Update in Lung Cancer 2014

An atlas of epithelial cell states and plasticity in lung adenocarcinoma

Understanding the cellular processes that underlie early lung adenocarcinoma (LUAD) development is needed to devise intervention strategies1. Here we studied 246,102 single epithelial cells from 16 early-stage LUADs and 47 matched normal lung samples. Epithelial cells comprised diverse normal and cancer cell states, and diversity among cancer cells was strongly linked to LUAD-specific oncogenic drivers. KRAS mutant cancer cells showed distinct transcriptional features, reduced differentiation and low levels of aneuploidy. Non-malignant areas surrounding human LUAD samples were enriched with alveolar intermediate cells that displayed elevated KRT8 expression (termed KRT8+ alveolar intermediate cells (KACs) here), reduced differentiation, increased plasticity and driver KRAS mutations. Expression profiles of KACs were enriched in lung precancer cells and in LUAD cells and signified poor survival. In mice exposed to tobacco carcinogen, KACs emerged before lung tumours and persisted for months after cessation of carcinogen exposure. Moreover, they acquired Kras mutations and conveyed sensitivity to targeted KRAS inhibition in KAC-enriched organoids derived from alveolar type 2 (AT2) cells. Last, lineage-labelling of AT2 cells or KRT8+ cells following carcinogen exposure showed that KACs are possible intermediates in AT2-to-tumour cell transformation. This study provides new insights into epithelial cell states at the root of LUAD development, and such states could harbour potential targets for prevention or intervention.

Tyrosine kinase inhibitors and their unique therapeutic potentialities to combat cancer

Cancer is one of the leading causes of death with a mortality rate of 12%. Although significant progress has been achieved in cancer research, the effective treatment of cancer remains the greatest global challenge in medicine. Dysregulation of tyrosine kinases (TK) is one of the characteristics of several types of cancers. Thus, drugs that target and inhibit these enzymes, known as TK inhibitors (TKIs), are considered vital chemotherapeutics to combat various types of cancer. The oral bioavailability of available TKIs and their targeted therapy are their potential benefits. Based on these characteristics, most TKIs are included in first/second-line therapy for the treatment of different cancers. This review aims to shed light on orally-active TKIs (natural and synthetic molecules) and their promising implication in the therapy of numerous types of tumors along with their mechanisms of action. Further, recent progress in the development of synthetic and isolation of natural TKIs is reviewed. A significant growth in research regarding the development of new-generation TKIs is made with time (23 FDA-approved TKIs from 2018) due to their better therapeutic response. Oral bioavailability should be considered as an important parameter while developing of new-generation TKIs; however, drug delivery systems can also be used to address issue of poor bioavailability to a certain extent. Moreover, clinical trials should be designed in consideration of the development of resistance and tumor heterogeneity.

Clinical significance of circulating tumor cells and metabolic signatures in lung cancer after surgical removal

Background

Lung cancer (LC) remains the deadliest form of cancer globally. While surgery remains the optimal treatment strategy for individuals with early-stage LC, what the metabolic consequences are of such surgical intervention remains uncertain.

Methods

Negative enrichment-fluorescence in situ hybridization (NE-FISH) was used in an effort to detect circulating tumor cells (CTCs) in pre- and post-surgery peripheral blood samples from 51 LC patients. In addition, targeted metabolomics analyses, multivariate statistical analyses, and pathway analyses were used to explore surgery-associated metabolic changes.

Results

LC patients had significantly higher CTC counts relative to healthy controls with 66.67% of LC patients having at least 1 detected CTC before surgery. CTC counts were associated with clinical outcomes following surgery. In a targeted metabolomics analysis, we detected 34 amino acids, 147 lipids, and 24 fatty acids. When comparing LC patients before and after surgery to control patients, metabolic shifts were detected via PLS-DA and pathway analysis. Further surgery-associated metabolic changes were identified when comparing LA (LC patients after surgery) and LB (LC patients before surgery) groups. We identified SM 42:4, Ser, Sar, Gln, and LPC 18:0 for inclusion in a biomarker panel for early-stage LC detection based upon an AUC of 0.965 (95% CI 0.900–1.000). This analysis revealed that SM 42:2, SM 35:1, PC (16:0/14:0), PC (14:0/16:1), Cer (d18:1/24:1), and SM 38:3 may offer diagnostic and prognostic benefits in LC.

Conclusions

These findings suggest that CTC detection and plasma metabolite profiling may be an effective means of diagnosing early-stage LC and identifying patients at risk for disease recurrence.

Synergistic combinations of paclitaxel and withaferin A against human non-small cell lung cancer cells

Platinum-taxane combination chemotherapy still represents the standard of care for advanced non-small cell lung cancer (NSCLC) with no targetable driver mutations. However, the efficacy of these drugs has plateaued at 10–14 months primarily due to dose-limiting toxicity, chemoresistance, and metastasis. Here, we explored the effects of withaferin A (WFA) alone and in combination with paclitaxel (PAC) on the growth, proliferation, migration, and invasion of human NSCLC cells. We show that the sensitivity of H1299 and A549 cells to concomitant treatment with PAC and WFA was greater than that of either PAC or WFA alone. Using the combination index and dose-reduction index, we demonstrated that various combinations (1:40, 1:20, 1:10) of PAC to WFA, respectively, were highly synergistic. In addition, PAC+WFA co-treatment synergistically inhibited colony formation, migration, invasion and increased the induction of apoptosis in H1299 and A549 cells. Interestingly, the synergism of PAC and WFA was not schedule-dependent but was enhanced when cells were pretreated with WFA indicating a chemo-sensitizing effect. Importantly, WFA was active against both PAC-sensitive (TS-A549) and PAC-resistant (TR-A549) cells both in vitro and in vivo. Mechanistically, WFA inhibits the proliferation of NSCLC cells via thiol oxidation. The effects of WFA were inhibited in the presence of N-acetyl cysteine and other thiol donors. Taken together, our results demonstrate the efficacy of WFA alone or alongside PAC on NSCLC cells and provide a strong rationale for further detailed testing in clinically relevant models for the development of PAC+WFA combination as an alternative therapeutic strategy for advanced NSCLC.

The Nucleolin Antagonist N6L Inhibits LINE1 Retrotransposon Activity in Non-Small Cell Lung Carcinoma Cells

Lung cancer is the most common cause of cancer death in the United States. The genome of non-small cell lung cancer (NSCLC), the most frequent lung cancer type, is strongly affected by Long Interspersed Nuclear Element (LINE1) insertions. Active LINE1s are repetitive DNA sequences that can amplify themselves in the genome utilizing a retrotransposition mechanism whereby LINE1 is copied via reverse transcription and inserted at target sites. ORF1p and ORF2p are LINE1 encoded proteins essential for LINE1 retrotransposition. LINE1s are silenced epigenetically in somatic tissues, and their reactivation has been associated with cancer pathogenesis. Here, we present evidence that nucleolin (NCL) regulates expression of LINE1-ORF1p (L1-ORF1p) in NSCLC cells. Genetic knockdown of NCL significantly inhibited expression of L1-ORF1p in various NSCLC cell lines. Treatment with the investigational NCL antagonist N6L ablated L1-ORF1p expression in all cell lines constitutively expressing L1-ORFp. N6L displayed a stronger antiproliferative activity in NSCLC tumor cell lines expressing the highest L1-ORF1p protein levels. Moreover, N6L treatment of nude mice bearing NSCLC tumor xenografts blocked L1-ORF1p expression and effectively inhibited tumor growth. These data indicate that L1-ORF1p expression is regulated by NCL and identify NCL as a novel promising target for pharmacological inhibition of LINE1.

Towards the Optical Detection of Field Cancerization in the Buccal Mucosa of Patients with Lung Cancer

INTRODUCTION

An increase in detection of early-stage asymptomatic lung tumors could increase the overall survival rate of lung cancer patients. A new approach to cancer (pre-)screening focusses on detecting field cancerization instead of the tumor itself. The objective of this study was to investigate the use of optical spectroscopy to detect field cancerization in the buccal mucosa of lung cancer patients.

METHODS

Optical buccal mucosa measurements were performed in lung cancer patients and controls using multidiameter single-fiber reflectance spectroscopy. We analyzed whether the measured optical parameters could distinguish lung cancer patients from controls.

RESULTS

Twenty-three lung cancer patients, 24 chronic obstructive pulmonary disease (COPD) control patients, and 36 non-COPD controls were included. The majority of tumors were non-small-cell lung carcinomas (96%) and classified as stage I (48%). The tissue scattering properties μs' and γ at 800 nm and the tissue bilirubin concentration were all near-significantly different (P=.072, 0.058, and 0.060, respectively) between the lung cancer and COPD group. μs' at 800 nm had a sensitivity of 74% and a specificity of 63%. The microvascular blood oxygen saturation of the lung cancer patients was also higher than the COPD patients (78% vs. 62%, P=.002), this is probably a consequence of the systemic effect of COPD.

CONCLUSIONS

We have demonstrated that μs' at 800 nm is increased in the buccal mucosa of patients with lung cancer compared to controls with COPD. This might be an indication of field cancerization in the oral cavity of patients with lung cancer.

Neurokinin-1 Receptor Antagonists as Anticancer Drugs

Background::

Human tumor cells lines and tumor samples overexpress the neurokinin-1 receptor (NK-1R). Substance P (SP), after binding to NK-1Rs, induces tumor cell proliferation, an antiapoptotic effect and promotes angiogenesis and the migration of cancer cells for invasion and metastasis.

Methods: :

In contrast, NK-1R antagonists block the previous pathophysiological actions mediated by SP. These antagonists promote the death of tumor cells by apoptosis. Peptide and non-peptide NK-1R antagonists have been reported.

Results: :

Peptide NK-1R antagonists show chemical modifications of the SP molecule (L-amino acids being replaced by D-amino acids), whereas non-peptide NK-1R antagonists include numerous compounds with different chemical compositions while showing similar stereochemical features (affinity for the NK- 1R). Currently, there are more than 300 NK-1R antagonists.

Conclusion::

In combination therapy with classic cytostatics, NK-1R antagonists have additive or synergic effects and minimize the side-effects of cytostatics. The effect of NK-1R antagonists as broad-spectrum anticancer drugs is reviewed and the use of these antagonists for the treatment of cancer is suggested.

Premalignant lesions of squamous cell carcinoma of the lung: The molecular make-up and factors affecting their progression

Squamous cell carcinoma (SCC), one of the most common forms of lung cancer, shows accelerated progression and aggressive growth and usually is observed at advanced stages. SCC originates from morphological changes in the bronchial epithelium that occur during chronic inflammation: basal cell hyperplasia, squamous metaplasia, and dysplasia I-III. However, the process is not inevitable; it can be stopped at any stage, remain in the stable state indefinitely and either progress or regress. The reasons and mechanisms of different scenarios of the evolution of premalignant lesions in the respiratory epithelium are not fully understood. In this review, we summarized the literature data (including our own data) regarding genetic, epigenetic, transcriptomic and proteomic profiles of the premalignant lesions and highlighted factors (environmental causes, inflammation, and gene polymorphism) that may govern their progression or regression. In conclusion, we reviewed strategies for lung cancer prevention and proposed new models and research directions for studying premalignant lesions and developing new tools to predict the risk of their malignant transformation.

Withaferin A inhibits Epithelial to Mesenchymal Transition in Non-Small Cell Lung Cancer Cells

Lung cancer is the leading cause of cancer-related deaths worldwide and in the United States. Despite recent advancements in treatment approaches, metastasis remains a major therapeutic challenge in lung cancer and explains the extremely poor prognosis. Epithelial to mesenchymal transition (EMT), a complex process of cellular reprogramming has become an attractive drug target because it plays a crucial role in the metastasis of non-small cell lung cancer (NSCLC). In the present study, we examined the effects of withaferin A (WFA), a plant-derived steroidal lactone on EMT in human NSCLC cell lines. First, we demonstrated that WFA displayed time- and concentration-dependent cytotoxicity on A549 and H1299 NSCLC cells. Then, cells were exposed to ≤ 0.5 µM WFA for ≤ 4 h to minimize cytotoxicity and determined its effects on EMT, cell adhesion, motility, migration, and invasion. EMT induction was performed by culturing cells in serum-free media containing TGFβ1 (5 ng/mL) and TNFα (25 ng/mL) for 48 h. We observed that pretreatment of cells with WFA inhibited cell adhesion, migration, and invasion of A549 and H1299 cells. Using western blot, immunofluorescence, and qRT-PCR analysis, we demonstrated that WFA suppressed TGFβ1 and TNFα-induced EMT in both cell lines. Mechanistically, WFA suppressed the phosphorylation and nuclear translocation of Smad2/3 and NF-κB in A549 and H1299 cells. Together, our study provides additional evidence demonstrating the inhibitory effects of WFA on EMT induction in NSCLC cells and further demonstrates the therapeutic potential of WFA against the metastasis in NSCLC.

Utilization of lung cancer cell lines for the study of lung cancer stem cells

Lung cancer is one of the most lethal types of cancer, and its poor prognosis is primarily due to drug resistance and cancer recurrence. As it is associated with a low five-year survival rate, lung cancer stem cells (LCSCs) have been the subject of numerous recent studies. For these studies of LCSCs, lung cancer cell lines are more commonly used than lung cancer tissues obtained from patients, as they are easier to acquire. The methods utilized for the identification of LCSCs from lung cancer cell lines include fluorescence activated cell sorting (FACS), magnetic activated cell sorting (MACS), sphere-forming assay and bacterial surface display library screening. As LCSCs have certain proteins expressed on the surface (CD133, CD44 and CD24) or in the cytoplasm (ALDH and ABCG2), which may act as specific markers, the most frequently used technique to identify and obtain LCSCs is FACS. The current lack of recognized biomarkers in LCSCs makes the identification of LCSCs problematic. Furthermore, the various proportions of LCSCs in specific cell lines, as revealed by numerous previous studies, may cause the LCSC model to be questioned with regard to whether the utilization of certain lung cancer cell lines is dependable for LCSC studies. The current review focuses on lung cancer cell lines that are used for the study of LCSCs and the methods available to identify LCSCs with various markers. The present study also aimed to determine the proportion of LCSCs present in specific cell lines reported by various studies, and to discuss the suitability of specific lung cancer cell lines for the study of LCSCs.

LINE-1 couples EMT programming with acquisition of oncogenic phenotypes in human bronchial epithelial cells

Although several lines of evidence have established the central role of epithelial-to-mesenchymal-transition (EMT) in malignant progression of non-small cell lung cancers (NSCLCs), the molecular events connecting EMT to malignancy remain poorly understood. This study presents evidence that Long Interspersed Nuclear Element-1 (LINE-1) retrotransposon couples EMT programming with malignancy in human bronchial epithelial cells (BEAS-2B). This conclusion is supported by studies showing that: 1) activation of EMT programming by TGF-β1 increases LINE-1 mRNAs and protein; 2) the lung carcinogen benzo(a)pyrene coregulates TGF-β1 and LINE-1 mRNAs, with LINE-1 positioned downstream of TGF-β1 signaling; and, 3) forced expression of LINE-1 in BEAS-2B cells recapitulates EMT programming and induces malignant phenotypes and tumorigenesis in vivo. These findings identify a TGFβ1-LINE-1 axis as a critical effector pathway that can be targeted for the development of precision therapies during malignant progression of intractable NSCLCs.

Smoking and Lung Cancer: A Geo-Regional Perspective

Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) represents the most frequently diagnosed subtype of this morbid malignancy. NSCLC is causally linked to tobacco consumption with more than 500 million smokers worldwide at high risk for this fatal malignancy. We are currently lagging in our knowledge of the early molecular (e.g., genomic) effects of smoking in NSCLC pathogenesis that would constitute ideal markers for early detection. This limitation is further amplified when considering the variable etiologic factors in NSCLC pathogenesis among different regions around the globe. In this review, we present our current knowledge of genomic alterations arising during early stages of smoking-induced lung cancer initiation and progression, including discussing the premalignant airway field of injury induced by smoking. The review also underscores the wider spectra and higher age-adjusted rates of tobacco (e.g., water-pipe smoke) consumption, along with elevated environmental carcinogenic exposures and relatively poorer socioeconomic status, in low-middle income countries (LMICs), with Lebanon as an exemplar. This “cocktail” of carcinogenic exposures warrants the pressing need to understand the complex etiology of lung malignancies developing in LMICs such as Lebanon.

Emerging uses of circulating tumor DNA in advanced stage non-small cell lung cancer

Targeted therapies have dramatically changed the treatment paradigm for a select group of patients with non-small cell lung cancer (NSCLC) whose tumors harbor targetable genetic aberrations. Patients with such genetic changes enjoy excellent responses to tyrosine kinase inhibitors (TKIs), but resistance is nearly inevitable. Resistance to first line TKIs is heterogeneous and multifactorial-multiple resistance mechanisms have been reported, and different metastatic foci in the same patient may have distinct resistance mechanisms. The recent approval of next-generation TKIs specific to particular resistance mechanisms, and the likely future approval of others, necessitates the acquisition of repeat molecular analysis at time of progression. Tumor tissue has traditionally been the preferred source to detect oncogenic driver and resistance mutations, but tissue biopsies are invasive and often difficult to obtain. The use of circulating tumor DNA (ctDNA), so-called "liquid biopsies", has emerged as a promising technique to molecularly profile tumors non-invasively and is becoming increasingly utilized in the routine management of lung cancer. This review will describe the current role of ctDNA in the management of lung cancer, and explore emerging data that point towards its increasingly important role in clinical care.

RETRACTED: Effects of lentivirus-mediated silencing of Periostin on tumor microenvironment and bone metastasis via the integrin-signaling pathway in lung cancer

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figures 1B, 3B, 5B, and 8A which appear to have a similar phenotype as seen in many other publications, as detailed here: https://pubpeer.com/publications/E266A07D28435DB334E8777CAC97E3; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. In addition, a portion of Figure 6B, ‘NC’ group appears to contain image similarities with Figure 6B, ‘si-Integrin-αvβ3’ group, and a portion of Figure 6B, ‘Blank’ group appears to contain image similarities with Figure 6B, ‘NC’ group. The journal requested that the corresponding author comment on these concerns and provide the raw data. However, the authors were not able to satisfactorily fulfill this request and therefore the Editor-in-Chief decided to retract the article.

Genetic Modifiers of Progression-Free Survival in Never-Smoking Lung Adenocarcinoma Patients Treated with First-Line Tyrosine Kinase Inhibitors

RATIONALE

Patients with non-small cell lung cancer (NSCLC) with mutated epidermal growth factor receptor (EGFR) are relatively sensitive to EGFR-tyrosine kinase inhibitor (TKI) treatment and have longer progression-free survival (PFS) when treated with EGFR-TKI compared with platinum-based chemotherapy. However, many patients with advanced NSCLC who have mutated EGFR do not respond to first-line EGFR-TKI treatment and still have shorter PFS.

OBJECTIVES

The aim of this study was to identify genetic variants associated with PFS among patients with lung adenocarcinoma who were treated with first-line EGFR-TKIs.

METHODS

A genome-wide association study on PFS was performed in never-smoking women diagnosed with lung adenocarcinoma and who were treated with first-line EGFR-TKIs (n = 128). Significant single-nucleotide polymorphisms (SNPs) were selected for follow-up association analysis (n = 198) and for replication assay in another independent cohort (n = 153).

MEASUREMENTS AND MAIN RESULTS

We identified SNPs at 4q12 associated with PFS at genome-wide significance (P < 10^-8) and with an estimated hazard ratio of more than 4. This association was also replicated in a larger but similar cohort and in an independent NSCLC cohort. Follow-up functional analyses showed that these SNPs were associated with the expression of EGFR, which encodes the TKI target, and with a nearby gene neuromedin-U, which encodes a G protein-coupled receptor ligand known to be involved in the progression of NSCLC. Considering these as possible prognostic biomarkers for the treatment of patients with late-stage lung cancer, we found that these SNPs were not associated with EGFR mutation status or with polymorphism of the Bcl2-interacting mediator of cell death gene.

CONCLUSIONS

Genetic variants in 4q12 merit further investigation to assess their potential as pharmacogenomic predictors for and to understand the biology underlying its influence on PFS in patients treated with TKI therapy.

Lung Cancer Diagnosis by Fine Needle Aspiration Is Associated With Reduction in Resection of Nonmalignant Lung Nodules

BACKGROUND

The rates of resection of nonmalignant lung nodules suspected preoperatively to be lung cancer vary widely and are reported to be as high as 40%. We determined the impact of the frequent use of computed tomography (CT)-guided fine needle aspiration (FNA) on the resection rate of nonmalignant nodules and frequency of resections of benign disease among patients undergoing evaluation for lung cancer resection operation in an academic medical center.

METHODS

Eligible patients underwent CT-guided FNA, surgical resection, or both during the 12-month period between July 2013 and July 2014 for known or suspected first primary resectable stage I-III lung cancer. Patient data were extracted from the electronic medical records.

RESULTS

One hundred ninety-seven patients underwent surgical resection; among them the overall resection rate of nonmalignant lesions was 13.1% (26/197). For those with preoperative FNA, the rate was 7.9% (11/139), and for those with no biopsy, the rate was 25.9% (15/58) (p = 0.001). The sensitivity and specificity of FNA biopsy were 96% and 98%, respectively. The false-negative rate was 3.9% (5/128).

CONCLUSIONS

The resection rate of nonmalignant nodules was significantly lower for patients with preoperative CT-guided FNA biopsy than in those without. The diagnostic accuracy of FNA in these patients at moderate to high risk for lung cancer is higher than that of positron emission tomography, with a low rate of adverse events. These findings suggest that the frequent use of preoperative diagnostic confirmation by FNA results in a low rate of nonmalignant resection.

Molecular Role of EGFR-MAPK Pathway in Patchouli Alcohol-Induced Apoptosis and Cell Cycle Arrest on A549 Cells In Vitro and In Vivo

Nowadays, chemotherapy is still the main effective treatment for cancer. Herb prescriptions containing Pogostemon cablin Benth (also known as "Guang-Huo-Xiang") have been widely used in Chinese medicine today. In our research, we found that patchouli alcohol, a compound isolated from the oil of Pogostemon cablin Benth, exerted antitumor ability against human lung cancer A549 cells ability both in vitro and in vivo. MTT assay was used to assess cell viability. Hoechst 33342 staining and TUNEL cover glass staining provided the visual evidence of apoptosis. Caspase activity measurement showed that patchouli alcohol activated caspase 9 and caspase 3 of mitochondria-mediated apoptosis. Consistently, patchouli alcohol inhibited the xenograft tumor in vivo. Further investigation of the underlying molecular mechanism showed that MAPK and EGFR pathway might contribute to the antitumor effect of patchouli alcohol. Our study proved that patchouli alcohol might be able to serve as a novel antitumor compound in the clinical treatment of lung cancer.

The International Epidemiology of Lung Cancer: Latest Trends, Disparities, and Tumor Characteristics

INTRODUCTION

Our aim was to update global lung cancer epidemiology and describe changing trends and disparities.

METHODS

We presented country-specific incidence and mortality from GLOBOCAN 2012 by region and socioeconomic factors via the Human Development Index (HDI). Between- and within-country incidence by histological type was analyzed by using International Agency for Research on Cancer data on cancer incidence on five continents. Trend analyses including data from the International Agency for Research on Cancer, cancer registries, and the WHO mortality database were conducted using joinpoint regression. Survival was compared between and within countries and by histological type.

RESULTS

In 2012, there were 1.82 and 1.59 million new lung cancer cases and deaths worldwide, respectively. Incidence was highest in countries with a very high HDI and lowest in countries with a low HDI (42.2 versus 7.9 in 100,000 for males and 21.8 versus 3.1 in 100,000 for females, respectively). In most countries with a very high HDI, as incidence in males decreased gradually (ranging from -0.3% in Spain to -2.5% in the United States each year), incidence in females continued to increase (with the increase ranging from 1.4% each year in Australia to 6.1% in recent years in Spain). Although histological type varied between countries, adenocarcinoma was more common than squamous cell carcinoma, particularly among females (e.g., in Chinese females, the adenocarcinoma-to-squamous cell carcinoma ratio was 6.6). Five-year relative survival varied from 2% (Libya) to 30% (Japan), with substantial within-country differences.

CONCLUSIONS

Lung cancer will continue to be a major health problem well through the first half of this century. Preventive strategies, particularly tobacco control, tailored to populations at highest risk are key to reducing the global burden of lung cancer.

Occult Lung Cancer Occluding a Pulmonary Vein with Suspected Venous Infarction, Mimicking Pneumonia and a Pulmonary Embolus

BACKGROUND

Patients with lung cancer present to the emergency department (ED) in a variety of ways. Symptoms are often nonspecific and can lead to a delay in diagnosis. Here, a lung cancer mimicked two illnesses, adding to the diagnostic complexity. This case highlights diagnostic pitfalls as well as advantages and limitations of imaging utilized in the emergency setting.

CASE REPORT

We report a case of an occult lung cancer occluding a pulmonary vein, which at first mimicked pneumonia and later a pulmonary embolism (PE) and arterial lung infarction. The patient presented to the ED with cough and a lung opacity on chest radiograph that was treated with antibiotics. However, recurrent visits to the ED with similar complaints were further investigated with computed tomography angiogram (CTA). At first the scan was considered positive for PE. Further inspection revealed that the CTA findings were not typical for PE, but rather a slow flow state likely caused by an occult mass occluding a pulmonary vein with venous infarction. Biopsy revealed a lung adenocarcinoma. In addition to the case presentation, the typical signs of PE on CTA with correlating images and diagnostic pitfalls are discussed. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report raises two themes that can be of interest to emergency physicians. The first is that lung cancer has many guises. Here it mimicked two distinctly different diseases, pneumonia and PE. The second is that, although CTA is highly sensitive and specific for diagnosing PE, it has limitations that may lead to false positive readings. When clinical signs and symptoms fail to correlate with the imaging diagnosis, alternative explanations should be sought.

The action and mechanism of myrislignan on A549 cells in vitro and in vivo

Myrislignan is a natural compound with little pharmacological study. In our investigation, we investigated the effect of myrislignan in the induction of apoptosis in A549 cells in vitro and in vivo. Myrislignan inhibited the proliferation of A549 cells in a dose- and time-dependent manner assayed by MTT. In addition, Hoechst flow cytometry showed that myrislignan significantly induced apoptosis and cell cycle arrest in A549 cells. The apoptosis and anti-cell proliferation was mediated by the activation of mitogen-activated protein kinase and the inhibition of epidermal growth factor receptor signal pathway, change of mitochondrial membrane potential, the releasing of c-Myc, the downregulation of the level of the anti-apoptotic protein Bcl-2, and the upregulation of the level of the pro-apoptotic protein Bax. In conclusion, those results reveal a potential mechanism for the anti-cancer effect of myrislignan on human lung cancer, while suggesting that myrislignan may be a promising compound for the treatment of lung cancer.

The diagnostic value of circulating cell free DNA quantification in non-small cell lung cancer: A systematic review with meta-analysis

OBJECTIVES

The aim of the current study was to assess the diagnostic value of circulating cell free DNA (cfDNA) quantification in discriminating non-small cell lung cancer (NSCLC) from healthy individuals.

MATERIALS AND METHODS

An electronic search was conducted on PubMed, EMBASE, Web of Science, and Cochrane Library. Eligible studies regarding to examine the diagnostic value of cfDNA in the detection of NSCLC were extracted and analyzed.

RESULTS

We identified 15 eligible studies with a total of 2125 patients. The pooled results for quantification of cfDNA in lung cancer screening in the included studies were as follows: sensitivity, 81% (95% confidence interval (CI), 76%-84%); specificity, 85% (95% CI, 77%-91%); diagnostic odds ratio, 23.87 (95% CI, 13.37-42.61); and areas under the summary receiver operating characteristic curves were 0.89 (95% CI, 0.86-0.92). Subgroup analyses according to the time of sample collection, sample materials, test method, reference gene and cutoff value did not improve sensitivity, but specificity could be significantly improved when we only included the studies using cfDNA sample before surgery or antitumor treatment and real-time PCR to detect cfDNA and human β-actin as a reference gene.

CONCLUSION

Quantification of cfDNA was a promising and effective biomarker for discriminating NSCLC from healthy individuals.

Typical Time to Treatment of Patients With Lung Cancer in a Multisite, US-Based Study

Introduction:

The importance of high-quality, timely lung cancer care and the need to have indicators to measure timeliness are increasingly discussed in the United States. This study explored when and why delays occur in lung cancer care and compared timeliness between two states with divergent disease incidence.

Methods:

Patients with small-cell or non–small-cell lung cancer were recruited through cancer centers, outpatient clinics, and community approaches, and interviewed over the phone. Statistical analysis of patient-reported dates included descriptive statistics and comparing time intervals between states and across the sites with Mann-Whitney U tests. Additionally, data from patients with longer timelines were qualitatively analyzed to identify possible reasons for delays.

Results:

On the basis of the dates reported by 275 patients, the median time from first presentation to a clinician to treatment was 52 days; 29% of patients experienced a wait of 90 days or more. Median times for key intervals were 36.5 days from abnormal radiograph to treatment, 9.5 days from initial presentation to specialist referral, 15 days from patient informed of diagnosis to first therapy, and 16 days from referral to treatment to first therapy. More than one quarter of patients perceived delays in care. No significant differences in length of time intervals were identified between states. Monitoring of small nodules, missed diagnosis, and other reasons for longer timelines were documented.

Conclusion:

Results defined typical time to treatment of patients with lung cancer across a variety of health systems and should facilitate establishing metrics for determining timeliness of lung cancer care.

Early Events in the Molecular Pathogenesis of Lung Cancer

The majority of cancer-related deaths in the United States and worldwide are attributed to lung cancer. There are more than 90 million smokers in the United States who represent a significant population at elevated risk for lung malignancy. In other epithelial tumors, it has been shown that if neoplastic lesions can be detected and treated at their intraepithelial stage, patient prognosis is significantly improved. Thus, new strategies to detect and treat lung preinvasive lesions are urgently needed in order to decrease the overwhelming public health burden of lung cancer. Limiting these advances is a poor knowledge of the earliest events that underlie lung cancer development and that would constitute markers and targets for early detection and prevention. This review summarizes the state of knowledge of human lung cancer pathogenesis and the molecular pathology of premalignant lung lesions, with a focus on the molecular premalignant field that associates with lung cancer development. Lastly, we highlight new approaches and models to study genome-wide alterations in human lung premalignancy in order to facilitate the discovery of new markers for early detection and prevention of this fatal disease. Cancer Prev Res; 9(7); 518-27. ©2016 AACR.

[Strategy for molecular testing in pulmonary carcinoma]

Nowadays, the analysis of theranostic molecular markers is central in the management of lung cancer. As those tumors are diagnosed in two third of the cases at an advanced stage, molecular screening is frequently performed on "small samples". The screening strategy starts by an accurate histopathological characterization, including on biopsies or cytological specimens. WHO 2015 provided a new classification for small biopsy and cytology, defining categories such as non-small cell carcinoma (NSCC), favor adenocarcinoma (TTF1 positive), or favor squamous cell carcinoma (p40 positive). Only the NSCC tumors, non-squamous, are eligible to molecular testing. A strategy aiming at tissue sparing for the small biopsies has to be organized. Tests corresponding to available drugs are prioritized. Blank slides will be prepared for immunohistochemistry and in situ hybridization based tests such as ALK. DNA will then be extracted for the other tests, EGFR mutation screening first associated or not to KRAS. Then, the emerging biomarkers (HER2, ROS1, RET, BRAF…) as well as potentially other markers in case of clinical trials, can been tested. The spread of next generation sequencing technologies, with a very sensitive all-in-one approach will allow the identification of minority clones. Eventually, the development of liquid biopsies will provide the opportunity to monitor the apparition of resistance clones during treatment. This non-invasive approach allows patients with a contraindication to perform biopsy or with non-relevant biopsies to access to molecular screening.