identified chromosome 5p15.33 as a lung cancer susceptibility region. To investigate further the genetic architecture of common variants in this region, we conducted a two‐stage fine‐mapping analysis discovered by targeted resequencing of 200 cases and 300 controls individually, and validated in multiethnic lung cancer Genome wide association studies (GWASs) with 12,843 cases and 12,639 controls. Two independent variants were identified in approximate conditional analysis with GCTA and consistently validated in lung cancer GWASs in both Asian and European populations. These were rs10054203 in TERT (resequencing: OR = 1.69, p = 2.70 × 10^?4; validation: OR = 1.34, p = 2.10 × 10^?23 for Asian, and OR = 1.09, p = 6.00 × 10^?3 for European), and rs397640 in CLPTM1L (resequencing: OR = 0.37, p = 1.19 × 10^?4; validation: OR = 0.75, p = 5.89 × 10^?8 for Asian, and OR = 0.90, p = 2.40 × 10^?2 for European). Expression quantitative trait loci analysis showed the risk allele (C) of rs10054203 was significantly associated with lower mRNA expression of CTD‐2245Ef15.3 (p = 0.019) and Tubulin Polymerization‐Promoting Protein (TPPP , p = 0.031) in 167 lung tissues. In conclusion, in this largest and first resequencing‐based fine‐mapping analysis of 5p15.33 region in Han Chinese, we identified two novel variants associated with lung cancer susceptibility. Further validation studies and functional work is required to confirm the roles of the newly discovered variants.     

SULT1A1 Arg213His polymorphism and lung cancer risk: a meta-analysis

Background: The SULT1A1 Arg213His polymorphism is reported to be associated with lung cancer risk. However, this relationship remains controversial. For better understanding a meta-analysis was therefore performed. Methods: An extensive search was performed to identify all case-control studies investigating association between SULT1A1 Arg213His polymorphism and lung cancer risk. The strength was assessed by odds ratio (OR) with the corresponding 95% confidence interval (95%CI). Results: A total of five publications covering 1,669 cases and 1,890 controls were included in this meta-analysis. No significant association between SULT1A1 Arg213His polymorphism and lung cancer risk was observed in overall comparisons in all genetic models (dominant model: OR=1.33, 95%CI=1.00-1.76, P=0.05; additive model: OR=1.30, 95%CI=0.93-1.81, P=0.12; recessive model: OR=1.21, 95%CI=0.89-1.66, P=0.23). However, on subgroup analysis, an elevated risk in mixed populations with variant His allele was revealed in the dominant model (OR=1.66, 95% CI=1.06-2.62, P=0.03). Furthermore, the SULT1A1 Arg213His polymorphism was associated with an increased risk of lung cancer in both females and males in the dominant model (females: OR=1.72, 95%CI=1.29-2.27, P=0.00; males: OR=1.46, 95%CI=1.19-1.78, P=0.00). No significant association between this polymorphism and different smoking status (smokers and non-smokers) and the other ethnicities (Asians and Caucasians) was shown. Conclusions: The results of this meta-analysis indicate that the SULT1A1 Arg213His polymorphism is not associated with lung cancer risk in Asians and Caucasians, but possible elevation for genotype (GA/AA) in mixed populations and males and females needs further investigation.     

Genome-wide association study identifies two new susceptibility loci for colorectal cancer at 5q23.3 and 17q12 in Han Chinese

Genome-wide association studies (GWAS) have reported a number of loci harboring common variants that influence risk of colorectal cancer (CRC) in European descent. But all the SNPs identified explained a small fraction of total heritability. To identify more genetic factors that modify the risk of CRC, especially Chinese Han specific, we conducted a three-stage GWAS including a screening stage (932 CRC cases and 966 controls) and two independent validations (Stage 2: 1,759 CRC cases and 1,875 controls; Stage 3: 943 CRC cases and 1,838 controls). In the combined analyses, we discovered two novel loci associated with CRC: rs12522693 at 5q23.3 (CDC42SE2-CHSY3, OR = 1.31, P = 2.08 × 10⁻⁸) and rs17836917 at 17q12 (ASIC2-CCL2, OR = 0.75, P = 4.55 × 10⁻⁸). Additionally, we confirmed two previously reported risk loci, rs6983267 at 8q24.21 (OR = 1.17, P = 7.17 × 10⁻⁷) and rs10795668 at 10p14 (OR = 0.86, P = 2.96 × 10⁻⁶) in our cohorts. These results bring further insights into the CRC susceptibility and advance our understanding on etiology of CRC.     

History of lung disease and risk of lung cancer in a population with high household fuel combustion exposures in rural China

History of chronic lung diseases and household coal use for heating and cooking are established risk factors of lung cancer; however, few studies have been able to explore these risk factors simultaneously. Xuanwei, China, has some of the highest rates of lung cancer in China and most residents experience substantial in-home coal smoke exposures. Using a population-based case–control study of 498 lung cancer cases and 498 age-matched controls, we evaluated the risk of lung cancer in relation to coal smoke exposure and history of chronic lung diseases, including chronic obstructive pulmonary disease (COPD), asthma, tuberculosis (TB), chronic bronchitis, and emphysema. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by conditional logistic regression adjusting for potential confounders. We observed an increased risk of lung cancer with history of any chronic lung disease among males (OR = 14.2; 95%CI = 4.3–46.9), females (OR = 2.6; 95%CI = 1.1–6.3), smokers (OR = 12.7; 95%CI = 3.5–45.8), and nonsmokers (OR = 2.6; 95%CI = 1.1–6.4). Specifically, TB (OR = 83.7; 95%CI = 11.0–634.7), COPD (OR = 3.2; 95%CI = 1.7–6.0), and emphysema and chronic bronchitis (OR = 3.3; 95%CI = 1.7–6.4) were associated with increased risks. These findings suggest that history of chronic lung diseases may also increase risk of lung cancer in populations with indoor coal smoke exposures.     

GSTT1基因多态性与中国四川汉族人群肺癌遗传易感性关系的研究

背景与目的GSTs可能参与机体致癌物的解毒反应，如保护个体免受吸烟的损害，因此GSTs基因多态性被认为是个体是否患癌的易感因素。本研究的目的是探讨GSTT1基因多念性与中国四川汉族人群肺癌遗传易感性的关系。方法采用病例对照和PCR—RFLP方法检测中国四川汉族人群肺癌患者150例和健康对照者152例的GSTT1基因缺失型的频率，并评价其与吸烟和肺癌遗传易感性的关系。结果①GSTT1（-）基因型在肺癌组和对照组分别为54．7％(82／150)和38．2％(58/152)．二者间比较有显著性差异(OR=1．681，95％CI=1，009～2．803，P=0．046)；②GSTT1(-)基因型患肺鳞癌(OR=2．969．95％CI=1．511～5．834。P=0．002)及肺腺癌(OR=2．095．95％CI=1．060～4．140，P=0．033)的风险性明显增加；③吸烟者中GSTT1(-)基因型者患肺癌的风险是GSTT1( )者的4．051倍；①GSTT1(-)基因型者中，吸烟者患肺癌的风险是不吸烟者的53．885倍；⑤吸烟≥20包年者中，GSTT1(-)基因型者患肺癌的风险是GSTT1( )者的4．296倍。结论①(GSTT1(-)基因型增加四川汉族人群患肺癌的风险性．特别是增加患肺鳞癌的风险；②GSTT1(-)基因型和吸烟之间存在交互作用，吸烟量越大且为GSTT1(-)基因型者则患肺癌的风险性越大。     

X射线损伤修复交叉互补基因1多态性与非吸烟女性肺癌易感性的关系

目的探讨X射线损伤修复交叉互补基因1（XRCCl）单核苷酸多态性与非吸烟女性肺癌易感性的关系。方法采用以医院患者为基础的病例一对照研究方法,非吸烟女性肺癌患者50例,非癌对照50例。以聚合酶链反应一限制性片段长度多态性（PCR—RFLP）方法检测XRCC1基因Arg399Gln多态性,计算各基因型的比值比（OR）,并探讨烹饪油烟暴露史与多态基因型交互作用对肺癌患癌风险的影响。结果肺癌组与对照组XRCC1 Arg399Gln多态基因型分布差异无统计学意义（P〉0．05）,而腺癌组基因型分布与对照组差异有统计学意义（P〈0．05）。相对于399Arg／Arg基因型,携带至少1个Gin等位基因的个体患肺腺癌的调整OR值为2．19（95％CI为0．73～6．61）,而XRCC1 399Gin／Gin基因型携带者的调整OR值为14．12（95％CI为2、14～92．95）。携带至少1个399Gln等位基因的烹饪油烟暴露者患肺腺癌的风险明显升高,调整OR值为6．29（95％c,为1．99～19、85）。结论XRCC1基因Arg399Gln多态可能是非吸烟女性肺腺癌的遗传易感因素,399Gln等位基因与烹饪油烟交互作用,可提高非吸烟女性肺腺癌的发病风险。     

Association of a common AGO1 variant with lung cancer risk: A two‐stage case–control study

Based on the important role of microRNA (miRNA) biosynthesis genes in carcinogenesis, we hypothesized that polymorphisms in the miRNA biosynthesis genes may modulate susceptibility to lung cancer. To test this hypothesis, we conducted a two‐stage study to evaluate the associations between single nucleotide polymorphisms (SNPs) in the miRNA biosynthesis genes and the risk of lung cancer. In stage 1 of the study, 24 SNPs in the 11 miRNA biosynthesis genes (DROSHA, DGCR8, RAN, XPO5, DICER, AGO1, AGO2, HIWI, GEMIN3, GEMIN4, and TRBP) were genotyped in 100 lung cancer patients and 100 healthy controls using a sequenome mass spectrometry‐based genotyping assay. One promising SNP (AGO1 rs636832A > G) was selected for stage 2 of the study, and genotyped by a melting‐curve analysis using fluorescence‐labeled hybridization probes in an independent set of 552 cases and 552 controls. The AGO1 rs636832A > G exhibited highly consistent results between the two stages of the study. In combined analysis, the 636832A > G was associated with a significantly decreased risk of lung cancer in a dose‐dependent manner (P_trend = 6.0 × 10^?4). Individuals with at least one rs636832G allele were at a significantly decreased risk of lung cancer compared with those with the AA genotype (adjusted odds ratio = 0.67, 95% confidence interval = 0.53–0.84, P = 4.0 × 10^?4). This finding suggests that the AGO1 rs636832A > G might be a useful marker for determining the susceptibility to lung cancer and that the AGO1 gene might be involved in the development of lung cancer. © 2010 Wiley‐Liss, Inc.