Precision Cut Lung Slices as a Preclinical Model for Non-Small Cell Lung Cancer Chemoprevention

Lung cancer chemoprevention is critical to addressing cancer burden in high-risk populations. Chemoprevention clinical trials rely on data from preclinical models; however, in vivo studies have high financial, technical, and staffing requirements. Precision cut lung slices (PCLS) provide an ex vivo model that maintains the structure and function of native tissues. This model can be used for mechanistic investigations and drug screenings and reduces the number of animals and time required to test hypotheses compared with in vivo studies. We tested the use of PCLS for chemoprevention studies, demonstrating recapitulation of in vivo models. Treatment of PCLS with the PPARγ agonizing chemoprevention agent iloprost produced similar effects on gene expression and downstream signaling as in vivo models. This occurred in both wild-type tissue and Frizzled 9 knockout tissue, a transmembrane receptor required for iloprost's preventive activity. We explored new areas of iloprost mechanisms by measuring immune and inflammation markers in PCLS tissue and media, and immune cell presence with immunofluorescence. To demonstrate the potential for drug screening, we treated PCLS with additional lung cancer chemoprevention agents and confirmed activity markers in culture. PCLS offers an intermediate step for chemoprevention research between in vitro and in vivo models that can facilitate drug screening prior to in vivo studies and support mechanistic studies with more relevant tissue environments and functions than in vitro models.

PREVENTION RELEVANCE

PCLS could be a new model for premalignancy and chemoprevention research, and this work evaluates the model with tissue from prevention-relevant genetic and carcinogen exposed in vivo mouse models, in addition to evaluating chemoprevention agents.

Prevention of Tobacco Carcinogen-Induced Lung Tumor Development by a Novel STAT3 Decoy Inhibitor

The STAT3 pathway is frequently overactive in non-small cell lung cancer (NSCLC), an often fatal disease with known risk factors including tobacco and chemical exposures. Whether STAT3 can be downmodulated to delay or prevent development of lung cancer resulting from an environmental exposure has not been previously tested. A circular oligonucleotide STAT3 decoy (CS3D) was used to treat mice previously exposed to the tobacco carcinogen nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. CS3D contains a double-stranded STAT3 DNA response element sequence and interrupts STAT3 signaling by binding to STAT3 dimers, rendering them unable to initiate transcription at native STAT3 DNA binding sites. An intermittent course of CS3D decreased the development of airway preneoplasias by 42% at 1 week posttreatment, reduced the progression of preneoplasia to adenomas by 54% at 8 weeks posttreatment, and reduced the size and number of resulting lung tumors by 49.7% and 29.5%, respectively, at 20 weeks posttreatment. No toxicity was detected. A mutant cyclic oligonucleotide with no STAT3 binding ability was used as a control. Chemopreventive effects were independent of the KRAS mutational status of the tumors. In lungs harvested during and after the treatment course with CS3D, airway preneoplasias had reduced STAT3 signaling. Chemopreventive effects were accompanied by decreased VEGFA expression, ablated IL6, COX-2, and p-NF-κB, and decreased pulmonary M2 macrophages and myeloid-derived suppressor cells. Thus, downmodulation of STAT3 activity using a decoy molecule both reduced oncogenic signaling in the airway epithelium and favored a lung microenvironment with reduced immunosuppression.

Non-Small Cell Lung Cancer: Epidemiology, Screening, Diagnosis, and Treatment

Lung cancer remains the leading cause of cancer deaths in the United States. In the past decade, significant advances have been made in the science of non-small cell lung cancer (NSCLC). Screening has been introduced with the goal of early detection. The National Lung Screening Trial found a lung cancer mortality benefit of 20% and a 6.7% decrease in all-cause mortality with the use of low-dose chest computed tomography in high-risk individuals. The treatment of lung cancer has also evolved with the introduction of several lines of tyrosine kinase inhibitors in patients with EGFR, ALK, ROS1, and NTRK mutations. Similarly, immune checkpoint inhibitors (ICIs) have dramatically changed the landscape of NSCLC treatment. Furthermore, the results of new trials continue to help us understand the role of these novel agents and which patients are more likely to benefit; ICIs are now part of the first-line NSCLC treatment armamentarium as monotherapy, combined with chemotherapy, or after definite chemoradiotherapy in patients with stage III unresectable NSCLC. Expression of programmed cell death protein-ligand 1 in malignant cells has been studied as a potential biomarker for response to ICIs. However, important drawbacks exist that limit its discriminatory potential. Identification of accurate predictive biomarkers beyond programmed cell death protein-ligand 1 expression remains essential to select the most appropriate candidates for ICI therapy. Many questions remain unanswered regarding the proper sequence and combinations of these new agents; however, the field is moving rapidly, and the overall direction is optimistic.

Prolonged lung cancer screening reduced 10-year mortality in the MILD trial: new confirmation of lung cancer screening efficacy

BACKGROUND

The National Lung Screening Trial showed that lung cancer (LC) screening by three annual rounds of low-dose computed tomography (LDCT) reduces LC mortality. We evaluated the benefit of prolonged LDCT screening beyond 5 years, and its impact on overall and LC specific mortality at 10 years.

DESIGN

The Multicentric Italian Lung Detection (MILD) trial prospectively randomized 4099 participants, to a screening arm (n = 2376), with further randomization to annual (n = 1190) or biennial (n = 1186) LDCT for a median period of 6 years, or control arm (n = 1723) without intervention. Between 2005 and 2018, 39 293 person-years of follow-up were accumulated. The primary outcomes were 10-year overall and LC specific mortality. Landmark analysis was used to test the long-term effect of LC screening, beyond 5 years by exclusion of LCs and deaths that occurred in the first 5 years.

RESULTS

The LDCT arm showed a 39% reduced risk of LC mortality at 10 years [hazard ratio (HR) 0.61; 95% confidence interval (CI) 0.39-0.95], compared with control arm, and a 20% reduction of overall mortality (HR 0.80; 95% CI 0.62-1.03). LDCT benefit improved beyond the 5th year of screening, with a 58% reduced risk of LC mortality (HR 0.42; 95% CI 0.22-0.79), and 32% reduction of overall mortality (HR 0.68; 95% CI 0.49-0.94).

CONCLUSIONS

The MILD trial provides additional evidence that prolonged screening beyond 5 years can enhance the benefit of early detection and achieve a greater overall and LC mortality reduction compared with NLST trial.

CLINICALTRIALS.GOV IDENTIFIER

NCT02837809.

Subcellular compartmentalization of PKM2 identifies anti-PKM2 therapy response in vitro and in vivo mouse model of human non-small-cell lung cancer

Pyruvate kinase M2 (PKM2) is an alternatively spliced variant, which mediates the conversion of glucose to lactate in cancer cells under normoxic conditions, known as the Warburg effect. Previously, we demonstrated that PKM2 is one of 97 genes that are overexpressed in non-small-cell lung cancer (NSCLC) cell lines. Herein, we demonstrate a novel role of subcellular PKM2 expression as a biomarker of therapeutic response after targeting this gene by shRNA or small molecule inhibitor (SMI) of PKM2 enzyme activity in vitro and in vivo. We examined two established lung cancer cell lines, nine patients derived NSCLC and three normal lung fibroblast cell lines for PKM2 mRNA, protein and enzyme activity by RT-qPCR, immunocytochemistry (ICC), and Western blot analysis. All eleven NSCLC cell lines showed upregulated PKM2 enzymatic activity and protein expression mainly in their cytoplasm. Targeting PKM2 by shRNA or SMI, NSCLC cells showed significantly reduced mRNA, enzyme activity, cell viability, and colony formation, which also downregulated cytosolic PKM2 and upregulated nuclear enzyme activities. Normal lung fibroblast cell lines did not express PKM2, which served as negative controls. PKM2 targeting by SMI slowed tumor growth while gene-silencing significantly reduced growth of human NSCLC xenografts. Tumor sections from responding mice showed >70% reduction in cytoplasmic PKM2 with low or undetectable nuclear staining by immunohistochemistry (IHC). In sharp contrast, non-responding tumors showed a >38% increase in PKM2 nuclear staining with low or undetectable cytoplasmic staining. In conclusion, these results confirmed PKM2 as a target for cancer therapy and an unique function of subcellular PKM2, which may characterize therapeutic response to anti-PKM2 therapy in NSCLC.

Phase I clinical trial of a novel autologous modified-DC vaccine in patients with resected NSCLC

BACKGROUND

The primary aim of this study was to evaluate the safety of a novel dendritic cell (DC) vaccine pulsed with survivin and MUC1, silenced with suppressor of cytokine signaling 1 (SOCS1), and immune stimulated with flagellin for patients with stage I to IIIA non-small cell lung cancer (NSCLC) in a phase I open-label, uncontrolled, and dose-escalation trial. Moreover, we evaluate the potential efficacy of this modified DC vaccine as secondary aim.

METHODS

The patients were treated with the vaccine at 1 × 106, 1 × 107and the maximum dose 8 × 107 at day 7, 14, and 21 after characterization of the vaccine phenotype by flow cytometry. The safety of the vaccine was assessed by adverse events, and the efficacy by the levels of several specific tumor markers and the patient quality of life.

RESULTS

The vaccine was well tolerated without dose-limiting toxicity even at higher doses. The most common adverse event reported was just grade 1 flu-like symptoms without unanticipated or serious adverse event. A significant decrease in CD3 + CD4 + CD25 + Foxp3+ T regulatory (Treg) cell number and increase in TNF-α and IL-6 were observed in two patients. Two patients showed 15% and 64% decrease in carcino-embryonic antigen and CYFRA21, respectively. The vaccination with the maximum dose significantly improved the patients'quality of life when administered at the highest dose. More importantly, in the long-term follow-up until February 17, 2017, 1 patient had no recurrence, 1 patients had a progressive disease (PD), and 1 patient was died in the low dose group. In the middle dose group, all 3 patients had no recurrence. In the high dose group, 1 patient was died, 1 patient had a PD, and the other 7 patients had no recurrence.

CONCLUSIONS

We provide preliminary data on the safety and efficacy profile of a novel vaccine against non-small cell lung cancer, which was reasonably well tolerated, induced modest antitumor activity without dose-limiting toxicity, and improved patients' quality of life. Further more, the vaccine maybe a very efficacious treatment for patients with resected NSCLC to prevent recurrence. Our findings on the safety and efficacy of the vaccine in this phase I trial warrant future phase II/III clinical trial.

MicroRNA-19a/b mediates grape seed procyanidin extract-induced anti-neoplastic effects against lung cancer

Oncomirs are microRNAs (miRNA) associated with carcinogenesis and malignant transformation. They have emerged as potential molecular targets for anti-cancer therapy. We hypothesize that grape seed procyanidin extract (GSE) exerts antineoplastic effects through modulations of oncomirs and their downstream targets. We found that GSE significantly down-regulated oncomirs miR-19a and -19b in a variety of lung neoplastic cells. GSE also increased mRNA and protein levels of insulin-like growth factor II receptor (IGF-2R) and phosphatase and tensin homolog (PTEN), both predicted targets of miR-19a and -19b. Furthermore, GSE significantly increased PTEN activity and decreased AKT phosphorylation in A549 cells. Transfection of miR-19a and -19b mimics reversed the up-regulations of IGF2R and PTEN gene expression and abrogated the GSE induced anti-proliferative response. Additionally, oral administration of leucoselect phytosome, comprised of standardized grape seed oligomeric procyanidins complexed with soy phospholipids, to athymic nude mice via gavage, significantly down-regulated miR-19a, -19b and the miR-17-92 cluster host gene (MIR17HG) expressions, increased IGF-2R, PTEN, decreased phosphorylated-AKT in A549 xenograft tumors, and markedly inhibited tumor growth. To confirm the absorption of orally administered GSE, plasma procyanidin B1 levels, between 60 and 90 min after gavage of leucoselect phytosome (400 mg/kg), were measured by LC/MS at week 2 and 8 of treatment; the estimated concentration that was associated with 50% growth inhibition (IC50) (1.3 μg/mL) in vitro was much higher than the IC50 (0.032-0.13 μg/ml) observed in vivo. Our findings reveal novel antineoplastic mechanisms by GSE and support the clinical translation of leucoselect phytosome as an anti-neoplastic and chemopreventive agent for lung cancer.

Chain elongation analog of resveratrol as potent cancer chemoprevention agent

Resveratrol is identified as a natural cancer chemoprevention agent. There has been a lot of interest in designing and developing resveratrol analogs with cancer chemoprevention activity superior to that of parent molecule and exploring their action mechanism in the past several decades. In this study, we have synthesized resveratrol analogs of compounds A-C via conjugated chain elongation based on isoprene unit retention strategy. Remarkably, cytotoxic activity analysis results indicated that compound B possesses the best proliferation inhibition activity for NCI-H460 cells in all the test compounds. Intriguingly, compound B displayed a higher cytotoxicity against human non-small cell lung cancer cells (NCI-H460) compared to normal human embryonic lung fibroblasts (MRC-5). Afterward, flow cytometry analysis showed that compound B would induce cell apoptosis. We further researched the action mechanism. When NCI-H460 cells were incubated by compound B for 6 or 9 h, respectively, the intracellular reactive oxygen species (ROS) level was enhanced obviously. With elevation of intracellular ROS level, flow cytometry measurement verified mitochondrial transmembrane potential collapse, which was accompanied by the up-regulation of Bax and down-regulation of Bcl-2. More interestingly, compound B increased the expression of caspase-9 and caspase-3, which induced cell apoptosis. Moreover, compound B arrested cell cycle in G0/G1 phase. These are all to provide useful information for designing resveratrol-based chemoprevention agent and understanding the action mechanism.

HER2-siRNA delivered by EGFR-specific single chain antibody inhibits NSCLC cell proliferation and tumor growth

Overexpression of human epidermal growth factor receptor type2 (HER2) is closely associated with aggressive progression and poor prognosis in non-small cell lung cancer (NSCLC). Here, we generated an EGFR-scFv-arginine nonamer peptide fusion protein (scFv-9R) as a cargo to deliver HER2 specific siRNA into HER2-positive NSCLC cells both in vitro and in vivo. HER2-siRNAs delivered by scFv-9R effeciently silenced HER2 expression in EGFR-positive NSCLC cells, and consequently resulted in G1 arrest and cell growth inhibition. Importantly, intravenous injection of scFv-9R/HER2-siRNA complex markedly suppressed growth of EGFR-positive NSCLC xenograft in nude mice, resulting from downregulated HER2 expression, reduced cell proliferation and enhanced cell apoptosis. Collectively, our study provides a novel therapeutic strategy for the treatment of EGFR-positive, HER2-overexpressed NSCLC.

Development and Evaluation of Patient Education Materials for Elderly Lung Cancer Patients

Patients treated for lung cancer are often elderly presenting a unique challenge for developing patient education materials. This study developed and evaluated a patient education pamphlet on lung stereotactic body radiotherapy (SBRT) designed specifically for an elderly population. The SBRT pamphlet was developed using a participatory design involving a convenience sample of patients. This prospective study assessed patient's opinions of pamphlet effectiveness through self-report questionnaires. The pamphlet was deemed "effective" if patients rated 16/18 evaluation statements as "strongly agree" or "agree." Demographic data and health literacy (Rapid Estimate of Adult Literacy in Medicine short-form (REALM-SF)) were also assessed. Patient opinion of pamphlet "effectiveness" was compared between patients with REALM-SF scores of 7 versus <7 using Fisher's exact test. The overall EQ-5D-5L score was compared for patients who did and did not find the pamphlet effective using the Wilcoxon-Mann-Whitney test. Thirty-seven patients participated. The median age was 76 years (range 56-93) and 22 patients (59 %) had ≤high school education. Most patients preferred to have verbal (65 %) or written (78 %) educational materials as opposed to online information or educational classes. Thirty-two patients (86 %) rated the pamphlet as effective. The proportion of patients who found the pamphlet effective was 85.7 versus 86.7 % (p = 1.00) in those with REALM 7 versus <7. The mean EQ-5D score was 67.5 (SD 19.1) versus 71.8 (SD 8.7) (p = 0.84) in those who found the pamphlet effective versus not. Participatory design is an effective method for developing education materials for challenging patient groups such as elderly patients. Despite advanced age and comorbidity, this patient group had adequate health literacy.

Nrf2-heme oxygenase-1 axis in mucoepidermoid carcinoma of the lung: Antitumoral effects associated with down-regulation of matrix metalloproteinases

Lung mucoepidermoid carcinoma (MEC) is a very poorly characterized rare subtype of non-small-cell lung cancer (NSCLC) associated with more favorable prognoses than other forms of intrathoracic malignancies. We have previously identified that heme oxygenase-1 (HO-1, encoded by HMOX1) inhibits MEC tumor growth and modulates the transcriptome of microRNAs. Here we investigate the role of a major upstream regulator of HO-1 and a master regulator of cellular antioxidant responses, transcription factor Nrf2, in MEC biology. Nrf2 overexpression in the NCI-H292 MEC cell line mimicked the phenotype of HO-1 overexpressing cells, leading to inhibition of cell proliferation and migration and down-regulation of oncogenic miR-378. HMOX1 silencing identified HO-1 as a major mediator of Nrf2 action. Nrf2- and HO-1 overexpressing cells exhibited strongly diminished expression of multiple matrix metalloproteinases and inflammatory cytokine interleukin-1β, which was confirmed in an NCI-HO-1 xenograft model. Overexpression of HO-1 altered not only human MMP levels in tumor cells but also murine MMP levels within tumor microenvironment and metastatic niche. This could possibly contribute to decreased metastasis to the lungs and inhibitory effects of HO-1 on MEC tumor growth. Our profound transcriptome analysis and molecular characterization of the mucoepidermoid lung carcinoma helps to understand the specific clinical presentations of these tumors, emphasizing a unique antitumoral role of the Nrf2-HO-1 axis.

Aspirin use and lung cancer risk: a possible relationship? Evidence from an updated meta-analysis

Background and Purpose

Growing evidence has emerged and controversial results reported on possible relationship between aspirin use and lung cancer risk. We, therefore, conducted this updated and comprehensive meta-analysis to evaluate this issue, with focus on dose-risk and duration-risk relationships.

Methods

We searched electronic databases including PUBMED, EMBASE and Cochrane library to identify eligible studies. Relative risk (RR) and its 95% confidence interval (CI) were used for cohort studies, while odds ratio (OR) were employed for case-control studies. The random effects and fixed effects models were used for analyses.

Results

18 studies were identified including 19835 lung cancer cases, which were eligible for inclusion in the present meta-analysis. Pooled data from case-control studies showed a significant inverse association between regular aspirin use and lung cancer risk. But for cohort studies, insignificant association was detected with little evidence of heterogeneity (RR: 1.05, 95%CI: 0.95 – 1.16; I²: 10.3%, p value: 0.351). In case-control studies, standard aspirin use (>325mg) was related to lower lung cancer incidence, compared with low-dose aspirin use (75–100mg). A similar trend was observed in cohort studies. Besides, when analysis was restricted to long time regular aspirin use (>5 years), insignificant results were reported in both cohort and case-control studies. Finally, regular aspirin use might result in higher reduction of non-small cell lung cancer incidence among men.

Conclusions

Our findings do not support the protective effect of regular aspirin use on lung cancer risk. Long time aspirin use, sex, dose and type of lung cancer might alter the effect of aspirin use on lung cancer risk. More well-designed studies are needed to further clarify these associations.

Cucurbitacin B Alters the Expression of Tumor-Related Genes by Epigenetic Modifications in NSCLC and Inhibits NNK-Induced Lung Tumorigenesis

Non-small cell lung cancer (NSCLC) represents almost 85% of total diagnosed lung cancer. Studies have shown that combination of DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors is effective against various cancers, including lung cancer. However, optimizing the synergistic dose regime is very difficult and involves adverse side effects. Therefore, in this study, we have shown that cucurbitacin B (CuB), a single bioactive triterpenoid compound, inhibits both DNMTs and HDACs starting at a very low dose of 60 nmol/L in NSCLC H1299 cells. The CuB-mediated inhibition of DNMTs and HDACs in H1299 cells leads to the reactivation of key tumor suppressor genes (TSG) such as CDKN1A and CDKN2A, as well as downregulation of oncogenes c-MYC and K-RAS and key tumor promoter gene (TPG), human telomerase reverse transcriptase (hTERT). The upregulation of TSGs and downregulation of TPG were consistently correlated with the alterations in their promoter methylation and histone modifications. This altered expression of TPG and TSGs is, at least in part, responsible for the inhibition of cellular proliferation and induction of cellular apoptosis in NSCLC. Furthermore, CuB treatment significantly inhibited the tumor incidence and multiplicity in 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in A/J mice, which was associated with the induction of apoptosis and inhibition of hyperproliferation in the lung tissues. Together, our study provides new insight into the CuB-mediated epigenetic alterations and its chemotherapeutic effects on lung cancer.

[Middle fraction radiotherapy for non-small cell lung cancer. Effect of increasing the total focal dose]

There were evaluated retrospectively the immediate and long-term results of radiotherapy in 259 patients with non-small cell lung cancer stages I-IV who had contraindications to surgery. Irradiation was carried out by middle fraction with single focal dose 3-4 Gr. We compared the results of treatment in two groups of patients differed in volume of total focal dose: I group (124 patients)--45 Gy, II group (125 patients)--60 Gy. An increase of total focal dose from 45 Gy to 60 Gy did not lead to an increase of the toxicity to vital organs including patients older than 60 years and patients with initially poorer somatic status. Disease-free survival significantly increased in total in the group with total focal dose 60 Gy and predominantly in tumors over 5 cm, in patients with ECOG 2-3 and in III-IV stage disease. An increase of total focal dose to 60 Gy in the group was significantly prolonged survival without local recurrences from 37% to 50% and by one-third reduced the frequency of locoregional recurrences. Identified benefits in overall and disease-specific survival the groups of non-small cell lung cancer patients with total focal dose 60 Gy compared with a group of non-small cell lung cancer patients who received radiotherapy in total focal dose 45 Gy at terms more than 5 years did not reach statistical significance.

Histamine-2 receptor antagonists and risk of lung cancer in diabetic patients – an exploratory analysis

PURPOSE

Histamine-2 receptor blockers (H2RBs) might have anti-tumorogenic effect, but the clinical effect on lung cancer occurrence was unclear.

METHODS

A total of 640,173 type 2 diabetic patients were identified from the Taiwan National Health Insurance claims database in 2000. Patients were followed from cohort entry to the earliest of cancer diagnosis, death, disenrollment from the national health insurance, or 31 December 2007. For each participant, H2RB use during the follow-up period was ascertained from the outpatient pharmacy prescription database. Patients with incident squamous cell carcinoma (SCC) and adenocarcinoma were included as cases and up to four age- and sex-matched controls were selected by risk-set sampling. Conditional logistic regression models were applied to estimate the association between H2RBs and lung cancer incidence.

RESULTS

A total of 1182 incident SCC and 2345 adenocarcinoma cases were identified, and 13,108 matched controls were selected. An increased risk was observed for H2RBs use <1 year with adjusted OR of 1.33 (95% confidence interval (CI): 1.22–1.44). After excluding all exposures occurring in the year before lung cancer diagnosis, H2RBs use with cumulative dosage ≥ 360 “defined daily doses” was associated with a significantly decreased risk of lung cancer (OR: 0.60; 95% CI: 0.38–0.96). When we stratified on types of lung cancer, the protective association of higher cumulative use of H2RBs seemed more evident for lung adenocarcinoma, with an adjusted OR of 0.49 (95% CI: 0.26–0.90).

CONCLUSIONS

Higher cumulative use of H2RBs might be associated with a reduced risk for non-small cell lung cancer in diabetic patients.

Prospects for population screening and diagnosis of lung cancer

Deaths from lung cancer exceed those from any other type of malignancy, with 1·5 million deaths in 2010. Prevention and smoking cessation are still the main methods to reduce the death toll. The US National Lung Screening Trial, which compared CT screening with chest radiograph, yielded a mortality advantage of 20% to participants in the CT group. International debate is ongoing about whether sufficient evidence exists to implement CT screening programmes. When questions about effectiveness and cost-effectiveness have been answered, which will await publication of the largest European trial, NELSON, and pooled analysis of European CT screening trials, we discuss the main topics that will need consideration. These unresolved issues are risk prediction models to identify patients for CT screening; radiological protocols that use volumetric analysis for indeterminate nodules; options for surgical resection of CT-identified nodules; screening interval; and duration of screening. We suggest that a demonstration project of biennial screening over a 4-year period should be undertaken.

A cost-utility analysis of lung cancer screening and the additional benefits of incorporating smoking cessation interventions

BACKGROUND

A 2011 report from the National Lung Screening Trial indicates that three annual low-dose computed tomography (LDCT) screenings for lung cancer reduced lung cancer mortality by 20% compared to chest X-ray among older individuals at high risk for lung cancer. Discussion has shifted from clinical proof to financial feasibility. The goal of this study was to determine whether LDCT screening for lung cancer in a commercially-insured population (aged 50-64) at high risk for lung cancer is cost-effective and to quantify the additional benefits of incorporating smoking cessation interventions in a lung cancer screening program.

METHODS AND FINDINGS

The current study builds upon a previous simulation model to estimate the cost-utility of annual, repeated LDCT screenings over 15 years in a high risk hypothetical cohort of 18 million adults between age 50 and 64 with 30+ pack-years of smoking history. In the base case, the lung cancer screening intervention cost $27.8 billion over 15 years and yielded 985,284 quality-adjusted life years (QALYs) gained for a cost-utility ratio of $28,240 per QALY gained. Adding smoking cessation to these annual screenings resulted in increases in both the costs and QALYs saved, reflected in cost-utility ratios ranging from $16,198 per QALY gained to $23,185 per QALY gained. Annual LDCT lung cancer screening in this high risk population remained cost-effective across all sensitivity analyses.

CONCLUSIONS

The findings of this study indicate that repeat annual lung cancer screening in a high risk cohort of adults aged 50-64 is highly cost-effective. Offering smoking cessation interventions with the annual screening program improved the cost-effectiveness of lung cancer screening between 20% and 45%. The cost-utility ratios estimated in this study were in line with other accepted cancer screening interventions and support inclusion of annual LDCT screening for lung cancer in a high risk population in clinical recommendations.

Decline in tested and self-reported cognitive functioning after prophylactic cranial irradiation for lung cancer: pooled secondary analysis of Radiation Therapy Oncology Group randomized trials 0212 and 0214

PURPOSE

To assess the impact of prophylactic cranial irradiation (PCI) on self-reported cognitive functioning (SRCF), a functional scale on the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30).

METHODS AND MATERIALS

Radiation Therapy Oncology Group (RTOG) protocol 0214 randomized patients with locally advanced non-small cell lung cancer to PCI or observation; RTOG 0212 randomized patients with limited-disease small cell lung cancer to high- or standard-dose PCI. In both trials, Hopkins Verbal Learning Test (HVLT)-Recall and -Delayed Recall and SRCF were assessed at baseline (after locoregional therapy but before PCI or observation) and at 6 and 12 months. Patients developing brain relapse before follow-up evaluation were excluded. Decline was defined using the reliable change index method and correlated with receipt of PCI versus observation using logistic regression modeling. Fisher's exact test correlated decline in SRCF with HVLT decline.

RESULTS

Of the eligible patients pooled from RTOG 0212 and RTOG 0214, 410 (93%) receiving PCI and 173 (96%) undergoing observation completed baseline HVLT or EORTC QLQ-C30 testing and were included in this analysis. Prophylactic cranial irradiation was associated with a higher risk of decline in SRCF at 6 months (odds ratio 3.60, 95% confidence interval 2.34-6.37, P<.0001) and 12 months (odds ratio 3.44, 95% confidence interval 1.84-6.44, P<.0001). Decline on HVLT-Recall at 6 and 12 months was also associated with PCI (P=.002 and P=.002, respectively) but was not closely correlated with decline in SRCF at the same time points (P=.05 and P=.86, respectively).

CONCLUSIONS

In lung cancer patients who do not develop brain relapse, PCI is associated with decline in HVLT-tested and self-reported cognitive functioning. Decline in HVLT and decline in SRCF are not closely correlated, suggesting that they may represent distinct elements of the cognitive spectrum.

Lung cancer patients' decisions about clinical trials and the theory of planned behavior

The theory of planned behavior explores the relationship between behavior, beliefs, attitudes, and intentions presupposing that behavioral intention is influenced by a person's attitude about the behavior and beliefs about whether individuals, who are important to them, approve or disapprove of the behavior (subjective norm). An added dimension to the theory is the idea of perceived behavioral control, or the belief that one has control over performing the behavior. The theory of planned behavior suggests that people may make greater efforts to perform a behavior if they feel they have a high level of control over it. In this examination of data, we explored the application of the theory of planned behavior to patient's decisions about participating in a clinic trial. Twelve respondents in this study had previously participated in a clinical trial for lung cancer and nine respondents had declined a clinical trial for lung cancer. The data were analyzed with regard to the four constructs associated with the theory of planned behavior: behavioral intention, attitude, subjective norm, and perceived behavioral control. Results indicate that the theory of planned behavior may be a useful tool to examine psychosocial needs in relation to behavioral intention of clinical trial participation.

Comparing the benefits of screening for breast cancer and lung cancer using a novel natural history model

To estimate the impact of early detection of cancer, knowledge of how quickly primary tumors grow and at what size they shed lethal metastases is critical. We developed a natural history model of cancer to estimate the probability of disease-specific cure as a function of tumor size, the tumor volume doubling time (TVDT), and disease-specific mortality reduction achievable by screening. The model was applied to non-small-cell lung carcinoma (NSCLC) and invasive ductal carcinoma (IDC), separately. Model parameter estimates were based on Surveillance Epidemiology and End Results (SEER) cancer registry datasets and validated on screening trials. Compared to IDC, NSCLC is estimated to have a lower probability of disease-specific cure at the same detected tumor size, shed lethal metastases at smaller sizes (median: 19 mm for IDC versus 8 mm for NSCLC), have a TVDT that is almost half as long (median: 252 days for IDC versus 134 days for NSCLC). Consequently, NSCLC is associated with a lower mortality reduction from screening at the same screen detection threshold and screening interval. In summary, using a similar natural history model of cancer, we quantify the disease-specific curability attributable to screening for breast cancer, and separately lung cancer, in terms of the TVDT and onset of lethal metastases.

Cost-effectiveness of computed tomography screening for lung cancer in the United States

INTRODUCTION

A randomized trial has demonstrated that lung cancer screening reduces mortality. Identifying participant and program characteristics that influence the cost-effectiveness of screening will help translate trial results into benefits at the population level.

METHODS

Six U.S. cohorts (men and women aged 50, 60, or 70 years) were simulated in an existing patient-level lung cancer model. Smoking histories reflected observed U.S. patterns. We simulated lifetime histories of 500,000 identical individuals per cohort in each scenario. Costs per quality-adjusted life-year gained ($/QALY) were estimated for each program: computed tomography screening; stand-alone smoking cessation therapies (4-30% 1-year abstinence); and combined programs.

RESULTS

Annual screening of current and former smokers aged 50 to 74 years costs between $126,000 and $169,000/QALY (minimum 20 pack-years of smoking) or $110,000 and $166,000/QALY (40 pack-year minimum), when compared with no screening and assuming background quit rates. Screening was beneficial but had a higher cost per QALY when the model included radiation-induced lung cancers. If screen participation doubled background quit rates, the cost of annual screening (at age 50 years, 20 pack-year minimum) was below $75,000/QALY. If screen participation halved background quit rates, benefits from screening were nearly erased. If screening had no effect on quit rates, annual screening costs more but provided fewer QALYs than annual cessation therapies. Annual combined screening/cessation therapy programs at age 50 years costs $130,500 to $159,700/QALY, when compared with annual stand-alone cessation.

CONCLUSIONS

The cost-effectiveness of computed tomography screening will likely be strongly linked to achievable smoking cessation rates. Trials and further modeling should explore the consequences of relationships between smoking behaviors and screen participation.

Soy isoflavones augment radiation effect by inhibiting APE1/Ref-1 DNA repair activity in non-small cell lung cancer

INTRODUCTION

Soy isoflavones sensitize cancer cells to radiation both in vitro and in vivo. To improve the effect of radiotherapy for non-small cell lung cancer, we assessed the potential of using a complementary approach with soy isoflavones.

METHODS

Human A549 non-small cell lung cancer cells were treated with soy isoflavones, radiation, or both and tested for cell growth. DNA double-strand breaks (DSBs) were detected by immunostaining for γ-H2AX foci. Expressions of γ-H2AX, HIF-1α, and APE1/Ref-1 were assessed by Western blots. DNA-binding activities of HIF-1α and NF-κB transcription factors were analyzed by electrophoretic mobility shift assay.

RESULTS

Soy isoflavones increased A549 cell killing induced by radiation. Multiple γ-H2AX foci were detectable at 1 hour after radiation but decreased at 24 hours after radiation. Soy isoflavones also caused DNA DSBs, but γ-H2AX foci increased over time. Soy isoflavones and radiation caused an increase in γ-H2AX foci, which persisted at 24 hours, indicating both increased DNA damage and inhibition of repair. Soy isoflavones inhibited the radiation-induced activity of the DNA repair/redox enzyme APE1/Ref-1 and the transcription factors NF-κB and HIF-1α. E3330, which inhibits the redox activity of APE1/Ref-1, did not alter the repair of radiation-induced DSBs. Methoxyamine, which inhibits APE1/Ref-1 DNA repair activity, partly blocked the decrease in radiation-induced DSBs at 24 hours, suggesting partial mitigation of radiation-induced DNA repair akin to the effect of soy combined with radiation, in agreement with cytotoxic assays.

CONCLUSIONS

Inhibition of APE1/Ref-1 DNA repair activity by soy could be involved in the mechanism by which soy alters DNA repair and leads to cell killing.

Biological Therapeutics Research and Development--GTCbio's Fifth Annual Conference. October 20-22, 2010, San Francisco, CA, USA

The Biological Therapeutics Research and Development--GTCbio's Fifth Annual Conference, held in San Francisco, included topics covering new therapeutic developments in the field of vaccines and peptide therapies. This conference report highlights selected presentations on the development of vaccines for NSCLC, DNA delivery platforms as vaccines, vaccine combination therapy for cancer, DNA vaccines for autoimmune diseases, and improved peptide therapeutics. Investigational drugs discussed include TG-4010 (Transgene), and a series of vaccines targeting autoimmune diseases, including BHT-3021 (Bayhill/Genentech) for type I diabetes, BHT-3009 (Bayhill) for multiple sclerosis and BHT-3034 (Bayhill) for myasthenia gravis.

Maintenance therapy for advanced non-small cell lung cancer: current status, controversies, and emerging consensus

Maintenance therapy refers to the use of an active therapeutic agent for extended duration following frontline induction therapy for patients with advanced stage non-small cell lung cancer (NSCLC). Multiple clinical trials reported within the last few months have shown a beneficial role for maintenance therapy especially in select patient groups characterized by histology and/or molecular profile. With the recent approval by the U.S. Food and Drug Administration and European Medicines Agency of pemetrexed for maintenance therapy, a new treatment paradigm has been introduced to the treatment of NSCLC. This article reviews recent data with maintenance therapy in advanced NSCLC and discusses the implications for routine patient care and future drug development.

Skeletal morbidity in lung cancer patients with bone metastases: demonstrating the need for early diagnosis and treatment with bisphosphonates

BACKGROUND

The skeleton is one of the most frequent sites for metastases from non-small cell lung cancer (NSCLC), and skeletal-related events (SREs) can decrease quality of life (QOL). However, limited guidance exists regarding the diagnosis and treatment of bone metastases in patients with NSCLC.

METHODS

Data on the burden of skeletal morbidity and the diagnosis and treatment of bone metastases in patients with NSCLC were obtained from reviewing the published literature (PubMed) and presentations and abstracts from recent oncology congresses.

RESULTS

Bone metastases are common but underdiagnosed in patients with NSCLC. Most NSCLC patients with bone metastases develop > or =1 SRE during their lifetimes. As survival improves with new treatment modalities, the prevalence of SREs is likely to increase. Direct costs of SREs and their subsequent supportive care are approximately $28,000 per patient. Although bone metastases often are not diagnosed until after the onset of symptoms, early treatment can delay the onset of potentially debilitating SREs. In patients with NSCLC and other solid tumors (n=773), zoledronic acid (ZOL; 4 mg via 15-min infusion every 3 weeks) delayed the median time to first on-study SRE by >80 days compared with placebo (p=0.009). Moreover, ZOL significantly reduced the ongoing risk of SREs by 32% versus placebo (p=0.016).

CONCLUSIONS

Skeletal morbidity is an important concern in patients with NSCLC. The incidence of SREs is expected to increase as survival improves in this setting. Prevention of SREs with therapies such as ZOL may preserve patients' QOL and possibly reduce healthcare costs.

Chemoprevention by Prunella vulgaris L. extract of non-small cell lung cancer via promoting apoptosis and regulating the cell cycle

Chemoprevention is one feasible approach to decreasing morbidity and mortality of non-small cell lung cancer (NSCLC). The present study aimed to explore the mechanisms of chemoprevention of NSCLC by Prunella vulgaris L. (PV) using a PV extract of 60% ethanol (P-60). In an A/J mouse model benzo[a]pyrene induction of lung tumors was significantly reduced difference by P-60 group. In addition, P-60 was found to have the ability to regulate cell cycle and induce apoptosis in SPC-A-1 cells. Therefore, we propose that P-60 has potential as a lung cancer chemopreventive agent.

Cancer vaccines for non-small-cell lung cancer

Lung cancer is globally the second most common form of cancer in both men and women and the single largest cause of cancer-related mortality in the world. It is a disease with poor prognosis and the survival statistics have scarcely improved since historical times. The advent of targeted therapies has caused an incremental increase in survival figures. Nevertheless, significant progress in treatment outcomes need to be achieved before any perceptible improvement in overall survival of lung cancer patients becomes evident. The use of active-specific immunotherapy or cancer vaccines for the treatment of lung cancer is still in its infancy. Nevertheless several cancer vaccines have demonstrated clinical effects and improvements in overall survival in phase II and phase III trials and several more clinical trials are currently ongoing. This review summarizes the recent developments in NSCLC vaccines.

Point mutation of K-ras gene in cisplatin-induced lung tumours in A/J mice

The risks of secondary lung cancer in patients with early stage non-small and small cell lung cancers are estimated to be 1-2% and 2-10% per patient per year, respectively. Surprisingly, the incidence of second primary cancer in locally advanced non-small cell lung cancer at 10 years, following cisplatin-based chemotherapy with concurrent radiotherapy, increases to 61%. Those patients, on the road to being cured, cannot overlook the possibility of developing a second primary cancer. We developed a second primary lung cancer model using cisplatin as a carcinogen in A/J mice to screen for chemopreventive agents for a second malignancy. In the primary lung tumour model, 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), benzo(a)pyrene (BaP), urethane induces specific K-ras mutations in codon 12, codon 12, and codon 61, respectively, in the A/J mice. In this study, we investigated the mechanisms of carcinogenicity by cisplatin in the A/J mice. In the cisplatin-induced tumours, we found no K-ras codon 12 mutation, which is the major mutation induced by NNK or BaP. K-ras gene mutations in codon 13 and codon 61 were found in one tumour (4%) and five tumours (17.8%), respectively. These findings suggest that cisplatin is partially related to K-ras codon 61 mutations, and that the mechanism of carcinogenicity by cisplatin is different from that by NNK or BaP.

Predicting recurrence following curative surgery in stage I non-small cell lung cancer patients using an angiogenesis-associated factor

There are still difficulties in determining the risk of recurrence to decide whether to perform selective adjuvant treatment for stage I non-small cell lung cancer. This study reviewed 122 stage I patients who underwent curative surgery to assess the usefulness of an angiogenesis-associated factor as a predictor of recurrence. By immunohistochemical examination, we collected information about tumor-induced vascular endothelial growth factor (VEGF)-A and -C expression at the primary site. During the median follow-up period of 120 months, the overall 10-year survival rate was 53.5%. The 10-year survival rates according to VEGF-A/C expression were as follows: VEGF-A high/VEGF-C high group, 26.0%; VEGF-A high/VEGF-C low group, 42.7%; VEGF-A low/VEGF-C high group, 73.1%; VEGF-A low/VEGF-C low group, 65.1%. The VEGF-A high/VEGF-C high group showed the worst outcome. The diagnostic values of the marker combination for predicting recurrence were as follows: sensitivity, 71.4%; specificity, 63.8%; and accuracy, 65.6%. When stratified by T factor, preferable high values for both negative predictive value and specificity were obtained in patients with stage IA disease. In order to select the patients eligible for selective adjuvant therapy at early stages, especially in stage IA disease, simultaneous assessment of tumor-induced VEGF-A/C warrants further study.

Pertuzumab, a novel HER dimerization inhibitor, inhibits the growth of human lung cancer cells mediated by the HER3 signaling pathway

A humanized anti-HER2 monoclonal antibody pertuzumab (Omnitarg, 2C4), binding to a different HER2 epitope than trastuzumab, is known as an inhibitor of heterodimerization of the HER receptors. Potent antitumor activity against HER2-expressing breast and prostate cancer cell lines has been clarified, but this potential is not clear against lung cancers. The authors investigated the in vitro anti-tumor activity of pertuzumab against eight non-small cell lung cancer cells expressing various members of the HER receptors. A lung cancer 11_18 cell line expressed a large amount of HER2 and HER3, and its cell growth was stimulated by an HER3 ligand, heregulin (HRG)-alpha. Pertuzumab significantly inhibited the HRG-alpha-stimulated cellular growth of the 11_18 cells. Pertuzumab blocked HRG-alpha-stimulated phosphorylation of HER3, mitogen-activated protein kinase (MAPK), and Akt. In contrast, pertuzumab failed to block epidermal growth factor (EGF)-stimulated phosphorylation of EGF receptor (EGFR) and MAPK. Immunoprecipitation showed that pertuzumab inhibited HRG-alpha-stimulated HER2/HER3 heterodimer formation. HRG-alpha-stimulated HER3 phosphorylation was also observed in the PC-9 cells co-overexpressing EGFR, HER2, and HER3, but the cell growth was neither stimulated by HRG-alpha nor inhibited by pertuzumab. The present results suggest that pertuzumab is effective against HRG-alpha-dependent cell growth in lung cancer cells through inhibition of HRG-alpha-stimulated HER2/HER3 signaling.

Prophylactic Cranial Irradiation for Patients with Lung Cancer

The central nervous system is a common site of metastasis in patients with small cell lung cancer (SCLC) and non-small-cell lung cancer. Despite advances in combined modality therapy, intracranial relapse continues to be a common site of recurrence and a major cause of morbidity for patients with lung cancer. Prophylactic cranial irradiation (PCI) has proven to be effective in reducing the incidence of brain metastases in patients with lung cancer. Based upon results of a metaanalysis demonstrating a small improvement in overall survival, PCI is now routinely offered to patients with limited-stage SCLC after a complete or near-complete response to initial treatment. However, many questions remain unanswered regarding the optimal dose, fractionation, and toxicity of PCI in patients with limited-stage SCLC. Additionally, the role of PCI in patients with extensive-stage SCLC and locally advanced non-small-cell lung cancer is unclear. Several important collaborative group trials are under way in an attempt to further define the role of PCI in patients with lung cancer.

The retinoid X receptor-selective ligand, LGD1069, inhibits tumor-induced angiogenesis via suppression of VEGF in human non-small cell lung cancer

The present study determined the influence of a retinoid X receptor agonist LGD1069 on angiogenesis in non-small cell lung cancer. In A549 xenograft models, treatment with LGD1069 inhibited the growth and CD31 expression compared with control. In vivo angiogenesis assay utilizing hollow fiber, LGD1069 reduced density of capillary network induced by tumor cells. To determine the basis of these observations, we examined the expression of VEGF and activation of JNK and ERK in A549 cells exposed to LGD1069. Our data showed that LGD1069 decrease the VEGF expression of tumor cells in a dose-dependent manner. Furthermore, it was demonstrated that the decreasing expression of VEGF was consist with inhibition of JNK and ERK activation induced by LGD1069. Collectively, our results suggest a role of LGD1069 in treatment for non-small cell lung cancer by inhibition of tumor-induced angiogenesis.

Epigenetic modulation of endogenous tumor suppressor expression in lung cancer xenografts suppresses tumorigenicity

Epigenetic changes involved in cancer development, unlike genetic changes, are reversible. DNA methyltransferase and histone deacetylase inhibitors show antiproliferative effects in vitro, through tumor suppressor reactivation and induction of apoptosis. Such inhibitors have shown activity in the treatment of hematologic disorders but there is little data concerning their effectiveness in treatment of solid tumors. FHIT, WWOX and other tumor suppressor genes are frequently epigenetically inactivated in lung cancers. Lung cancer cell clones carrying conditional FHIT or WWOX transgenes showed significant suppression of xenograft tumor growth after induction of expression of the FHIT or WWOX transgene, suggesting that treatments to restore endogenous Fhit and Wwox expression in lung cancers would result in decreased tumorigenicity. H1299 lung cancer cells, lacking Fhit, Wwox, p16(INK4a) and Rassf1a expression due to epigenetic modifications, were used to assess efficacy of epigenetically targeted protocols in suppressing growth of lung tumors, by injection of 5-aza-2-deoxycytidine (AZA) and trichostatin A (TSA) in nude mice with established H1299 tumors. High doses of intraperitoneal AZA/TSA suppressed growth of small tumors but did not affect large tumors (200 mm(3)); lower AZA doses, administered intraperitoneally or intratumorally, suppressed growth of small tumors without apparent toxicity. Responding tumors showed restoration of Fhit, Wwox, p16(INKa), Rassf1a expression, low mitotic activity, high apoptotic fraction and activation of caspase 3. These preclinical studies show the therapeutic potential of restoration of tumor suppressor expression through epigenetic modulation and the promise of re-expressed tumor suppressors as markers and effectors of the responses.

A review of vaccine clinical trials for non-small cell lung cancer

Recent evidence suggests that vaccines which enhance tumour antigen recognition may provide clinical benefit to subsets of non-small cell lung cancer patients. In this review, a variety of peptide-, gene- and cell-based clinical vaccine approaches targeting non-small cell lung cancer patients are reviewed. Results consistently demonstrate lack of toxicity. Examples of prolonged stable disease, tumour shrinkage response and survival benefit in comparison with historical and low-dose control groups have been demonstrated. Specific vaccines fulfilling justification for Phase III evaluation based on these results include LBLP25, TGF-beta2 antisense gene vaccine and GVAX.

Epidermal Growth Factor Receptor (EGFR) Antibody Down-regulates Mutant Receptors and Inhibits Tumors Expressing EGFR Mutations

Activating mutations in the kinase domain of the EGF receptor have been reported in non-small cell lung cancer. The majority of tumors expressing these mutants are sensitive to ATP mimetics that inhibit the EGFR tyrosine kinase. The effect of antibodies that bind to the ectodomain of the receptor is less clear. We report herein the effects and mechanisms of action of the antibody cetuximab in lung cancer cells that naturally express receptor mutations and in ErbB-null 32D hematopoietic cells transfected with mutant EGFR. Treatment with cetuximab down-regulated EGFR levels and inhibited cell growth both in vitro and in vivo. This was associated with inhibition of ligand-independent EGFR signaling. These effects were seen in 32D cells arguing the growth inhibitory action was not because of the blockade of autocrine ligand action. Both antibody-induced EGFR down-regulation and inhibition of growth required receptor dimerization as monovalent Fab fragments only eliminated receptor levels or reduced cell proliferation in the presence of antihuman IgG. Finally, cetuximab inhibited growth of H1975 lung cancer cells and xenografts, which expressed L858R/T790M EGFR and were resistant to EGFR tyrosine kinase inhibitors. These data suggest that cetuximab is an effective therapy against mutant EGFR-expressing cancer cells and thus can be considered in combination with other anti-EGFR molecules.

Present and future of lung cancer vaccines

New approaches are needed to improve the current treatment of lung cancer. Inducing an immune response against lung tumour cells with vaccines represents an attractive therapy. However, lung tumours had not been considered good targets for vaccine therapy and, therefore, immune approaches have not been studied extensively in this setting. Current experimental strategies for antitumour vaccines include the generation of active immune responses against specific tumour antigens. Understanding the mechanisms of antitumour immunity and identifying relevant tumour-specific antigens will probably improve therapeutic strategies and provide avenues for the future of lung cancer therapy. There have been a number of preclinical immunotherapy trials suggesting activity, and a smaller number of human clinical trials using various vaccines in lung cancer. Initial data from these trials have shown preliminary evidence of induction of immune responses and suggest clinical activity. This paper reviews some of the most important developments in vaccines for lung cancer.

Vaccination with BLP25 liposome vaccine to treat non-small cell lung and prostate cancers

The identification of tumor-associated/-specific antigens and an increased understanding of the ways in which antigens are processed and presented has led to a revived interest in cancer vaccines as a therapeutic strategy. BLP25 liposome (L-BLP25) vaccine is a cancer vaccine that targets the exposed core peptide of the MUC1 tumor-associated antigen. Studies in advanced-stage non-small cell lung cancer demonstrate that L-BLP25 vaccine has the potential to extend the survival of patients with Stage IIIB locoregional non-small cell lung cancer and maintain quality of life for longer. L-BLP25 vaccine also shows promise for prostate cancer patients, having the potential to prolong prostate-specific antigen doubling time in men with biochemical failure post prostatectomy. These clinically meaningful results with a relatively nontoxic therapeutic vaccine are very encouraging and suggest potential for L-BLP25 to fulfill an unmet medical need.

Prevention of lung cancer progression by bexarotene in mouse models

Bexarotene (Targretin), is a synthetic high-affinity RXR receptor agonist with limited affinity for RAR receptors. Bexarotene has shown efficacy in a phase I/II trial of non-small-cell lung cancers. However, the chemopreventive efficacy of bexarotene has not been determined in mouse lung cancer models. In this study, we have investigated the ability of bexarotene to inhibit lung tumor progression in the mutant A/J mouse models with genetic alterations in p53 or K-ras, two of the most commonly altered genes in human lung tumorigenesis. Mice were administered vinyl carbamate (VC), a carcinogen, by a single intraperitoneal injection (i.p.) at 6 weeks of age. Bexarotene was given by gavage starting at 16 weeks after VC and was continued for 12 weeks. Although all mice developed lung tumors, only 7% of lung tumors were adenocarcinomas in wild-type mice, whereas 22 and 26% of lung tumors were adenocarcinomas in p53 transgenic or K-ras heterozygous deficient mice. Bexarotene inhibited both tumor multiplicity and tumor volume in mice of all three genotypes. Furthermore, bexarotene reduced the progression of adenoma to adenocarcinoma by approximately 50% in both p53(wt/wt)K-ras(ko/wt) and p53(wt/wt)K-ras(wt/wt) mice. Thus, bexarotene appears to be an effective preventive agent against lung tumor growth and progression.

Matrix metalloproteinase inhibitor MMI-166 inhibits lymphogenous metastasis in an orthotopically implanted model of lung cancer

Matrix metalloproteinases (MMP) are considered to be critically involved in tumor invasion and the metastasis of various cancers. MMI-166 is a selective inhibitor of matrix metalloproteinase (MMP-2, MMP-9, and MMP-14). The purpose of this study was to evaluate the effects of MMI-166 on both the growth of the implanted tumor and the lymph node metastasis of the mediastinum and prolonging the life span, using an orthotopic implantation model of the Ma44-3 cancer cell line. We examined the anti-invasive effect of MMI-166 in lung cancer cell lines using an in vitro invasion assay. Next, we examined the anticancer effect of MMI-166 in vivo. MMI-166 (200 mg/kg body weight) or a vehicle was administered orally to the orthotopically implanted lung cancer model. MMI-166 dose-dependently inhibited the invasion of cancer cell lines with expressions of MMP-2 and/or MMP-9 in vitro. In vivo, MMI-166 significantly inhibited mediastinal lymph node metastasis in this orthotopic model (weight of the mediastinum: control, 0.089 +/- 0.009 versus MMI-166, 0.069 +/- 0.008 mg; P = 0.005; metastatic area: control, 93,495 +/- 55,747 versus MMI-166, 22,747 +/- 17,478 pixels; P = 0.045). MMI-166 prolonged the life span by 6 days in median survival time in the orthotopically implanted model (P = 0.039). These results showed that MMI-166 could possibly inhibit lymph node metastasis and prolong the life span in lung cancer patients.

Chemoprevention Strategies for Patients with Lung Cancer in the Context of Screening

Despite major advances in the treatment and management of lung cancer, most patients with lung cancer eventually die of this disease. Because conventional therapies have failed to make a major impact on survival, newer approaches are necessary in the battle against lung cancer. Better understanding of molecular biology of several tumors has led to novel targeted therapeutic approaches with potential utility in cancer treatment in general and lung cancer in particular. In addition to smoking cessation, targeting individuals at high risk by use of early detection or aiming at reversal of premalignant lesions seem like attractive strategies. In light of the noted improvement in molecular diagnostic tools and targeted therapies, the question of chemoprevention in the context of early detection deserves a closer look. In this article, we review what has been achieved in the area of chemoprevention and discuss possible prospects that may help reduce lung cancer mortality in the context of early detection.

Apigenin Inhibits Expression of Vascular Endothelial Growth Factor and Angiogenesis in Human Lung Cancer Cells: Implication of Chemoprevention of Lung Cancer

Apigenin is a natural dietary flavonoid. It has recently been shown to have anticancer effects on prostate and ovarian cancer cells. However, the molecular basis of the effect of apigenin on cancer cells remains to be elucidated. In this study, we found that apigenin inhibited A549 lung cancer cell proliferation and vascular endothelial growth factor (VEGF) transcriptional activation in a dose-dependent manner. In an attempt to understand the mechanism of apigenin-inhibited VEGF expression, we found that apigenin inhibited VEGF transcriptional activation through the hypoxia-inducible factor 1 (HIF-1) binding site and specifically decreased HIF-1alpha but not HIF-1beta subunit expression in the cells. In our efforts to understand the signaling pathway that mediates VEGF transcriptional activation, we found that apigenin inhibited AKT and p70S6K1 activation. When testing the effect of apigenin in vivo, we found that apigenin significantly inhibited tumor growth in nude mice. Apigenin inhibited HIF-1alpha and VEGF expression in the tumor tissues, suggesting an inhibitory effect of apigenin on angiogenesis. To confirm this, we showed that apigenin inhibited angiogenesis in nude mice using the Matrigel assay. HIF-1alpha and VEGF are well known inducers of angiogenesis. Our data suggested that apigenin may inhibit human lung cancer angiogenesis by inhibiting HIF-1alpha and VEGF expression, thus providing a novel explanation for the anticancer action of apigenin.

A DNA vaccine targeting Fos-related antigen 1 enhanced by IL-18 induces long-lived T-cell memory against tumor recurrence

A novel vaccination strategy induced specific CD8(+) T cell-mediated immunity that eradicated spontaneous and experimental pulmonary cancer metastases in syngeneic mice and was also effective in a therapeutic setting of established breast cancer metastases. This was achieved by targeting transcription factor Fos-related antigen 1(Fra-1), overexpressed by many tumor cells, with an ubiquitinated DNA vaccine against Fra-1, coexpressing secretory IL-18. Insight into the immunologic mechanisms involved was provided by adoptive transfer of T lymphocytes from successfully immunized BALB/c mice to syngeneic severe combined immunodeficient (SCID) mice. Specifically, long-lived T memory cells were maintained dormant in nonlymphoid tissues by IL-18 in the absence of tumor antigen. Importantly, a second tumor cell challenge of these SCID mice restored both, robust tumor-specific cytotoxicity and long-lived T-cell memory, capable of eradicating established pulmonary cancer metastases, suggesting that this vaccine could be effective against tumor recurrence.