Participant selection for lung cancer screening by risk modelling (the Pan-Canadian Early Detection of Lung Cancer [PanCan] study): a single-arm, prospective study.

BACKGROUND: Results from retrospective studies indicate that selecting individuals for low-dose CT lung cancer screening on the basis of a highly predictive risk model is superior to using criteria similar to those used in the National Lung Screening Trial (NLST; age, pack-year, and smoking quit-time). We designed the Pan-Canadian Early Detection of Lung Cancer (PanCan) study to assess the efficacy of a risk prediction model to select candidates for lung cancer screening, with the aim of determining whether this approach could better detect patients with early, potentially curable, lung cancer. METHODS: We did this single-arm, prospective study in eight centres across Canada. We recruited participants aged 50-75 years, who had smoked at some point in their life (ever-smokers), and who did not have a self-reported history of lung cancer. Participants had at least a 2% 6-year risk of lung cancer as estimated by the PanCan model, a precursor to the validated PLCOm2012 model. Risk variables in the model were age, smoking duration, pack-years, family history of lung cancer, education level, body-mass index, chest x-ray in the past 3 years, and history of chronic obstructive pulmonary disease. Individuals were screened with low-dose CT at baseline (T0), and at 1 (T1) and 4 (T4) years post-baseline. The primary outcome of the study was incidence of lung cancer. This study is registered with ClinicalTrials.gov, number NCT00751660. FINDINGS: 7059 queries came into the study coordinating centre and were screened for PanCan risk. 15 were duplicates, so 7044 participants were considered for enrolment. Between Sept 24, 2008, and Dec 17, 2010, we recruited and enrolled 2537 eligible ever-smokers. After a median follow-up of 5·5 years (IQR 3·2-6·1), 172 lung cancers were diagnosed in 164 individuals (cumulative incidence 0·065 [95% CI 0·055-0·075], incidence rate 138·1 per 10 000 person-years [117·8-160·9]). There were ten interval lung cancers (6% of lung cancers and 6% of individuals with cancer): one diagnosed between T0 and T1, and nine between T1 and T4. Cumulative incidence was significantly higher than that observed in NLST (4·0%; p<0·0001). Compared with 593 (57%) of 1040 lung cancers observed in NLST, 133 (77%) of 172 lung cancers in the PanCan Study were early stage (I or II; p<0·0001). INTERPRETATION: The PanCan model was effective in identifying individuals who were subsequently diagnosed with early, potentially curable, lung cancer. The incidence of cancers detected and the proportion of early stage cancers in the screened population was higher than observed in previous studies. This approach should be considered for adoption in lung cancer screening programmes. FUNDING: Terry Fox Research Institute and Canadian Partnership Against Cancer.

Probability of cancer in pulmonary nodules detected on first screening CT.

BACKGROUND: Major issues in the implementation of screening for lung cancer by means of low-dose computed tomography (CT) are the definition of a positive result and the management of lung nodules detected on the scans. We conducted a population-based prospective study to determine factors predicting the probability that lung nodules detected on the first screening low-dose CT scans are malignant or will be found to be malignant on follow-up. METHODS: We analyzed data from two cohorts of participants undergoing low-dose CT screening. The development data set included participants in the Pan-Canadian Early Detection of Lung Cancer Study (PanCan). The validation data set included participants involved in chemoprevention trials at the British Columbia Cancer Agency (BCCA), sponsored by the U.S. National Cancer Institute. The final outcomes of all nodules of any size that were detected on baseline low-dose CT scans were tracked. Parsimonious and fuller multivariable logistic-regression models were prepared to estimate the probability of lung cancer. RESULTS: In the PanCan data set, 1871 persons had 7008 nodules, of which 102 were malignant, and in the BCCA data set, 1090 persons had 5021 nodules, of which 42 were malignant. Among persons with nodules, the rates of cancer in the two data sets were 5.5% and 3.7%, respectively. Predictors of cancer in the model included older age, female sex, family history of lung cancer, emphysema, larger nodule size, location of the nodule in the upper lobe, part-solid nodule type, lower nodule count, and spiculation. Our final parsimonious and full models showed excellent discrimination and calibration, with areas under the receiver-operating-characteristic curve of more than 0.90, even for nodules that were 10 mm or smaller in the validation set. CONCLUSIONS: Predictive tools based on patient and nodule characteristics can be used to accurately estimate the probability that lung nodules detected on baseline screening low-dose CT scans are malignant. (Funded by the Terry Fox Research Institute and others; ClinicalTrials.gov number, NCT00751660.).

Plant Polyphenols as Chemopreventive Agents for Lung Cancer.

Lung cancer may be prevented by a diet rich in fruits and vegetables as they are enriched with dietary antioxidant polyphenols, such as flavonoids, proanthocyanidins, lignans, stilbenes, and phenolic acids. Dietary polyphenols exert a wide range of beneficial biological functions beyond their antioxidative properties and are involved in regulation of cell survival pathways leading to anticarcinogenic and antimutagenic functions. There are sufficient evidence from in vitro, in vivo, and epidemiological studies to suggest that the dietary intervention of polyphenols in cancer prevention, including the chemopreventive ability of dietary polyphenols, act against lung carcinogens. Cohort and epidemiological studies in selected risk populations have evaluated clinical effects of polyphenols. Polyphenols have demonstrated three major actions: antioxidative activity, regulation of phase I and II enzymes, and regulation of cell survival pathways against lung carcinogenesis. They have also shown an inverse association of lung cancer occurrences among high risk populations who consumed considerable amounts of fruits and vegetables in their daily diet. In in vitro cell culture experimental models, polyphenols bind with electrophilic metabolites from carcinogens, inactivate cellular oxygen radicals, prevent membrane lipid peroxidation and DNA oxidative damage, and adduct formation. Further, polyphenols enhance the detoxifying enzymes such as the phase II enzymes, glutathione transferases and glucuronosyl transferases.

Synergistic antitumor effects of regulatory T cell blockade combined with pemetrexed in murine malignant mesothelioma.

CD4(+)CD25(+) regulatory T cells (Tregs) can promote the growth of some tumors, but it is unknown whether this is true for all tumors, including malignant pleural mesothelioma. We have previously shown that the existence of Tregs was associated with poor survival in patients with malignant pleural mesothelioma. In this study, using an intrathoracic murine model of malignant mesothelioma (MM), we provide evidence suggesting that Treg blockade could enhance survival when combined with pemetrexed in established tumor. AC29 murine MM cells were injected into the right pleural cavity of CBA mice for tumor development. Four days after the tumor injection, tumor-bearing mice were then treated with pemetrexed alone, Treg blockade alone, or a combination of pemetrexed and Treg blockade. We observed a synergistic antitumor effect of Treg blockade combined with pemetrexed resulting in prolonged survival. The combination of Treg blockade and pemetrexed was associated with decreased tumor-infiltrating Tregs, increased IL-2 production, dendritic cell maturation, and increased CD3(+)CD8(+)IFN-gamma(+) tumor-infiltrating T cells when compared with mice treated with pemetrexed alone or Treg blockade alone. The survival benefit was abrogated if anti-CD8 mAb was administered simultaneously. Likewise, the survival benefit resulting from the combined Treg blockade with pemetrexed was not observed when immunodeficient mice were used. Therefore, this study suggests that Treg blockade combined with pemetrexed can suppress mesothelioma growth in established tumor in vivo through an immune-mediated process. This study also validates a new intrathoracic tumor model of pleural effusion to explore the role of antitumor immunity in murine MM.

Lung cancer risk in never-smokers: a population-based case-control study of epidemiologic risk factors.

BACKGROUND: We conducted a case-control study in the greater Toronto area to evaluate potential lung cancer risk factors including environmental tobacco smoke (ETS) exposure, family history of cancer, indoor air pollution, workplace exposures and history of previous respiratory diseases with special consideration given to never smokers. METHODS: 445 cases (35% of which were never smokers oversampled by design) between the ages of 20-84 were identified through four major tertiary care hospitals in metropolitan Toronto between 1997 and 2002 and were frequency matched on sex and ethnicity with 425 population controls and 523 hospital controls. Unconditional logistic regression models were used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the associations between exposures and lung cancer risk. RESULTS: Any previous exposure to occupational exposures (OR total population 1.6, 95% CI 1.4-2.1, OR never smokers 2.1, 95% CI 1.3-3.3), a previous diagnosis of emphysema in the total population (OR 4.8, 95% CI 2.0-11.1) or a first degree family member with a previous cancer diagnosis before age 50 among never smokers (OR 1.8, 95% CI 1.0-3.2) were associated with increased lung cancer risk. CONCLUSIONS: Occupational exposures and family history of cancer with young onset were important risk factors among never smokers.

Pathologic assessment of radiofrequency ablation of pulmonary metastases.

PURPOSE: To evaluate pathologically the effectiveness of radiofrequency (RF) ablation in the treatment of pulmonary metastases. MATERIALS AND METHODS: Patients with multiple pulmonary metastases scheduled for surgical resection were prospectively enrolled. Patients underwent RF ablation of one percutaneously accessible tumor and within 2-4 weeks underwent surgical resection of the ablated tumor and any additional lesions. Resected tumors all were assessed by routine light microscopy, and selected tumors were assessed by immunohistochemistry with MIB1 and proliferative cell nuclear antigen (PCNA). Relationship of ablation zone to the tumor and viability of the ablated tumors were assessed. RESULTS: Nine patients (four men and five women) 46-76 years of age were included in the study. Four patients had metastatic colorectal carcinoma, and five patients had metastases from soft tissue sarcomas. Ablated tumors ranged from 1.0-3.0 cm in diameter. Each target lesion was completely encompassed by the ablation zone. All tumor tissue within the ablation zone showed characteristic changes of coagulative necrosis with hematoxylin and eosin staining. Tumors showed preservation of MIB1 staining but loss of PCNA protein staining. RF ablation resulted in complete coagulative necrosis of all the pulmonary metastases treated in the study. CONCLUSIONS: Although this series is small, it provides histologic support for RF ablation as an effective treatment for selected pulmonary metastases.

Initial treatment strategies and outcomes for multifocal bronchioloalveolar carcinoma.

BACKGROUND: Bronchioloalveolar carcinoma (BAC) commonly presents as multifocal disease. Management of multifocal BAC remains controversial and may include surgical resection, systemic therapy, surveillance, or a combination of these strategies. Knowledge of current practice patterns and outcomes could help to inform future research. MATERIALS AND METHODS: Medical records of patients with BAC were retrospectively reviewed, and regression analyses were conducted to correlate demographic parameters, disease characteristics, and treatment modality with clinical outcomes. RESULTS: Of the 109 cases identified, 85 patients were eligible for study, 26% with unifocal and 74% with multifocal BAC. Median age at diagnosis was 65 years; the majority of the patients were female (64%), were non-Asian (82%), and had a smoking history (66%). In the subset with multifocal BAC, 24% of the cases were confined to one lobe, 76% affected multiple lobes, and 40% involved both lungs. The primary treatment modality for multifocal disease included surgical resection (78%), systemic therapy (14%), and observation (8%). In multivariate analyses, extensive disease (> or = 3 lobes involved) and medical oncology assessment predicted treatment with systemic therapy (odds ratio [OR], 8.68; P = .03 and OR, 1.68; P < .01, respectively). The presence of extensive disease and the receipt of systemic therapy were associated with higher likelihood of disease progression (hazard ratio [HR], 8.62; P = .02 and HR, 8.46; P = .02, respectively). CONCLUSION: Initial treatment choices and referral patterns for multifocal BAC were diverse and influenced by clinical selection, whereby patients with extensive disease were more likely to discuss and receive systemic therapy. Surgery and surveillance were reasonable treatment options for selected patients. The precise roles of the various treatment strategies for multifocal BAC require further evaluation.

Health-related quality of life and anxiety in the PAN-CAN lung cancer screening cohort.

OBJECTIVES: The impact of lung cancer screening with low-dose chest CT (LDCT) on participants' anxiety levels and health-related quality of life (HRQoL) is an important consideration in the implementation of such programmes. We aimed to describe changes in anxiety and HRQoL in a high-risk Canadian cohort undergoing LDCT lung cancer screening. METHODS: 2537 subjects who had 2% or greater lung cancer risk over 6 years using a risk prediction tool were recruited from eight centres across Canada in the Pan-Canadian Early Detection of Lung Cancer Study (2008-2010). We compared HRQoL and anxiety levels before and after screening of 1237 participants with LDCT (excluding a subset of 1300 participants who also underwent autofluorescence bronchoscopy screening), as well as after investigations performed because of a positive screening examination. The 12-item short-form Physical and Mental Component Scales (SF-12), EQ-5D-3L scores and State Trait Anxiety Inventory-State anxiety were used at each assessment. RESULTS: Overall, there were no clinically significant differences in HRQoL outcomes between baseline and each of the survey time points following initial screening. No mean change in anxiety in the overall cohort was noted following baseline LDCT, but more participants had clinically significant increase in anxiety versus decrease after baseline screening (increase >minimal clinically important difference (MCID) (n=180) vs decrease >MCID (n=50), p<0.001). This finding persisted but to a lesser degree at the 12 month time point (increase >MCID (n=146) vs decrease >MCID (n=87), p<0.001). CONCLUSIONS: CT screening for lung cancer has no major overall impact on HRQoL among participants, although a minority of participants (number-needed-to-harm=7 after baseline screening and 18 at 1 year) demonstrated clinically significant increased anxiety levels. TRIALREGISTRATION NUMBER: NCT00751660; Results.

A novel trans-lymphatic drug delivery system: implantable gelatin sponge impregnated with PLGA-paclitaxel microspheres.

A translymphatic drug delivery system which incorporates poly-lactide-co-glycolide-paclitaxel (PLGA-PTX) or PLGA-rhodamine microspheres into gelatin sponge matrix is described. The system combines the sustained release properties of PLGA-PTX with the structural advantages of gelatin matrix that can be implanted directly to the lymphatic site for both therapeutic and prophylactic purposes. The PLGA microspheres were prepared using spray drying technique. The particles were in the size range of 1-8 microm, suitable for intraperitoneal and intrapleural lymphatic targeting delivery. Scanning electron microscopy revealed the homogeneous distribution of PLGA microspheres in the porous sponge network. The release of PTX was mainly controlled by the degradation of the PLGA. Crosslinking gelatin using carbodiimide reduced the biodegradation of the sponge and thereby delayed the release of the PLGA in vitro. In vivo lymphatic delivery was assessed in both healthy rats and rats bearing orthotopic lung cancer. Intraperitoneal and intrapleural implantation of the sponge impregnated with PLGA microspheres resulted in spontaneous absorption of the particles in the lymphatic system. It is concluded that the system provides great potential for targeted delivery of therapeutic agent to the lymphatic system especially for the control of lymphatic metastasis in cancer.

Patient-Derived Xenograft Establishment from Human Malignant Pleural Mesothelioma.

Purpose: Malignant pleural mesothelioma (MPM) is a rare but aggressive disease with few therapeutic options. The tumor-stromal interface is important in MPM, but this is lost in cell lines, the main model used for preclinical studies. We sought to characterize MPM patient-derived xenografts (PDX) to determine their suitability as preclinical models and whether tumors that engraft reflect a more aggressive biological phenotype.Experimental Design: Fresh tumors were harvested from extrapleural pneumonectomy, decortication, or biopsy samples of 50 MPM patients and implanted subcutaneously into immunodeficient mice and serially passaged for up to five generations. We correlated selected mesothelioma biomarkers between PDX and patient tumors, and PDX establishment with the clinical pathologic features of the patients, including their survival. DNA of nine PDXs was profiled using the OncoScan FFPE Express platform. Ten PDXs were treated with cisplatin and pemetrexed.Results: A PDX was formed in 20 of 50 (40%) tumors implanted. Histologically, PDX models closely resembled the parent tumor. PDX models formed despite preoperative chemotherapy and radiotherapy. In multivariable analysis, patients whose tumors formed a PDX had significantly poorer survival when the model was adjusted for preoperative treatment (HR, 2.46; 95% confidence interval, 1.1-5.52; P = 0.028). Among 10 models treated with cisplatin, seven demonstrated growth inhibition. Genomic abnormalities seen in nine PDX models were similar to that previously reported.Conclusions: Patients whose tumors form PDX models have poorer clinical outcomes. MPM PDX tumors closely resemble the genotype and phenotype of parent tumors, making them valuable models for preclinical studies. Clin Cancer Res; 23(4); 1060-7. ©2016 AACR.

The Cost-Effectiveness of High-Risk Lung Cancer Screening and Drivers of Program Efficiency.

INTRODUCTION: Lung cancer risk prediction models have the potential to make programs more affordable; however, the economic evidence is limited. METHODS: Participants in the National Lung Cancer Screening Trial (NLST) were retrospectively identified with the risk prediction tool developed from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. The high-risk subgroup was assessed for lung cancer incidence and demographic characteristics compared with those in the low-risk subgroup and the Pan-Canadian Early Detection of Lung Cancer Study (PanCan), which is an observational study that was high-risk-selected in Canada. A comparison of high-risk screening versus standard care was made with a decision-analytic model using data from the NLST with Canadian cost data from screening and treatment in the PanCan study. Probabilistic and deterministic sensitivity analyses were undertaken to assess uncertainty and identify drivers of program efficiency. RESULTS: Use of the risk prediction tool developed from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial with a threshold set at 2% over 6 years would have reduced the number of individuals who needed to be screened in the NLST by 81%. High-risk screening participants in the NLST had more adverse demographic characteristics than their counterparts in the PanCan study. High-risk screening would cost $20,724 (in 2015 Canadian dollars) per quality-adjusted life-year gained and would be considered cost-effective at a willingness-to-pay threshold of $100,000 in Canadian dollars per quality-adjusted life-year gained with a probability of 0.62. Cost-effectiveness was driven primarily by non-lung cancer outcomes. Higher noncurative drug costs or current costs for immunotherapy and targeted therapies in the United States would render lung cancer screening a cost-saving intervention. CONCLUSIONS: Non-lung cancer outcomes drive screening efficiency in diverse, tobacco-exposed populations. Use of risk selection can reduce the budget impact, and screening may even offer cost savings if noncurative treatment costs continue to rise.

Targeting colloidal particulates to thoracic lymph nodes.

BACKGROUND: Thoracic lymphatics and lymph nodes can be affected by cancer and other diseases. Micro- or nanoparticulates are used as carriers for therapeutic agents. We investigated the lymphatic distribution after intrapleural administration of three different particulates. METHODS: Various micro- and nanoparticles of charcoal, polystyrene and poly(lactide-co-glycolide) were administered into the pleural space of rats to study the lymphatic distribution of particles from the pleural cavity to the thoracic lymph nodes. Experimental animal models included healthy rats, rats following pneumonectomy and rats bearing orthotopic lung cancer to mimic relevant clinical scenarios and pathophysiology. Macroscopic examination, light microscopy, fluorescence microscopy complemented by transmission electron microscopy analysis of the lymphatic tissue allowed precise mapping and detection of the particulates in the thoracic lymphatic system. RESULTS: We found that (1) the particles studied are cleared by the regional thoracic lymphatic system when placed in the pleural space; (2) the lymphatic uptake occurred as early as 3h after injection and is primarily through the parietal pleura; (3) the transport of particles to regional lymph nodes was consistently found in all three animal models; (4) particles of 0.7-2 microm in size give the best lymphatic distribution. CONCLUSIONS: Regional thoracic lymphatics and lymph nodes can be accessed by colloidal particles injected into the pleural space.

Expression of chicken ovalbumin upstream promoter-transcription factor II enhances invasiveness of human lung carcinoma cells.

Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) plays an essential role in angiogenesis and development. It is differentially expressed in tumor cell lines, but its role in carcinogenesis is largely unknown. We demonstrate here that noninvasive human lung cancer cells become invasive when COUP-TFII was expressed. The expression of extracellular matrix degrading proteinases, such as matrix metalloproteinase 2 and urokinase-type plasminogen activator, was up-regulated in these cells. This finding was confirmed by transduction of different human lung cancer cell lines with COUP-TFII protein and also by using antisense expression. We observed disorganization of actin filaments and focal adhesion kinase phosphorylation in COUP-TFII-transfected human lung cancer cells in addition to the increase in extracellular metalloproteinase activity. These results suggest that COUP-TFII may be considered as a new target for anticancer therapies.

Modeling of lung cancer by an orthotopically growing H460SM variant cell line reveals novel candidate genes for systemic metastasis.

Endobronchial implantation of NCI-H460 cells into the nude rat generates a primary lung tumor with mediastinal lymph node spread, but rarely systemic metastases. We isolated tumor cells from mediastinal nodes, orthotopically reimplanted the cells into nude rats and repeated this four times to derive a cell line, designated H460SM, that spontaneously metastasizes to bone, kidney, brain, soft tissue and contralateral lung. H460SM cells demonstrated higher invasive activity in vitro than parental NCI-H460 cells. Spectral karyotyping revealed a new inversion within 17q and loss of an extra normal copy of chromosome 14 present in parental NCI-H460 cells. Expression profiling of orthotopic primary tumors revealed differential expression of 360 genes. Of these, 173 were represented in the probe set of a 19.2K OCI cDNA microarray previously used to profile the gene expression of surgically resected lung cancer specimens. We have computationally validated clinical importance of these genes by using in silico analysis of 18 cases of pulmonary adenocarcinoma, which were split into two patient groups with markedly different clinical outcome. The model identifies additional novel candidate genes for the progression of lung cancer to systemic metastases and poor prognosis.

Novel candidate tumor marker genes for lung adenocarcinoma.

Using the representational difference analysis (RDA) technique on pooled mRNA of five primary lung adenocarcinomas and their corresponding non-neoplastic lung tissues, we identified six genes that were putatively overexpressed in this type of lung cancer. Five corresponded to previously isolated genes, while one (Lc19) matched with the sequence of an unannotated EST. Real-time RT-PCR analyses of expression levels in a panel of 34 paired primary non-small cell lung cancer (NSCLC) and corresponding grossly normal appearing lung tissues confirmed the common overexpression of these genes in non-small cell lung cancer. Among these genes, overexpression of Lc19, hyaluronan binding protein 2 (HABP2) and crystalline-mu appeared more specific to adenocarcinoma, whereas ceruloplasmin, integrin alpha-11 and collagen type XI alpha 1 were overexpressed at high frequency among both adenocarcinoma and squamous cell carcinoma. These genes represent novel candidate tumor biomarker genes for NSCLC and its histological subtypes.

Preoperative assessment: an anesthesiologist's perspective.

Advances in anesthesia and surgery have made it so that almost any patient with a resectable lung malignancy is now an operative candidate given a full understanding of the risks and after appropriate investigation. This situation necessitates a change in the paradigm that anesthesiologists use for preoperative assessment. Understanding and stratifying the perioperative risks allows the anesthesiologist to develop a systematic focused approach to these patients at the time of the initial contact and immediately before induction, which can be used to guide anesthetic management.

Stability and heterogeneity of expression profiles in lung cancer specimens harvested following surgical resection.

One of the major concerns in microarray profiling studies of clinical samples is the effect of tissue sampling and RNA extraction on data. We analyzed gene expression in lung cancer specimens that were serially harvested from tumor mass and snap-frozen at several intervals up to 120 minutes after surgical resection. Global gene expression was profiled on cDNA microarrays, and selected stress and hypoxia-activated genes were evaluated using real-time reverse transcription polymerase chain reaction (RT-PCR). Remarkably, similar gene expression profiles were obtained for the majority of samples regardless of the time that had elapsed between resection and freezing. Real-time RT-PCR studies showed significant heterogeneity in the expression levels of stress and hypoxia-activated genes in samples obtained from different areas of a tumor specimen at one time point after resection. The variations between multiple samplings were significantly greater than those of elapsed time between sampling/freezing. Overall samples snap-frozen within 30 to 60 minutes of surgical resection are acceptable for gene expression studies, thus making sampling and snap-freezing of tumor samples in a routine surgical pathology laboratory setting feasible. However, sampling and pooling from multiple sites of each tumor may be necessary for expression profiling studies to overcome the molecular heterogeneity present in tumor specimens.

Early combined treatment with carboplatin and the MMP inhibitor, prinomastat, prolongs survival and reduces systemic metastasis in an aggressive orthotopic lung cancer model.

We studied the synthetic matrix metalloproteinase inhibitor (MMPI) prinomastat (AG3340) in a well-established NCI-H460 orthotopic lung cancer model that exhibits highly predictable regional and systemic metastatic patterns. Both primary and metastatic tumors express the matrix metalloproteinases (MMP-2), MT1-MMP (MMP-14) and tissue inhibitor of metalloproteinases (TIMP-2). The anti-tumor activity of prinomastat was investigated both as a single agent and in combination therapy with carboplatin. Treatment with both carboplatin (at two dose levels) and prinomastat commenced when the primary lung cancer was approximately 200-300 mg in size and without gross or microscopic evidence of metastases. As single agents, prinomastat significantly reduced the incidence of kidney metastasis, but had no effect on metastatic frequency to other organs. As single agents neither drug enhanced length of survival over control animals, although microvessel counts in prinomastat-treated tumors were lower than in tumors from control animals (P<0.01). In combination prinomastat and the lower dose of carboplatin significantly enhanced survival over control animals, and over animals treated with carboplatin alone (P<0.05). Tolerance to this combination was assessed with body weight and serum biochemistries. At the higher carboplatin dose, toxicity became evident both as a single agent and in combination with prinomastat. Our results suggest that the administration of prinomastat in combination with standard cytotoxic chemotherapy during early stages of tumor growth and metastasis may prolong survival in non-small cell lung cancer (NSCLC) patients.

Validating the prognostic value of marker genes derived from a non-small cell lung cancer microarray study.

We previously reported that our cDNA microarray analysis of primary non-small cell lung carcinoma (NSCLC) could predict for patients at increased risk of cancer recurrence. From the result of this analysis, we selected 11 genes that were considered candidate prognostic marker genes and used the realtime reverse transcription polymerase chain reaction (RT-PCR) to investigate their expression in the same set of NSCLC cases used in the microarray study. Cluster analysis of the realtime RT-PCR data separated these patients into two groups with significantly different disease-free survivals (log-rank test, P < 0.017). In contrast, cluster analysis failed to confirm the prognostic significance of the realtime RT-PCR results for these 11 genes in a validation series of 92 NSCLC cases. In univariate analysis, hypoxia inducible factor 1alpha, Rho-GDP dissociation inhibitor (GDI) alpha (RhoGDI) and Citron/rho-interacting serine-threonine kinase 21 (Citron K21) were significant prognostic factors for disease-free survival in the entire cohort of 130 NSCLC patients, but none were significant in multivariate analysis. The results demonstrate that the prognostic significance of microarray (SAM) results can be partially validated using realtime RT-PCR, but secondary validation using larger and independent series of tumors is necessary to identify true prognostic marker genes.

Animal models for studying lung cancer and evaluating novel intervention strategies.

The pathogenesis of lung cancer progression, invasion and metastasis remains undefined. Clinically relevant laboratory models of the disease could greatly facilitate its clarification. Model systems of lung cancer that accurately reflect different biologic properties and disease stages are necessary to ensure proper experimental design of studies aimed at increasing our understanding of the disease. Such models are also essential tools to accelerate development of new therapies for lung cancer. In this review we summarize the available lung cancer model systems in use today and define both their utility and limitations.