Molecular genetics of lung cancer in people who have never smoked

MiR-1976/NCAPH/P65 axis inhibits the malignant phenotypes of lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a malignancy with an abysmal survival rate. High metastasis is the leading cause of the low survival rate of LUAD. NCAPH, an oncogene, is involved in the carcinogenesis of LUAD. However, the regulation of NCAPH in LUAD remains controversial. In this work, we identified an up-regulation of NCAPH in LUAD tissues. Patients who expressed more NCAPH had shorter overall survival (OS). Furthermore, NCAPH overexpression promoted LUAD cell migration while inhibiting apoptosis. MiR-1976 and miR-133b were predicted to target NCAPH expression by searching TargetScan and linkedomics databases. Following that, we confirmed that miR-1976 suppressed NCAPH by directly targeting a 7-bp region of NCAPH 3' untranslated regions (UTR). In addition, increased expression of miR-1976 decreased the proliferation & migration and promoted apoptosis of LUAD cells, and the re-introduction of NCAPH reversed these influences. Furthermore, the xenograft and metastasis mouse models also confirmed that miR-1976 inhibited tumor growth and metastasis in vivo by targeting NCAPH. Finally, we found that MiR-1976 targeting NCAPH blocked the activation of NF-κB. In conclusion, miR-1976 inhibits NCAPH activity in LUAD and acts as a tumor suppressor. The miR-1976/NCAPH/NF-κB axis may, in the future, represent crucial diagnostic and prognostic biomarkers and promising therapeutic options.

KRASG12C Inhibitor as a Treatment Option for Non-Small-Cell Lung Cancer with Comorbid Interstitial Pneumonia

Non-small-cell lung cancer (NSCLC) with comorbid interstitial pneumonia (IP) is a population with limited treatment options and a poor prognosis. Patients with comorbid IP are at high risk of developing fatal drug-induced pneumonitis, and data on the safety and efficacy of molecularly targeted therapies are lacking. KRAS mutations have been frequently detected in patients with NSCLC with comorbid IP. However, the low detection rate of common driver gene mutations, such as epidermal growth factor receptor and anaplastic lymphoma kinase, in patients with comorbid IP frequently results in inadequate screening for driver mutations, and KRAS mutations may be overlooked. Recently, sotorasib and adagrasib were approved as treatment options for advanced NSCLC with KRASG12C mutations. Although patients with comorbid IP were not excluded from clinical trials of these KRASG12C inhibitors, the incidence of drug-induced pneumonitis was low. Therefore, KRASG12C inhibitors may be a safe and effective treatment option for NSCLC with comorbid IP. This review article discusses the promise and prospects of molecular-targeted therapies, especially KRASG12C inhibitors, for NSCLC with comorbid IP, along with our own clinical experience.

Runx3 Restoration Regresses K-Ras-Activated Mouse Lung Cancers and Inhibits Recurrence

Oncogenic K-RAS mutations occur in approximately 25% of human lung cancers and are most frequently found in codon 12 (G12C, G12V, and G12D). Mutated K-RAS inhibitors have shown beneficial results in many patients; however, the inhibitors specifically target K-RASG12C and acquired resistance is a common occurrence. Therefore, new treatments targeting all kinds of oncogenic K-RAS mutations with a durable response are needed. RUNX3 acts as a pioneer factor of the restriction (R)-point, which is critical for the life and death of cells. RUNX3 is inactivated in most K-RAS-activated mouse and human lung cancers. Deletion of mouse lung Runx3 induces adenomas (ADs) and facilitates the development of K-Ras-activated adenocarcinomas (ADCs). In this study, conditional restoration of Runx3 in an established K-Ras-activated mouse lung cancer model regressed both ADs and ADCs and suppressed cancer recurrence, markedly increasing mouse survival. Runx3 restoration suppressed K-Ras-activated lung cancer mainly through Arf-p53 pathway-mediated apoptosis and partly through p53-independent inhibition of proliferation. This study provides in vivo evidence supporting RUNX3 as a therapeutic tool for the treatment of K-RAS-activated lung cancers with a durable response.

Identification of EGFR mutation status in male patients with non-small-cell lung cancer: role of 18F-FDG PET/CT and serum tumor markers CYFRA21-1 and SCC-Ag

BACKGROUND

The high incidence of epidermal growth factor receptor (EGFR) mutations is usually found in female patients with lung adenocarcinoma who have never-smoked. However, reports concerning male patients are scarce. Thus, this study aimed to explore a novel approach based on ¹⁸F-fluoro-2-deoxy-2-deoxyglucose (¹⁸F-FDG) PET/CT and serum tumor markers (STMs) to determine EGFR mutation status in male patients with non-small-cell lung cancer (NSCLC).

METHODS

A total of 121 male patients with NSCLC were analyzed between October 2019 and March 2022. All patients underwent ¹⁸F-FDG PET/CT scan before treatment and monitored 8 STMs (cytokeratin 19 fragment [CYFRA21-1], squamous cell carcinoma-related antigen [SCC-Ag], carcinoembryonic antigen [CEA], neuron-specific enolase [NSE], carbohydrate antigen [CA] 50, CA125, CA72-4, and ferritin). A comparison was done between EGFR mutant and wild-type patients in terms of the maximum standardized uptake value of primary tumors (pSUV_max) and 8 STMs. We performed receiver operating characteristic (ROC) curve and multiple logistic regression analyses to determine predictors for EGFR mutation status.

RESULTS

EGFR mutations were detected in 39 patients (32.2%). Compared with patients with EGFR wild-type, EGFR-mutant patients had lower concentrations of serum CYRFA21-1 (2.65 vs. 4.01, P = 0.002) and SCC-Ag (0.67 vs. 1.05, P = 0.006). No significant differences of CEA, NSE, CA 50, CA125, CA72-4 and ferritin were found between the two groups. The presence of EGFR mutations was significantly associated with low pSUV_max (< 8.75), low serum SCC-Ag (< 0.79 ng/mL) and CYFRA21-1 (< 2.91 ng/mL) concentrations. The area under ROC curve values were 0.679, 0.655, 0.685 and 0.754, respectively, for low CYFRA21-1, SCC-Ag, pSUV_max and the combination of these three factors.

CONCLUSIONS

We demonstrated that low concentrations of CYFRA21-1 and SCC-Ag, as well as low pSUV_max, were associated with EGFR mutations, and that the combination of these factors resulted in a higher differentiation of EGFR mutation status in male patients with NSCLC.

The role of psychiatry in quality of life in young patients with non-small cell lung cancer

Background

Lung cancer is often seen in geriatric patients, with an age of onset of approximately 60 years. Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related mortality in the United States and around the world. Young patients are rarely diagnosed with lung cancer, with less than 3.5% of patients presenting with this tumor at an age less than 45. In this paper, we examine NSCLC in young patients, between 18 and 35 years of age, which most commonly occurs in non-smokers and is characterized by a higher proportion of adenocarcinoma histology and advanced disease at presentation. These patients often present with metastasis involving one organ and they test positive for driver gene mutations including, but not limited to, epidermal growth factor receptor (EGFR), tyrosine kinase inhibitor (TKI) sensitive mutation and anaplastic lymphoma kinase (ALK). We addressed depression and anxiety and their effect on quality of life (QOL) and attempted to examine how improvement in QOL in these young patients could affect their course of illness and prognosis.

Methods

We conducted a literature review using PubMed, Cochrane, and Google search. We concentrated our search on two elements, reviewing approximately 50 articles focusing on the driver mutations EGFR and ALK as well as genetic mapping of lung adenocarcinoma in patients aged 18–35 years old. We also conducted a review of approximately 30 articles focusing on quality of life in the context of anxiety and depression within this patient population.

Results

We have described a case of a 28-year-old male with new-onset metastatic lung adenocarcinoma that we had treated in our hospital. He was found to have mutations in EGFR and ALK rearrangement. We aimed to address his depression, anxiety, and poor QOL in the context of his diagnosis. Due to his presenting symptoms leading to the diagnosis of adjustment disorder, he was treated with pharmacotherapy as well as conventional therapy to improve his QOL. Due to the time required to identify mutations, our patient passed away before a more targeted treatment could be offered.

Conclusion

It is important to fully explore the nature of the cancer, including mutation types. Our case demonstrates that the detection of the driver gene mutation EGFR and/or ALK rearrangement could affect treatment and prognosis in this patient population. There are many studies available that highlight targeted therapies for these mutations as well as chemotherapy and radiation. Psychiatry has a significant role in improving quality of life in these patients, which could enhance their response to treatment and survival. Involving psychiatry early in the course results in lower rates of depression, anxiety and premature death.

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Detection of the driver gene mutation EGFR and or ALK rearrangement could affect treatment within the young adult population.

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Early psychiatric intervention can improve quality of life.

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Early psychiatric intervention can lower rates of depression, anxiety, and suicidal ideation.

Genomic landscape of lung adenocarcinomas in different races

Background

Lung adenocarcinoma is a molecularly heterogeneous disease. Several studies, including The Cancer Genome Atlas Research Network (TCGA) and Lung Cancer Mutation Consortium (LCMC), explored the genetic alterations among different ethnic groups. However, minority groups are often under-represented in these relevant studies and the genomic alterations among racial groups are not fully understood.

Methods

We analyze genomic characteristics among racial groups to understand the diversities and their impact on clinical outcomes.

Results

Native Americans had significantly higher rates of insertions and deletions than other races (P<0.001). Among patients with lung adenocarcinomas, EGFR and KRAS were the highest discrepancy genes in the different racial groups (P<0.001). The EGFR exon 21 L858R point mutation was three times higher in Asians than in all other races (P<0.001). Asians, Whites, and Blacks had 4.7%, 3.1%, and 1.8% ALK rearrangement, respectively (P<0.001). White patients had the highest rates of reported KRAS G12C (15.51%) than other races (P<0.001). Whites (17.2%), Blacks (15.1%), and Other (15.7%) had higher rates of STK11 mutation than Asians (3.94%) (P<0.001). RET rearrangement and ERBB2 amplification were more common in Asian patients than in Other racial groups. Apart from point mutations, structural variations, and fusion genes, we identified a significant amount of copy number alterations in each race.

Conclusions

The tumor genomic landscape is significantly distinct in different races. This data would shed light on the understanding of molecular alterations and their impacts on clinical management in different lung cancer patients.

Cuproptosis-related lncRNA predict prognosis and immune response of lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) accounts for 50% of lung cancers, with high mortality and poor prognosis. Long non-coding RNA (lncRNA) plays a vital role in the progression of tumors. Cuproptosis is a newly discovered form of cell death that is highly investigated. Therefore, in the present study, we aimed to investigate the role of cuproptosis-related lncRNA signature in clinical prognosis prediction and immunotherapy and the relationship with drug sensitivity.

MATERIAL AND METHODS

Genomic and clinical data were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and cuproptosis-related genes were obtained from cuproptosis-related studies. The prognostic signature was constructed by co-expression analysis and Cox regression analysis. Patients were divided into high and low risk groups, and then, a further series of model validations were carried out to assess the prognostic value of the signature. Subsequently, lncRNAs were analyzed for gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes Enrichment (KEGG), immune-related functions, and tumor mutation burden (TMB). Finally, we used tumor immune dysfunction and exclusion (TIDE) algorithms on immune escape and immunotherapy of cuproptosis-related lncRNAs, thereby identifying its sensitivity toward potential drugs for LUAD.

RESULTS

A total of 16 cuproptosis-related lncRNAs were obtained, and a prognostic signature was developed. We found that high-risk patients had worse overall survival (OS) and progression-free survival (PFS) and higher mortality. Independent prognostic analyses, ROC, C-index, and nomogram showed that the cuproptosis-related lncRNAs can accurately predict the prognosis of patients. The nomogram and heatmap showed a distinct distribution of the high- and low-risk cuproptosis-related lncRNAs. Enrichment analysis showed that the biological functions of lncRNAs are associated with tumor development. We also found that immune-related functions, such as antiviral activity, were suppressed in high-risk patients who had mutations in oncogenes. OS was poorer in patients with high TMB. TIDE algorithms showed that high-risk patients have a greater potential for immune escape and less effective immunotherapy.

CONCLUSION

To conclude, the 16 cuproptosis-related lncRNAs can accurately predict the prognosis of patients with LUAD and may provide new insights into clinical applications and immunotherapy.

Sex disparity of lung cancer risk in non-smokers: a multicenter population-based prospective study based on China National Lung Cancer Screening Program

Background:

Non-smokers account for a large proportion of lung cancer patients, especially in Asia, but the attention paid to them is limited compared with smokers. In non-smokers, males display a risk for lung cancer incidence distinct from the females—even after excluding the influence of smoking; but the knowledge regarding the factors causing the difference is sparse. Based on a large multicenter prospective cancer screening cohort in China, we aimed to elucidate the interpretable sex differences caused by known factors and provide clues for primary and secondary prevention.

Methods:

Risk factors including demographic characteristics, lifestyle factors, family history of cancer, and baseline comorbidity were obtained from 796,283 Chinese non-smoking participants by the baseline risk assessment completed in 2013 to 2018. Cox regression analysis was performed to assess the sex difference in the risk of lung cancer, and the hazard ratios (HRs) that were adjusted for different known factors were calculated and compared to determine the proportion of excess risk and to explain the existing risk factors.

Results:

With a median follow-up of 4.80 years, 3351 subjects who were diagnosed with lung cancer were selected in the analysis. The lung cancer risk of males was significantly higher than that of females; the HRs in all male non-smokers were 1.29 (95% confidence interval [CI]: 1.20–1.38) after adjusting for the age and 1.38 (95% CI: 1.28–1.50) after adjusting for all factors, which suggested that known factors could not explain the sex difference in the risk of lung cancer in non-smokers. Known factors were 7% (|1.29–1.38|/1.29) more harmful in women than in men. For adenocarcinoma, women showed excess risk higher than men, contrary to squamous cell carcinoma; after adjusting for all factors, 47% ([1.30–1.16]/[1.30–1]) and 4% ([7.02–6.75]/[7.02–1])) of the excess risk was explainable in adenocarcinoma and squamous cell carcinoma. The main causes of gender differences in lung cancer risk were lifestyle factors, baseline comorbidity, and family history.

Conclusions:

Significant gender differences in the risk of lung cancer were discovered in China non-smokers. Existing risk factors did not explain the excess lung cancer risk of all non-smoking men, and the internal causes for the excess risk still need to be explored; most known risk factors were more harmful to non-smoking women; further exploring the causes of the sex difference would help to improve the prevention and screening programs and protect the non-smoking males from lung cancers.

Effects of cigarette smoking on metabolic activity of lung cancer on baseline 18F-FDG PET/CT

Background

Never-smokers with lung cancer usually have a higher survival rate than that of smokers. The high metabolic activity of lung cancer on ¹⁸F-2-Fluoro-2-deoxyglucose (¹⁸F-FDG) PET/CT generally indicates a poor outcome. However, there is a lack of reports on the association between cigarette smoking and ¹⁸F-FDG metabolic activity in patients with lung cancer. In this study, we aimed to investigate the effects of cigarette smoking on metabolic activity of lung cancer on ¹⁸F-FDG PET/CT.

Materials and Methods

A total of 338 patients (230 males, 108 females; mean age: 66.3, range 34-86) with pathologically diagnosed lung cancer were enrolled from September 2019 to April 2021. All patients underwent baseline ¹⁸F-FDG PET/CT and the maximum standard uptake value (SUVmax) of the primary tumor (pSUVmax), lymph node (nSUVmax) and distant metastasis (mSUVmax) were measured. The associations between cigarette smoking status, clinical stage, pathological subtypes and metabolic parameters on ¹⁸F-FDG PET/CT were analyzed.

Results

Of the 338 patients, cigarette smoking was identified in 153 patients (45.3%) and the remaining 185 (54.7%) were never-smokers. Smoking was found more frequently in males, squamous cell carcinoma (SCC) and stage III-IV diseases. The pSUVmax in smokers was significantly higher than that in never-smokers (t = 3.386, P < 0.001), but the nSUVmax and mSUVmax revealed no statistically significant differences (t = 0.399, P = 0.690 and t = 0.057, P = 0.955; respectively). With the increase of cumulative smoking dose, pSUVmax increased significantly (r = 0.217, P < 0.001). In addition, the pSUVmax in patients with stage III-IV was significantly higher than that in stage I-II (t = 8.509, P < 0.001). Smokers showed a higher pSUVmax than never-smokers for patients with stage I-II (t = 3.106, P = 0.002), but not in stage III-IV (t = 0.493, P = 0.622). The pSUVmax was significantly different among patients with different pathological subtypes of lung cancer (F = 11.45, P < 0.001), while only the adenocarcinoma (ADC) and SCC groups showed a difference in pSUVmax (t = 6.667, P < 0.001). Smokers with ADC showed a higher pSUVmax when compared to never-smokers, but not in SCC. There were no significant differences of pSUVmax between smokers and never-smokers at stage I-II ADC or SCC and stage III-IV ADC or SCC.

Conclusions

This study demonstrated a close association between cigarette smoking and the metabolic activity of lung cancer and suggests that smoking may be a potential risk factor of higher pSUVmax in early lung cancer on ¹⁸F-FDG PET/CT.

Causal associations between dietary antioxidant vitamin intake and lung cancer: A Mendelian randomization study

Background

Oxidative stress is currently considered to be closely related to the occurrence of respiratory tumors, especially lung cancer. Many observational studies have shown that increased antioxidant intake can reduce the risk of lung cancer, but the results are still controversial. Therefore, we performed a two-sample Mendelian randomized (MR) analysis to clarify the causal relationship between antioxidant vitamins and lung cancer.

Methods

To assess the causal effect of dietary antioxidant vitamin intake on lung cancer, we conducted a two-sample MR analysis and we extracted single-nucleotide polymorphisms (SNPs) that are associated with antioxidants from genome-wide association studies (GWASs) of the UK biobank. We gathered summary data for lung cancer from the International Lung Cancer Consortium (ILCCO), including 11,348 cases and 15,861 controls, and applied the inverse-variance weighted (IVW) method as the primary MR analysis, and performed a sensitivity analysis to verify the results.

Results

The results showed that higher dietary retinol intake was causally associated with lung cancer overall [odds ratio (OR) = 1.844, 95% CI, 1.359-2.502, p = 0.00009], squamous cell lung cancer (OR = 2.162, 95% CI, 1.117-4.183, p = 0.022), and lung adenocarcinoma (OR = 1.706, 95% CI, 1.084-2.685, p = 0.021). Additionally, carotene was positively correlated with lung adenocarcinoma (OR = 1.510, 95% CI, 1.002-2.276, p = 0.049). However, there was a non-significant relationship between the intake of other dietary antioxidants (vitamin C and vitamin E) and lung cancer.

Conclusion

Our research showed that dietary retinol intake has an adverse impact on lung cancer, and carotene might increase the risk of adenocarcinoma. This highlights the importance of revealing the underlying mechanisms of dietary antioxidant vitamins in lung cancer and delivers an important health message that dietary antioxidant vitamin intake may not be necessary for the prevention of lung cancer. It also provides a basis for future research.

A Robust Seven-Gene Signature Associated With Tumor Microenvironment to Predict Survival Outcomes of Patients With Stage III-IV Lung Adenocarcinoma

Background

Due to the relatively insidious early symptoms of lung adenocarcinoma (LUAD), most LUAD patients are at an advanced stage at the time of diagnosis and lose the best chance of surgical resection. Mounting evidence suggested that the tumor microenvironment (TME) was highly correlated with tumor occurrence, progress, and prognosis. However, TME in advanced LUAD remained to be studied and reliable prognostic signatures based on TME in advanced LUAD also had not been well-established. This study aimed to understand the cell composition and function of TME and construct a gene signature associated with TME in advanced LUAD.

Methods

The immune, stromal, and ESTIMATE scores of each sample from The Cancer Genome Atlas (TCGA) database were, respectively, calculated using an ESTIMATE algorithm. The LASSO and Cox regression model were applied to select prognostic genes and to construct a gene signature associated with TME. Two independent datasets from the Gene Expression Omnibus (GEO) were used for external validation. Twenty-two subsets of tumor-infiltrating immune cells (Tiics) were analyzed using the CIBERSORT algorithm.

Results

Favorable overall survival (OS) and progression-free survival (PFS) were found in patients with high immune score (p = 0.048 and p = 0.028; respectively) and stromal score (p = 0.024 and p = 0.025; respectively). Based on the immune and stromal scores, 453 differentially expressed genes (DEGs) were identified. Using the LASSO and Cox regression model, a seven-gene signature containing AFAP1L2, CAMK1D, LOXL2, PIK3CG, PLEKHG1, RARRES2, and SPP1 was identified to construct a risk stratification model. The OS and PFS of the high-risk group were significantly worse than that of the low-risk group (p < 0.001 and p < 0.001; respectively). The receiver operating characteristic (ROC) curve analysis confirmed the good potency of the seven-gene signature. Similar findings were validated in two independent cohorts. In addition, the proportion of macrophages M2 and Tregs was higher in high-risk patients (p = 0.041 and p = 0.022, respectively).

Conclusion

Our study established and validated a seven-gene signature associated with TME, which might serve as a prognosis stratification tool to predict survival outcomes of advanced LUAD patients. In addition, macrophages M2 polarization may lead to worse prognosis in patients with advanced LUAD.

Use of tyrosine kinase inhibitors during pregnancy for oncogenic-driven advanced non-small cell lung carcinoma

INTRODUCTION

Lung cancer associated with pregnancy is rare but on the increase. The use of tyrosine kinase inhibitor (TKI) therapy for advanced oncogenic-driven non-small cell lung carcinoma (NSCLC) has improved overall survival. Oncological and obstetric outcomes of patients diagnosed with NSCLC and treated by TKIs during pregnancy have been poorly evaluated.

METHODS

Three cases of NSCLC treated by TKIs during pregnancy were collected from the prospective database of the Cancer Associé à La Grossesse (CALG) network (France) in addition to eight cases identified by a systematic review performed between 2000 and 2021.

RESULTS

Among the eleven reported patients, six received an EGFR- and five an ALK-TKI. All patients were young nonsmokers and four had brain metastases at diagnosis. TKI treatment was initiated during the first trimester for three patients. Premature delivery was induced in 10/11 patients. Anamnios occurred in one patient treated by osimertinib and trastuzumab. Five newborns were hypotrophic. No newborn malformations were observed. Diffusion of the TKIs, confirmed by blood cord sampling, represented about 1/3 (EGFR-TKI) and 1/8 (ALK-TKI) of the maternal concentration. No developmental abnormalities were observed in the children (follow-up 30 months). The anti-tumor efficacy and tolerance of TKIs, when reported, appears similar to that described in the general population.

CONCLUSIONS

Our results support the rationale for using TKIs during pregnancy, both in terms of maternal NSCLC disease control and the relatively mild effects on the fetus. Our data will serve to better inform patients about the risks associated with TKIs used during pregnancy, contributing to shared decision making.

Smoking, chromosomal aberrations, and cancer incidence in healthy subjects

Chromosomal aberrations (CAs) in peripheral blood lymphocytes can be used as biomarkers of cancer risk. Cytogenetic tests were conducted on 2396 healthy Hungarian individuals and cancer incidence was followed up from 1989 to 2018. Venous blood samples were obtained from the subjects and metaphases from lymphocyte cultures were prepared. We compared the CA frequencies of the various smoking (1-5; 6-10; 11-19; or 20-40 cigarettes/day) and exposure (irradiation; chemical industry; chemical research laboratory) groups. Chromatid break (p = 0.0002), total aberration (p = 0.002), and aberrant cell (p = 0.001) frequencies were higher in smokers than in non-smokers. For very heavy smokers, total CAs were significantly higher than for non-smokers (<0.001) or less intensive smokers (p = 0.003-0.0006). Intensity of smoking was a predictor of chromosomal aberrations, while duration was not. During follow-up, 177 (7.3 %) cancer cases were found. A Cox-regression model showed that subjects with cell values ≥2 CAs developed cancer more frequently (hazard ratio = 1.39; 95 % CI, 1.02-1.90). The relative risks of cancer were 1.06 (95 % CI 0.53-2.06) for light smokers and 1.74 (95 % CI 1.08-2.77) for very heavy smokers. The distributions of cancer sites showed differences between smoker and non-smoker groups: in male smokers, lung cancer, in non-smokers, prostate, and in females (both groups) breast cancer were most common. Cancer incidence correlated with chromosome aberrations; smoking was not a confounder in this relationship.

High discrepancy in thrombotic events in non-small cell lung cancer patients with different genomic alterations

Background

Acute complications, such as venous thromboembolism (VTE), are common in patients with advanced severe lung cancers. However, current VTE risk scores cannot adequately identify high-risk patients with non-small cell lung cancer (NSCLC). The study proposed to elucidated the incidence of thromboembolism (TE) in patients with different oncogenic aberrations and the impact of these aberrations on the efficacy of targeted therapy in patients with NSCLC.

Methods

A systemic review was conducted in Web of Science, PubMed, Embase and the Cochrane Library to evaluate the incidence of TE in different molecular subtypes of NSCLC. Data from patients diagnosed of advanced NSCLC who harboring anaplastic lymphoma kinase (ALK) or ROS proto-oncogene 1 receptor tyrosine kinase (ROS1) rearrangements since 2016 to 2019 were also retrospectively collected. A meta-analysis with random-effects model, sensitivity analysis and publication bias were performed. The principal summary measure was incidence of thrombotic events in NSCLC patients. And the efficacy of tyrosine kinase inhibitor (TKI) therapy was compared between the two subgroups.

Results

A total of 5,767 cases from 20 studies were included in the analysis of the incidence of thrombosis in patients with different oncogenic alterations. The pooled analysis showed a higher risk of thrombosis in ROS1-fusion types (41%, 95% CI: 35-47%) and ALK-fusion types (30%, 95% CI: 24-37%) than in EGFR-mutation (12%, 95% CI: 8-17%), KRAS-mutation (25%, 95% CI: 13-50%), and wild-type (14%, 95% CI: 10-20%) cases. A high prevalence of thrombosis (ALK: 24.4%; ROS1: 32.6%) was observed in the Shanghai Pulmonary Hospital (SPH) cohort of 224 patients with ALK or ROS1 fusion. Furthermore, patients with embolism had significantly shorter progression-free survival (PFS) after TKI therapy than those without embolism, both in the ALK+ cohort (5.6 vs. 12.9 months, P<0.0001) and in the ROS1+ cohort (9.6 vs. 17.6 months, P=0.0481).

Conclusions

NSCLC patients with ALK/ROS1 rearrangements are more likely to develop thrombosis than patients with other oncogenic alterations. Thrombosis may also be associated with an inferior response and PFS after TKI therapy.

Are developmentally missing teeth a predictive risk marker of malignant diseases in non-syndromic individuals? A systematic review

Background:

Different genes and loci that are associated with non-syndromic developmental tooth agenesis (TA) have the same causation pathway in the development of tumours including breast cancer (BC), epithelial ovarian cancer (EOC), colorectal cancer (CRC) and lung cancer (LC).

Objectives:

To assess the link between TA and the development of cancer.

Search sources:

This registered review included a comprehensive search of electronic databases (Cochrane Central Register of Controlled Trials [CENTRAL], LILACS, Scopus, Web of Science and Medline via Ovid) until 1 April 2020, supplemented by manual, grey literature and reference lists search. There was no restriction in term of date of publication, gender, race or type of hypodontia.

Data selection:

The primary outcome was the relationship between TA and cancer. The secondary outcome was to identify the genetic correlation between TA and cancer.

Data extraction:

Study selection, data extraction and risk of bias assessment were performed independently and induplicate by two reviewers, with disputes resolved by a third reviewer.

Results:

Eight studies with a moderate-high risk of bias were included in the final review, with a total of 5821 participants. Due to the heterogeneity among the included studies, the data were presented narratively. Limited studies reported a high prevalence of EOC (19.2%–20%) and CRC (82%–100%) in individuals with TA (depending on the study) compared to those without TA (3% for EOC and 0% for CRC). While others reported a weak correlation between EOC and CRC and TA ( P > 0.05). Weak evidence suggested a strong correlation between breast, cervical uterine and prostate cancers and TA ( P < 0.05).

Conclusions:

Though low-quality evidence suggests a link between TA and cancer, it was not possible to verify that TA can hold a predictive value as a marker for cancers. Further research is needed to confirm the association.

Registration:

PROSPERO (CRD42020139751).

Concomitant Pathogenic Mutations and Fusions of Driver Oncogenes in Tumors

Driver oncogene alterations have always been one of leading causes in the process of occurrence and development of tumors. And the effects of driver oncogene alterations on tumorigenesis and progression in different kinds of tumors have been studied heatedly. And the roles that the driver oncogenes alterations play have been elucidated clearly in previous studies. The phenomenon of concomitant driver oncogenes mutations and driver genes fusions has gained much concentration in the past two decades. And a growing number of studies reported this phenomenon, either coexistence or mutually exclusivity. Here we reviewed on the phenomenon of concomitant mutations in three common types of carcinomas—lung cancer, thyroid cancer, and leukemia, which have been studied relatively more detailed and more general compared with others.

K-Ras-Activated Cells Can Develop into Lung Tumors When Runx3-Mediated Tumor Suppressor Pathways Are Abrogated

K-RAS is frequently mutated in human lung adenocarcinomas (ADCs), and the p53 pathway plays a central role in cellular defense against oncogenic K-RAS mutation. However, in mouse lung cancer models, oncogenic K-RAS mutation alone can induce ADCs without p53 mutation, and loss of p53 does not have a significant impact on early K-RAS-induced lung tumorigenesis. These results raise the question of how K-RAS-activated cells evade oncogene surveillance mechanisms and develop into lung ADCs. RUNX3 plays a key role at the restriction (R)-point, which governs multiple tumor suppressor pathways including the p14ARF-p53 pathway. In this study, we found that K-RAS activation in a very limited number of cells, alone or in combination with p53 inactivation, failed to induce any pathologic lesions for up to 1 year. By contrast, when Runx3 was inactivated and K-RAS was activated by the same targeting method, lung ADCs and other tumors were rapidly induced. In a urethane-induced mouse lung tumor model that recapitulates the features of K-RAS-driven human lung tumors, Runx3 was inactivated in both adenomas (ADs) and ADCs, whereas K-RAS was activated only in ADCs. Together, these results demonstrate that the R-point-associated oncogene surveillance mechanism is abrogated by Runx3 inactivation in AD cells and these cells cannot defend against K-RAS activation, resulting in the transition from AD to ADC. Therefore, K-RAS-activated lung epithelial cells do not evade oncogene surveillance mechanisms; instead, they are selected if they occur in AD cells in which Runx3 has been inactivated.

Genetic Determinants of Lung Cancer Prognosis in Never Smokers: A Pooled Analysis in the International Lung Cancer Consortium

BACKGROUND

Lung cancer remains the leading cause of cancer death worldwide, with 15% to 20% occurring in never smokers. To assess genetic determinants for prognosis among never smokers, we conducted a genome-wide investigation in the International Lung Cancer Consortium (ILCCO).

METHODS

Genomic and clinical data from 1,569 never-smoking patients with lung cancer of European ancestry from 10 ILCCO studies were included. HRs and 95% confidence intervals of overall survival were estimated. We assessed whether the associations were mediated through mRNA expression-based 1,553 normal lung tissues from the lung expression quantitative trait loci (eQTL) dataset and Genotype-Tissue Expression (GTEx). For cross-ethnicity generalization, we assessed the associations in a Japanese study (N = 887).

RESULTS

One locus at 13q22.2 was associated with lung adenocarcinoma survival at genome-wide level, with carriers of rs12875562-T allele exhibiting poor prognosis [HR = 1.71 (1.41-2.07), P = 3.60 × 10-8], and altered mRNA expression of LMO7DN in lung tissue (GTEx, P = 9.40 × 10-7; Lung eQTL dataset, P = 0.003). Furthermore, 2 of 11 independent loci that reached the suggestive significance level (P < 10-6) were significant eQTL affecting mRNA expression of nearby genes in lung tissues, including CAPZB at 1p36.13 and UBAC1 at 9q34.3. One locus encoding NWD2/KIAA1239 at 4p14 showed associations in both European [HR = 0.50 (0.38-0.66), P = 6.92 × 10-7] and Japanese populations [HR = 0.79 (0.67-0.94), P = 0.007].

CONCLUSIONS

Based on the largest genomic investigation on the lung cancer prognosis of never smokers to date, we observed that lung cancer prognosis is affected by inherited genetic variants.

IMPACT

We identified one locus near LMO7DN at genome-wide level and several potential prognostic genes with cis-effect on mRNA expression. Further functional genomics work is required to understand their role in tumor progression.

Smoking habit and chemo-radiotherapy and/or surgery affect the sensitivity of EGFR plasma test in non-small cell lung cancer

OBJECTIVE

This study aimed to identify the influential factors for the sensitivity of epidermal growth factor receptor (EGFR) plasma test in non-small cell lung cancer (NSCLC). The mutations were detected in tumor tissue and matched plasma samples from 125 newly diagnosed adenocarcinoma, clinical-stage IIIB-IV patients, and compared the diagnostic values of EGFR plasma test between groups of clinical characteristics. The influential factors for the sensitivity were identified and assessed by logistic regression.

RESULTS

EGFR mutations were detected in 65 (52.0%) tumor tissue and 50 (40.0%) matched plasma samples (P = 0.028). Compared to the tissue method, the concordance rate, sensitivity, and specificity of the EGFR plasma test were 86.4%, 75.4%, and 98.3%, respectively. Notably, we found that sensitivity of the test is higher in non-smokers (84.1%) compared to smokers (57.1%, P = 0.018), and in treatment naïve subjects (85.7%) compared to whom undergone chemo-radiotherapy with/without surgery before testing (56.5%, P = 0.009). Furthermore, the highest sensitivity was attained in patients without these two factors (90.3%), whilst the lowest value was noted in those with both factors (40.0%, P = 0.004). The multivariable analysis confirmed that smoking habit and treatment history have independently negative impacts on sensitivity (OR = 0.24, P = 0.019, and OR = 0.36, P = 0.047, respectively).

Long non-coding RNA-ZNF281 upregulates PTEN expression via downregulation of microRNA-221 in non-small cell lung cancer

A recent study reported that zinc finger protein (ZNF)281 is a tumor-suppressive long non-coding (lnc)RNA in glioma. The present study investigated the role of ZNF281 in non-small cell lung cancer (NSCLC). ZNF281 expression in paired cancer and non-cancerous tissues from patients with NSCLCs was analyzed by RNA extraction and reverse transcription-quantitative-PCR. A 5-year follow up on patients was performed to analyze the prognostic value of ZNF281 for NSCLC. Cell transfections of ZNF281 or phosphatase and tensin homolog (PTEN) expression vector and microRNA (miR)-221 mimic were performed to analyze the relationship between ZNF281, miR-221 and PTEN. Cell apoptosis and proliferation were analyzed using Cell Counting Kit-8 and flow cytometry, respectively. In patients with NSCLC, expression levels of ZNF281 were significantly lower in cancer tissues compared with in non-cancerous tissues, and lower levels of ZNF281 expression in cancerous tissues predicted poor survival. In NSCLC cells, ZNF281 overexpression resulted in upregulated PTEN and downregulated miR-221 expression, whereas cells with miR-221 overexpression exhibited downregulated PTEN expression and unaffected ZNF281 expression. In addition, ZNF281 and PTEN overexpression resulted in accelerated cell apoptosis and inhibited the cell proliferation of NSCLC cells. Notably, miR-221 overexpression exhibited an opposite effect and attenuated the functions of ZNF281 and PTEN overexpression. Therefore, ZNF281 may upregulate PTEN via downregulation of miR-221 in NSCLC, resulting in inhibition of cancer cell proliferation and the promotion of apoptosis.

Clinical and Genomic Characteristics of Small Cell Lung Cancer in Never Smokers: Results From a Retrospective Multicenter Cohort Study

BACKGROUND

Small cell lung cancer (SCLC) has the strongest association with smoking among lung cancers. The characteristics of never smokers with SCLC is not known.

RESEARCH QUESTION

Are the clinical characteristics, prognostic factors, survival, genomic alterations, and tumor mutational burdens of SCLC in patients who have never smoked different from those who have smoked?

STUDY DESIGN AND METHODS

A retrospective multicenter cohort study of patients with clinician-confirmed SCLC was performed with the use of a longitudinal and nationally representative electronic medical records database. Smoking history was assessed through technology-enabled abstraction and confirmed for never smokers via chart review. Genomic characteristics of never smoker patients with SCLC were examined with the use of a next-generation sequencing-based gene panel and whole exome sequencing.

RESULTS

One hundred of 5,632 patients (1.8%) with SCLC were never smokers. Relative to smokers, never smokers were more likely to be female (66.0% vs 52.4%; P = .009) and present with extensive stage (70.0% vs 62.2%; P = .028). Never smokers had a higher proportion of patients in age groups 35 to 49 years (7.0% vs 3.0%; P = .006) and ≥80 years (17.0% vs 8.2%; P = .006). Known risk factors for lung cancer were found in <20% of never smokers. There were no overall survival differences between never smokers and smokers. Among patients with available genomic data (n = 9), never smoker SCLC were characterized by lower tumor mutational burden, a lower frequency of TP53 mutations, and an absence of mutational signatures related to tobacco exposure.

INTERPRETATION

The sex- and age-specific distribution of SCLC among never smokers, along with differences that were identified by genomic analyses, suggests a distinct biology of SCLC in never smokers compared with smokers.

Smoking Status and Survival Among a National Cohort of Lung and Colorectal Cancer Patients

INTRODUCTION

The purpose of this study was to explore the association of smoking status and clinically relevant duration of smoking cessation with long-term survival after lung cancer (LC) or colorectal cancer (CRC) diagnosis. We compared survival of patients with LC and CRC who were never-smokers, long-term, medium-term, and short-term quitters, and current smokers around diagnosis.

METHODS

We studied 5575 patients in Cancer Care Outcomes Research and Surveillance (CanCORS), a national, prospective observational cohort study, who provided smoking status information approximately 5 months after LC or CRC diagnosis. Smoking status was categorized as: never-smoker, quit >5 years prior to diagnosis, quit between 1-5 years prior to diagnosis, quit less than 1 year before diagnosis, and current smoker. We examined the relationship between smoking status around diagnosis with mortality using Cox regression models.

RESULTS

Among participants with LC, never-smokers had lower mortality risk compared with current smokers (HR 0.71, 95% CI 0.57 to 0.89). Among participants with CRC, never-smokers had a lower mortality risk as compared to current smokers (HR 0.79, 95% CI 0.64 to 0.99).

CONCLUSIONS

Among both LC and CRC patients, current smokers at diagnosis have higher mortality than never-smokers. This effect should be further studied in the context of tumor biology. However, smoking cessation around the time of diagnosis did not affect survival in this sample.

IMPLICATIONS

The results from our analysis of patients in the CanCORS consortium, a large, geographically diverse cohort, show that both LC and CRC patients who were actively smoking at diagnosis have worse survival as compared to never-smokers. While current smoking is detrimental to survival, cessation upon diagnosis may not mitigate this risk.

The Metabolic Remodelling in Lung Cancer and Its Putative Consequence in Therapy Response

Lung cancer is the leading cause of cancer-related deaths worldwide in both men and women. Conventional chemotherapy has failed to provide long-term benefits for many patients and in the past decade, important advances were made to understand the underlying molecular/genetic mechanisms of lung cancer, allowing the unfolding of several other pathological entities. Considering these molecular subtypes, and the appearance of promising targeted therapies, an effective personalized control of the disease has emerged, nonetheless benefiting a small proportion of patients. Although immunotherapy has also appeared as a new hope, it is still not accessible to the majority of patients with lung cancer.The metabolism of energy and biomass is the basis of cellular survival. This is true for normal cells under physiological conditions and it is also true for pathophysiologically altered cells, such as cancer cells. Thus, knowledge of the metabolic remodelling that occurs in cancer cells in the sense of, on one hand, surviving in the microenvironment of the organ in which the tumour develops and, on the other hand, escaping from drugs conditioned microenvironment, is essential to understand the disease and to develop new therapeutic approaches.

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.

Deleterious Pulmonary Surfactant System Gene Mutations in Lung Adenocarcinomas Associated With Usual Interstitial Pneumonia

Purpose

Usual interstitial pneumonia (UIP) is a risk factor for lung carcinogenesis. This study was performed to characterize mutagenesis and mutational target genes underlying lung carcinogenesis in patients with UIP.

Patients and Methods

A cohort of 691 Japanese patients with lung adenocarcinoma (LADC), of whom 54 had UIP and 637 did not, was studied for driver oncogene aberrations. Whole-exome analysis was performed for 296 cases, including 51 with UIP, to deduce mutagenic processes and identify commonly affected genes. Logistic regression analysis was used to detect associations of gene aberrations with clinicopathological factors.

Results

The EGFR mutation was markedly less prevalent in patients with LADC with UIP than in those without (1.9% [one of 54] v. 49.9% [318 of 637]; P < .001), even in heavy smokers (25.3% [38 of 150] of patients with > 40 pack-years; P < .001). Mutational signature analysis indicated that UIP-positive LADCs develop through accumulation of single-nucleotide and indel mutations caused by smoking. Pulmonary surfactant system genes (PSSGs) NKX2-1/TTF1, SFTPA1, SFTPA2, SFTPB, and SFTPC were identified as targets for mutations (preferentially indels), and mutations were specifically associated with shorter overall survival of patients with UIP-positive LADC, independent of pathologic stage (hazard ratio, 4.9; 95% CI, 1.7 to 14.4; P = .0037).

Conclusion

LADCs with UIP develop through mutational events caused by smoking, independently of EGFR mutation. PSSGs were identified as a mutational target and as a novel prognostic factor in UIP-positive LADC. PSSG deficiency might increase the malignancy of tumor cells by increasing the tumor-promoting effects of UIP.

Lung cancer in never-smokers - what are the differences?

INTRODUCTION

Characteristics of never-smokers with lung cancer are still not fully clarified. The aim of this study was to compare never-smokers and ever-smokers with non-small cell lung cancer (NSCLC) regarding patient and tumor characteristics.

METHODS

All consecutive newly NSCLC patients with known smoking status diagnosed between 2011 and 2015 were included in this retrospective cohort study. Clinical, histological, and molecular characteristics were compared between ever-smokers and never-smokers.

RESULTS

Of the 558 included patients, 125 (22.4%) were never-smokers. These patients were more likely to be female (74% vs. 7%, p < .001), older (67 vs. 66 years-old, p = .019), and have adenocarcinoma (93% vs. 65%, p < .001). Never-smokers took longer to seek medical care after the symptoms onset (3 vs. 2 months, p < .001), regardless of the symptoms, histological type, or gender (OR: 1.2 [1.4-2.0]). The metastatic pattern was different in never-smokers: pleural metastases were more frequent (OR: 2.1 [1.1-4.0]), regardless of the histological type and gender. Never-smokers had a higher prevalence of ALK translocations (26% vs. 4%, p < .001) and EGFR mutations (36% vs. 8%, p < .001). The type of EGFR mutation was also significantly different between groups.

CONCLUSIONS

Never-smokers with NSCLC present distinct demographic and clinical characteristics. The characteristics of tumor also differ between never-smokers and ever-smokers, which may suggest different carcinogenic pathways.

Involvement of TP53 and TP16 expression in human papillomavirus-associated non-small cell lung cancer

Human papilloma virus (HPV) infection has previously been reported to be associated with TP53 and TP16 expression in Japanese and Taiwanese patients with lung cancer, but data for advanced non-small cell lung cancer (NSCLC) patients is limited. The present study examined the association between HPV infection and TP53 and TP16 expression in Chinese patients with advanced NSCLC. HPV DNA was detected in 20 out of 83 (24%) lung tumors, and was observed more frequently in non-smokers, patients with lymph node metastasis, and patients with poorly differentiated tumors (P=0.048, P=0.044 and P=0.024, respectively). Thirteen (65%) out of 20 HPV-infected tumors were positive for TP53 expression while eight (40%) were positive for TP16 expression. Multivariate analysis revealed that poor differentiation alone (OR=0.163) was an independent predictive factor of HPV infection in NSCLC. TP16-positive patients had a significantly longer survival time when compared with TP16-negative patients (P<0.001, log-rank test), a trend a not observed for TP53. Our results suggest that TP53 and TP16 protein expression is not associated with the expression of HPV DNA, but that TP16 expression may be an independent prognostic factor of long survival in advanced NSCLC.

EGFR gene copy number as a predictive/biomarker for patients with non-small-cell lung cancer receiving tyrosine kinase inhibitor treatment: a systematic review and meta-analysis

Epidermal growth factor receptor (EGFR) gene copy number has been proposed as a candidate biomarker for predicting treatment response to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in patients with advanced non-small-cell lung cancer (NSCLC). MEDLINE, PubMed, Cochrane, and Google Scholar databases were searched until October 21, 2015 using the following search terms: lung neoplasms/lung cancer/non-small cell lung cancer/NSCLC, EGFR, gene amplification, copy number, erlotinib, gefitinib, tyrosine-kinase inhibitor/TKI, predictor. 17 studies were included in the analysis with a total of 2047 patients. The overall analysis found that increased EGFR gene copy number was associated with higher overall response rate (ORR), overall survival (OS) and progression-free survival (PFS; p values ≤0.008) compared with patients without a high EGFR gene copy number. Subgroup analysis found that in a population of patients who were primarily Caucasian, a higher EGFR gene copy number was also associated with increased ORR, OS, and PFS (p values ≤0.018). The results were similar in a population of Asian patients, except that a higher EGFR gene copy number was not associated with improved OS (p=0.248). Sensitivity analysis indicated that no one study overly influenced the results and that the findings are robust. The result of the analysis found that EGFR gene copy number was associated with increased OS and PFS, supporting the idea that EGFR gene copy number is a biomarker for response to EGFR-TKI therapy in patients with advanced NSCLC.

Alcohol consumption and lung cancer risk in never smokers

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Lung Cancer in Never Smokers

Lung cancer is predominantly associated with cigarette smoking; however, a substantial minority of patients with the disease have never smoked. In the US it is estimated there are 17,000-26,000 annual deaths from lung cancer in never smokers, which as a separate entity would be the seventh leading cause of cancer mortality. Controversy surrounds the question of whether or not the incidence of lung cancer in never-smokers is increasing, with more data to support this observation in Asia. There are several factors associated with an increased risk of developing lung cancer in never smokers including second hand smoke, indoor air pollution, occupational exposures, and genetic susceptibility among others. Adenocarcinoma is the most common histology of lung cancer in never smokers and in comparison to lung cancer in smokers appears less complex with a higher likelihood to have targetable driver mutations.

Resistance to Therapy

Identification of driver mutations in adenocarcinoma of the lung has revolutionized the treatment of this disease. It is now standard of care to look for activating mutations in epidermal growth factor receptor (EGFR), and translocations in anaplastic lymphoma kinase (ALK) or ROS1 in all newly diagnosed adenocarcinoma of the lung, and in many patients with squamous cell carcinoma as well. Recognition of multiple other lung cancer driver mutations has also expanded treatment options. Targeted treatments of these mutations lead to rapid and prolonged responses, but resistance inevitably develops. Until recently, traditional chemotherapy was the only alternative at that time, but better understanding of resistance mechanisms has lead to additional therapeutic options. These mechanisms of resistance and treatments are the focus of this chapter. Understanding of mechanisms of chemotherapy resistance is touched upon, along with a brief discussion of immune checkpoint inhibitors.

Lung cancer screening with low-dose computed tomography: Experiences from a tertiary hospital in Taiwan

BACKGROUND/PURPOSE

Lung cancer screening using low-dose computed tomography (CT) has been reported to reduce lung cancer-specific mortality for smokers at high risk. However, despite different characteristics of lung cancer in Asia, there are few data concerning this specific population for screening. We aim to analyze the performance of lung cancer screening with low-dose CT concurrent with chest radiography in Taiwan, with reference to international experience.

METHODS

During the 1-year period from January 2012 to December 2012, we conducted a retrospective, single-center population-based screening program for lung cancer in the setting of annual medical examinations. Participants were asymptomatic adults without prior history of any cancer. Low-dose CT and chest radiography were offered to all individuals. Baseline CT evaluations were defined as positive if any noncalcified nodule≥4 mm in diameter, which were then classified as solid, pure ground-glass or partial ground-glass opacity.

RESULTS

Of 3339 individuals, we detected 34 cancers, yielding an overall cancer detection rate of 1.02%. There was a particularly high cancer detection rate of 6.2% (8/129) in the high-risk group aged younger than 50 years with a positive family history of all types of cancers in first-degree relatives. Adenocarcinomas accounted for 88% (30/34) of cancers and 99% of them were early-stage (including carcinoma in situ and Stage I). The probability of cancers was significant higher in nodules with interval growth (odds ratio 257.89, p = 0.0002). There was no significant difference in the probability of cancers between ground glass opacity nodules and solid nodules (odds ratio 1.16, p=0.72). Of all screen-detected cancers, 61.76% (21/34) were chest radiographically occult.

CONCLUSION

Low-dose CT is effective to detect early lung cancers. Further establishment of selection criteria for lung cancer screening, specifically for Asian individuals, is definitely warranted.

Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for Thirteen Cancer Types

BACKGROUND

Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites.

METHODS

Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers.

RESULTS

GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures.

CONCLUSION

Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.

Molecular profile of lung cancer in never smokers

Tobacco smoking is the most common cause of lung cancer, but approximately 10–25% of patients with lung cancer are life-long never smokers. The cause of lung cancer in never smokers is unknown, although tobacco-smoke exposure may play a role in some of these patients. Lung cancer that develops in the absence of significant tobacco-smoke exposure appears to be a unique disease entity with novel genomic and epigenomic alterations and activation of molecular pathways that are not generally seen in tobacco-smoke-induced lung cancer. These molecular alterations are very likely responsible for the unique clinico-pathological features of lung cancer in never smokers (LCINS), and some of these molecular alterations – such as the activating EGFR TK mutations and EML4–ALK fusion – significantly influence therapeutic choices and treatment outcomes. In the last few years there has been a number of studies exploring the molecular characteristics of LCINS, and some of them have reported new and significant findings. Here we review the key findings from these studies and discuss their potential therapeutic implications.

Timeliness of Diagnosing Lung Cancer: Number of Procedures and Time Needed to Establish Diagnosis: Being Right the First Time

To study number of procedures and time to diagnose lung cancer and factors affecting the timeliness of clinching this diagnosis. Retrospective cohort study of lung cancer patients who consecutively underwent diagnostic bronchoscopy in 1 year (October 2013 to September 2014). Out of 101 patients diagnosed with lung cancer from bronchoscopy, average time interval between first abnormal computed tomogram (CT) scan-to-1st procedure, 1st procedure-to-diagnosis, and 1st abnormal CT scan-to-diagnosis was 16 ± 26, 11 ± 19, and 27 ± 33 days, respectively. These intervals were significantly longer in those requiring repeat procedures. Multivariate analysis revealed inconclusive 1st procedure to be the predictor of prolonged (>30 days) CT scan to diagnosis time (P = 0.04). Twenty-nine patients (28.7%) required repeat procedures (n = 63). Reasons behind repeating the procedures were inadequate procedure (n = 14), inaccessibility of lesion (n = 9), inappropriate procedure (n = 5), mutation analysis (n = 2), and others (n = 2). Fifty had visible endo-bronchial lesion, 20 had positive bronchus sign, and 83 had enlarged mediastinal/hilar lymph-nodes or central masses adjacent to the airways. Fewer procedures, and shorter procedure to diagnosis time, were observed in those undergoing convex probe endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) (P = 0.04). Most patients exhibit enlarged mediastinal lymph node or mass adjacent to the central airway accessible by convex probe EBUS-TBNA. Hence, combining it with conventional bronchoscopic techniques such as bronchoalveolar lavage, brush, and forceps biopsy increases detection rate, and reduces number of procedures and time to establish diagnosis. This may translate into cost and resource savings, timeliness of diagnosis, greater patient satisfaction, and conceivably better outcomes.

Ribonucleotide reductase subunit M2 predicts survival in subgroups of patients with non-small cell lung carcinoma: effects of gender and smoking status

Background

Ribonucleotide reductase catalyzes the conversion of ribonucleotide diphosphates to deoxyribonucleotide diphosphates. The functional enzyme consists of two subunits - one large (RRM1) and one small (RRM2 or RRM2b) subunit. Expression levels of each subunit have been implicated in prognostic outcomes in several different types of cancers.

Experimental Design

Immunohistochemistry for RRM1 and RRM2 was performed on a lung cancer tissue microarray (TMA) and analyzed. 326 patients from the microarray were included in this study.

Results

In non-small cell lung cancer (NSCLC), RRM2 expression was strongly predictive of disease-specific survival in women, non-smokers and former smokers who had quit at least 10 years prior to being diagnosed with lung cancer. Higher expression was associated with worse survival. This was not the case for men, current smokers and those who had stopped smoking for shorter periods of time. RRM1 was not predictive of survival outcomes in any subset of the patient group.

Conclusion

RRM2, but not RRM1, is a useful predictor of survival outcome in certain subsets of NSCLC patients.

Efficacy of erlotinib in previously treated patients with advanced non-small cell lung cancer: analysis of the Chinese subpopulation in the TRUST study

OBJECTIVE

This study is to analyze the data of Chinese subpopulation in the Tarceva Lung Cancer Survival Treatment Study (TRUST-China) which was a global Phase IV study designed to provide erlotinib to previously treated patients with Stage IIIB/IV non-small cell lung cancer.

METHODS

Patients with pathologically confirmed, unresectable Stage IIIB/IV non-small cell lung cancer who were previously failed on or unsuitable for chemotherapy or radiotherapy were given erlotinib (150 mg/day, oral) until disease progression, intolerable toxicity or death. Efficacy and toxicity of the agent were evaluated.

RESULTS

In total, 519 patients Chinese patients were analyzed. The TRUST-China had similar baseline characteristics to TRUST-Global except the greater percentage of adenocarcinoma and non-smoker cases. The response rate and disease control rate were 24.7 and 75.3%, respectively. Median progression-free survival and overall survival were 6.4 and 15.4 months in the general Chinese population in the TRUST, and 10.2 and 18.9 months in non-smokers with adenocarcinoma (n = 254). Median progression-free survival and overall survival were significantly longer in non-smokers with adenocarcinoma than those in other groups (P ≤ 0.0001 and P ≤ 0.0001, respectively). Eastern Cooperative Oncology Group Performance Status (≥ 2 vs. ≤ 1, hazard ratio = 1.746, P < 0.0001) and histology (squamous cell carcinoma vs. adenocarcinoma, hazard ratio = 1.595, P = 0.0008) were independent risk factors that affected survival according to Cox regression multivariate analysis.

CONCLUSIONS

We confirmed the efficacy and safety of erlotinib in Chinese patients. Non-smoking patients with adenocarcinoma histology had the best clinical benefits. (NCT00949910).

RARβ2 hypermethylation is associated with poor recurrence-free survival in never-smokers with adenocarcinoma of the lung

Background

This study was aimed at investigating if the effect of RARβ2 hypermethylation on recurrence-free survival (RFS) in non-small cell lung cancer (NSCLC) depends on one’s smoking status and specific interacting proteins.

Results

We retrospectively analyzed the expressions of five proteins using immunohistochemistry in archival formalin-fixed and paraffin-embedded tissues from 578 NSCLC patients who had undergone surgical resection from 1994 through 2004. Promoter methylation of RARβ2 was assessed by bisulfite pyrosequencing. Recurrence was found in 268 (46%) of 578 NSCLCs with a median follow-up period of 4.8 years. Overexpression of β-catenin, c-MET, cyclin D1, and EGFR occurred in 55%, 72%, 51%, and 41% of the patients, respectively. E-cadherin expression was negative in 62% of the patients, and RARβ2 hypermethylation was found in 37%. The abnormal expression of c-MET (P = 0.002) and EGFR (P = 0.001) was found to be highly prevalent in never-smokers. RARβ2 hypermethylation was significantly associated with poor recurrence-free survival (RFS) in 128 never-smokers with adenocarcinoma (P = 0.01) For parsimonious model building, the five proteins were clustered into three groups (β-catenin and E-cadherin; c-MET; cyclin D1 and EGFR) by an unsupervised hierarchical clustering and were included in a multivariate analysis. Cox proportional hazard analysis showed that RARβ2 hypermethylation was significantly associated with poor RFS in 128 never-smokers with adenocarcinoma (adjusted hazard ratio [HR] = 2.19, 95% confidence interval [CI] = 1.28 to 3.47; P = 0.009), after adjusting for interacting proteins.

Conclusions

The present study suggests that RARβ2 hypermethylation may be an independent prognostic factor of RFS in never-smokers with adenocarcinoma of the lung.

Molecular analysis of human papillomavirus in never-smokers with non-small cell lung cancer

The causes of lung cancer in never-smokers remain unclear. The potential contribution of human papillomavirus (HPV) to the carcinogenesis of non-small cell lung cancer (NSCLC) has been reported. In 2008, a prospective registry of never-smokers with NSCLC was established at the Kinki-Chuo Chest Medical Center, Sakai, Osaka, Japan. Never-smokers with NSCLC were consecutively enrolled onto the registry. Of these patients, 114 with large tumor specimens, the majority of which were surgical tissues, were selected. In total, 23 of the most clinically relevant HPV types were assayed using polymerase chain reaction amplification of the viral genome. Following exclusion of samples with suboptimal quality, DNA was extracted from 96 formalin-fixed paraffin-embedded samples. These 96 cases consisted of 82 females (85.4%) and 14 males (14.6%), with a median age of 67 years (range, 29-83). Almost all cases (93.8%) were of the adenocarcinoma histological subtype. Despite confirmation of the quality and amount of DNA, HPV type 6 was detected in only one case (1.1%). Furthermore, no other samples examined were positive for any other HPV types. The results therefore suggest that HPV does not play a major role as the driving oncogenic event in never-smokers with NSCLC.

Pulmonary adenocarcinoma: implications of the recent advances in molecular biology, treatment and the IASLC/ATS/ERS classification

A decade ago, lung cancer could conveniently be classified into two broad categories-either the small cell lung carcinoma (SCLC), or the non-small cell lung carcinoma (NSCLC), mainly to assist in further treatment related decision making. However, the understanding regarding the eligibility of adenocarcinoma histology for treatments with agents such as pemetrexed and bevacizumab made it a necessity for NSCLC to be classified into more specific sub-groups. Then, the availability of molecular targeted therapy with oral tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib not only further emphasized the need for accurate sub-classification of lung cancer, but also heralded the important role of molecular profiling of lung adenocarcinomas. Given the remarkable advances in molecular biology, oncology and radiology, a need for felt for a revised classification for lung adenocarcinoma, since the existing World Health Organization (WHO) classification of lung cancer, published in the year 2004 was mainly a pathological system of classification. Thus, there was a combined effort by the International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS) and the European Respiratory Society (ERS) with an effort to inculcate newly established perspectives from clinical, molecular and radiological aspects in evolving a modern classification for lung adenocarcinomas. This review provides a summary of the recent advances in molecular biology and molecular targeted therapy with respect to lung adenocarcinoma. Also, a brief summation of the salient recommendations provided in the IASLC/ATS/ERS classification of lung adenocarcinomas is provided. Lastly, a discussion regarding the future prospects with lung adenocarcinoma is included.

Molecular biology of lung cancer

Lung cancers are characterised by abundant genetic diversity with relatively few recurrent mutations occurring at high frequency. However, the genetic alterations often affect a common group of oncogenic signalling pathways. There have been vast improvements in our understanding of the molecular biology that underpins lung cancer in recent years and this has led to a revolution in the diagnosis and treatment of lung adenocarcinomas (ADC) based on the genotype of an individual's tumour. New technologies are identifying key and potentially targetable genetic aberrations not only in adenocarcinoma but also in squamous cell carcinoma (SCC) of the lung. Lung cancer mutations have been identified in v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), epidermal growth factor receptor (EGFR), BRAF and the parallel phosphatidylinositol 3-kinase (PI3K) pathway oncogenes and more recently in MEK and HER2 while structural rearrangements in ALK, ROS1 and possibly rearranged during transfection (RET) provide new therapeutic targets. Amplification is another mechanism of activation of oncogenes such as MET in adenocarcinoma, fibroblastgrowth factor receptor 1 (FGFR1) and discoidin domain receptor 2 (DDR2) in SCC. Intriguingly, many of these genetic alternations are associated with smoking status and with particular racial and gender differences, which may provide insight into the mechanisms of carcinogenesis and role of host factors in lung cancer development and progression. The role of tumour suppressor genes is increasingly recognised with aberrations reported in TP53, PTEN, RB1, LKB11 and p16/CDKN2A. Identification of biologically significant genetic alterations in lung cancer that lead to activation of oncogenes and inactivation of tumour suppressor genes has the potential to provide further therapeutic opportunities. It is hoped that these discoveries may make a major contribution to improving outcome for patients with this poor prognosis disease.

HOXA9 inhibits migration of lung cancer cells and its hypermethylation is associated with recurrence in non-small cell lung cancer

This study was aimed at understanding the clinicopathological significance of HOXA9 hypermethylation in non-small cell lung cancer (NSCLC). HOXA9 hypermethylation was characterized in six lung cancer cell lines, and its clinicopathological significance was analyzed using methylation-specific PCR in 271 formalin-fixed paraffin-embedded tissues and 27 fresh-frozen tumor and matched normal tissues from 298 NSCLC patients, and Ki-67 expression was analyzed using immunohistochemistry. The promoter region of HOXA9 was highly methylated in six lung cancer cell lines, but not in normal bronchial epithelial cells. The loss of expression was restored by treatment of the cells with a demethylating agent, 5-aza-2'-deoxycytidine (5-Aza-dC). Transient transfection of HOXA9 into H23 lung cancer cells resulted in the inhibition of cell migration but not proliferation. Conversely, sequence-specific siRNA-mediated knockdown of HOXA9 enhanced cell migration. The mRNA levels of HOXA9 in 27 fresh-frozen tumor tissues were significantly lower than in matched normal tissues (P<0.0001; Wilcoxon signed-rank test). HOXA9 hypermethylation was found in 191 (70%) of 271 primary NSCLCs. HOXA9 hypermethylation was not associated with tumor size (P=0.12) and Ki-67 proliferation index (P=0.15). However, patients with HOXA9 hypermethylation had poor recurrence-free survival (hazard ratio=3.98, 95% confidence interval = 1.07-17.09, P=0.01) in never-smokers, after adjusting for age, sex, tumor size, adjuvant therapy, pathologic stage, and histology. In conclusion, the present study suggests that HOXA9 inhibits migration of lung cancer cells and its hypermethylation is an independent prognostic factor for recurrence-free survival in never-smokers with NSCLC.

Nondisruptive p53 mutations are associated with shorter survival in patients with advanced non-small cell lung cancer

PURPOSE

TP53 mutations in early-stage non-small cell lung cancer (NSCLC) may be associated with worse survival but their prognostic role in advanced NSCLC is controversial. In addition, it remains unclear whether mutated patients represent a clinically homogeneous group.

EXPERIMENTAL DESIGN

We retrospectively examined TP53 mutations and outcome in a training cohort of 318 patients with stage IIIB-IV NSCLC: 125 epidermal growth factor receptor (EGFR) wild-type (wt) and 193 EGFR mutated (mut). An independent validation cohort of 64 EGFR-mut patients was subsequently analyzed. Mutations were classified as "disruptive" and "nondisruptive" according to their predicted degree of disturbance of the p53 protein structure and function.

RESULTS

In the training cohort, TP53 mutations were found in 43 of the 125 EGFR-wt patients (34.4%). Of these, 28 had nondisruptive TP53 mutations and a median overall survival (OS) of 8.5 months, compared with 15.6 months for the remaining 97 patients (P=0.003). In the EGFR-mut group, TP53 mutations were found in 50 of the 193 patients (25.9%). The OS for the 26 patients with TP53 nondisruptive mutations was 17.8 months versus 28.4 months for the remaining 167 patients (P=0.04). In the validation cohort, the 11 patients with nondisruptive TP53 mutations had a median OS of 18.1 months compared with 37.8 months for the 53 remaining patients (P=0.006). In multivariate analyses, nondisruptive TP53 mutations had an independent, significant association with a shorter OS.

CONCLUSIONS

Nondisruptive mutations in the TP53 gene are an independent prognostic factor of shorter survival in advanced NSCLC.