Lung Cancer in Never Smokers: A Review

Proteogenomic Characterization Reveals Therapeutic Vulnerabilities in Lung Adenocarcinoma

To explore the biology of lung adenocarcinoma (LUAD) and identify new therapeutic opportunities, we performed comprehensive proteogenomic characterization of 110 tumors and 101 matched normal adjacent tissues (NATs) incorporating genomics, epigenomics, deep-scale proteomics, phosphoproteomics, and acetylproteomics. Multi-omics clustering revealed four subgroups defined by key driver mutations, country, and gender. Proteomic and phosphoproteomic data illuminated biology downstream of copy number aberrations, somatic mutations, and fusions and identified therapeutic vulnerabilities associated with driver events involving KRAS, EGFR, and ALK. Immune subtyping revealed a complex landscape, reinforced the association of STK11 with immune-cold behavior, and underscored a potential immunosuppressive role of neutrophil degranulation. Smoking-associated LUADs showed correlation with other environmental exposure signatures and a field effect in NATs. Matched NATs allowed identification of differentially expressed proteins with potential diagnostic and therapeutic utility. This proteogenomics dataset represents a unique public resource for researchers and clinicians seeking to better understand and treat lung adenocarcinomas.

The effect of susceptibility variants, identified in never-smoking female lung cancer cases, on male smokers

BACKGROUND/AIMS

Genome wide and candidate gene association studies have identified polymorphisms associated with the risk of lung cancer in never-smokers. This study was conducted to evaluate the association between 11 polymorphisms identified in female never smokers and the lung cancer risk in male smokers.

METHODS

This study included 714 lung cancer patients and 626 healthy controls. The polymorphisms were genotyped using SEQUENOM MassARRAY iPLEX assay or Taq-Man assay.

RESULTS

Two polymorphisms were associated with the risk of lung cancer in male smokers, as in female never smokers. Male smokers carrying the rs4975616 variant allele had a significantly decreased risk of lung cancer (in a codominant model: odds ratio, 0.77; 95% confidence interval, 0.61 to 0.96; p = 0.02). The rs9387478 polymorphism also reduced lung cancer risk in male smokers (in a codominant model: odds ratio, 0.85; 95% confidence interval, 0.73 to 0.997; p = 0.046). In a stratified analysis, the association between these polymorphisms and the risk of lung cancer was predominant in lighter smokers and for cases of adenocarcinoma.

CONCLUSION

These results suggest that a subset of polymorphisms known to be associated with the risk of lung cancer in female never smokers is also associated with the risk of lung cancer in male smokers.

Non-Small Cell Lung Carcinoma Presenting With Severe Tracheal Deviation: A Case Report

Non-small cell lung carcinoma (NSCLC) is usually diagnosed in adults between the ages of 18-35 years. Here, we present a case of a young adult who presented with severe tracheal deviation and was diagnosed with advanced-stage NSCLC with no past medical or social histories; she presented with worsening right arm pain, numbness, and tingling over the course of three weeks. She presented to an urgent care center that prescribed her nonsteroidal anti-inflammatory drugs (NSAIDs) and muscle relaxants without any symptom improvement. Her pain continued to worsen, and she went to the emergency department (ED) where an X-ray and CT angiogram were performed revealing a large right lung mass severely compressing the trachea. Biopsies confirmed non-small cell lung cancer and the patient was started on chemotherapy. As clinicians, sometimes we do not pay attention to young patients with nonspecific complaints. This case clearly reflects the importance of proper evaluation of symptoms even though there is low clinical suspicion.

MiR-449b-5p targets lncRNA PSMG3-AS1 to suppress cancer cell proliferation in lung adenocarcinoma

BACKGROUND

PSMG3-AS1 has been characterized as an oncogenic lncRNA in breast cancer, while its role in other cancers is unknown. This study investigated the role of PSMG3-AS1 in lung adenocarcinoma (LUAD).

METHODS

This study included 64 LUAD patients (42 males and 22 females) who were enrolled between May 2012 and May 2014. RT-qPCR was used to evaluate the expression levels of lncRNA. Cell proliferation analysis was performed using CCK-8 kit.

RESULTS

We found that upregulation of PSMG3-AS1 in LUAD predicted the poor survival of patients. MiR-449b-5p is downregulated in LUAD and the expression levels of LUAD were inversely correlated with the expression levels of PSMG3-AS1. MiR-449b-5p was predicted to target PSMG3-AS1, and overexpression of miR-449b-5p resulted in the downregulation of PSMG3-AS1 in LUAD cells. Cell proliferation analysis showed that overexpression of PSMG3-AS1 resulted in increased rate of cell proliferation. Overexpression of miR-449b-5p reduced the enhancing effects of PSMG3-AS1 on cell proliferation.

CONCLUSIONS

Therefore, miR-449b-5p may target PSMG3-AS1 in LUAD to suppress cancer cell proliferation.

LINC00958 Accelerates Cell Proliferation and Migration in Non-Small Cell Lung Cancer Through JNK/c-JUN Signaling

Non-small cell lung cancer (NSCLC) denotes the most common type of lung cancers with high mortality globally. Long non-coding RNAs (lncRNAs) with differential expression have been indicated to be participants in the pathogenesis and development of cancer. However, the precise role of lncRNAs in NSCLC is still largely obscure. In this study, we explored a newly discovered intergenic lncRNA LINC00958 in NSCLC. First of all, the online databases suggested that LINC00958 was slightly expressed in human normal lung tissues but upregulated in LUSC tissues. Besides, the upregulation of LINC00958 in both lung adenocarcinoma (LUAD) and LUSC cell lines was easily found when compared with the normal BEAS-2B cells. In addition, we elucidated that knockdown of LINC00958 led to impaired proliferation, induced apoptosis, and hampered migration in LUAD cells. Moreover, a typical oncogenic pathway, JNK signaling, was verified to be involved in LINC00958-contributed LUAD development. Of note, we explained that LINC00958 exerted the tumor-promoting function in LUAD by enhancing the transactivation of p-c-JUN through activating JNK signaling. Meanwhile, we also revealed that LINC00958 was transcriptionally regulated by c-JUN. In addition, earlier findings were also suitable for LUSC cells. By and large, our work illustrated that LINC00958 facilitates tumorigenesis in NSCLC by activating the JNK/c-JUN signaling pathway, indicating a new road for diagnosis and treatment of both LUAD and LUSC.

A cohort study on the association of MDM2 SNP309 with lung cancer risk in Bangladeshi population

BACKGROUND/AIMS

Bangladesh is a densely populated country with an increased incidence of lung cancer, mostly due to smoking. Therefore, elucidating the association of mouse double minute 2 homolog (MDM2) single nucleotide polymorphism (SNP) 309 (rs2279744) with lung cancer risk from smoking in Bangladeshi population has become necessary.

METHODS

DNA was extracted from blood samples of 126 lung cancer patient and 133 healthy controls. The MDM2 SNP309 was genotyped by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP), using the restriction enzymes MspA1I. Logistic regression was then carried out to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the risk of lung cancer. A meta-analysis of SNP309 was also carried out on 12,758 control subjects and 11,638 patient subjects.

RESULTS

In multivariate logistic regression, significantly increased risk of lung cancer was observed for MDM2 SNP309 in the dominant model (TG + GG vs. TT: OR, 2.13; 95% CI, 1.29 to 3.53). Stratification analysis revealed that age, sex, obesity, and smoking also increases the risk of lung cancer when carrying the MDM2 SNP309. Our meta-analysis revealed that MDM2 SNP309 was considerably associated with lung cancer in Asian populations (TG + GG vs. TT: OR, 1.32; 95% CI , 1.12 to 1.56; p = 0.019 for heterogeneity).

CONCLUSION

The MDM2 SNP309 was associated with high risk of lung cancer in Bangladeshi and Asian population, particularly with increased age, smoking, and body mass index.

Protective effects of 17-β-oestradiol and phytoestrogen on age-induced oxidative stress and inhibition of surfactant synthesis in rat type II pneumocytes

Epidemiological data suggest protective effects of oestrogen and phytoestrogen on lung tissue. This study aimed to elucidate the role of 17-β-oestradiol and phytoestrogen in age-related inhibition of surfactant synthesis and oxidative stress in rat type II pneumocytes. Forty male and 66 female Wistar rats were used. Female rats were randomly kept intact or ovariectomized at age 12 months. At age 22 months, ovariectomized rats received 17-β-oestradiol, soy extract, or no treatment. Oxidative stress markers CO, NO, cGMP and lipid peroxide (LPO), antioxidant enzymes and phosphatidylcholine (PC) were measured in cultured type II pneumocytes isolated at ages 2, 14, 18, 22 and 24 months. Old, male and ovariectomized rats showed significantly higher CO, NO, cGMP and LPO and lower PC content and antioxidant enzymes. 17-β-oestradiol and phytoestrogen significantly reversed these effects. In conclusion, aging and oestrogen deprivation decreased PC synthesis and altered the redox status in type II pneumocytes, which were partially restored by 17-β-oestradiol or soy supplementation.

Lung cancer occurrence attributable to passive smoking among never smokers in China: a systematic review and meta-analysis

Background

Quantifying the occurrence of lung cancer due to passive smoking is a necessary step when forming public health policy. In this study, we estimated the proportion of lung cancer cases attributable to passive smoking among never smokers in China.

Methods

Six databases were searched up to July 2019 for original observational studies reporting relative risks (RRs) or odds ratios (ORs) for the occurrence of lung cancer associated with passive smoking in Chinese never smokers. The population attributable fraction (PAF) was then calculated using the combined proportion of lung cancer cases exposed to passive smoking and the pooled ORs from meta-analysis. Data are reported with their 95% confidence intervals.

Results

We identified 31 case-control studies of never smokers and no cohort studies. These comprised 9,614 lung cancer cases and 13,093 controls. The overall percentages of lung cancers attributable to passive smoking among never smokers were 15.5% (9.0-21.4%) for 9 population-based studies and 22.7% (16.6-28.3%) for 22 hospital-based studies. The PAFs for women were 17.9% (11.4-24.0%) for the population-based studies and 20.9% (14.7-26.7%) for the hospital-based studies. The PAF for men was only calculable for hospital-based studies, which was 29.0% (95% CI: 8.0-45.2%). Among women, the percentage of lung cancer cases attributable to household exposure (19.5%) was much higher than that due to workplace exposure (7.2%).

Conclusions

We conclude that approximately 16% of lung cancer cases among never smokers in China are potentially attributable to passive smoking. This is slightly higher among women (around 18%), with most cases occurring due to household exposure.

Influence of Chronic Obstructive Pulmonary Disease on Volatile Organic Compounds in Patients with Non-small Cell Lung Cancer

INTRODUCTION

The etiology of lung cancer is multifactorial. Exposure to tobacco smoke and the role played by the carcinogenic compounds that it contains would explain the common association between lung cancer and chronic obstructive pulmonary disease (COPD), a disease which is very much linked to tobacco use. In both diseases, sustained inflammation is caused by increased oxidative stress (for example, lipid peroxidation). This generates low molecular weight substances called volatile organic compounds (VOC) that are excreted during breathing. VOC metabolomics provides an indirect measure of oxidative stress.

OBJECTIVE

The aim of this study was to establish the relative influence of COPD on the VOC profile in patients with non-small cell lung cancer (NSCLC), by first studying the possible variation of VOC associated with lung cancer histology.

PATIENTS AND METHODS

Exhaled air was tested in 107 NSCLC patients, who were divided into 2groups: NSCLC with COPD and non-COPD with NSCLC. The exhaled air sample was obtained with the BIOVOC® sampler, and transferred to desorption tubes for later analysis by thermal desorption-gas chromatography-mass spectrometry. The VOC analysis showed lineal aldehydes and carboxylic acids.

RESULTS AND CONCLUSIONS

No statistically significant differences were found in VOC associated with histology. NSCLC and COPD patients present a 1.7-fold (1.1-2.7) probability of detection of propionic acid (95% CI: 1.22- 6.2) than patients without COPD or NSCLC (P = 0.013).

Predicting Lung Cancer Occurrence in Never-Smoking Females in Asia: TNSF-SQ, a Prediction Model

BACKGROUND

High disease burden suggests the desirability to identify high-risk Asian never-smoking females (NSF) who may benefit from low-dose CT (LDCT) screening. In North America, one is eligible for LDCT screening if one satisfies the U.S. Preventive Services Task Force (USPSTF) criteria or has model-estimated 6-year risk greater than 0.0151. According to two U.S. reports, only 36.6% female patients with lung cancer met the USPSTF criteria, while 38% of the ever-smokers ages 55 to 74 years met the USPSTF criteria.

METHODS

Using data on NSFs in the Taiwan Genetic Epidemiology Study of Lung Adenocarcinoma and the Taiwan Biobank before August 2016, we formed an age-matched case-control study consisting of 1,748 patients with lung cancer and 6,535 controls. Using these and an estimated age-specific lung cancer 6-year incidence rate among Taiwanese NSFs, we developed the Taiwanese NSF Lung Cancer Risk Models using genetic information and simplified questionnaire (TNSF-SQ). Performance evaluation was based on the newer independent datasets: Taiwan Lung Cancer Pharmacogenomics Study (LCPG) and Taiwan Biobank data after August 2016 (TWB2).

RESULTS

The AUC based on the NSFs ages 55 to 70 years in LCPG and TWB2 was 0.714 [95% confidence intervals (CI), 0.660-0.768]. For women in TWB2 ages 55 to 70 years, 3.94% (95% CI, 2.95-5.13) had risk higher than 0.0151. For women in LCPG ages 55 to 74 years, 27.03% (95% CI, 19.04-36.28) had risk higher than 0.0151.

CONCLUSIONS

TNSF-SQ demonstrated good discriminative power. The ability to identify 27.03% of high-risk Asian NSFs ages 55 to 74 years deserves attention.

IMPACT

TNSF-SQ seems potentially useful in selecting Asian NSFs for LDCT screening.

Multiple genome pattern analysis and signature gene identification for the Caucasian lung adenocarcinoma patients with different tobacco exposure patterns

Background

When considering therapies for lung adenocarcinoma (LUAD) patients, the carcinogenic mechanisms of smokers are believed to differ from those who have never smoked. The rising trend in the proportion of nonsmokers in LUAD urgently requires the understanding of such differences at a molecular level for the development of precision medicine.

Methods

Three independent LUAD tumor sample sets—TCGA, SPORE and EDRN—were used. Genome patterns of expression (GE), copy number variation (CNV) and methylation (ME) were reviewed to discover the differences between them for both smokers and nonsmokers. Tobacco-related signature genes distinguishing these two groups of LUAD were identified using the GE, ME and CNV values of the whole genome. To do this, a novel iterative multi-step selection method based on the partial least squares (PLS) algorithm was proposed to overcome the high variable dimension and high noise inherent in the data. This method can thoroughly evaluate the importance of genes according to their statistical differences, biological functions and contributions to the tobacco exposure classification model. The kernel partial least squares (KPLS) method was used to further optimize the accuracies of the classification models.

Results

Forty-three, forty-eight and seventy-five genes were identified as GE, ME and CNV signatures, respectively, to distinguish smokers from nonsmokers. Using only the gene expression values of these 43 GE signature genes, ME values of the 48 ME signature genes or copy numbers of the 75 CNV signature genes, the accuracies of TCGA training and SPORE/EDRN independent validation datasets all exceed 76%. More importantly, the focal amplicon in Telomerase Reverse Transcriptase in nonsmokers, the broad deletion in ChrY in male nonsmokers and the greater amplification of MDM2 in female nonsmokers may explain why nonsmokers of both genders tend to suffer LUAD. These pattern analysis results may have clear biological interpretation in the molecular mechanism of tumorigenesis. Meanwhile, the identified signature genes may serve as potential drug targets for the precision medicine of LUAD.

LncRNA MAGI2-AS3 Upregulates Cytokine Signaling 1 by Sponging miR-155 in Non-Small Cell Lung Cancer

Background: MAGI2-AS3 has been reported to be a tumor suppressor in breast cancer and bladder cancer. This study analyzed the role of MAGI2-AS3 in non-small cell lung cancer (NSCLC). Results: The authors found that MAGI2-AS3 and suppressor of cytokine signaling 1 (SOCS-1) were both downregulated in NSCLC. MAGI2-AS3 and SOCS-1 were significantly and positively correlated in NSCLC tumor tissues. During follow-up, low levels of MAGI2-AS3 and SOCS-1 were found to be significantly correlated with patients' poor survival. In NSCLC cells, MAGI2-AS3 overexpression mediated the upregulated, while miR-155 expression mediated the downregulated SOCS-1 overexpression. RNA binding analysis showed that MAGI2-AS3 may be a sponge of miR-155. Cell proliferation revealed decreased cell proliferation rate of NSCLC cells after MAGI2-AS3 and SOCS-1 overexpression. MiR-155 played an opposite role and reduced the effects of MAGI2-AS3 overexpression. Conclusion: Therefore, MAGI2-AS3 upregulates cytokine signaling 1 by sponging miR-155 to inhibit NSCLC cell proliferation.

Type 2 diabetes mellitus does not increase the risk of lung cancer among never-smokers: a nationwide cohort study

Previous studies have reported higher incidences of lung cancer among smokers diagnosed with diabetes than those without. Accordingly, this study investigated whether type 2 diabetes mellitus (T2DM) diagnosis alone can be associated with increased lung cancer incidences among never-smokers in the Korean population. Newly diagnosed never-smoking T2DM patients were identified from the nationwide longitudinal cohort of health examination data of South Korea (2002-2013). Cox proportional hazards regression model was employed to estimate the hazard ratios (HRs) and 95% confidence interval (CI) of lung cancer in the T2DM patient and abnormal fasting blood sugar (FBS) groups. T2DM (HR =0.91, 95% CI: 0.71 to 1.17) and abnormal FBS level are no significant association with lung cancer incidence based on the given HR. T2DM does not increase the risk of lung cancer among never-smokers. A large cohort study affirms minimal impact of T2DM on lung cancer development in the never-smoking Korean population.

Clinical characteristics and survival in non-small cell lung cancer patients by smoking history: a population-based cohort study

Introduction: Approximately, 10-15% of lung cancer patients have never smoked. Previous epidemiological studies on non-tobacco associated lung cancer have been hampered by selected data from a small number of hospitals or limited numbers of patients. By use of data from large population-based registers with national coverage, this study aims to compare characteristics and survival of patients with non-small cell lung cancer (NSCLC) with different smoking histories.Methods: Swedish national population-based registers were used to retrieve data on patients diagnosed with primary NSCLC between 2002 and 2016. The Kaplan-Meier method and Cox proportional hazard models were used to estimate overall survival and lung cancer-specific survival by smoking history.Results: In total, 41,262 patients with NSCLC were included. Of those, 4624 (11%) had never smoked. Never-smokers were more often women and older compared to ever smokers (current and former). Adenocarcinoma was proportionally more common in never-smokers (77%) compared to current (52%) and former smokers (57%). Stage IV disease was more common in never-smokers (57%) than in current (48%) and former smokers (48%). Epidermal growth factor receptor mutation was observed more in never-smokers (37%) compared to current (5%) and former smokers (9%). Both lung cancer-specific and overall survival were higher for never-smokers compared to current smokers.Conclusions: The observed differences in characteristics between never-smokers and smokers, and the higher survival in never-smokers compared to smokers from this large population-based study provide further evidence that lung cancer in never-smokers is clinically different to tobacco-associated lung cancer. The findings from this study emphasise the need for an improved understanding of genetics, pathogenesis, mechanisms and progression of non-tobacco associated lung cancer that may help prevent lung cancer or identify individually targeted treatments.

Differential gene expression analysis of HNSCC tumors deciphered tobacco dependent and independent molecular signatures

Head and neck cancer is the sixth most common cancer worldwide, with tobacco as the leading cause. However, it is increasing in non-tobacco users also, hence limiting our understanding of its underlying molecular mechanisms. RNA-seq analysis of cancers has proven as effective tool in understanding disease etiology. In the present study, RNA-Seq of 86 matched Tumor/Normal pairs, of tobacco smoking (TOB) and non-smokers (N-TOB) HNSCC samples analyzed, followed by validation on 375 similar datasets. Total 2194 and 2073 differentially expressed genes were identified in TOB and N-TOB tumors, respectively. GO analysis found muscle contraction as the most enriched biological process in both TOB and N-TOB tumors. Pathway analysis identified muscle contraction and salivary secretion pathways enriched in both categories, whereas calcium signaling and neuroactive ligand-receptor pathway was more enriched in TOB and N-TOB tumors respectively. Network analysis identified muscle development related genes as hub node i. e. ACTN2, MYL2 and TTN in both TOB and N-TOB tumors, whereas EGFR and MYH6, depicts specific role in TOB and N-TOB tumors. Additionally, we found enriched gene networks possibly be regulated by tumor suppressor miRNAs such as hsa-miR-29/a/b/c, hsa-miR-26b-5p etc., suggestive to be key riboswitches in regulatory cascade of HNSCC. Interestingly, three genes PKLR, CST1 and C17orf77 found to show opposite regulation in each category, hence suggested to be key genes in separating TOB from N-TOB tumors. Our investigation identified key genes involved in important pathways implicated in tobacco dependent and independent carcinogenesis hence may help in designing precise HNSCC diagnostics and therapeutics strategies.

A link between environmental pollution and civilization disorders: a mini review

Most civilization disorders have a complex etiology, involving factors such as genetics, lifestyle, and environmental pollution (EP) due to different chemicals. Among harmful chemicals, the major ones include particulate matter (PM), nitrogen oxides, polycyclic aromatic hydrocarbons (PAHs), heavy metals, pesticides, plasticizers, polychlorinated biphenyls (PCBs), dioxins, furans, some food additives, hormones, and antibiotics. In fact, potential pollutants are countless and most of them have never been evaluated in terms of their toxicity and health risks, especially that new chemicals emerge all the time due to interactions between the existing ones. It is almost impossible to determine the effects of these new compounds on health. Previous studies have revealed a broad spectrum of diseases related to pollution. EP has been associated with an increased incidence of some malignancies, an increased rate of all-cause mortality, development or exacerbation of cardiovascular diseases, recurrent infections, impairment of intellectual and psychomotor development in children, development of type 2 diabetes, respiratory and immune system diseases, and also brain degenerative disorders. EP is an important cause of morbidity and mortality worldwide, generating high health care costs. Global pollution questions the common recommendation to eat vegetables, fruit, and fish regularly as part of a healthy diet, if they do not have ecological certification. Research in the fields of ecology, biology, and toxicology is needed to determine which environmental contaminants are the most hazardous to wildlife and humans and at what levels. Only an interdisciplinary cooperation and measures to raise public awareness could help improve environmental protection.

Thymoquinone (2-Isoprpyl-5-methyl-1, 4-benzoquinone) as a chemopreventive/anticancer agent: Chemistry and biological effects

Cancer remains the topmost disorders of the mankind and number of cases is unceasingly growing at unprecedented rates. Although the synthetic anti-cancer compounds still hold the largest market in the modern treatment of cancer, natural agents have always been tried and tested for potential anti-cancer properties. Thymoquinone (TQ), a monoterpene and main ingredient in the essential oil of Nigella sativa L. has got very eminent rankings in the traditional systems of medicine for its anti-cancer pharmacological properties. In this review we summarized the diverse aspects of TQ including its chemistry, biosynthesis, sources and pharmacological properties with a major concern being attributed to its anti-cancer efficacies. The role of TQ in different aspects involved in the pathogenesis of cancer like inflammation, angiogenesis, apoptosis, cell cycle regulation, proliferation, invasion and migration have been described. The mechanism of action of TQ in different cancer types has been briefly accounted. Other safety and toxicological aspects and some combination therapies involving TQ have also been touched. A detailed literature search was carried out using various online search engines like google scholar and pubmed regarding the available research and review accounts on thymoquinone upto may 2019. All the articles reporting significant addition to the activities of thymoquinone were selected. Additional information was acquired from ethno botanical literature focusing on thymoquinone. The compound has been the centre of attention for a long time period and researched regularly in quite considerable numbers for its various physicochemical, medicinal, biological and pharmacological perspectives. Thymoquinone is studied for various chemical and pharmacological activities and demonstrated promising anti-cancer potential. The reviewed reports confirmed the strong anti-cancer efficacy of thymoquinone. Further in-vitro and in-vivo research is strongly warranted regarding the complete exploration of thymoquinone in ethnopharmacological context.

Correlation Study of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Pathological Subtypes of Invasive Lung Adenocarcinoma and Prognosis

Purpose: To investigate the correlation between ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) metabolic parameters and clinicopathological factors in pathological subtypes of invasive lung adenocarcinoma and prognosis.

Patients and Methods: Metabolic parameters and clinicopathological factors from 176 consecutive patients with invasive lung adenocarcinoma between August 2008 and August 2016 who underwent ¹⁸F-FDG PET/CT examination were retrospectively analyzed. Invasive lung adenocarcinoma was divided into five pathological subtypes:lepidic predominant adenocarcinoma (LPA), acinar predominant adenocarcinoma (APA), papillary predominant adenocarcinoma (PPA), solid predominant adenocarcinoma (SPA), and micropapillary predominant adenocarcinoma (MPA). The differences in metabolic parameters [maximal standard uptake value (SUVmax), mean standard uptake value (SUVmean), total lesion glycolysis (TLG), and metabolic tumor volume (MTV)] and tumor diameter for different pathological subtypes were analyzed. Patients were divided into two groups according to their prognosis: good prognosis group (LPA, APA, PPA) and poor prognosis group (SPA, MPA). Logistic regression was used to filter predictors and construct a predictive model, and areas under the receiver operating curve (AUC) were calculated. Cox regression analysis was performed on prognostic factors.

Results: 82 (46.6%) females and 94 (53.4%) males of patients with invasive lung adenocarcinoma were enrolled in this study. Metabolic parameters and tumor diameter of different pathological subtype had statistically significant (P < 0.05). The predictive model constructed using independent predictors (Distant metastasis, Ki-67, and SUVmax) had good classification performance for both groups. The AUC for SUVmax was 0.694 and combined with clinicopathological factors were 0.745. Cox regression analysis revealed that Stage, TTF-1, MTV, and pathological subtype were independent risk factors for patient prognosis. The hazard ratio (HR) of the poor prognosis group was 1.948 (95% CI 1.042–3.641) times the good prognosis group. The mean survival times of good and poor prognosis group were 50.2621 (95% CI 47.818–52.706) and 35.8214 (95% CI 27.483–44.159) months, respectively, while the median survival time was 47.00 (95% CI 45.000–50.000) and 31.50 (95% CI 23.000–49.000) months, respectively.

Conclusion: PET/CT metabolic parameters combined with clinicopathological factors had good classification performance for the different pathological subtypes, which may provide a reference for treatment strategies and prognosis evaluation of patients.

Bioinformatics and functional analyses of key genes in smoking-associated lung adenocarcinoma

Smoking is one of the most important factors associated with the development of lung cancer. However, the signaling pathways and driver genes in smoking-associated lung adenocarcinoma remain unknown. The present study analyzed 433 samples of smoking-associated lung adenocarcinoma and 75 samples of non-smoking lung adenocarcinoma from the Cancer Genome Atlas database. Gene Ontology (GO) analysis was performed using the Database for Annotation, Visualization and Integrated Discovery and the ggplot2 R/Bioconductor package. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed using the R packages RSQLite and org.Hs.eg.db. Multivariate Cox regression analysis was performed to screen factors associated with patient survival. Kaplan-Meier and receiver operating characteristic curves were used to analyze the potential clinical significance of the identified biomarkers as molecular prognostic markers for the five-year overall survival time. A total of 373 differentially expressed genes (DEGs; |log2-fold change|≥2.0 and P<0.01) were identified, of which 71 were downregulated and 302 were upregulated. These DEGs were associated with 28 significant GO functions and 11 significant KEGG pathways (false discovery rate <0.05). Two hundred thirty-eight proteins were associated with the 373 differentially expressed genes, and a protein-protein interaction network was constructed. Multivariate regression analysis revealed that 7 mRNAs, cytochrome P450 family 17 subfamily A member 1, PKHD1 like 1, retinoid isomerohydrolase RPE65, neurotensin receptor 1, fetuin B, insulin-like growth factor binding protein 1 and glucose-6-phosphatase catalytic subunit, significantly distinguished between non-smoking and smoking-associated adenocarcinomas. Kaplan-Meier analysis demonstrated that patients in the 7 mRNAs-high-risk group had a significantly worse prognosis than those of the low-risk group. The data obtained in the current study suggested that these genes may serve as potential novel prognostic biomarkers of smoking-associated lung adenocarcinoma.

Morbidity Profile of Cases Attended Oncology Center of Mansoura University (OCMU), Egypt: A Cross-Sectional Study

Objectives

In Egypt, the National Cancer Registry Program integrates hospital-based data from multiple Egyptian governorates to obtain representative rates. Unfortunately, Dakahlia (one of the largest Egyptian governorates) was not integrated in the National Cancer Registry Program. This research aimed to acquire malignancy rates from the Oncology Center of Mansoura University, which is one of the two oncology centers present in Dakalia Governorate in Egypt.

Methods

Electronic records of patients who attended the Oncology Center of Mansoura University during 2016 were accessed with permission. Analysis was performed to extract diagnostic categories (age, gender, and geographic distribution of cases).

Results

Most commonly diagnosed malignancies were breast cancer which represented about 10% of cases in the Oncology Center of Mansoura University during 2016. This was followed by leukemia (3.80%), lymphoma (3.59%), and liver cancer (3.44%). Diagnoses encountered included benign and malignant tumors as well as non-tumor diagnoses. The Mansoura district had the highest proportionate rate of breast cancer cases. Females in the age group ≥ 35 < 60 years had the highest incidence of malignancy cases across all diagnoses.

Conclusion

The burden of breast cancer in Mansoura district is high. Risk factors need further evaluation with a recommendation to perform an environmental risk assessment.

The oncogenic role of CB2 in the progression of non-small-cell lung cancer

BACKGROUND

Several studies have verified the important role of cannabinoid and cannabinoid receptor agonists in tumor progression. However, little is known about the precise role of CB2 expression level in the progression of non-small-cell lung cancer (NSCLC).

METHODS

The expression of CB2 in NSCLC tissues and corresponding paracancerous tissues was examined using immunohistochemical staining assay. The expression of CB2 was silenced by siRNA interference and loss-of-function assays were performed to investigate the biological function of CB2 in the proliferation, migration, invasion, and apoptosis of NSCLC cells. The expression of related proteins was detected using western blot analysis.

RESULTS

In this study, we observed that CB2 was up-regulated in NSCLC tissues and the up-regulation was correlated with tumor size and advanced NSCLC pathological grading. Moreover, compared with the control group, silencing of CB2 decreased the proliferation, migration and invasion abilities of A549 and H1299 cells, and induced apoptosis by regulation of Bcl-2/Bax axis and active Caspase3. Furthermore, CB2 knockdown inactivated the Akt/mTOR/P70S6K pathway by decreasing the level of p-Akt, p-mTOR and expression of P70S6K in A549 and H1299 cells.

CONCLUSION

Our data suggested that targeting CB2 may inhibit the growth and survival of NSCLC cells, which the Akt/mTOR/P70S6K pathway may be involved in. These results confer the pro-oncogenic role of CB2 in the progression of NSCLC, thus improving our understanding of CB2 in tumor progression.

Predicting the survival of patients with lung adenocarcinoma using a four-gene prognosis risk model

Lung adenocarcinoma (LAD) is difficult to diagnose as it tends to be small in size and metastasize early. The aim of the present study was to investigate prognostic factors for patients with LAD and establish a prognosis risk model. A training set consisting of clinical and RNA sequencing data from 503 patients with LAD, as well as expression data from a further 59 LAD and adjacent tissues, was obtained from The Cancer Genome Atlas. Additionally, a validation dataset was acquired from the Gene Expression Omnibus database (GSE26939), which included clinical and gene expression data from 115 patients. Using the DESeq2 package to compare expression between LAD and adjacent tissues, differentially expressed genes (DEGs) were identified. On the basis of survival and the random forests for survival, regression and classification package, genes for constructing the prognosis risk model were selected. The prognosis risk model was constructed and validated using the survival package. Subsequently, high- and low-risk groups were compared using the Limma package to identify DEGs, and enrichment analysis was performed using the web-based gene set analysis toolkit. A protein-protein interaction network was visualized using Cytoscape software. There were 18,567 DEGs between the LAD samples and the adjacent tissues, and 363 DEGs between the high- and low-risk groups. Of these, four genes were selected for constructing the prognosis risk model, myosin IE (MYO1E), endoplasmic reticulum oxidoreductase 1α (ERO1L), C1q and tumor necrosis factor-related protein 6 (C1QTNF6) and family with sequence similarity 83, member A (FAM83A). The survival time of high- and low-risk groups in the validation set were significantly different. Functional enrichment revealed that the genes that interacted with MYO1E, ERO1L, C1QTNF6 and FAM83A separately were enriched in 'cell cycle regulation', 'synthesis and assembly of nucleic acids', 'histone modification and cell cycle progression' and 'cell secretion process'. The four-gene prognosis risk model could potentially be used for predicting the survival of patients with LAD.

Heterogeneous tumor features and treatment outcome between males and females with lung cancer (LC): Do gender and sex matter?

Lung cancer (LC) is the leading cause of cancer-related death worldwide, despite a decreasing incidence rate in recent years, especially in men. Most risk factors for LC could be linked to an individual's reproductive system and secondary sex characteristics ('sex-related') and/or to some physical, behavioral and personality traits ('gender-related') peculiar to males rather than females or vice versa. An imbalance of these etiologic factors could explain why some LC features may differ between sexes. For this review, an extended literature data collection was performed, using keywords to identify 'sex/gender' and 'LC'. Differences between genders in LC epidemiology, pathological and molecular characteristics, loco-regional and/or systemic treatments outcome and prognosis were systematically analyzed. The possible predictive role of physio-pathological factors in males and females paves the way for a personalized therapeutic approach, emphasizing the need to include gender as a stratification factor in future clinical trials design.

Association between Family History of Cancer and Lung Cancer Risk among Japanese Men and Women

Although cigarette smoking is a major risk factor for lung cancer, genetic susceptibility may also affect lung cancer risk. To explore the role of genetic risk, this case-control study investigated the association between family history of cancer at several sites and lung cancer risk. A total of 1,733 lung cancer cases and 6,643 controls were selected from patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2009. Information on family history of cancer was collected using a self-administered questionnaire and odds ratios (ORs) were estimated by unconditional logistic regression. Family history of lung cancer in first-degree relatives was associated with an increased risk of lung cancer among both sexes. According to histology and type of relatives, a parental history of lung cancer was significantly associated with an increased risk of female adenocarcinoma (OR = 1.72). Stratification by smoking status revealed that this significant positive association in women was limited to ever-smokers (OR = 4.13). In men, a history of lung cancer in siblings was significantly associated with an increased risk of small cell carcinoma (OR = 2.28) and adenocarcinoma (OR = 2.25). Otherwise, positive associations between history of breast (OR = 1.99) and total (OR = 1.71) cancers in siblings and the risk of male adenocarcinoma were observed. These results suggest that inherited genetic susceptibility may contribute to the development of lung cancer. In men, shared exposure to environmental factors among siblings may also be responsible for the increase in lung cancer risk.

SOX2 promoter hypermethylation in non-smoking Taiwanese adults residing in air pollution areas

BACKGROUND

Both SOX2 promoter methylation and air pollution have been associated with lung cancer risk. However, little has been done to assess SOX2 promoter methylation in individuals living in air pollution areas. The aim of this study was to investigate SOX2 promoter methylation in non-smoking Taiwanese adults living in areas with different levels of air pollution especially particulate matter with diameter < 2.5 μm (PM2.5).

METHODS

A total of 1142 individuals aged 30-70 years were recruited. Data on SOX2 methylation, residence, age, and exposure to second-hand smoke (SHS) among others were extracted from the Taiwan Biobank dataset (2008-2015). After excluding former and current smokers, alongside those with incomplete information, a total of 461 non-smokers comprising 176 men and 285 women were included in the study. Participants' residences were grouped under northern and central/southern areas because air pollution (PM2.5) is lower in northern compared to central and southern areas.

RESULTS

The methylation levels in men (0.16310 ± 0.01230) and women (0.15740 ± 0.01240) were significantly different (P < .0001). In both sexes, the SOX2 promoter region was shown to be significantly hypermethylated in central and southern areas compared with the northern areas. The regression coefficient (β) was 0.00331 (P = 0.0257) in men and 0.00514 (P < .0001) in women.

CONCLUSION

SOX2 was significantly hypermethylated in both men and women residing in central and southern areas. The consistency in the results for both sexes shows that SOX2 promoter methylation could serve as a potential biomarker for industrial air pollution exposure. Moreover, it might reflect predisposition to cancer. Hence, healthy non-smokers at precancerous stages who have not been clinically diagnosed could be identified.

Perinodular and Intranodular Radiomic Features on Lung CT Images Distinguish Adenocarcinomas from Granulomas

Purpose To evaluate ability of radiomic (computer-extracted imaging) features to distinguish non-small cell lung cancer adenocarcinomas from granulomas at noncontrast CT. Materials and Methods For this retrospective study, screening or standard diagnostic noncontrast CT images were collected for 290 patients (mean age, 68 years; range, 18-92 years; 125 men [mean age, 67 years; range, 18-90 years] and 165 women [mean age, 68 years; range, 33-92 years]) from two institutions between 2007 and 2013. Histopathologic analysis was available for one nodule per patient. Corresponding nodule of interest was identified on axial CT images by a radiologist with manual annotation. Nodule shape, wavelet (Gabor), and texture-based (Haralick and Laws energy) features were extracted from intra- and perinodular regions. Features were pruned to train machine learning classifiers with 145 patients. In a test set of 145 patients, classifier results were compared against a convolutional neural network (CNN) and diagnostic readings of two radiologists. Results Support vector machine classifier with intranodular radiomic features achieved an area under the receiver operating characteristic curve (AUC) of 0.75 on the test set. Combining radiomics of intranodular with perinodular regions improved the AUC to 0.80. On the same test set, CNN resulted in an AUC of 0.76. Radiologist readers achieved AUCs of 0.61 and 0.60, respectively. Conclusion Radiomic features from intranodular and perinodular regions of nodules can distinguish non-small cell lung cancer adenocarcinomas from benign granulomas at noncontrast CT. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Nishino in this issue.

Brain Metastases from Lung Cancer: Is MET an Actionable Target?

The process of metastatic dissemination begins when malignant cells start to migrate and leave the primary mass. It is now known that neoplastic progression is associated with a combination of genetic and epigenetic events. Cancer is a genetic disease and this pathogenic concept is the basis for a new classification of tumours, based precisely on the presence of definite genetic lesions to which the clones are addicted. Regarding the scatter factor receptors MET and Recepteur d'Origin Nantais (RON), it is recognised that MET is an oncogene necessary for a narrow subset of tumours (MET-addicted) while it works as an adjuvant metastogene for many others. This notion highlights that the anti-MET therapy can be effective as the first line of intervention in only a few MET-addicted cases, while it is certainly more relevant to block MET in cases of advanced neoplasia that exploit the activation of the invasive growth program to promote dissemination in other body parts. Few data are instead related to the role played by RON, a receptor homologous to MET. We have already demonstrated an implication of MET and RON genes in brain metastases from lung cancer. On this basis, the aim of this work is to recapitulate and dissect the molecular basis of metastatic brain dissemination from lung cancer. The latter is among the big killers and frequently gives rise to brain metastases, most often discovered at diagnosis. Molecular mechanisms leading to tumour spread to the brain are mostly unknown and in turn these tragic cases are still lacking effective therapies. Based on previously published data from our group, we aim to summarise and analyse the pathogenic mechanisms leading to activation of the scatter factor receptor in brain metastatic lesions of lung primaries, from the point of view of replacing the currently used empirical treatment with a more targeted approach.

Inhibitory Effect of (2R)-1-(1-Benzofuran-2-yl)-N-propylpentan-2-amine on Lung Adenocarcinoma

BPAP is a potent enhancer substance with catecholaminergic and serotoninergic activity in the brain. It was discovered that it is also effective against certain types of experimental cancers, showing the most promising results in case of lung cancer. That is why we tested its efficacy in two different doses in a newly developed EGFR wild type mouse lung adenocarcinoma xenograft model. Experiments were conducted on FVB/N and SCID mouse strains treated with low and high dose of BPAP. Body weight, survival, and tumor volumes were recorded. Furthermore, the activity of major signaling pathways of NSCLC such as MAPK and Akt/mTOR as well as cell cycle regulation were determined. Significant inhibition of tumor growth was exerted by both doses, but the mechanism of action was different. High dose directly inhibited, whereas low dose activated the main signaling pathways. Exposure to low dose BPAP resulted in elevated activity of the mTOR pathway together with p16^INK-induced cell cycle arrest, a typical feature of geroconversion, a senescent state characterized by loss of cell proliferation. Finally the events culminated in cell cycle inhibition point in case of both doses mirrored by the decrease of cyclin D1, CDK4 and PCNA. In addition, BPAP treatment had a beneficial effect on bodyweight suggesting that the compound at least in part is able to compensate the cancer-related wasting. In view of the low toxicity and confirmed antitumor effect of BPAP against experimental lung adenocarcinoma, this novel compound deserves further attention.

Radon induced mitochondrial dysfunction in human bronchial epithelial cells and epithelial-mesenchymal transition with long-term exposure

Radon is a naturally occurring radionuclide, which has a wide environmental distributed. It emits multiple high linear energy transfer (LET) alpha particles during radiative decay, and has been regarded as a human carcinogen by the International Agency for Research on Cancer. Currently, residential radon exposure is considered as the second highest cause of lung cancer and the leading cause among nonsmokers. Radon exposure leads to genomic instability, which causes the accumulation of multiple genetic changes and leads to cancer development. However, the molecular basis underlying carcinogenesis, especially the radon-induced changes to mitochondria, has not been fully elucidated. The aim of this study was to explore the dynamic changes in mitochondria along with the cell transformations induced by long-term radon exposure. A malignant transformation model of BEAS-2B cells was established with upto 40 times the usual radon exposure (20 000 Bq m-3, 30 min each time every 3 days). Long-term radon exposure induced EMT-like transformation of epithelial cells in our study, evidenced by decrease in epithelial markers and increase in mesenchymal markers, as well as the loss of cell-cell adhesion and alterations to the morphology of cells from compact shape to a spindle shaped, fibroblast-like morphology. Additionally, the proliferation and migration of cells were increased and apoptosis was decreased with long-term radon exposure. Furthermore, mitochondrial function was up-regulated and the levels of oxidative stress were repressed with long-term radon exposure. Our work explored the dynamic changes of mitochondrial in radon induced malignant transformation of lung bronchial epithelial cells, which could partially elucidate the role of mitochondria in radon induced cell malignancy.

Role of Low-Dose Computerized Tomography in Lung Cancer Screening among Never-Smokers

INTRODUCTION

The incidence of lung cancer among never-smokers has been increasing rapidly. The U. S. National Lung Screening Trial and the NELSON trial showed that screening using low-dose computerized tomography (LDCT) effectively reduced lung cancer mortality among heavy smokers. However, its effectiveness in never-smokers has not been well investigated. This study investigated the role of LDCT in lung cancer screening among never-smokers.

METHODS

The study was designed as a single-center, retrospective cohort study. We analyzed the data on patients who underwent LDCT screening between May 2003 and June 2016. Nodules detected by computerized tomography were classified according to the Lung Imaging Reporting and Data System criteria. The detection rate and lung cancer outcomes (type of cancer, staging of lung cancer, and mortality) according to smoking history were determined.

RESULTS

Of the 28,807 enrolled patients, 12,176 were never-smokers; of these patients, 7744 (63.6%) were women and 1218 (10.0%) were found to have lung nodules. Overall, lung cancer was diagnosed in 55 never-smokers (0.45%). In contrast, lung cancer was diagnosed in 143 (0.86%) of the 16,631 ever-smokers. Of the never-smokers with lung cancer, 51 (92.7%) presented with stage I disease, and all patients had adenocarcinomas.

CONCLUSIONS

In the never-smoker population, LDCT screening helped to detect a significant number of lung cancers. Most of these lung cancers were detected at a very early stage. The positive results of the National Lung Screening Trial in the United States and the NELSON trial may have established the value of LDCT screening for heavy smokers, but future research should consider the value of using LDCT screening in the never-smoker population.

Runs of homozygosity associate with decreased risks of lung cancer in never-smoking East Asian females

Although genome-wide association studies (GWASs) have identified some risk single-nucleotide polymorphisms in East Asian never-smoking females, the unexplained missing heritability is still required to be investigated. Runs of homozygosity (ROHs) are thought to be a type of genetic variation acting on human complex traits and diseases. We detected ROHs in 8,881 East Asian never-smoking women. The summed ROHs were used to fit a logistic regression model which noteworthily revealed a significant association between ROHs and the decreased risk of lung cancer (P < 0.05). We identified 4 common ROHs regions located at 2p22.1, which were significantly associated with decreased risk of lung cancer (P = 2.00 × 10^-4 - 1.35 × 10^-4). Functional annotation was conducted to investigate the regulatory function of ROHs. The common ROHs were overlapped with potential regulatory elements, such as active epigenome elements and chromatin states in lung-derived cell lines. SOS1 and ARHGEF33 were significantly up-regulated as the putative target genes of the identified ROHs in lung cancer samples according to the analysis of differently expressed genes. Our results suggest that ROHs could act as recessive contributing factors and regulatory elements to influence the risk of lung cancer in never-smoking East Asian females.

Angiotensin converting enzyme inhibitors and risk of lung cancer: population based cohort study

OBJECTIVE

To determine whether the use of angiotensin converting enzyme inhibitors (ACEIs), compared with use of angiotensin receptor blockers, is associated with an increased risk of lung cancer.

DESIGN

Population based cohort study.

SETTING

United Kingdom Clinical Practice Research Datalink.

PARTICIPANTS

A cohort of 992 061 patients newly treated with antihypertensive drugs between 1 January 1995 and 31 December 2015 was identified and followed until 31 December 2016.

MAIN OUTCOME MEASURES

Cox proportional hazards models were used to estimate adjusted hazard ratios with 95% confidence intervals of incident lung cancer associated with the time varying use of ACEIs, compared with use of angiotensin receptor blockers, overall, by cumulative duration of use, and by time since initiation.

RESULTS

The cohort was followed for a mean of 6.4 (SD 4.7) years, generating 7952 incident lung cancer events (crude incidence 1.3 (95% confidence interval 1.2 to 1.3) per 1000 person years). Overall, use of ACEIs was associated with an increased risk of lung cancer (incidence rate 1.6 v 1.2 per 1000 person years; hazard ratio 1.14, 95% confidence interval 1.01 to 1.29), compared with use of angiotensin receptor blockers. Hazard ratios gradually increased with longer durations of use, with an association evident after five years of use (hazard ratio 1.22, 1.06 to 1.40) and peaking after more than 10 years of use (1.31, 1.08 to 1.59). Similar findings were observed with time since initiation.

CONCLUSIONS

In this population based cohort study, the use of ACEIs was associated with an increased risk of lung cancer. The association was particularly elevated among people using ACEIs for more than five years. Additional studies, with long term follow-up, are needed to investigate the effects of these drugs on incidence of lung cancer.

Novel platinum agents and mesenchymal stromal cells for thoracic malignancies: state of the art and future perspectives

INTRODUCTION

Non-small cell lung cancer and malignant pleural mesothelioma represent two of the most intriguing and scrutinized thoracic malignancies, presenting interesting perspectives of experimental development and clinical applications.

AREAS COVERED

In advanced non-small cell lung cancer, molecular targeted therapy is the standard first-line treatment for patients with identified driver mutations; on the other hand, chemotherapy is the standard treatment for patients without EGFR mutations or ALK rearrangement or those with unknown mutation status. Once considered an ineffective therapy in pulmonary neoplasms, immunotherapy has been now established as one of the most promising therapeutic options. Mesenchymal stromal cells are able to migrate specifically toward solid neoplasms and their metastatic localizations when injected intravenously. This peculiar cancer tropism has opened up an emerging field to use them as vectors to deliver antineoplastic drugs for targeted therapies.

EXPERT OPINION

Molecular targeted therapy and immunotherapy are the new alternatives to standard chemotherapy. Mesenchymal stromal cells are a new promising tool in oncology and-although not yet utilized in the clinical practice, we think they will represent another main tool for cancer therapy and will probably play a leading role in the field of nanovectors and molecular medicine.

Common cancer-driver mutations and their association with abnormally methylated genes in lung adenocarcinoma from never-smokers

OBJECTIVES

Lung adenocarcinoma in never-smokers accounts for 15-20% of all lung cancer. Although targetable mutations are more prevalent in these tumors, the biological and clinical importance of coexisting and/or mutually exclusive abnormalities is just emerging. This study evaluates the relationships between common genetic and epigenetic aberrations in these tumors.

MATERIALS AND METHODS

Next-generation sequencing was employed to screen 20 commonly mutated cancer-driver genes in 112 lung adenocarcinomas from never-smokers. The relationship of these mutations with cancer-related methylation of 59 genes, and geographical/ethnic differences in the prevalence for mutations compared to multiple East Asian never-smoker lung adenocarcinoma cohorts was studied.

RESULTS

The most common driver mutation detected in 40% (45/112) of the tumors was EGFR, followed by TP53 (18%), SETD2 (11%), and SMARCA4 (11%). Over 72% (81/112) of the cases have mutation of at least one driver gene. While 30% (34/112) of the tumors have co-mutations of two or more genes, 42% (47/112) have only one driver gene mutation. Differences in the prevalence for some of these mutations were seen between adenocarcinomas in East Asian versus US (mainly Caucasian) never-smokers including a significantly lower rate of EGFR mutation among the US patients. Interestingly, aberrant methylation of multiple cancer-related genes was significantly associated with EGFR wildtype tumors. Among 15 differentially methylated genes by EGFR mutation, 14 were more commonly methylated in EGFR wildtype compared to mutant tumors. These findings were independently validated using publicly available data.

CONCLUSION

Most lung adenocarcinomas from never-smokers harbor targetable mutation/co-mutations. In the absence of EGFR mutation that drives 40% of these tumors, EGFR wildtype tumors appear to develop by acquiring aberrant promoter methylation that silences tumor-suppressor genes.

Transcription Factors Contribute to Differential Expression in Cellular Pathways in Lung Adenocarcinoma and Lung Squamous Cell Carcinoma

Lung cancers are broadly classified into small cell lung cancers and non-small cell lung cancers (NSCLC). Lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) are two common subtypes of NSCLC, and despite the fact that both occur in lung tissues, these two subtypes show a number of different pathological characteristics. To investigate the differences and seek potential therapy targets, we used bioinformatics methods to analyze RNA-Seq data from different aspects. The previous studies and comparative pathway enrichment analysis on publicly available data showed that expressed or inhibited genes are different in two cancer subtypes through important pathways. Some of these genes could not only affect cell function through expression, but also could regulate other genes' expression by binding to a specific DNA sequence. This kind of genes is called transcription factor (TF) or sequence-specific DNA-binding factor. Transcription factors play important roles in controlling gene expression in carcinoma pathways. Our results revealed transcription factors that may cause differential expression of genes in cellular pathways of LUAD and LUSC, which provide new clues for study and treatment. Once such TF is NFE2l2 which may regulate genes in the Wnt signaling pathway, and the MAPK signaling pathway, thus leading to an increase the cell growth, cell division, and gene transcription. Another TF-XBP1 has high correlation with genes related to cell adhesion molecules and cytokine-cytokine receptor interaction pathways that may further affect the immune system. Moreover, the two TF and high correlated genes also show similar patterns in an independent GEO data set.

Heuristic value-based framework for lung cancer decision-making

Heuristics and the application of fast-and-frugal trees may play a role in establishing a clinical decision-making framework for value-based oncology. We determined whether clinical decision-making in oncology can be structured heuristically based on the timeline of the patient's treatment, clinical intuition, and evidence-based medicine. A group of 20 patients with advanced non-small cell lung cancer (NSCLC) were enrolled into the study for extensive treatment analysis and sequential decision-making. The extensive clinical and genomic data allowed us to evaluate the methodology and efficacy of fast-and-frugal trees as a way to quantify clinical decision-making. The results of the small cohort will be used to further advance the heuristic framework as a way of evaluating a large number of patients within registries. Among the cohort whose data was analyzed, substitution and amplification mutations occurred most frequently. The top five most prevalent genomic alterations were TP53 (45%), ALK (40%), LRP1B (30%), CDKN2A (25%), and MYC (25%). These 20 cases were analyzed by this clinical decision-making process and separated into two distinctions: 10 straightforward cases that represented a clearer decision-making path and 10 complex cases that represented a more intricate treatment pathway. The myriad of information from each case and their distinct pathways was applied to create the foundation of a framework for lung cancer decision-making as an aid for oncologists. In late-stage lung cancer patients, the fast-and-frugal heuristics can be utilized as a strategy of quantifying proper decision-making with limited information.

Irreversible tyrosine kinase inhibition of epidermal growth factor receptor with afatinib in EGFR activating mutation-positive advanced non-small-cell lung cancer

Despite recent advances in the systemic therapy of non-small-cell lung cancer (nsclc), the prognosis for stage iv disease remains poor. The discovery of targetable mutations has led to new treatment options. The most common mutations, the EGFR activating mutations, are present in about 50% of Asian patients and up to 15% of white patients. First-generation reversible epidermal growth factor receptor (egfr) tyrosine kinase inhibitors (tkis) have led to improved survival in patients positive for EGFR activating mutations, but resistance eventually leads to disease progression. The irreversible egfr tki afatinib was developed to counter such resistance. The clinical efficacy of afatinib has been shown in first-line studies comparing it with both cytotoxic chemotherapy and first-generation egfr tkis. Afatinib has also shown continued benefit beyond progression while a patient is taking an egfr inhibitor. Furthermore, its toxicity profile is both predictable and manageable. The results of the principal clinical trials assessing afatinib are reviewed here.

Incidence of lung cancer histologic cell-types according to neighborhood factors: A population based study in California

BACKGROUND

The relationships between neighborhood factors (i.e., neighborhood socioeconomic status (nSES) and ethnic enclave) and histologic subtypes of lung cancer for racial/ethnic groups, particularly Hispanics and Asian American/Pacific Islanders (AAPIs), are poorly understood.

METHODS

We conducted a population-based study of 75,631 Californians diagnosed with lung cancer from 2008 through2012. We report incidence rate ratios (IRRs) for lung cancer histologic cell-types by nSES among racial/ethnic groups (non-Hispanic (NH) Whites, NH Blacks, Hispanics and AAPIs) and according to Hispanic or Asian neighborhood ethnic enclave status among Hispanics and AAPIs, respectively. In addition, we examined incidence jointly by nSES and ethnic enclave.

RESULTS

Patterns of lung cancer incidence by nSES and ethnic enclave differed across race/ethnicity, sex, and histologic cell-type. For adenocarcinoma, Hispanic males and females, residing in both low nSES and high nSES neighborhoods that were low enclave, had higher incidence rates compared to those residing in low nSES, high enclave neighborhoods; males (IRR, 1.17 [95% CI, 1.04-1.32] and IRR, 1.15 [95% CI, 1.02-1.29], respectively) and females (IRR, 1.29 [95% CI, 1.15-1.44] and IRR, 1.51 [95% CI, 1.36-1.67], respectively). However, AAPI males residing in both low and high SES neighborhoods that were also low enclave had lower adenocarcinoma incidence.

CONCLUSIONS

Neighborhood factors differentially influence the incidence of lung cancer histologic cell-types with heterogeneity in these associations by race/ethnicity and sex. For Hispanic males and females and AAPI males, neighborhood ethnic enclave status is strongly associated with lung adenocarcinoma incidence.

Circular RNAs as novel biomarkers with regulatory potency in human diseases

Circular RNAs (circRNAs) are a large class of noncoding RNAs characterized with closed loop structures without 3′ and 5′ polar ends. They can roughly be divided into exonic circRNAs, exon–intron circRNAs and circular intronic RNAs. CircRNAs are characterized with stability, prevalence, specificity and conservation, which arouse great interest in circRNAs as disease biomarkers. Their abilities to sponge to miRNAs, cis-regulate parent genes, bind to proteins and encode proteins endow circRNAs a critical role of regulation in eukaryotic cells. This concise review focuses on circRNAs as functional biomarkers and therapeutic targets in both tumor and nontumorous diseases.

Although they were discovered in 1970s, circular RNAs (circRNAs) have attracted great interest only relatively recently. Instead of genome ‘junk matters’, circRNAs are now considered as promising biomarkers and treatment targets. CircRNAs are involved in numerous cancer-related and noncancer diseases, such as lung cancer, gastric cancer, cardiovascular diseases, diabetes mellitus and so on. This review outlines the classification, characterization and function of circRNAs, with a specific focus on recent studies concerning the role of circRNAs in human diseases.

Latest perspectives of orally bioavailable 2,4-diarylaminopyrimidine analogues (DAAPalogues) as anaplastic lymphoma kinase inhibitors: discovery and clinical developments

The course of anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) therapy has improved impressively. The Food and Drug Administration (FDA) has approved crizotinib (Xalkori, Pfizer) as a first-in-class tyrosine kinase inhibitor (TKI) that demonstrated a substantial objective response rate (ORR) and remarkable progression-free survival (PFS). However, acquired resistance to crizotinib is still a major concern especially as the central nervous system (CNS) remains the most common sites of relapse. To combat disease resistance, limited PFS and poor CNS exposure exhibited by crizotinib (Xalkori, Pfizer) led to the discovery of numerous next generation ALK-TKIs and surprisingly most of them are 2,4-Diarylaminopyrimidine Analogues (DAAPalogues). To date, DAAPalogues have been investigated extensively to display their superior potency against numerous kinase targets especially ALK/ROS1. This review describes hit-to-drug evolution strategies, activity spectra, milestones related to medicinal chemistry discovery efforts and scalable synthetic pathways of clinically emerging DAAPalouges which are either progressing as investigational or preclinical candidates. In addition, the significance of DAAPalogues to treat the patients with ALK+-NSCLC in clinical settings has been detailed. This review is beneficial for medicinal chemists and researchers contributing to discovering ALK-TKIs to overcome existing issues related to DAAPalouges in the drug discovery process.

Lung cancer in never smokers from the Princess Margaret Cancer Centre

Introduction

Lung cancer in never smokers represents a distinct epidemiological, clinical, and molecular entity.

Results

Most 712 never smoking lung cancer patients were female (72%) with a median age at diagnosis of 62.2 years (18–94). Caucasians (46%), East Asians (42%), adenocarcinoma histology (87%) and presentation with metastatic disease at diagnosis (59%) were common. Of 515 patients with available archival tissue, the most common identified single mutations were EGFR (52.2%), followed by ALK (7.5%), KRAS (2.3%), TP53 (1.3%), ERBB2 (1%), BRAF (0.4%), PIK3CA (0.4%), SMAD4 (0.4%), CTNNB1 (0.2%), AKT1 (0.2%), and NRAS (0.2%); 8% tumors had multiple mutations, while 25.8% had none identified. Median overall survival (mOS) was 42.2 months (mo) for the entire cohort. Patients with mutations in their tumors had significantly better mOS (69.5 mo) when compared to those without (31.0 mo) (HR = 0.59; 95% CI: 0.44–0.79; p < 0.001). Earlier stage (p < 0.001), adenocarcinoma histology (p = 0.012), good performance status (p < 0.001) and use of targeted therapy (p < 0.001) were each independently associated with longer survival. Patients with ALK-translocation-positive tumours have significantly longer OS compared to those without any mutations (p = 0.0029) and to those with other and null mutations (p = 0.022).

Conclusions

Lung cancer in never smokers represents a distinct clinical and molecular entity characterized by a high incidence of targetable mutations and long survival.

Methods

We analyzed retrospectively the data from electronic patient records of never smokers diagnosed with lung cancer treated at the Princess Margaret Cancer Centre (Toronto) between 1988–2015 to characterize demographic and clinical features, pathology, molecular profile (using hotspot or targeted sequencing panels), treatment and survival.