Screening for lung cancer with low-dose spiral computed tomography

Screening for lung cancer: challenges for the thoracic surgeon

Lung cancer is a global health burden and is among the most common and deadly of all malignancies worldwide. Early detection of resectable and potentially curable disease may reduce the overall death rate from lung cancer. However, at the present time, screening for lung cancer is not recommended by most clinical societies and health care agencies in the United States. This article discusses the history of, and rationale for, lung cancer screening, addresses optimization of screening protocols, and describes our current approach for the evaluation of small pulmonary nodules referred for surgical management.

Scientific frontiers: emerging technologies for salivary diagnostics

Saliva, a biofluid historically well-studied biochemically and physiologically, has entered the post-genomic 'omics' era, where its proteomic, genomic, and microbiome constituents have been comprehensively deciphered. The translational path of these salivary constituents has begun toward a variety of personalized individual medical applications, including early detection of cancer. Salivary diagnostics is a late-comer, but it is catching up where dedicated resources, like the Salivaomics Knowledge Base (SKB), now have taken center stage in the dissemination of the diagnostic potentials of salivary biomarkers and other translational and clinical utilities.

Small peripheral lung adenocarcinoma: CT and histopathologic characteristics and prognostic implications

Since the introduction of computed tomography (CT), detection of small lung cancer, especially small peripheral adenocarcinoma, is common. Recently, the morphological characteristics, including thin-section CT and pathologic findings, and prognosis of small peripheral lung adenocarcinomas have been studied extensively. The radiologic and microscopic findings correlate well with each other and are closely associated with tumour prognosis. Most importantly, some subtypes of small lung adenocarcinomas with specific CT or pathologic features are curable. Therefore, all defining characteristics (CT, pathologic and prognostic) of this kind of tumour should be integrated to improve our understanding, provide guidelines for management and accurately assess its prognosis.

Can computer assisted diagnosis (CAD) be used as a screening tool in the detection of pulmonary nodules when using 64-slice multidetector computed tomography?

OBJECTIVES

To evaluate (1) whether or not the addition of computer-assisted diagnosis (CAD) to 64-slice multidetector computed tomography (CT) can be used as a screening tool for detection of pulmonary nodules in routine CT chest examinations and (2) whether or not to advocate the incorporation of CAD as a screening tool into our daily practice.

MATERIALS AND METHODS

A retrospective cross-sectional analysis of 109 consecutive patients who had all undergone routine contrast-enhanced CT chest examinations for indications other than lung cancer at the Radiology Department of Aga Khan University Hospital, Karachi, between November 2010 and January 2011. All examinations were evaluated in terms of the detection of pulmonary nodules by a consultant radiologist and CAD (ImageChecker CT Algorithm R2 Technology) software. The ability of CAD software to detect pulmonary nodules was evaluated against the reference standard. In addition, a chest radiologist also calculated the number of pulmonary nodules. The sensitivity and specificity of the CAD software were calculated against the reference standard by using a 2 × 2 table. The Mann-Whitney U test was applied to compare the performances of CAD and the radiologist.

RESULTS

CAD detected 610 pulmonary nodules while the radiologist detected only 113. The reference standard declared 198 pulmonary nodules to be true nodules. CAD detected 95% of all true nodules (189/198), whereas the radiologist detected only 57% (113/198). In the detection of true pulmonary nodules, CAD had 98% sensitivity compared with the radiologist who had 57% sensitivity; the statistical difference between their performances had a P value <0.001.

CONCLUSION

Considering the high sensitivity of CAD to detect nearly all true pulmonary nodules, we advocate its application as a screening tool in all CT chest examinations for the early detection of pulmonary nodules and lung carcinoma.

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

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

Factors determining successful computed tomography-guided localization of lung nodules

OBJECTIVES

To investigate the factors related to the successful computed tomography-guided nodule localization for subsequent nodule excision.

METHODS

We retrospectively reviewed the medical records for 181 patients who had undergone computed tomography-guided nodule localization using hook wire and subsequent video-assisted thoracic surgery resection for lung nodules. The demographic factors, nodule factors, and technical factors were reviewed to determine what affects effective nodule localization for video-assisted thoracic surgery resection using both univariate and multivariate models.

RESULTS

A total of 174 patients were included in our study. Successful localization was accomplished in 166 patients (95%). Univariate analysis implicated patient age, nodule solidity, zonal location, and a sufficient distance between the hook wire tip and pleural surface as significant factors for successful localization. Multivariate analysis focused on the distance between the wire tip and pleural surface as the sole independent factor for successful localization (P = .012).

CONCLUSIONS

The distance between the hook wire tip and pleural surface was the major significant factor for successful computed tomography-guided nodule localization for subsequent video-assisted thoracic surgery resection. Thus, the localization of a hook wire adjacent to a target nodule with sufficient depth from the pleural surface is crucial to the success of the procedure.

Robust, standardized quantification of pulmonary emphysema in low dose CT exams

RATIONALE AND OBJECTIVES

The aim of this study was to present and evaluate a fully automated system for emphysema quantification on low-dose computed tomographic images. The platform standardizes emphysema measurements against changes in the reconstruction algorithm and slice thickness.

MATERIALS AND METHODS

Emphysema was quantified in 149 patients using a fully automatic, in-house developed software (the Robust Automatic On-Line Pulmonary Helper). The accuracy of the system was evaluated against commercial software, and its reproducibility was assessed using pairs of volume-corrected images taken 1 year apart. Furthermore, to standardize quantifications, the effect of changing the reconstruction parameters was modeled using a nonlinear fit, and the inverse of the model function was then applied to the data. The association between quantifications and pulmonary function testing was also evaluated. The accuracy of the in-house software compared to that of commercial software was measured using Spearman's rank correlation coefficient, the mean difference, and the intrasubject variability. Agreement between the methods was studied using Bland-Altman plots. To assess the reproducibility of the method, intraclass correlation coefficients and Bland-Altman plots were used. The statistical significance of the differences between the standardized data and the reference data (soft-tissue reconstruction algorithm B40f; slice thickness, 1 mm) was assessed using a paired two-sample t test.

RESULTS

The accuracy of the method, measured as intrasubject variability, was 3.86 mL for pulmonary volume, 0.01% for emphysema index, and 0.39 Hounsfield units for mean lung density. Reproducibility, assessed using the intraclass correlation coefficient, was >0.95 for all measurements. The standardization method applied to compensate for variations in the reconstruction algorithm and slice thickness increased the intraclass correlation coefficients from 0.87 to 0.97 and from 0.99 to 1.00, respectively. The correlation of the standardized measurements with pulmonary function testing parameters was similar to that of the reference (for the emphysema index and the obstructive subgroup: forced expiratory volume in 1 second, -0.647% vs -0.615%; forced expiratory volume in 1 second/forced vital capacity, -0.672% vs -0.654%; and diffusing capacity for carbon monoxide adjusted for hemoglobin concentration, -0.438% vs -0.523%).

CONCLUSIONS

The new emphysema quantification method presented in this report is accurate and reproducible and, thanks to its standardization method, robust to changes in the reconstruction parameters.

Growth rate of lung cancer recognized as small solid nodule on initial CT findings

INTRODUCTION

To study the characteristics of lung cancer, appearing as small solid nodules on initial computed tomography (CT) findings, and to determine an appropriate follow-up duration so as to differentiate between malignancy and benign tumor.

METHODS

We analyzed the records of 34 patients who had undergone surgical resection of lung cancer, which appeared as small solid nodules on initial CT findings. We studied the CT findings, volume doubling times (VDT), follow-up durations, pathological and clinical findings.

RESULTS

VDT is classified as follows: (1) slow growth group (SGG), with a VDT of more than 700 days and (2) rapid growth group (RGG), with a VDT of less than 700 days. The median VDT of the SGG was 1083 days, and the RGG was 256 days (p<0.01). The median duration for follow-up of the SGG was 1218 days, and 179 days for the RGG. A statistical difference was noted in the follow-up durations (p<0.01). There were no statistical differences in the preoperative thin-section CT (TSCT) findings, or in the pathological findings. The RGG included more patients with smoking histories. The CT findings of RGG tended to reveal changed in base lung field such as emphysema, and lung fibrosis.

CONCLUSIONS

Generally, lung cancer appearing as small solid nodules on initial CT findings grew rapidly, but there were some cases which displayed slow growth patterns. These cases required follow up for over two years, before diagnosis was possible. We concluded the appropriate maximum followup duration is three years.

Lung cancer at a University Hospital in Saudi Arabia: A four-year prospective study of clinical, pathological, radiological, bronchoscopic, and biochemical parameters

OBJECTIVES AND BACKGROUND

Lung cancer accounts for 4% of all newly diagnosed cancers in Saudi Arabia. The pattern of presentation is unknown. The objectives of this study were to assess the clinical, radiological, pathological, biochemical and bronchoscopic abnormalities in lung cancer patients and to compare our findings with those reported in the literature.

METHODS

A total of 114 patients with proven lung cancer were selected for the study. A questionnaire concerning patients' demographic data was obtained; the abnormalities and the cell types of lung cancer were recorded prospectively in each subject.

RESULTS

A total of 114 patients with lung cancer were studied. Mean age ± SD was (59.8 ± 10.8) years, and (71.1%) were smokers and 95.1% of them were male, (90.1%) smoked >20 pack/yr (96.2%) for 20 years or more. Cough (76.3%) and clubbing (40.4%) were the most common symptom and physical abnormality respectively. The right lung (64.9%) was more commonly affected than the left (37.7%). Metastases were present in (49.1%) at presentation. The right and left upper bronchi (24% vs. 16%) were the mostly affected. Hypercalcemia was more common in squamous cell, while hyponatremia was more common in adenocarcinoma, and small cell. Squamous cell carcinoma was the most common cell type (51.8%) and significantly associated with smoking (P ≤ 0.001)

CONCLUSION

Squamous cell carcinoma was the most common cell type, and significantly associated with smoking. The incidence of metastasis was high at presentation. The right lung and right upper bronchus were often affected. Hypercalcemia and hyponatremia were the most common biochemical abnormalities.

Inconsistencies in findings from the early lung cancer action project studies of lung cancer screening

Long-standing guidelines against screening high-risk individuals for lung cancer may change following the publication of the randomized National Lung Screening Trial (NLST), which shows a benefit of computed tomography compared with chest x-ray screening. Guideline panels will likely also seek additional information from nonrandomized studies of computed tomography screening, such as the Early Lung Cancer Action Project (ELCAP). However, for the ELCAP findings to be incorporated into new guidelines, some inconsistencies in the published data should first be resolved. Specifically, some of the reports from ELCAP appear to contradict others in terms of important endpoints, and several findings from ELCAP appear to be statistically improbable or outliers when compared with analyses and studies by other research groups. Clarification of both internal and external inconsistencies is a prerequisite for evaluation of the body of work published by ELCAP investigators.

Magnetic resonance imaging for lung cancer detection: experience in a population of more than 10,000 healthy individuals

BACKGROUND

Recent refinements of lung MRI techniques have reduced the examination time and improved diagnostic sensitivity and specificity. We conducted a study to assess the feasibility of MRI for the detection of primary lung cancer in asymptomatic individuals.

METHODS

A retrospective chart review was performed on images of lung parenchyma, which were extracted from whole-body MRI examinations between October 2000 and December 2007. 11,766 consecutive healthy individuals (mean age, 50.4 years; 56.8% male) were scanned using one of two 1.5-T scanners (Sonata and Sonata Maestro, Siemens Medical Solutions, Erlangen, Germany). The standard protocol included a quick whole-lung survey with T2-weighted 2-dimensional half Fourier acquisition single shot turbo spin echo (HASTE) and 3-dimensional volumetric interpolated breath-hold examination (VIBE). Total examination time was less than 10 minutes, and scanning time was only 5 minutes. Prompt referrals and follow-ups were arranged in cases of suspicious lung nodules.

RESULTS

A total of 559 individuals (4.8%) had suspicious lung nodules. A total of 49 primary lung cancers were diagnosed in 46 individuals: 41 prevalence cancers and 8 incidence cancers. The overall detection rate of primary lung cancers was 0.4%. For smokers aged 51 to 70 years, the detection rate was 1.4%. TNM stage I disease accounted for 37 (75.5%). The mean size of detected lung cancers was 1.98 cm (median, 1.5 cm; range, 0.5-8.2 cm). The most histological types were adenocarcinoma in 38 (77.6%).

CONCLUSION

Rapid zero-dose MRI can be used for lung cancer detection in a healthy population.

An epigenetic marker panel for detection of lung cancer using cell-free serum DNA

PURPOSE

We investigated the feasibility of detecting aberrant DNA methylation of some novel and known genes in the serum of lung cancer patients.

EXPERIMENTAL DESIGN

To determine the analytic sensitivity, we examined the tumor and the matched serum DNA for aberrant methylation of 15 gene promoters from 10 patients with primary lung tumors by using quantitative methylation-specific PCR. We then tested this 15-gene set to identify the more useful DNA methylation changes in the serum of a limited number of lung cancer patients and controls. In an independent set, we tested the six most promising genes (APC, CDH1, MGMT, DCC, RASSF1A, and AIM1) for further elucidation of the diagnostic application of this panel of markers.

RESULTS

Promoter hypermethylation of at least one of the genes studied was detected in all 10 lung primary tumors. In majority of cases, aberrant methylation in serum DNA was accompanied by methylation in the matched tumor samples. In the independent set, using a single gene that had 100% specificity (DCC), 35.5% (95% CI: 25-47) of the 76 lung cancer patients were correctly identified. For patients without methylated DCC, addition of a logistic regression score that was based on the five remaining genes improved sensitivity from 35.5% to 75% (95% CI: 64-84) but decreased the specificity from 100% to 73% (95% CI: 54-88).

CONCLUSION

This approach needs to be evaluated in a larger test set to determine the role of this gene set in early detection and surveillance of lung cancer.

Evaluation of reader variability in the interpretation of follow-up CT scans at lung cancer screening

PURPOSE

To measure reader agreement in determining whether lung nodules detected at baseline screening computed tomography (CT) had changed at subsequent screening examinations and to evaluate the variability in recommendations for further follow-up.

MATERIALS AND METHODS

All subjects were enrolled in the National Lung Screening Trial (NLST), and each participant consented to the use of their de-identified images for research purposes. The authors randomly selected 100 cases of nodules measuring at least 4.0 mm at 1-year screening CT that were considered by the original screening CT reader to be present on baseline CT scans; nodules considered by the original reader to have changed were oversampled. Selected images from each case showing the entire nodule at both examinations were preloaded on a picture archiving and communication system workstation. Nine radiologists served as readers, and they evaluated whether the nodule was present at baseline and recorded the bidimensional measurements and nodule characteristics at each examination, presence or absence of change, results of screening CT, and follow-up recommendations (high-level follow-up, low-level follow-up, no follow-up).

RESULTS

On the basis of reviews during case selection, five nodules seen at follow-up were judged not to have been present at baseline; for 19 of the remaining 95 cases, at least one reader judged the nodule not to have been present at baseline. For the 76 nodules that were unanimously considered to have been present at baseline, 21%-47% (mean ± standard deviation, 30% ± 9) were judged to have grown. The κ values were similar for growth (κ = 0.55) and a positive screening result (κ = 0.51) and were lower for a change in margins and attenuation (κ = 0.27-0.31). The κ value in the recommendation of high- versus low-level follow-up was high (κ = 0.66).

CONCLUSION

Reader agreement on nodule growth and screening result was moderate to substantial. Agreement on follow-up recommendations was lower.

Small-cell lung cancer-associated autoantibodies: potential applications to cancer diagnosis, early detection, and therapy

Small-cell lung cancer (SCLC) is the most aggressive lung cancer subtype and lacks effective early detection methods and therapies. A number of rare paraneoplastic neurologic autoimmune diseases are strongly associated with SCLC. Most patients with such paraneoplastic syndromes harbor high titers of antibodies against neuronal proteins that are abnormally expressed in SCLC tumors. These autoantibodies may cross-react with the nervous system, possibly contributing to autoimmune disease development. Importantly, similar antibodies are present in many SCLC patients without autoimmune disease, albeit at lower titers. The timing of autoantibody development relative to cancer and the nature of the immune trigger remain to be elucidated. Here we review what is currently known about SCLC-associated autoantibodies, and describe a recently developed mouse model system of SCLC that appears to lend itself well to the study of the SCLC-associated immune response. We also discuss potential clinical applications for these autoantibodies, such as SCLC diagnosis, early detection, and therapy.

Dose reduction strategies for thoracic multidetector computed tomography: background, current issues, and recommendations

This review will summarize the current background knowledge about radiation exposure related to thoracic computed tomography (CT). It will also review the historical development in this area. This will be followed by a summary of current efforts to reduce dose with respect to predefined clinical indications. Finally, the review will indicate future strategies for further dose reduction in thoracic CT imaging and give practical recommendations for everyday use.

Modeling the mortality reduction due to computed tomography screening for lung cancer

BACKGROUND

The efficacy of computed tomography (CT) screening for lung cancer remains controversial because results from the National Lung Screening Trial are not yet available. In this study, the authors used data from a single-arm CT screening trial to estimate the mortality reduction using a modeling-based approach to construct a control comparison arm.

METHODS

To estimate the potential lung cancer mortality reduction because of CT screening, a previously developed and validated model was applied to the screening trial to predict the number of lung cancer deaths in the absence of screening. By using age, gender, and smoking characteristics matching those of the trial participants, the model was used to simulate 5000 trials in the absence of CT screening to produce the expected number of lung cancer deaths along with 95% confidence intervals (95% CIs), while adjusting for healthy volunteer bias.

RESULTS

There were 64 observed lung cancer deaths in the screening cohort (n = 7995), whereas the model predicted 117.7 deaths (95% CI, 98 deaths-139 deaths), indicating a mortality reduction of 45.6% (P < .001). When a more conservative healthy volunteer adjustment was applied, 111.3 lung cancer deaths were predicted (95% CI, 91 deaths-132 deaths), for a lung cancer-specific mortality reduction of 42.5% (P < .001).

CONCLUSIONS

The results of the current study indicate that CT screening along with early stage treatment can reduce lung cancer-specific mortality. This mortality reduction is greatly influenced by the protocol of nodule follow-up and treatment, and the length of follow-up.

Unlocking biomarker discovery: large scale application of aptamer proteomic technology for early detection of lung cancer

Background

Lung cancer is the leading cause of cancer deaths worldwide. New diagnostics are needed to detect early stage lung cancer because it may be cured with surgery. However, most cases are diagnosed too late for curative surgery. Here we present a comprehensive clinical biomarker study of lung cancer and the first large-scale clinical application of a new aptamer-based proteomic technology to discover blood protein biomarkers in disease.

Methodology/Principal Findings

We conducted a multi-center case-control study in archived serum samples from 1,326 subjects from four independent studies of non-small cell lung cancer (NSCLC) in long-term tobacco-exposed populations. Sera were collected and processed under uniform protocols. Case sera were collected from 291 patients within 8 weeks of the first biopsy-proven lung cancer and prior to tumor removal by surgery. Control sera were collected from 1,035 asymptomatic study participants with ≥10 pack-years of cigarette smoking. We measured 813 proteins in each sample with a new aptamer-based proteomic technology, identified 44 candidate biomarkers, and developed a 12-protein panel (cadherin-1, CD30 ligand, endostatin, HSP90α, LRIG3, MIP-4, pleiotrophin, PRKCI, RGM-C, SCF-sR, sL-selectin, and YES) that discriminates NSCLC from controls with 91% sensitivity and 84% specificity in cross-validated training and 89% sensitivity and 83% specificity in a separate verification set, with similar performance for early and late stage NSCLC.

Conclusions/Significance

This study is a significant advance in clinical proteomics in an area of high unmet clinical need. Our analysis exceeds the breadth and dynamic range of proteome interrogated of previously published clinical studies of broad serum proteome profiling platforms including mass spectrometry, antibody arrays, and autoantibody arrays. The sensitivity and specificity of our 12-biomarker panel improves upon published protein and gene expression panels. Separate verification of classifier performance provides evidence against over-fitting and is encouraging for the next development phase, independent validation. This careful study provides a solid foundation to develop tests sorely needed to identify early stage lung cancer.

Screening for lung cancer with low-dose computed tomography: a systematic review and meta-analysis of the baseline findings of randomized controlled trials

OBJECTIVES

Lung cancer is the leading cause of death among all cancers. An estimated 29% of the global population older than 15 years currently smokes tobacco. The presence of a high risk population, relatively asymptomatic nature of the disease in the early phase, and relatively good prognosis when discovered early makes screening for lung cancer an attractive proposition. We performed a systematic review and a meta-analysis of the baseline results of randomized controlled trials so far published, which included more than 14,000 patients. Analysis was used to determine whether data was for or against the screening of lung cancers using low-dose computed tomography (LDCT).

DESIGN

Random effect meta regression model of meta-analysis and systematic review.

METHODS

We performed a systematic review and a meta-analysis of the current literature to determine whether screening for lung cancer in a high-risk population with computed tomography improves outcomes. A search strategy using Medline was employed, studies selected based on preset criteria and application of exclusion criteria, and data collected and analyzed for statistical significance.

RESULTS

Screening for lung cancer using LDCT resulted in a significantly higher number of stage I lung cancers (odds ratio 3.9, 95% confidence interval [CI] 2.0-7.4), higher number of total non-small cell lung cancers (odds ratio 5.5, 95% CI 3.1-9.6), and higher total lung cancers (odds ratio 4.1, 95% CI 2.4-7.1). Screening using LDCT also resulted in increased detection of false-positive nodules (odds ratio 3.1, 95% CI 2.6-3.7) and more unnecessary thoracotomies for benign lesions (event rate 3.7 per 1000, 95% CI 3.5-3.8). For every 1000 individuals screened with LDCT for lung cancer, 9 stage I non-small cell lung cancer and 235 false-positive nodules were detected, and 4 thoracotomies for benign lesions were performed.

CONCLUSIONS

The baseline data from six randomized controlled trials offer no compelling data in favor or against the use of LDCT screening for lung cancer. We await the final results of these randomized controlled trials to improve our understanding of the effectiveness of LDCT in the screening for lung cancer and its effect on mortality.

The National Lung Screening Trial: overview and study design

The National Lung Screening Trial (NLST) is a randomized multicenter study comparing low-dose helical computed tomography (CT) with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer, which is the leading cause of cancer-related death in the United States. Five-year survival rates approach 70% with surgical resection of stage IA disease; however, more than 75% of individuals have incurable locally advanced or metastatic disease, the latter having a 5-year survival of less than 5%. It is plausible that treatment should be more effective and the likelihood of death decreased if asymptomatic lung cancer is detected through screening early enough in its preclinical phase. For these reasons, there is intense interest and intuitive appeal in lung cancer screening with low-dose CT. The use of survival as the determinant of screening effectiveness is, however, confounded by the well-described biases of lead time, length, and overdiagnosis. Despite previous attempts, no test has been shown to reduce lung cancer mortality, an endpoint that circumvents screening biases and provides a definitive measure of benefit when assessed in a randomized controlled trial that enables comparison of mortality rates between screened individuals and a control group that does not undergo the screening intervention of interest. The NLST is such a trial. The rationale for and design of the NLST are presented.

Consequences of screening in lung cancer: development and dimensionality of a questionnaire

OBJECTIVE

The objective of this study was to extend the Consequences of Screening (COS) Questionnaire for use in a lung cancer screening by testing for comprehension, content coverage, dimensionality, and reliability.

METHODS

In interviews, the suitability, content coverage, and relevance of the COS were tested on participants in a lung cancer screening program. The results were thematically analyzed to identify the key consequences of abnormal and false-positive screening results. Item Response Theory and Classical Test Theory were used to analyze data. Dimensionality, objectivity, and reliability were established by item analysis, examining the fit between item responses and Rasch models.

RESULTS

Eight themes specifically relevant for participants in lung cancer screening results were identified: "self-blame,""focus on symptoms,""stigmatization,""introvert,""harm of smoking,""impulsivity,""empathy," and "regretful of still smoking." Altogether, 26 new items for part I and 16 new items for part II were generated. These themes were confirmed to fit a partial-credit Rasch model measuring different constructs including several of the new items.

CONCLUSION

In conclusion, the reliability and the dimensionality of a condition-specific measure with high content validity for persons having abnormal or false-positive lung cancer screening results have been demonstrated. This new questionnaire called Consequences of Screening in Lung Cancer (COS-LC) covers in two parts the psychosocial experience in lung cancer screening. Part I: "anxiety,""behavior,""dejection,""sleep,""self-blame,""focus on airway symptoms,""stigmatization,""introvert," and "harm of smoking." Part II: "calm/relax,""social network,""existential values,""impulsivity,""empathy," and "regretful of still smoking."

Lung cancer-associated auto-antibodies measured using seven amino acid peptides in a diagnostic blood test for lung cancer

Autoantibody profiling is a developing approach that incorporates immune recognition of myriad aberrant cancer proteins into a single diagnostic assay. We have previously described methodology to screen T7-phage NSCLC-cDNA libraries for phage-expressed proteins recognized by NSCLC-associated antibodies, and developed a multiplex assay that has excellent ability to discriminate NSCLC from control samples. This follow-up report describes the development and testing of a diagnostic autoantibody assay that uses seven amino-acid peptides as capture proteins. A random-peptide M13-phage library was screened for proteins recognized by cancer-associated antibodies. One hundred twenty-one NSCLC case and control samples were divided into two groups for training and validation, or alternately, evaluated sequentially in a leave-one-out analysis. Candidate antibody-markers were ranked by statistical discrimination between cases and controls. Receiver-Operating-Characteristic (ROC-AUC) suggested the predictive potential of various marker combinations. A five-marker combination (AUC = 0.982) afforded 90% sensitivity and 73% specificity in a training-and-testing strategy. Leave-one-out validation provided similar class prediction. Data confirm the potential of antibody profiling to provide high levels of cancer prediction. Random peptide libraries offer a universal source of capture proteins for antibody profiling that obviates the need for tumor-specific library construction and abrogates inherent problems with tumor heterogeneity during biomarker discovery.

Pulmonary nodules in workers exposed to urban stressor

By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM(10), NO2 and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid suspicious lung nodules. In conclusion, the use of chest LD-CT in workers at risk helps identify suspicious solid lung nodules at early stage.

Evaluation of a method of computer-aided detection (CAD) of pulmonary nodules with computed tomography

PURPOSE

The authors sought to compare the sensitivity and reading time obtained using computer-aided detection (CAD) software as second reader (SR) or concurrent reader (CR) in the identification of pulmonary nodules.

MATERIALS AND METHODS

Unenhanced CT scans of 100 consecutive cancer patients were retrospectively reviewed by four readers to identify all solid, noncalcified pulmonary nodules ranging from 3 to 30 mm in diameter. The sensitivity and reading time of each reader and of CAD alone were calculated at 3-mm and 5-mm thresholds with respect to the reference standard, consisting of a consensus reading by the four radiologists involved in the study. The McNemar test was used to compare the sensitivities obtained by reading without CAD (readers 1 and 2), with CAD as SR (readers 1 and 2 with a 2-month delay), and with CAD as CR (readers 3 and 4). The paired Student's t test was used to compare reading times. A value of p<0.05 was considered statistically significant.

RESULTS

A total of 258 and 224 nodules were identified at 3-mm and 5-mm thresholds, respectively. The sensitivity of CAD alone was 62.79% and 67.41% at the 3-mm and 5-mm threshold values respectively, with 4.15 and 2.96 false-positive findings per examination. CAD as SR produced a significant increase in sensitivity (p<0.001) in nodule detection with respect to reading without CAD both at 3 mm (12.01%) and 5 mm (10.04%); the average increase in sensitivity obtained when comparing CAD as SR to CAD as CR was statistically significant (p<0.025) both at the 3-mm (5.35%) and 5-mm (4.68%) thresholds. CAD as CR produced a nonsignificant increase in sensitivity compared with reading without CAD (p>0.05). Mean reading time using CAD as SR (330 s) was significantly longer than reading without CAD (135 s, p<0.001) and reading with CAD as CR (195 s, p<0.025).

CONCLUSIONS

The use of CAD as CR, without any significant increase in reading time, produces no significant increase in sensitivity in pulmonary nodule detection when compared with reading without CAD (p>0.05); CAD as SR, at the cost of longer reading times, increases sensitivity when compared with reading without CAD (p<0.001) or with CAD as CR (p<0.025).

Lung cancer: Morphological and functional approach to screening, staging and treatment planning

Lung cancer is a major problem in public health and constitutes the leading cause of cancer-related mortality in the world. Lung cancer screening with low-dose computed tomography is promising but needs to overcome many difficulties, such as the large number of incidentally discovered nodules, the radiation dose delivered to the patient during a whole screening program and its cost. The ultimate target point represented by the reduction of lung cancer-related mortality needs to be proved in large, well-designed, randomized, multicenter, prospective trials. Lung cancer staging by morphological tools seems to be limited owing to the presence of metastases in normal-sized lymph nodes. In this context, multidetector computed tomography cannot be used alone but is useful in conjunction with molecular imaging and MRI. Today, flurodeoxglucose PET-CT appears to be the most accurate method for lung cancer staging and may prevent unnecessary thoracotomies. For treatment planning, flurodeoxglucose PET-CT is playing an increasing role in radiotherapy planning at the target selection and definition steps.

Tgf-beta signaling pathway in lung adenocarcinoma invasion

The histologic distinction between bronchioloalveolar carcinoma and other adenocarcinomas is tissue invasion. The clinical importance of lung adenocarcinoma invasion is supported by several recent studies indicating that the risk of death in nonmucinous bronchioloalveolar carcinoma is significantly lower than that of pure invasive tumors and in tumors with greater than 0.5 cm of fibrosis or linear invasion. Using microarray gene expression profiling of human tumors, dysregulation of transforming growth factor-beta signaling was identified as an important mediator of tumor invasion. Subsequent studies showed that the CC chemokine regulated on activation, normal T cell expressed, and presumably secreted was up-regulated in invasive tumors and was required for invasion in cells with repressed levels of the transforming growth factor-beta type II receptor. Taken together, these studies illustrate how information gained from global expression profiling of tumors can be used to identify key pathways and genes mediating tumor growth, invasion, and metastasis.

Assessing the impact of incidental findings in a lung cancer screening study by using low-dose computed tomography

PURPOSE

To assess the prevalence and nature of incidental findings (IF) seen in low-dose computed tomographies (LDCT) from a lung cancer screening study for at-risk individuals.

MATERIALS AND METHODS

Radiology reports from LDCTs of 4073 participants of a lung cancer screening study were retrospectively reviewed for findings other than lung nodules, that is, IFs, which were regarded as actionable. The frequency, nature, and expected cost of these IFs, and their anticipated follow-up were estimated.

RESULTS

There were 880 IFs described in 782 study participants (19%); the median age of the participants was 62 years (range, 46-80 years). More IFs were found in men (55%) than in women. The majority of these findings were noncardiovascular (76%), for which imaging was suggested for 74%. There were 7 severe IFs (0.8%) that merited immediate attention. Seven known cancers were diagnosed from follow-ups of the IFs. The majority of IFs (n = 486 [55%]) would require imaging follow-up if clinically indicated, with an estimated total a cost of CAN$45,500 to CAN$51,000 to provide initial diagnostic workup.

CONCLUSION

IFs on lung cancer screening studies are not uncommon and frequently require imaging or other follow-up for definitive diagnoses and to assess their clinical relevance. The implication of IFs has to be considered when determining a cost-effective and ethical protocol for the utilisation of LDCT in a high-risk population.

Low-dose volumetric computed tomography for quantification of emphysema in asymptomatic smokers participating in an early lung cancer detection trial

PURPOSE

High-resolution computed tomography (CT) is a validated method to quantify the extent of pulmonary emphysema. In this study, we assessed the reliability of low-dose volumetric CT (LDCT) for the quantification of emphysema and its correlation with spirometric indices of airway obstruction.

MATERIALS AND METHODS

The study population consisted of 102 consecutive current and former smokers participating in a lung cancer screening trial. All subjects underwent spirometry testing and LDCT at entry and a LDCT after 12 months. The extent of emphysema was estimated by 2 techniques; by using the lung attenuation threshold analysis and by visual assessment of the 2 independent radiologists. The reproducibility of these determinations was assessed using test-retest reliability and kappa coefficient of agreement. The correlation of LDCT-based emphysema determinations with indices of airway obstruction on spirometry was also calculated.

RESULTS

Eighty percent of the participants were male, with a mean (standard deviation) age of 54.5 (7.5) years, and median pack-years (interquartile range) of 20 (24). Test-retest reliability of all LDCT-based emphysema determinations was very good (intraclass correlation coefficient of 0.92 for the volume of emphysema, and 0.93 for the emphysema index or emphysema volume/total lung volume). Similarly, there was an excellent interrater agreement for visual assessment of emphysema (kappa coefficient=0.91). Higher volumes of emphysema measured quantitatively or visually significantly correlated with spirometric markers of airway obstruction.

CONCLUSIONS

Volumetric LDCT is a reliable and valid technique for the quantification of emphysema in asymptomatic smokers.

Epidermal growth factor receptor mutation and pathologic-radiologic correlation between multiple lung nodules with ground-glass opacity differentiates multicentric origin from intrapulmonary spread

INTRODUCTION

No standard guidelines detailing recommendations for the selection and treatment for multiple lung nodules with ground-glass opacity (GGO) have been established. For treatment decision, we analyzed epidermal growth factor receptor (EGFR)/K-ras somatic aberrations and pathologic-radiologic correlation in multiple lung nodules presented as GGO to differentiate multifocal lesions from intrapulmonary spread.

METHODS

Twenty-four patients with multiple lung nodules presented as GGO were identified to investigate somatic mutations of EGFR (exon 18-21) and K-ras (codons 2, 13, and 61). This series included 18 atypical adenomatous hyperplasias (AAH), 15 bronchioloalveolar carcinomas (BAC), and 23 adenocarcinomas (ADC) obtained from 24 patients.

RESULTS

High frequency of discordant EGFR mutations (17 of 24, 70.8%) could discriminate tumor clonality (18 of 24, 75%) of multiple lung neoplastic nodules presented as GGO. EGFR mutations were common in AAH (38.9%), BAC (46.7%), and ADC (39.1%). In case 4, AAH and BAC had different mutational changes, and in case 10, the BAC lesion contains EGFR mutation that is not in the invasive ADC. In case 17, the BAC had more mutational changes than the carcinoma. The pure GGO appearance in the radiologic examination corresponded preinvasive pathologic change.

CONCLUSIONS

This study showed that synchronous BAC and/or ADC can have different EGFR or K-ras mutational profiles suggesting these lesions arise as independent events rather than intrapulmonary spread or systemic metastasis. This has significant implication in staging and treatment. These findings might be a clue to establish guidelines of the multiple neoplastic lung nodules with GGO.

The reduction of image noise and streak artifact in the thoracic inlet during low dose and ultra-low dose thoracic CT

Increased pixel noise and streak artifact reduce CT image quality and limit the potential for radiation dose reduction during CT of the thoracic inlet. We propose to quantify the pixel noise of mediastinal structures in the thoracic inlet, during low-dose (LDCT) and ultralow-dose (uLDCT) thoracic CT, and assess the utility of new software (quantum denoising system and BOOST3D) in addressing these limitations. Twelve patients had LDCT (120 kV, 25 mAs) and uLDCT (120 kV, 10 mAs) images reconstructed initially using standard mediastinal and lung filters followed by the quantum denoising system (QDS) to reduce pixel noise and BOOST3D (B3D) software to correct photon starvation noise as follows: group 1 no QDS, no B3D; group 2 B3D alone; group 3 QDS alone and group 4 both QDS and B3D. Nine regions of interest (ROIs) were replicated on mediastinal anatomy in the thoracic inlet, for each patient resulting in 3456 data points to calculate pixel noise and attenuation. QDS reduced pixel noise by 18.4% (lung images) and 15.8% (mediastinal images) at 25 mAs. B3D reduced pixel noise by approximately 8% in the posterior thorax and in combination there was a 35.5% reduction in effective radiation dose (E) for LDCT (1.63-1.05 mSv) in lung images and 32.2% (1.55-1.05 mSv) in mediastinal images. The same combination produced 20.7% reduction (0.53-0.42 mSv) in E for uLDCT, for lung images and 17.3% (0.51-0.42) for mediastinal images. This quantitative analysis of image quality confirms the utility of dedicated processing software in targeting image noise and streak artifact in thoracic LDCT and uLDCT images taken in the thoracic inlet. This processing software potentiates substantial reductions in radiation dose during thoracic LDCT and uLDCT.

The LoG characteristic scale: a consistent measurement of lung nodule size in CT imaging

Nodule growth as observed in computed tomography (CT) scans acquired at different times is the primary feature to malignancy of indeterminate small lung nodules. In this paper, we propose the estimation of nodule size through a scale-space representation which needs no segmentation and has high intra- and inter-operator reproducibility. Lung nodules usually appear in CT images as blob-like patterns and can be analyzed in the scale-space by Laplacian of Gaussian ( LoG ) kernels. For each nodular pattern the LoG scale-space signature was computed and the related characteristic scale adopted as measurement of nodule size. Both in vitro and in vivo validation of LoG characteristic scale were carried out. In vitro validation was done by 40 nondeformable phantoms and 10 deformable phantoms. A close relationship between the characteristic scale and the equivalent diameter, i.e., the diameter of the sphere having the same volume of nodules, (Pearson correlation coefficient was 0.99) and, for nodules undergoing little deformations (obtained at constant volume), small variability of the characteristic scale was observed. The in vivo validation was performed on low and standard-dose CT scans collected from the ITALUNG screening trial (86 nodules) and from the LIDC public data set (89 solid nodules and 40 part-solid nodules or ground-glass opacities). The Pearson correlation coefficient between characteristic scale and equivalent diameter was 0.83-0.93 for ITALUNG and 0.68-0.83 for LIDC data set. Intra- and inter-operator reproducibility of characteristic scale was excellent: on a set of 40 lung nodules of ITALUNG data, two radiologists produced identical results in repeated measurements. The scan-rescan variability of the characteristic scale was also investigated on 86 two-year-stable solid lung nodules (each one observed, on average, in four CT scans) identified in the ITALUNG screening trial: a coefficient of repeatability of about 0.9 mm was observed. Experimental evidence supports the clinical use of the LoG characteristic scale to measure nodule size in CT imaging.

Lung cancer screening--are we there yet?

BACKGROUND

Lung cancer is the most lethal cancer and most cases are the result of cigarette smoking. Although a high risk target population for screening can be defined, and although early stage lung cancer has a much better prognosis than advanced disease, there is still no clear evidence that lung cancer screening decreases mortality. Accordingly, current guidelines suggest that there is no evidence to support routine screening. Although randomized studies in the 1970('s) which used chest x-ray and sputum for screening were clearly negative in the last 20 years more sensitive screening tools such as chest computed tomography have revolutionized the field. However, randomized controlled trials of computed tomography have only recently been launched. AIMS OF THIS REVIEW: Our objectives are to provide the reader with the rationale for screening for lung cancer, to review the older screening studies and their limitations, and to summarize the current knowledge and ongoing trials of lung cancer screening.

LITERATURE SEARCH

A literature search using Medline was conducted from 1966 onwards searching for articles with relevant key words such as lung cancer screening chest X - ray low dose computerized tomography cancer screening guideline. When appropriate additional references were found from the bibliographies of identified papers of interest.

CONCLUSIONS

Recent uncontrolled multicenter studies of chest computed tomography scans show encouraging results. However, until data from, large properly designed and appropriately analyzed randomized controlled trials which may overcome research biases is available, the benefit of lung cancer screening, if any is still unknown.

An up to date look at lung cancer screening

Lung cancer is the leading cause of cancer-related death worldwide. At the time of initial presentation, most patients are at an advance stage of disease and have a poor associated prognosis. Those diagnosed and treated at earlier stages have a significantly better outcome with 5-year survival for stage I disease approaching 75%. Ideally a screening strategy for lung cancer would detect disease at an earlier stage and allow for potential surgical cure. The purpose of this review is to examine past and current evidence as it relates to lung cancer screening.

Extracardiac findings in cardiac computed tomographic angiography in patients at low to intermediate risk for coronary artery disease

PURPOSE

To evaluate the prevalence, clinical significance, interobserver agreement, and follow-up of extracardiac findings on coronary computed tomographic angiography (CTA).

METHODS

A prospectively recruited cohort of 80 patients at low to intermediate risk of having coronary artery disease underwent CTA with field of view imaging from lung apices to upper abdomen. Two staff radiologists read each scan independently. Scans read by reader no. 1 were read as part of routine clinical practice, and the findings were subsequently reclassified to potentially significant, as defined by requiring clinical or radiologic follow-up, and insignificant by a separate observer, whereas reader no. 2 retrospectively read and autonomously classified the findings as potentially significant or insignificant.

RESULTS

Reader no. 1 found 7 potentially significant findings in 7 patients and 33 insignificant findings in 29 patients. Reader no. 2 found 10 potentially significant findings in 10 patients and 59 insignificant findings in 42 patients. Inter-rater agreement was moderate (kappa = 0.49; 95% confidence interval, 0.31-0.67) for the presence vs the absence of extracardiac findings and moderate (kappa = 0.52; 95% confidence interval, 0.15-0.89) for the presence of potentially significant extracardiac findings. The most common potentially significant finding was possibly malignant lung nodule (n = 6 [reader 1], 4 [reader 2]). Four patients with potentially significant findings received follow-up imaging, and 1 patient underwent biopsy, which was complicated by pneumothorax. No diagnoses of malignancy were made.

CONCLUSIONS

Extracardiac findings are frequent and moderately reproducible, however, in this study, not associated with clinical benefit. Large prospective studies are required to establish whether reporting of extracardiac findings is associated with improved patient outcomes.

Enhanced CT images by the wavelet transform improving diagnostic accuracy of chest nodules

The objective of this study was to compare the diagnostic accuracy in the interpretation of chest nodules using original CT images versus enhanced CT images based on the wavelet transform. The CT images of 118 patients with cancers and 60 with benign nodules were used in this study. All images were enhanced through an algorithm based on the wavelet transform. Two experienced radiologists interpreted all the images in two reading sessions. The reading sessions were separated by a minimum of 1 month in order to minimize the effect of observer's recall. The Mann-Whitney U nonparametric test was used to analyze the interpretation results between original and enhanced images. The Kruskal-Wallis H nonparametric test of K independent samples was used to investigate the related factors which could affect the diagnostic accuracy of observers. The area under the ROC curves for the original and enhanced images was 0.681 and 0.736, respectively. There is significant difference in diagnosing the malignant nodules between the original and enhanced images (z = 7.122, P < 0.001), whereas there is no significant difference in diagnosing the benign nodules (z = 0.894, P = 0.371). The results showed that there is significant difference between original and enhancement images when the size of nodules was larger than 2 cm (Z = -2.509, P = 0.012, indicating the size of the nodules is a critical evaluating factor of the diagnostic accuracy of observers). This study indicated that the image enhancement based on wavelet transform could improve the diagnostic accuracy of radiologists for the malignant chest nodules.

Chest tomosynthesis: technical principles and clinical update

Digital tomosynthesis is a radiographic technique that can produce an arbitrary number of section images of a patient from a single pass of the X-ray tube. It utilizes a conventional X-ray tube, a flat-panel detector, a computer-controlled tube mover, and special reconstruction algorithms to produce section images. While it does not have the depth resolution of computed tomography (CT), tomosynthesis provides some of the tomographic benefits of CT but at lower cost and radiation dose than CT. Compared to conventional chest radiography, chest tomosynthesis results in improved visibility of normal structures such as vessels, airway and spine. By reducing visual clutter from overlying normal anatomy, it also enhances detection of small lung nodules. This review article outlines the components of a tomosynthesis system, discusses results regarding improved lung nodule detection from the recent literature, and presents examples of nodule detection from a clinical trial in human subjects. Possible implementation strategies for use in clinical chest imaging are discussed.

Potential clinical and economic consequences of noncardiac incidental findings on cardiac computed tomography

OBJECTIVES

We sought to determine the incidence, clinical significance, and potential financial impact of noncardiac incidental findings (IF) identified with cardiac computed tomography (CT).

BACKGROUND

Cardiac CT is gaining acceptance and may lead to the frequent discovery of extracardiac IF.

METHODS

Consecutive patients undergoing cardiac CT had noncardiac structures evaluated after full field of view (32 to 50 cm) reconstruction. IF were categorized as clinically significant (CS), indeterminate, or clinically insignificant. Patient follow-up was performed by telephone, and verified with hospital records and/or communication with physicians.

RESULTS

Of 966 patients (58 +/- 16 years of age, 55.4% men, >98% outpatients), 401 (41.5%) patients had noncardiac IF. A total of 12 (1.2%) patients had CS findings, and 68 (7.0%) patients had indeterminate findings. At follow-up (18.4 +/- 7.6 months), none of the indeterminate findings became CS. Although 3 patients with indeterminate findings were diagnosed with malignant lesions, they were unrelated to the IF. After adjusting for age, IF were not an independent predictor of noncardiac death. Noncardiac death and cancer death in patients with and without IF were not statistically different. One patient suffered a major complication related to the investigation of an IF. The total direct cost associated with investigating IF was Canadian $57,596 (U.S. $83,035).

CONCLUSIONS

Although noncardiac IF are common, clinically significant or indeterminate IF are less prevalent. Rates of death were similar in patients with and without IF, and IF was not an independent predictor of noncardiac death. The investigation of IF is not without cost or risk. Larger studies are required to assess the potential mortality benefit of identifying IF.

Pulmonary nodules: do we need a separate algorithm for non-solid lesions?

This article describes the aetiology, epidemiology and clinical significance of incidental non-solid pulmonary nodules. Non-solid nodules are more likely malignant. If malignant, they are mostly due to atypical adenomatous hyperplasia and bronchioloalveolar carcinoma. As these may be negative on positron emission tomography and slow growing, the diagnostic algorithms that are used for solid nodules have to be modified for non-solid nodules.

Lung cancer screening update

PURPOSE OF REVIEW

Lung cancer is a health problem of global proportions. Despite intensive research over many years, the prognosis is still very poor. For the surgery to be effective, tumours need to be recognized early. Computed tomography (CT) is significantly more sensitive than chest radiograph for identifying small, asymptomatic lung cancers. Although low-dose CT screening observational trials have demonstrated that survival for all tumour types and sizes detected were extremely high, there is no clear evidence that low-dose CT screening reduces deaths from lung cancer. Only the results of ongoing randomized controlled trials can reveal a real benefit of screening in terms of mortality reduction.

RECENT FINDINGS

We summarize the protocols and the preliminary results of the lung cancer screening randomized controlled trial and the problems linked to the detection of suspected early cancer.

SUMMARY

Today, we cannot already prove the ultimate mortality benefit of lung cancer screening with low-dose CT nor we can confirm that this approach is not harmful. We are waiting the final analysis of randomized controlled trials for lung cancer mortality. Even if is widely accepted that pooling data of randomized controlled trials could be of help to get powerful results in terms of mortality reduction in shorter follow-up time, this opportunity is still under evaluation.

Psychological impact of computed tomography screening for lung cancer and occupational pulmonary disease among asbestos-exposed workers

The objective of this study was to investigate the psychological impact of screening for lung cancer and occupational pulmonary disease among asbestos-exposed workers. Altogether, 633 workers were screened with chest computed tomography (627 men, 6 women, mean age 64.5 years). Participants' views on the necessity of screening,awareness of asbestos-exposure risks, their perceived lung cancer risk, trial adherence intention, health anxiety,and worry about lung cancer were assessed. Health anxiety was reduced significantly after screening (P < 0.001). After 1 year, no significant long-term psychological differences were found between those who immediately received clear results and those who were submitted to additional examinations because of positive findings. In conclusion,computed tomography screening of pulmonary disease was well accepted and did not produce excessive long-term anxiety or other negative psychological effects,which could prevent the participation in the future screening programs.

A randomized study of lung cancer screening with spiral computed tomography: three-year results from the DANTE trial

RATIONALE

Screening for lung cancer with modern imaging technology may decrease lung cancer mortality, but encouraging results have only been obtained in uncontrolled studies.

OBJECTIVES

To explore the effect of screening with low-dose spiral computed tomography (LDCT) on lung cancer mortality. Secondary endpoints are incidence, stage at diagnosis, and resectability.

METHODS

Male subjects, aged 60 to 75 years, smokers of 20 or more pack-years, were randomized to screening with LDCT or control groups. All participants underwent a baseline, once-only chest X-ray and sputum cytology examination. Screening-arm subjects had LDCT upon accrual to be repeated every year for 4 years, whereas controls had a yearly medical examination only.

MEASUREMENTS AND MAIN RESULTS

A total of 2,811 subjects were randomized and 2,472 were enrolled (LDCT, 1,276; control, 1,196). After a median follow-up of 33 months, lung cancer was detected in 60 (4.7%) patients receiving LDCT and 34 (2.8%) control subjects (P = 0.016). Resectability rates were similar in both groups. More patients with stage I disease were detected by LDCT (54 vs. 34%; P = 0.06) and fewer cases were detected in the screening arm due to intercurrent symptoms. However, the number of advanced lung cancer cases was the same as in the control arm. Twenty patients in the LDCT group (1.6%) and 20 controls (1.7%) died of lung cancer, whereas 26 and 25 died of other causes, respectively.

CONCLUSIONS

The mortality benefit from lung cancer screening by LDCT might be far smaller than anticipated.

Cost of a 5-year lung cancer survivor: symptomatic tumour identification vs proactive computed tomography screening

Background:

Our objective was to analyse the cost effectiveness of computed tomography (CT) screening for lung cancer in terms of the cost per long-term survivor, which has not been evaluated to date.

Methods:

Estimations were computed based on data from the Surveillance, Epidemiology, and End Results registries covering years 1999–2003. The design framework of our model allowed for the incorporation of multiple values taken from the epidemiological and clinical literature to be utilised for cost inputs, scope of patients screened, diagnostic staging, and survival percentages applied separately to two cohorts: age 40–79 and 60–79 years. This enabled the analysis of over 1400 scenarios, each containing a unique set of input values, for which the estimated cost per 5-year survivor (CP5YS) was compared between the symptom-detected and proactive screening approaches.

Results:

Estimated CP5YS were higher for the symptom-detected approach in all 729 scenarios analysed for the cohort ages 60–79 years, ranging from approximately $5800 to $116 700 increased cost per 5-year survivor (CP5YS). For the cohort ages 40–79 years, 75% of the 729 scenarios analysed showed increased CP5YS for the symptom-detected approach ranging from $5700 to $110 000 increased CP5YS. Total costs and total 5-year survivors were higher for the proactive screening method for all scenarios analysed across both cohorts with increases ranging from 50–256% and 98–309%, respectively.

Conclusion:

The predicted increase in long-term survival with CT screening and the potential for better utilisation of health-care dollars in terms of CP5YS, particularly when screening patients over the age of 60 years, are critically important considerations in directing effective future lung cancer management strategy.