Lung cancer: epidemiology, etiology, and prevention

Novel and convenient method to evaluate the character of solitary pulmonary nodule-comparison of three mathematical prediction models and further stratification of risk factors

Objective

To study risk factors that affect the evaluation of malignancy in patients with solitary pulmonary nodules (SPN) and verify different predictive models for malignant probability of SPN.

Methods

Retrospectively analyzed 107 cases of SPN with definite post-operative histological diagnosis whom underwent surgical procedures in China-Japan Friendship Hospital from November of 2010 to February of 2013. Age, gender, smoking history, malignancy history of patients, imaging features of the nodule including maximum diameter, position, spiculation, lobulation, calcification and serum level of CEA and Cyfra21-1 were assessed as potential risk factors. Univariate analysis model was used to establish statistical correlation between risk factors and post-operative histological diagnosis. Receiver operating characteristic (ROC) curves were drawn using different predictive models for malignant probability of SPN to get areas under the curves (AUC values), sensitivity, specificity, positive predictive values, negative predictive values for each model, respectively. The predictive effectiveness of each model was statistically assessed subsequently.

Results

In 107 patients, 78 cases were malignant (72.9%), 29 cases were benign (27.1%). Statistical significant difference was found between benign and malignant group in age, maximum diameter, serum level of Cyfra21-1, spiculation, lobulation and calcification of the nodules. The AUC values were 0.786±0.053 (Mayo model), 0.682±0.060 (VA model) and 0.810±0.051 (Peking University People’s Hospital model), respectively.

Conclusions

Serum level of Cyfra21-1, patient’s age, maximum diameter of the nodule, spiculation, lobulation and calcification of the nodule are independent risk factors associated with the malignant probability of SPN. Peking University People’s Hospital model is of high accuracy and clinical value for patients with SPN. Adding serum index (e.g. Cyfra21-1) into the prediction models as a new risk factor and adjusting the weight of age in the models might improve the accuracy of prediction for SPN.

First result of differentiated communication--to smokers and non-smokers--in order to increase the voluntary participation rate in lung screening

Background

Lung cancer is the most common fatal malignacy and also the primary cause of cancer mortality. Participation in lung screening is an important step in diagnosing patient in early stage and it can promise better outcomes. The aim of this preliminary study was to determinate the differences in the participation rate of smokers and non-smokers in lung cancer screening and to determine the communication strategies to increase the participation rate.

Methods

In the given period of time (from May to August 2012) out of 1426 people who participated in the lung screening program 1,060 adult volunteers (331 males and 729 females, average age 54.0±9.3 years), completed fully and anonymously author’s questionnaire that contained 28 questions. 25.7% of the respondents were smokers (n=272), 64.6% have never smoked, while 9.7% were former smokers.

Results

Mostly former smokers considered lung screening as an effective method for early detection of pulmonary diseases (86.4%). The most important source (41.0%) of information was the general practitioner. The participation rate of non-smokers is higher in lung screening than the ratio of non-smokers in the population. The unclear data suggest that smokers need distinct, concise messages to know why they should regularly undergo lung screening and doctors have a major role in this.

Conclusions

We found that smokers significantly more frequently took part in lung screening annually. It is positive that the participation rate of former smokers is higher than non-smokers, it is just a bit lower than the participation rate of smokers—both in annual and biannual participation. The participation rate of non-smokers is higher in lung screening than the rate of non-smokers in the population.

Smoking and smoking cessation in relation to the development of co-existing non-small cell lung cancer with chronic obstructive pulmonary disease

Previous studies have identified a mixed-phenotype of non-small cell lung cancer (NSCLC) with co-existing chronic obstructive pulmonary disease (COPD). Although NSCLC and COPD share a common risk factor in smoking, whether and how smoking may contribute to the coexistence of NSCLC with COPD (NSCLC-COPD) is unclear. Our study suggests that cigarette smoking is the major risk factor for the development of NSCLC-COPD, especially in females and among patients with squamous cell carcinoma subtype.

Haemoptysis as a prognostic factor in lung adenocarcinoma after curative resection

Background:

Haemoptysis is a common symptom of lung cancer. Its prognostic role and mechanisms are still poorly understood.

Methods:

We retrospectively reviewed 666 consecutive patients with primary lung adenocarcinoma who underwent complete resection. The prognostic value of haemoptysis with respect to overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) was analysed. To further explore the possible mechanisms of haemoptysis, we evaluated vascular endothelial growth factor (VEGF) expression, tumour necrosis, vascular invasion and extratumoural microvessel density (MVD) in 112 randomly selected patients.

Results:

Haemoptysis predicted poor OS, DSS and DFS in operable lung adenocarcinoma (all P<0.001). In addition, haemoptysis was associated with high white blood cell (WBC) count (P=0.032), high fibrinogen (Fib; P<0.001), high tumour greatest dimension (P<0.001), severe vascular invasion (P=0.002) and central tumour location (P<0.001). We obtained no statistically significant differences of VEGF expression, tumour necrosis and extratumoural MVD in haemoptysis and non-haemoptysis groups.

Conclusion:

Our study demonstrates that haemoptysis predicts poor OS, DSS and DFS in lung adenocarcinoma after curative resection. Vascular invasion rather than angiogenesis or tumour necrosis could be the most important mechanism of haemoptysis in lung adenocarcinoma.

Biomarkers in Exhaled Breath Condensate and Serum of Chronic Obstructive Pulmonary Disease and Non-Small-Cell Lung Cancer

Chronic obstructive pulmonary disease (COPD) and lung cancer are leading causes of deaths worldwide which are associated with chronic inflammation and oxidative stress. Lung cancer, in particular, has a very high mortality rate due to the characteristically late diagnosis. As such, identification of novel biomarkers which allow for early diagnosis of these diseases could improve outcome and survival rate. Markers of oxidative stress in exhaled breath condensate (EBC) are examples of potential diagnostic markers for both COPD and non-small-cell lung cancer (NSCLC). They may even be useful in monitoring treatment response. In the serum, S100A8, S100A9, and S100A12 of the S100 proteins are proinflammatory markers. They have been indicated in several inflammatory diseases and cancers including secondary metastasis into the lung. It is highly likely that they not only have the potential to be diagnostic biomarkers for NSCLC but also prognostic indicators and therapeutic targets.

Improving cellular uptake and in vivo tumor suppression efficacy of liposomal oligonucleotides by urea as a chemical penetration enhancer

BACKGROUND

Liposomes are among the most widely used carriers for the delivery of antisense oligonucleotides (AsODNs) to intracellular targets. Although different strategies have been employed, the question of how to improve liposomal uptake and enhance the release of AsODN into cytoplasm still remains to be answered with respect to the use of a safe, easy and economic method. In the present study, the possibility of enhancing such processes at cellular and animal levels using urea as a penetration enhancer was investigated.

METHODS

To perform this investigation, a cationic liposome containing an AsODN against protein kinase (PKC)-α was prepared, and the effect of urea on its cellular internalization and the related sequence-specific inhibition of gene expression in human lung adenocarcinoma A549 cells were investigated by flow cytometry and the reverse transcriptase-polymerase chain reaction, respectively. In in vivo studies, a xenograft lung tumor was established in nude mice by A549 cells and the enhancement effect of urea toward the effects of liposomal AsODN on tumor growth was investigated.

RESULTS

Cellular studies revealed that urea treatment increases liposomal uptake and the release of AsODN into the cytoplasm by approximately 40%. Sequence-specific inhibition of target gene PKC-α expression was also increased by approximately two-fold by urea at 200-300 nM AsODN. In animal studies, urea significantly decreased the tumor volume (approximately 40%) and increased its doubling time from approximately 13 days to 17 days.

CONCLUSIONS

Urea, and possibly other membrane fluidizers, could be regarded as penetration enhancers for liposomal AsODN delivery and may improve the therapeutic effect of these gene-therapy vectors at both cellular and animal levels.

Influence of medical comorbidities on the presentation and outcomes of stage I-III non-small-cell lung cancer

BACKGROUND

Non-small-cell lung cancer presentation, treatment, and outcomes vary widely according to socioeconomic factors and other patient characteristics. To determine whether medical comorbidities account for these observations, we incorporated a validated medical comorbidity index into an analysis of patients diagnosed with stage I to III NSCLC.

PATIENTS AND METHODS

We performed a retrospective analysis of consecutive patients diagnosed with stage I to III NSCLC. Demographic, tumor, and comorbidity data were obtained from hospital tumor registries and individual patient records. The association between variables was assessed using multivariate logistic regression and survival analysis.

RESULTS

A total of 454 patients met criteria for analysis. The median age was 65 years, and 51% were men. Individuals with a higher Charlson Comorbidity Index (CCI) were significantly more likely to present with early stage (stage I-II) NSCLC than were patients with lower CCI (odds ratio, 1.72; 95% confidence interval, 1.14-2.63; P = .01), although this association lost statistical significance (P = .21) in a multivariate model. In multivariate logistic regression, overall survival remained associated with all variables: age, sex, race, insurance type, stage, histology, and CCI (P = .0007). The CCI was associated with survival for patients with early stage (P = .02) and locally advanced (P = .02) disease.

CONCLUSION

In this cohort of patients with stage I to III NSCLC, increasing comorbidity burden had a nonsignificant association with diagnosis at earlier disease stage. Although comorbidity burden was significantly associated with outcome for early stage and locally advanced disease, it did not account for survival differences based on multiple other patient and disease characteristics.

Fisetin: a dietary antioxidant for health promotion

SIGNIFICANCE

Diet-derived antioxidants are now being increasingly investigated for their health-promoting effects, including their role in the chemoprevention of cancer. In general, botanical antioxidants have received much attention, as they can be consumed for longer periods of time without any adverse effects. Flavonoids are a broadly distributed class of plant pigments that are regularly consumed in the human diet due to their abundance. One such flavonoid, fisetin (3,3',4',7-tetrahydroxyflavone), is found in various fruits and vegetables, such as strawberry, apple, persimmon, grape, onion, and cucumber.

RECENT ADVANCES

Several studies have demonstrated the effects of fisetin against numerous diseases. It is reported to have neurotrophic, anticarcinogenic, anti-inflammatory, and other health beneficial effects.

CRITICAL ISSUES

Although fisetin has been reported as an anticarcinogenic agent, further in-depth in vitro and in vivo studies are required to delineate the mechanistic basis of its observed effects. In this review article, we describe the multiple effects of fisetin with special emphasis on its anticancer activity as investigated in cell culture and animal models.

FUTURE DIRECTIONS

Additional research focused toward the identification of molecular targets could lead to the development of fisetin as a chemopreventive/chemotherapeutic agent against cancer and other diseases.

Raw garlic consumption as a protective factor for lung cancer, a population-based case-control study in a Chinese population

Protective effect of garlic on the development of cancer has been reported in the in vitro and in vivo experimental studies; however, few human epidemiologic studies have evaluated the relationship. A population-based case-control study has been conducted in a Chinese population from 2003 to 2010, with the aim to explore the association between raw garlic consumption and lung cancer. Epidemiologic data were collected by face-to-face interviews using a standard questionnaire among 1,424 lung cancer cases and 4,543 healthy controls. Unconditional logistic regression was used to estimate adjusted ORs and their 95% confidence intervals (CI), and to evaluate ratio of ORs (ROR) for multiplicative interactions between raw garlic consumption and other risk factors. After adjusting for potential confounding factors, raw garlic consumption of 2 times or more per week is inversely associated with lung cancer (OR = 0.56; 95% CI, 0.44-0.72) with a monotonic dose-response relationship (Ptrend < 0.001). Furthermore, strong interactions at either additive and/or multiplicative scales were observed between raw garlic consumption and tobacco smoking [synergy index (SI) = 0.70; 95% CI, 0.57-0.85; and ROR = 0.78; 95% CI, 0.67-0.90], as well as high-temperature cooking oil fume (ROR = 0.77; 95% CI, 0.59-1.00). In conclusion, protective association between intake of raw garlic and lung cancer has been observed with a dose-response pattern, suggesting that garlic may potentially serve as a chemopreventive agent for lung cancer. Effective components in garlic in lung cancer chemoprevention warrant further in-depth investigation.

Rare pleural tumors

Primary pleural tumors other than mesothelioma account for fewer than 1% of all lung cancers, and consequently they pose diagnostic and management challenges. Their treatment must be targeted toward the specific tumor type and is often quite different from the treatment for mesothelioma or metastases. Despite the best efforts at diagnosing and treating these tumors, the prognosis associated with some of the benign and many of the malignant variants of these tumors remains poor. In this review, we describe the radiologic and pathologic features of the less common primary pleural tumors and propose a diagnostic approach to their evaluation.

Deep vein thrombosis and lung cancer in a patient with psoriasis under anti-tumor necrosis factor treatment: a case study

We describe a case of a patient with severe generalized psoriasis treated with etanercept, who developed deep vein thrombosis and 1 year later developed solid lung cancer. Anti-tumor necrosis factor therapies have been a powerful addition to the therapy of psoriasis; nevertheless, the treatment might be associated with adverse events, such as venous thromboembolism or malignancies. Available data regarding these specific adverse reactions are rather conflictive; therefore, more observational studies and registry reports for long-term risk assessment are needed.

nm23-H1 gene driven by hTERT promoter induces inhibition of invasive phenotype and metastasis of lung cancer xenograft in mice

BACKGROUND

Lung cancer is the leading cause of cancer death in both men and women worldwide. Tumor metastasis is an essential aspect of lung cancer progression and patient death. The nm23-H1 gene has been extensively investigated as a metastasis suppressor gene. Our previous studies have revealed: that a significant relationship exists between the low-level expression nm23-H1 in primary non-small cell lung cancer (NSCLC) with increased metastasis and a poor prognosis; that L9981-nm23-H1 cells (a nm23-H1 transfactant cell) exhibited lower cell proliferation rates, more G0/G1 phase growth, and an increase in apoptosis with a dramatic decrease in the tumor cells' ability to invade than L9981 cells did; and that L9981- nm23-H1 cells also demonstrated a significantly reduced lymph node and distant metastatic capacity in vivo than L9981 cells did in nude mice.

METHODS

In this study, we construct a plasmid containing the nm23-H1 gene, which was driven by the human telomerase reverse transcriptase (hTERT) promoter. We evaluated the anti-invasion and anti-metastatic effects of pGL3-hTP-nm23 on L9981, a human large cell lung cancer cell line with nm23-H1 negative expression, by transwell assay in vitro and bioluminescence in nude mice models. The toxicity of pGL3-hTP-nm23 and its effects on tumor growth were evaluated in nude mice models after gene therapy. The cell cycles, apoptosis, and proliferation of the nm23-H1 transfactant were also detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay) and flow cytometry (FCM).

RESULTS

The results showed that the hTERT-promoter dramatically drives nm23-H1 gene expression, and induces inhibition of cell growth and migration in L9981-luc cells and MRC-5 cells in vitro. nm23-H1 also significantly inhibited the tumorigenesis and distant metastasis of L9981-luc cell in vivo. Moreover, no obvious side effect was detected in normal mouse tissues after intratumoral injection of the vector.

CONCLUSION

The treatment of the nm23-H1 gene driven by hTERT promoter appears to be a promising approach for the gene therapy of nm23-H1 low-expressed tumors.

Smoking cessation interventions for lung cancer patients

SUMMARY Worldwide, lung cancer contributes to over 1.4 million deaths per year. Smoking cessation is strongly recommended in clinical practice guidelines for lung cancer management, yet evidence suggests a translational gap between evidence and practice. There are significant health benefits following smoking cessation even after a short period of time. Long-term implications for lung cancer patients include improvements in quality of life, reductions in postoperative complications and reductions in 12-month mortality. Evidence suggests that combining pharmacotherapy, in particular varenicline tartrate (varenicline), with cognitive and behavioral interventions offers the best opportunity for successful long-term abstinence. This review summarizes the latest evidence for smoking cessation interventions in lung cancer patients, identifies gaps in current clinical practice and highlights priority areas for future research.

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

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

Detection of Merkel cell polyomavirus with a tumour-specific signature in non-small cell lung cancer

Background:

We searched for a viral aetiology for non-small cell lung cancer (NSCLC), focusing on Merkel cell polyomavirus (MCPyV).

Methods:

We analysed 112 Japanese cases of NSCLC for the presence of the MCPyV genome and the expressions of RNA transcripts and MCPyV-encoded antigen. We also conducted the first analysis of the molecular features of MCPyV in lung cancers.

Results:

PCR revealed that 9 out of 32 squamous cell carcinomas (SCCs), 9 out of 45 adenocarcinomas (ACs), 1 out of 32 large-cell carcinomas, and 1 out of 3 pleomorphic carcinomas were positive for MCPyV DNA. Some MCPyV DNA-positive cancers expressed large T antigen (LT) RNA transcripts. Immunohistochemistry showed that MCPyV LT antigen was expressed in the tumour cells. The viral integration sites were identified in one SCC and one AC. One had both episomal and integrated/truncated forms. The other carried an integrated MCPyV genome with frameshift mutations in the LT gene.

Conclusion:

We have demonstrated the expression of a viral oncoprotein, the presence of integrated MCPyV, and a truncated LT gene with a preserved retinoblastoma tumour-suppressor protein-binding domain in NSCLCs. Although the viral prevalence was low, the tumour-specific molecular signatures support the possibility that MCPyV is partly associated with the pathogenesis of NSCLC in a subset of patients.

Occupational and environmental causes of lung cancer

Because tobacco smoking is a potent carcinogen, secondary causes of lung cancer are often diminished in perceived importance. The goal of this review is to describe the occurrence and recent findings of the 27 agents currently listed by the International Agency for Research on Cancer (IARC) as lung carcinogens. The IARC's updated assessments of lung carcinogens provide a long-overdue resource for consensus opinions on the carcinogenic potential of various agents. Supplementary new information, with a focus on analytic epidemiologic studies that has become available since IARC's most recent evaluation, are also discussed.

Influence of common genetic variation on lung cancer risk: meta-analysis of 14 900 cases and 29 485 controls

Recent genome-wide association studies (GWASs) have identified common genetic variants at 5p15.33, 6p21-6p22 and 15q25.1 associated with lung cancer risk. Several other genetic regions including variants of CHEK2 (22q12), TP53BP1 (15q15) and RAD52 (12p13) have been demonstrated to influence lung cancer risk in candidate- or pathway-based analyses. To identify novel risk variants for lung cancer, we performed a meta-analysis of 16 GWASs, totaling 14 900 cases and 29 485 controls of European descent. Our data provided increased support for previously identified risk loci at 5p15 (P = 7.2 × 10(-16)), 6p21 (P = 2.3 × 10(-14)) and 15q25 (P = 2.2 × 10(-63)). Furthermore, we demonstrated histology-specific effects for 5p15, 6p21 and 12p13 loci but not for the 15q25 region. Subgroup analysis also identified a novel disease locus for squamous cell carcinoma at 9p21 (CDKN2A/p16(INK4A)/p14(ARF)/CDKN2B/p15(INK4B)/ANRIL; rs1333040, P = 3.0 × 10(-7)) which was replicated in a series of 5415 Han Chinese (P = 0.03; combined analysis, P = 2.3 × 10(-8)). This large analysis provides additional evidence for the role of inherited genetic susceptibility to lung cancer and insight into biological differences in the development of the different histological types of lung cancer.

Distribution of effervescent inhalable nanoparticles after pulmonary delivery: an in vivo study

Background: Effervescent inhalable nanoparticles (NPs) have previously been shown to be a promising alternative to conventional lung cancer treatment in animals. This study investigates the biodistribution of effervescent inhalable NPs after a single dose administration via pulmonary route in lung cancer-bearing mice. Methods & results: Whole-body autoradiography and confocal laser-scanning microscopy (CLSM) were used to investigate the distribution of inhalable NPs loaded in an effervescent microcarrier. Inhalable doxorubicin-loaded NPs were tagged with 14C for whole-body autoradiography, or with fluorescein isothiocyanate for CLSM imaging. After pulmonary delivery, NPs were widely disseminated in the lungs with a long retention time (24 h). The heart was radioactivity free at all time points of the study. CLSM images showed that inhalable NPs were taken up by cells and that doxorubicin was released to the cell nuclei. Conclusion: This is the first study to investigate the distribution of inhalable NPs in a lung cancer-bearing animal model. Inhalable NPs achieved deep lung deposition, were actively released from microcarrier particles, spread to different parts of the lung and released doxorubicin in vivo. These NP characteristics contribute to the efficacy of effervescent inhalable NPs as a lung cancer treatment.

Biomarkers in diabetes: hemoglobin A1c, vascular and tissue markers

Biomarkers are conventionally defined as "biological molecules that represent health and disease states." They typically are measured in readily available body fluids (blood or urine), lie outside the causal pathway, are able to detect subclinical disease, and are used to monitor clinical and subclinical disease burden and response to treatments. Biomarkers can be "direct" endpoints of the disease itself, or "indirect" or surrogate endpoints. New technologies (such as metabolomics, proteomics, genomics) bring a wealth of opportunity to develop new biomarkers. Other new technologies enable the development of nonmolecular, functional, or biophysical tissue-based biomarkers. Diabetes mellitus is a complex disease affecting almost every tissue and organ system, with metabolic ramifications extending far beyond impaired glucose metabolism. Biomarkers may reflect the presence and severity of hyperglycemia (ie, diabetes itself) or the presence and severity of the vascular complications of diabetes. Illustrative examples are considered in this brief review. In blood, hemoglobin A1c (HbA1c) may be considered as a biomarker for the presence and severity of hyperglycemia, implying diabetes or prediabetes, or, over time, as a "biomarker for a risk factor," ie, hyperglycemia as a risk factor for diabetic retinopathy, nephropathy, and other vascular complications of diabetes. In tissues, glycation and oxidative stress resulting from hyperglycemia and dyslipidemia lead to widespread modification of biomolecules by advanced glycation end products (AGEs). Some of these altered species may serve as biomarkers, whereas others may lie in the causal pathway for vascular damage. New noninvasive technologies can detect tissue damage mediated by AGE formation: these include indirect measures such as pulse wave analysis (a marker of vascular dysfunction) and more direct markers such as skin autofluorescence (a marker of long-term accumulation of AGEs). In the future, we can be optimistic that new blood and tissue-based biomarkers will enable the detection, prevention, and treatment of diabetes and its complications long before overt disease develops.