How do climate change experiments alter plot-scale climate?

To understand and forecast biological responses to climate change, scientists frequently use field experiments that alter temperature and precipitation. Climate manipulations can manifest in complex ways, however, challenging interpretations of biological responses. We reviewed publications to compile a database of daily plot-scale climate data from 15 active-warming experiments. We find that the common practices of analysing treatments as mean or categorical changes (e.g. warmed vs. unwarmed) masks important variation in treatment effects over space and time. Our synthesis showed that measured mean warming, in plots with the same target warming within a study, differed by up to 1.6  ∘ C (63% of target), on average, across six studies with blocked designs. Variation was high across sites and designs: for example, plots differed by 1.1  ∘ C (47% of target) on average, for infrared studies with feedback control (n = 3) vs. by 2.2  ∘ C (80% of target) on average for infrared with constant wattage designs (n = 2). Warming treatments produce non-temperature effects as well, such as soil drying. The combination of these direct and indirect effects is complex and can have important biological consequences. With a case study of plant phenology across five experiments in our database, we show how accounting for drier soils with warming tripled the estimated sensitivity of budburst to temperature. We provide recommendations for future analyses, experimental design, and data sharing to improve our mechanistic understanding from climate change experiments, and thus their utility to accurately forecast species' responses.

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.

Diatoms response to salinity changes: investigations using single pulse and cross polarisation magic angle spinning 29Si NMR spectra

Diatoms Thalassiosira pseudonana and Chaetoceros muelleri (Bacillariophyceae) were cultured at three different salinities (26, 36 and 46 practical salinity units (PSU)) and their silica content examined using natural abundance 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. The samples were investigated using both single pulse (SP) and cross-polarisation (CP) MAS experiments. In addition, samples of T. pseudonana were examined using variable contact time CP MAS experiments allowing the dynamics (TSiH and T1rρH) of CP to be determined. Comparison of SP and CP results revealed a change to a less condensed silica state when diatoms were cultured at salinities away from optimal (36 PSU). Further, an increased amount of organic material (but not its composition) was determined to be present for such samples affecting CP experiments. The location of the organic material, on the diatom surface or within the frustule, was unable to be determined.

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.

Use of a marketing plan for recruitment to a lung cancer screening study

1548

Background: Recruitment to clinic trials is typically poor. Among barriers to recruitment may be the limited knowledge of trialists with respect to marketing techniques. Improvements in marketing could decrease recruitment time and shorten the time to access new interventions. We hypothesized that a marketing plan would improve recruitment to a lung cancer screening study. Methods: The Pan-Canadian Early Detection of Lung Cancer Trial recruited subjects from 8 centres to a screening study of low-dose CT scan and autofluorescence bronchoscopy. Recruitment processes were undertaken independently at each centre. One centre (M) used marketing expertise and a marketing plan, including surveying study candidates for motivators, resulting in specific newsprint advertisements. Screened trial candidates provided demographic and tobacco use data and indicated how they had heard about the study (bus, friend/family, MD, mail, newsprint, radio, TV, other). No site paid for radio or TV time. We used regression analyses to assess whether newsprint advertisements were more effective for recruitment at site M compared with all other sites. Results: From 2008 to 2010, 7059 candidates contacted all centres for eligibility screening, including 779 at centre M. Overall, 50.2% were female; median age was 59 yrs. Compared with other centres, candidates at centre M had less education (p < 0.001), a higher median 3-year lung cancer risk (2.3 vs 2.0%, p < 0.001), but were more likely to have learned of the study by newsprint (58.8 vs 53.3%, chi-squared p = 0.004), and were more likely to be recruited (44.0 vs 34.9%, p < 0.001). It was more likely that newsprint was the driver for screening contact among candidates with higher education level (OR 1.05/level), higher age (OR 1.03 / yr) and contact at site M (OR 1.31) (all < 0.001). Recruitment after eligibility screening was higher when newsprint was the driver for contact on univariable but not multivariable analysis. Conclusions: The effectiveness of newsprint advertising in motivating study contact may be improved by the formal use of marketing expertise. Newsprint advertising may improve the likelihood of recruitment after study screening, possibly through improved initial self-screening by the candidate. Clinical trial information: NCT00751660.

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.

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.

Tetra-porphyrin molecular tweezers: two binding sites linked via a polycyclic scaffold and rotating phenyl diimide core

The synthesis of a tetra-porphyrin molecular tweezer with two binding sites is described. The bis-porphyrin binding sites are aligned by a polycyclic scaffold and linked via a freely rotating phenyl diimide core. Synthesis was achieved using a divergent approach employing a novel coupling method for linking two polycyclic units to construct the core, with a copper(ii)-mediated phenyl boronic acid coupling found to extend to our polycyclic imide derivative. We expect this chemistry to be a powerful tool in accessing functional polycyclic supramolecular architectures in applications where north/south reactivity and/or directional interactions between modules are important. Porphyrin receptor functionalisation was undertaken last, by a four-fold ACE coupling reaction on the tetra-epoxide derivative of the core.

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.

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.).

Randomized, double-blind, placebo-controlled, phase III chemoprevention trial of selenium supplementation in patients with resected stage I non-small-cell lung cancer: ECOG 5597

PURPOSE

Selenium has been reported to have chemopreventive benefits in lung cancer. We conducted a double-blind, placebo-controlled trial to evaluate the incidence of second primary tumors (SPTs) in patients with resected non-small-cell lung cancer (NSCLC) receiving selenium supplementation.

PATIENTS AND METHODS

Patients with completely resected stage I NSCLC were randomly assigned to take selenized yeast 200 μg versus placebo daily for 48 months. Participation was 6 to 36 months postoperatively and required a negative mediastinal node biopsy, no excessive vitamin intake, normal liver function, negative chest x-ray, and no other evidence of recurrence.

RESULTS

The first interim analysis in October 2009, with 46% of the projected end points accumulated, showed a trend in favor of the placebo group with a low likelihood that the trial would become positive; thus, the study was stopped. One thousand seven hundred seventy-two participants were enrolled, with 1,561 patients randomly assigned. Analysis was updated in June 2011 with the maturation of 54% of the planned end points. Two hundred fifty-two SPTs (from 224 patients) developed, of which 98 (from 97 patients) were lung cancer (38.9%). Lung and overall SPT incidence were 1.62 and 3.54 per 100 person-years, respectively, for selenium versus 1.30 and 3.39 per 100 person-years, respectively, for placebo (P = .294). Five-year disease-free survival was 74.4% for selenium recipients versus 79.6% for placebo recipients. Grade 1 to 2 toxicity occurred in 31% of selenium recipients and 26% of placebo recipients, and grade ≥ 3 toxicity occurred in less than 2% of selenium recipients versus 3% of placebo recipients. Compliance was excellent. No increase in diabetes mellitus or skin cancer was detected.

CONCLUSION

Selenium was safe but conferred no benefit over placebo in the prevention of SPT in patients with resected NSCLC.

Morphological preservation of carbonaceous plant fossils in blueschist metamorphic rocks from New Zealand

Morphological and chemical evidence of ancient life is widespread in sedimentary rocks retrieved from shallow depths in the Earth's crust. Metamorphism is highly detrimental to the preservation of biological information in rocks, thus limiting the geological record in which traces of life might be found. Deformation and increasing pressure/temperature during deep burial may alter the morphology as well as the composition and structure of both the organic and mineral constituents of fossils. However, microspore fossils have been previously observed in intensely metamorphosed rocks. It has been suggested that their small size, and/or the nature of the polymer composing their wall, and/or the mineralogy of their surrounding matrix were key parameters explaining their exceptional preservation. Here, we describe the remarkable morphological preservation of plant macrofossils in blueschist metamorphic rocks from New Zealand containing lawsonite. Leaves and stems can be easily identified at the macroscale. At the microscale, polygonal structures with walls mineralized by micas within the leaf midribs and blades may derive from the original cellular ultrastructure or, alternatively, from the shrinkage during burial of the gelified remnants of the leaves in an abiotic process. Processes and important parameters involved in the remarkable preservation of these fossils during metamorphism are discussed. Despite the excellent morphological preservation, the initial biological polymers have been completely transformed to graphitic carbonaceous matter down to the nanometer scale. This occurrence demonstrates that plant macrofossils may experience major geodynamic processes such as metamorphism and exhumation involving deep changes and homogenization of their carbon chemistry and structure but still retain their morphology with remarkable integrity even if they are not shielded by any hard-mineralized concretion.

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.

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.

Trimodality therapy with induction chemotherapy followed by extrapleural pneumonectomy and adjuvant high-dose hemithoracic radiation for malignant pleural mesothelioma

PURPOSE

Malignant pleural mesothelioma (MPM) remains associated with poor outcome. We examined the results of trimodality therapy with cisplatin-based chemotherapy followed by extrapleural pneumonectomy (EPP) and adjuvant high-dose (50 to 60 Gy) hemithoracic radiation therapy for MPM.

PATIENTS AND METHODS

We conducted a retrospective review of all patients prospectively evaluated for trimodality therapy protocol between January 2001 and December 2007 in our institution.

RESULTS

A total of 60 patients were suitable candidates. Histology was epithelioid (n = 44) or biphasic (n = 16). Chemotherapy regimens included cisplatin/vinorelbine (n = 26), cisplatin/pemetrexed (n = 24), cisplatin/raltitrexed (n = 6), or cisplatin/gemcitabine (n = 4). EPP was performed in 45 patients, and hemithoracic radiation therapy to at least 50 Gy was administered postoperatively to 30 patients. Completion of the trimodality therapy in the absence of mediastinal node involvement was associated with the best survival (median survival of 59 months v <or= 14 months in the remaining patients, P = .0003). The type of induction chemotherapy had no significant impact on survival. Pathologic nodal status remained a significant predictor of poor survival despite completion of the trimodality therapy. After completion of the protocol, the 5-year disease-free survival was 53% for patients with N0 disease, reaching 75% in patients with ypT1-2N0 and 45% in patients with ypT3-4N0.

CONCLUSION

This large, single-center experience with induction chemotherapy followed by EPP and adjuvant high-dose hemithoracic radiation for MPM shows that half of the patients are able to complete this protocol. The results are encouraging for patients with N0 disease. However, N2 disease remains a major factor impacting on survival, despite completion of the entire trimodality regimen.

Effect of particle size on the lymphatic distribution of 111Indium-aminopolystyrene through intrapleural administration

The study examined the impact of size on lymphatic particle distribution through intrapleural (ipl.) administration. Aminopolystyrene of three sizes, 0.29 microm, 2.18 microm, and 11.2 microm were radiolabeled with 111Indium and their biodistributions were evaluated in rats after ipl administration. Animals received either particles of three different sizes (4 mg, 200 microCi/animal) or unconjugated 111Indium as control. The percentage of injected dose (%ID) per organ or sample was determined for left (L) and right (R) mediastinal lymph nodes (LN), blood, lung, and pleural wash. The biodistribution of 2.18 microm 111In-aminopolystyrene was further investigated at 6 h, 24 h, 48 h, and 72 h following ipl administration to examine the possible particle retention time. The 2.18 microm particles had significantly higher uptake in both LLN and RLN compared to other sizes. The systemic uptake was minimal. At 72 h, there was still 3.2 +/- 3.2% and 2.1 +/- 1.8% of injected dose retained in the LLN and RLN, respectively. Scintigraphic imaging revealed significant accumulation of the radioactivity in mediastinal nodes. Particle size has significant impact on lymphatic particle distribution through ipl administration. Approximately 2 microm seems to be a suitable size.

Three-gene prognostic classifier for early-stage non small-cell lung cancer

PURPOSE

Several microarray studies have reported gene expression signatures that classify non-small-cell lung carcinoma (NSCLC) patients into different prognostic groups. However, the prognostic gene lists reported to date overlap poorly across studies, and few have been validated independently using more quantitative assay methods.

PATIENTS AND METHODS

The expression of 158 putative prognostic genes identified in previous microarray studies was analyzed by reverse transcription quantitative polymerase chain reaction in the tumors of 147 NSCLC patients. Concordance indices and risk scores were used to identify a stage-independent set of genes that could classify patients with significantly different prognoses.

RESULTS

We have identified a three-gene classifier (STX1A, HIF1A, and CCR7) for overall survival (hazard ratio = 3.8; 95% CI, 1.7 to 8.2; P < .001). The classifier was also able to stratify stage I and II patients and further improved the predictive ability of clinical factors such as histology and tumor stage. The predictive value of this three-gene classifier was validated in two large independent microarray data sets from Harvard and Duke Universities.

CONCLUSION

We have identified a new three-gene classifier that is independent of and improves on stage to stratify early-stage NSCLC patients with significantly different prognoses. This classifier may be tested further for its potential value to improve the selection of resected NSCLC patients in adjuvant therapy.

Improved results of induction chemoradiation before surgical intervention for selected patients with stage IIIA-N2 non–small cell lung cancer

OBJECTIVE

Optimal management of stage IIIA-N2 non-small cell lung cancer remains controversial. The surgical arm of the North American Intergroup 0139 trial was adopted as the standard treatment for patients with resectable N2 disease at the University Health Network. Results after 7 years of experience are reported.

METHODS

This is a retrospective study of consecutive patients with biopsy-proved T1-3 N2 M0 lung cancer who underwent induction chemoradiation before surgical intervention from January 1997 through August 2004. Induction chemotherapy consisted of cisplatin, 50 mg/m2, on days 1 and 8; etoposide, 50 mg/m2, on days 1 to 5, weeks 1 and 5; and concurrent daily external beam radiotherapy to 45 Gy. Lung resection was performed within 6 weeks of completion of chemoradiation, followed by 2 further cycles of consolidation chemotherapy.

RESULTS

Between January 1997 and August 2004, 40 patients were treated according to this protocol (25% T1, 62.5% T2, 7.5% T3, and 5% T4). Overall and disease-free median survivals were 40 and 37.1 months, respectively, whereas overall and disease-free 3-year survivals were 51.7% and 52.3%, respectively. R0 resection was achieved in 92.5%. The overall operative mortality rate was 7.5% (0% for lobectomy and 27% for pneumonectomy). Notably, all mortalities occurred within the first 2 years of our experience with this regimen.

CONCLUSION

Chemoradiation before pulmonary resection in carefully selected patients with surgically resectable stage IIIA (N2) non-small cell lung cancer can lead to improved overall and disease-free survival.

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.

Impact of lymph node metastasis on outcome after extrapleural pneumonectomy for malignant pleural mesothelioma

OBJECTIVES

Extrapleural pneumonectomy is a therapeutic option for selected patients with malignant pleural mesothelioma. The impact of lymph node metastasis on the site of recurrence and the role of mediastinoscopy in the selection of patients for extrapleural pneumonectomy, however, remain unclear.

METHODS

We reviewed 50 consecutive patients undergoing extrapleural pneumonectomy for malignant pleural mesothelioma in our institution between January 1993 and March 2005.

RESULTS

The median survival was 11 months, with a 3-year survival of 24%. Survival was significantly worse for patients with N2 disease than for those with no lymph node metastasis (median survival 10 months vs 29 months, respectively, P = .005). Patient sex, histologic cell type, stage, and N2 disease, but not mediastinoscopy, had significant impacts on survival according to univariate analysis. In a multivariate analysis, however, only the presence of N2 disease remained a significant predictor of poor outcome. The proportion of patients with N2 disease and the long-term survival was similar regardless of whether preoperative mediastinoscopy yielded a negative result. The initial site of recurrence was determined in 28 patients (locoregional in 10 and distant in 18). The presence of N2 disease had no impact on the site of recurrence. Adjuvant hemithoracic radiation therapy, however, significantly decreased the risk of locoregional recurrence.

CONCLUSIONS

The presence of N2 disease negatively affects the prognosis of patients with malignant pleural mesothelioma. Mediastinoscopy, however, seems to have a limited role in patient selection for extrapleural pneumonectomy. Adjuvant hemithoracic radiation therapy but not N2 disease affects the risk of locoregional recurrence.

Integrin-linked kinase inhibitor KP-392 demonstrates clinical benefits in an orthotopic human non-small cell lung cancer model

INTRODUCTION

The overexpression of integrin-linked kinase (ILK) has been implicated in the promotion of tumor invasion and metastasis. We studied the anticancer effects of KP-392, a potent selective inhibitor of ILK in the NCI-H460 cell line. In vitro, KP-392 inhibited ILK activity of H460 cells. In vivo, the effect of KP-392 was investigated in a metastatic H460 orthotopic lung cancer model.

METHODS

Intraperitoneal KP-392 (5 mg/day per animal) was administered both alone and in combination with cisplatin (5 mg/kg per week for 3 weeks). In group I, all treated animals were followed until death to assess therapeutic effect on survival. In group II, tumor growth and metastasis were evaluated by sacrificing one animal from each treatment when a control animal died.

RESULTS

Both cisplatin and KP-392 significantly enhanced survival (37.8 +/- 3.7 and 34.9 +/- 5.2 days) compared with the control (30.2 +/- 3.6 days, p < 0.0001 and p = 0.0418, respectively), and the survival benefit from combination treatment was greater than that of either agent alone (45.8 +/- 3.9 days, p < 0.0001). Although KP-392 alone did not impact the incidence of metastasis, in combination with cisplatin a consistent trend of inhibition was seen for metastases in the kidney, bone, and the contralateral lung. KP-392 was well tolerated throughout the study. KP-392 demonstrated increased tumor necrosis and decreased nuclear phospho-protein kinase/Akt but did not change the levels of phospho-extracellular signal-regulated kinase 1/2.

CONCLUSIONS

ILK inhibitor does not enhance the toxicity of standard chemotherapy and may have a beneficial therapeutic effect in lung cancer.

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.

Occurrence of the Perfect Stage of Powdery Mildew of Sugar Beets in Southern Montana in 2003

Wide spread powdery mildew infections on sugar beets were observed at the Southern Agricultural Experiment Station in Huntley, MT during September, 2003. Throughout the area, lower leaves were frequently heavily covered by the vegetative stage of the fungus with plants at the edge of the field having clearly visible abundant mature (black) and immature (brown) globose ascocarps on the leaf surfaces and stems. The fruiting structures had mostly branched appendages and were imbedded in the superficial mycelium. Their diameter ranged from 70 to 100 μm. Each ascocarp contained five to eight asci with one to four ascospores (mostly three) per ascus. Elliptical ascospores were hyaline and measured 20 to 25 μm long and 12 to 20 μm wide. On the basis of the descriptions given for isolates from Idaho and Colorado (1) and the usage of Erysiphe polygoni DC for powdery mildew on sugar beet in the United States, this isolate may be classified as E. polygoni DC. However, measurements taken show that ascocarps, asci, and ascospores also fall within the range of E. betae (Vanha) Weltz. as described by Weltzien (2). We strongly suggest that these species be compared by using rDNA analysis of the ITS region to determine whether they are separate species. If survival of the ascocarps and the viability and pathogenicity of the ascospores can be confirmed, epidemics of sugar beet powdery mildew could be understood as local and regional events that are not dependant on long distance dispersal of conidiospores. The occurrence of the perfect stage also could lead to the more frequent appearance of new races through genetic recombination. References: (1) J. J Gallian and L. E. Hanson. Plant Dis. 87:200, 2003. (2) H. C. Weltzien. Phytopathol. Z. 47:123, 1963.

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.

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.

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.

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.

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.

Predicting length of stay out of hospital following lung resection using preoperative health status measures

Studies evaluating predictors of operative outcome for lung resection have focused on physiological measures of cardiorespiratory impairment, but these have proved inadequate. This study evaluated the predictive abilities of six preoperative variables: the global quality of life (QL), social function (SF), and emotional function (EF) scales of the European Organization for the Research and Treatment of Cancer's (EORTC) QLQ-C30 questionnaire, 6-min walk distance (6MWD), forced expiratory volume (FEV1), and diffusion capacity (DLCO). Operative outcome was represented by the surrogate measure length of stay, out of hospital within the first 30 days (LOSOH). A single-centre prospective cohort study evaluating 70 subjects was conducted using multiple regression. LOSOH was bimodally distributed, therefore analysis was undertaken for the entire sample and for two separate groups (A and B). Group B (n = 4) experienced severe complications (LOSOH = 0-5 days) and was too small for statistical analysis. Group A (n = 66) suffered fewer and less severe complications (LOSOH = 14-26 days). For the entire sample, age was the sole predictor of LOSOH (R2 = 0.123, p = 0.003). In Group A, the strongest predictors of LOSOH were global QL score and 6MWD (R2 = 0.224, p < 0.001). LOSOH was inversely correlated with complications. While it remains difficult to predict severe complications in this population, within Group A, health status measures demonstrated a limited ability to predict LOSOH.

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.

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 for pulmonary resection

Because of recent advances in anesthesia and surgery, almost any patient with a resectable lung malignancy is now an operative candidate, given a full understanding of the risks and provided he or she is investigated appropriately. This progress necessitates a change in the paradigm that one uses 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 then can be used to guide anesthetic management (Fig. 7).

Validation of an orthotopic model of human lung cancer with regional and systemic metastases

BACKGROUND

We developed an orthotopic model of human lung cancer that exhibits highly predictable regional and systemic metastases. This study examines the response of the model when treated with conventional and experimental chemotherapy.

METHODS

NCI-H460 tumor fragments were implanted into the right caudal lung lobe of a nude rat. Treatment commenced 2 weeks later. We assessed response by comparing primary tumor and mediastinal lymph node weights, total body weight, and length of survival with untreated, tumor-bearing control animals. We also calculated the incidence of metastasis to kidney, bone, brain, and contralateral lung in treated versus untreated animals.

RESULTS

Mitomycin and cisplatin showed broad activity against primary and metastatic disease. The matrix metalloproteinase inhibitor batimastat, low-dose cisplatin, and mitomycin significantly prolonged survival. High-dose cisplatin caused renal toxicity that shortened survival. Brain metastases did not respond to mitomycin, consistent with its poor blood-brain barrier penetration.

CONCLUSIONS

Responses were similar to NCI-H460 in vitro data and consistent with clinical experience for these drugs. Drug-related toxicities similar to those seen in clinical practice were detected.

The biology of some intraerythrocytic parasites of fishes, amphibia and reptiles

Fishes, amphibia and reptiles, the ectothermic vertebrates, are hosts for a variety of intraerythrocytic parasites including protists, prokaryotes, viruses and structures of uncertain status. These parasites may experience host temperature fluctuations, host reproductive strategies, population genetics, host habitat and migratory behaviour quite unlike those of endothermic hosts. Few blood infections of fishes, amphibia and reptiles have proven pathogenicity, in contrast to the many intraerythrocytic parasites of mammals and some birds which harm their hosts. Although not given the attention afforded to intraerythrocytic parasites of endotherms, those of ectotherms have been studied for more than a century. This review reports on the diversity, general biology and phylogeny of intraerythrocytic parasites of ectotherms. The existence of taxonomic confusion is emphasized and the main taxonomic features of most of the 23 better characterized genera, particularly the kinetoplastid and apicomplexan protists, are summarized. Transmission of protistan infections of aquatic ectotherms is also discussed. Leeches can transfer sporozoties or merozoites to the vertebrate host during feeding. Dormant sporozoites of Lankesterella may permit transmission of species of this genus between vertebrates by predation. The fish haemogregarine, Haemogregarina bigemina, probably has gnathiid isopods, rather than leeches, as its definitive hosts. Hepatozoon spp. in aquatic hosts, and Progarnia of caiman, may also use invertebrate hosts other than leeches. Protistan infections of terrestrial or semi-terrestrial hosts are transmitted by a variety of arthropods, or, in some cases, leeches, contaminated paratenic hosts, or sporocysts free in water. Transfer of protists between vertebrates by predation and congenitally may also occur. The biology of the host cells of these infections, the red blood cells of ectotherm vertebrates, is summarized and compared with that of mammalian erythrocytes. Erythropoiesis, the nature of the surface molecules (especially the possible existence of a major histocompatibility complex), the haemoglobins, and the shape and size of erythrocytes are discussed. The exoerythrocytic sites in which protists, prokaryotes, viruses and structures of uncertain status exist before erythrocyte entry are described. Tissue merogony, tissue cysts and invasion of the white cell series occur in a variety of protistan infections. Intraerythrocytic stages of protistan infections are also discussed, including modes of entry to erythrocytes, survival mechanisms, and multiplication. The impact of infection on host populations is difficult to assess, in part because there is no agreement in the literature on the criteria used to evaluate parasite-induced cost to the host. Almost all studies have been on haemogregarine and Plasmodium infections in, mainly, lizards, but also fishes and snakes. Some infections may be responsible for mortality in their hosts, but hosts themselves may be short-lived, or have a limited ability to recover from infection.

A study of smoking, p53 tumor suppressor gene alterations and non-small cell lung cancer

PURPOSE

The purpose of this study was to investigate the relationship between smoking and p53 tumor suppressor gene alterations, and their association with clinicopathologic features and prognosis in non-small cell lung cancer (NSCLC).

METHODS

For 111 of 119 stage I-III NSCLC patients that had been followed prospectively, tumor p53 protein accumulation was measured immunohistochemically (IHC). Staining was evaluated as a score (p53IHCS) combining intensity and percent distribution.

RESULTS

Forty-eight of 111 (43%) tumors had p53IHCS > 1. p53 IHC was associated with increasing tumor size (T) (p = 0.035), nodal status (N) (p = 0.091), stage (p = 0.054), and histology: squamous cell carcinoma (70%) and adenocarcinoma (27%) (p = 0.0002). In logistic regression analysis, p53 IHC was associated with squamous cell histology versus other histotypes [adjusted odds ratio (OR)5.90, 95% confidence interval (CI) 2.34-14.90]. p53 IHC was not associated with smoking variables. In multivariate proportional hazards analysis, p53IHCS and pack-years smoked (PY), both as continuous variables, were negative prognostic factors. The adjusted hazard ratios (HR) for the survival outcome recurrence for p53IHCS and PY were 1.20 (95% CI 1.02-1.40) and 1.03 (95% CI 1.01-1.04), and for death due to recurrent disease (DRD) were 1.35 (95% CI 1.11-1.64) and 1.03 (95% CI 1.01-1.04), respectively. Comparing the 75th percentile to the baseline 0, the adjusted HR for p53IHCS (5 vs. 0) was 4.5 and for PY (55 vs. 0) was 5.1 for the outcome DRD. Both variables demonstrated a dose-response relationship with survival.

CONCLUSIONS

PY and p53IHCS are significant, independent and important predictors of recurrence and DRD in stage I-III NSCLC.