Screening for lung cancer with low-dose computed tomography: a review of current status

Estimation of Preclinical State Onset Age and Sojourn Time for Heavy Smokers in Lung Cancer

Estimation of the three key parameters: onset age of the preclinical state, sojourn time and screening sensitivity is critical in cancer screening, since all other terms are functions of the three. A novel link function to connect sensitivity with time in the preclinical state and the likelihood method were used in this project; since sensitivity depends on how long one has entered the preclinical state relative to the total sojourn time. Simulations using Markov Chain Monte Carlo and maximum likelihood estimate were carried out to estimate the key parameters for male and female heavy smokers separately in the low-dose computed tomography group of the National Lung Screening Trial. Sensitivity for male and female heavy smokers were 0.883 and 0.915 respectively at the onset of the preclinical state, and increased to 0.972 and 0.981 at the end. The mean age to make the transition into the preclinical state was 70.94 or 71.15 for male and female heavy smokers respectively, and 90% of heavy smokers at risk for lung cancer would enter the preclinical state in age interval (55.7, 85.8) for males and (54.2, 87.7) for females, and the transition peaked around age 69 for both genders. The mean sojourn time in the preclinical state was 1.43 and 1.49 years, and the 99% credible intervals for the sojourn time were (0.21, 2.96) and (0.37, 2.69) years for male and female heavy smokers correspondingly. Based on the result, low-dose CT should be started at age 55 and ended before 85 for heavy smokers. This provided important information to policy makers.

Radiation Therapy Planning of Thoracic Tumors: A Review of Challenges Associated With Lung Toxicities and Potential Perspectives of Gallium-68 Lung PET/CT Imaging

Despite the introduction of new radiotherapy techniques, such as intensity modulated radiation therapy or stereotactic body radiation therapy, radiation induced lung injury remains a significant treatment related adverse event of thoracic radiation therapy. Functional lung avoidance radiation therapy is an emerging concept in the treatment of lung disease to better preserve lung function and to reduce pulmonary toxicity. While conventional ventilation/perfusion (V/Q) lung scintigraphy is limited by a relatively low spatial and temporal resolution, the recent advent of ⁶⁸Gallium V/Q lung PET/CT imaging offers a potential to increase the accuracy of lung functional mapping and to better tailor lung radiation therapy plans to the individual's lung function. Lung PET/CT imaging may also improve our understanding of radiation induced lung injury compared to the current anatomical based dose–volume constraints. In this review, recent advances in radiation therapy for the management of primary and secondary lung tumors and in V/Q PET/CT imaging for the assessment of functional lung volumes are reviewed. The new opportunities and challenges arising from the integration of V/Q PET/CT imaging in radiation therapy planning are also discussed.

Prevalence and burden of bronchiectasis in a lung cancer screening program

INTRODUCTION

The prevalence of bronchiectasis in the general population and in individuals undergoing lung cancer screening with low dose computed tomography (LDCT) is unknown. The aim of this study is to estimate the prevalence and impact of bronchiectasis in a screening lung cancer program.

METHODS

3028 individuals participating in an international multicenter lung cancer screening consortium (I-ELCAP) were selected from 2000 to 2012. Patients with bronchiectasis on baseline CT were identified and compared to selected controls. Detection of nodules, need for additional studies and incidence of cancer were analyzed over the follow-up period.

RESULTS

The prevalence of bronchiectasis was 11.6%(354/3028). On the baseline LDCT, the number of subjects with nodules identified was 189(53.4%) in patients with bronchiectasis compared to 63(17.8%) in controls (p<0.001). The occurrence of false positives was higher in subjects with bronchiectasis (26%vs17%;p = 0.003). During follow-up, new nodules were more common among subjects with bronchiectasis (17%vs.12%; p = 0.008). The total number of false positives during follow-up was 29(17.06%) for patients with bronchiectasis vs. 88(12.17%) for controls (p = 0.008).The incidence rate of lung cancer during follow-up was 6.8/1000 and 5.1/1000 person-years for each group respectively (p = 0.62).

CONCLUSIONS

Bronchiectasis are common among current and former smokers undergoing lung cancer screening with LDCT. The presence of bronchiectasis is associated with greater incidence of new nodules and false positives on baseline and follow-up screening rounds. This leads to an increase need of diagnostic tests, although the lung cancer occurrence is not different.

Identification of lung cancer gene markers through kernel maximum mean discrepancy and information entropy

BACKGROUND

The early diagnosis of lung cancer has been a critical problem in clinical practice for a long time and identifying differentially expressed gene as disease marker is a promising solution. However, the most existing gene differential expression analysis (DEA) methods have two main drawbacks: First, these methods are based on fixed statistical hypotheses and not always effective; Second, these methods can not identify a certain expression level boundary when there is no obvious expression level gap between control and experiment groups.

METHODS

This paper proposed a novel approach to identify marker genes and gene expression level boundary for lung cancer. By calculating a kernel maximum mean discrepancy, our method can evaluate the expression differences between normal, normal adjacent to tumor (NAT) and tumor samples. For the potential marker genes, the expression level boundaries among different groups are defined with the information entropy method.

RESULTS

Compared with two conventional methods t-test and fold change, the top average ranked genes selected by our method can achieve better performance under all metrics in the 10-fold cross-validation. Then GO and KEGG enrichment analysis are conducted to explore the biological function of the top 100 ranked genes. At last, we choose the top 10 average ranked genes as lung cancer markers and their expression boundaries are calculated and reported.

CONCLUSION

The proposed approach is effective to identify gene markers for lung cancer diagnosis. It is not only more accurate than conventional DEA methods but also provides a reliable method to identify the gene expression level boundaries.

Lung Cancer Screening, Version 3.2018, NCCN Clinical Practice Guidelines in Oncology

Lung cancer is the leading cause of cancer-related mortality in the United States and worldwide. Early detection of lung cancer is an important opportunity for decreasing mortality. Data support using low-dose computed tomography (LDCT) of the chest to screen select patients who are at high risk for lung cancer. Lung screening is covered under the Affordable Care Act for individuals with high-risk factors. The Centers for Medicare & Medicaid Services (CMS) covers annual screening LDCT for appropriate Medicare beneficiaries at high risk for lung cancer if they also receive counseling and participate in shared decision-making before screening. The complete version of the NCCN Guidelines for Lung Cancer Screening provides recommendations for initial and subsequent LDCT screening and provides more detail about LDCT screening. This manuscript focuses on identifying patients at high risk for lung cancer who are candidates for LDCT of the chest and on evaluating initial screening findings.

Solitary peribronchiolar metaplasia showing a sub-solid nodule on computed tomography

Recent advances in radiographic imaging and thoracic surgery have facilitated surgery for small lung tumors by eliminating the need for pathological diagnosis. To date, we have experienced two cases of small lung tumors that were surgically resected without pathological diagnosis as malignant. Computed tomography (CT) revealed sub-solid nodules in the peripheral lung. After tumor resection, both tumors were pathologically diagnosed as peribronchiolar metaplasia. To the best of our knowledge, solitary peribronchiolar metaplasia showing a sub-solid nodule on CT imaging has not previously been reported.

Racial Differences in Smoking-related Disease Risk Perceptions Among Adults Completing Lung Cancer Screening: Follow-up Results from the ACRIN/NLST Ancillary Study

Previous work suggests that, compared to white adults, black adults have lower perceived risk for smoking-related diseases (SRDs), which may influence cessation behavior and health outcomes; however, racial differences in SRD risk perceptions among high-risk patients (i.e., a group that exhibits elevated risk for SRDs) following lung screening remain unknown. This paper thus examined differences in risk perceptions for lung cancer and other SRDs among black and white National Lung Screening Trial (NLST) participants. We administered a 10-item measure of perceived lifetime risk of lung cancer and other SRD (Smoking Risk Perceptions Scale; SRPS) to NLST participants at 1 year following lung screening to (1) establish the internal consistency of the SRPS for both black and white participants, (2) compare smoking-related disease risk perceptions between black and white participants, and (3) identify predictors of risk perceptions for black and white participants using multivariable linear regression models. We determined the SRPS items loaded onto two factors (personal and comparative risks; Cronbach's alpha = 0.93 and 0.95 for 1743 white and 194 black participants, respectively), thus demonstrating high internal consistency for both black and white adults. Compared to white participants, black adults demonstrated lower SRD risk perceptions (SRPS range = 10-50, mean difference = 2.55, SE = 0.50, p < 0.001), even after adjusting for smoking status and sociodemographics. Younger age, female gender, higher education, white race, and current smoking status were independently associated with high risk perceptions. Sociodemographic factors associated with lower risk perceptions resemble factors related to continued smoking. Findings suggest current and former black smokers are at risk of having lower risk perceptions for lung cancer and SRDs than white adults following lung cancer screening; these differences may explain observed racial differences in cessation outcomes. Although similar factors influence black and white adults' beliefs, risk perceptions may differentially impact smoking behavior among these groups. Behavior change models that guide tobacco treatment approaches, particularly for high-risk black smokers, should consider the influence of cultural factors on risk perceptions and cessation efforts.

Non-intubated thoracoscopic surgery for lung cancer in patients with impaired pulmonary function

Background

Patients with impaired lung function or chronic obstructive pulmonary disease (COPD) are considered high-risk for intubated general anesthesia, which may preclude them from surgical treatment of their lung cancers. We evaluated the feasibility of non-intubated video-assisted thoracoscopic surgery (VATS) for the surgical management of lung cancer in patients with impaired pulmonary function.

Methods

From August 2009 to June 2015, 28 patients with impaired lung function (preoperative forced expiratory volume in 1 second <70% of the predicted value) underwent non-intubated VATS using a combination of thoracic epidural anesthesia or intercostal nerve block, and intra-thoracic vagal block with target-controlled sedation.

Results

Eighteen patients had primary lung cancers, 4 had metastatic lung cancers, and 6 had non-malignant lung tumors. In the patients with primary lung cancer, lobectomy was performed in 4, segmentectomy in 3 and wedge resection in 11, with lymph node sampling adequate for staging. One patient required conversion to intubated one-lung ventilation because of persistent wheezing and labored breathing. Five patients developed air leaks more than 5 days postoperatively while subcutaneous emphysema occurred in 6 patients. Two patients developed acute exacerbations of pre-existing COPD, and new-onset atrial fibrillation after surgery occurred in 1 patient. The median duration of postoperative chest tube drainage was 3 days while the median hospital stay was 6 days.

Conclusions

Non-intubated VATS resection for pulmonary tumors is technically feasible. It may be applied as an alternative to intubated general anesthesia in managing lung cancer in selected patients with impaired pulmonary function.

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.

Stereotactic Body Radiotherapy for Early-Stage Multiple Primary Lung Cancers

BACKGROUND

Patients with multiple primary lung cancers increasingly receive multiple courses of stereotactic body radiotherapy (SBRT). We aimed to clarify the efficacy and safety of such treatments.

PATIENTS AND METHODS

We reviewed a prospective lung SBRT database of patients treated for stage I non-small-cell lung cancer between June 2004 and December 2015.

RESULTS

A total of 374 patients received a single course of SBRT, 14 received synchronous SBRT, 48 received metachronous SBRT alone, and 108 received surgery and metachronous SBRT. Median follow-up was 37.0 months for survivors. Patients who received a single course had a 3-year overall survival (OS) of 54.2% (95% confidence interval [CI], 48.8-59.3), 3-year freedom from progression (FFP) of 67.3% (95% CI, 60.9-72.9), and grade 3 or higher toxicity of 3.5%. Compared to single-course patients, patients receiving metachronous SBRT alone and patients receiving surgery and metachronous SBRT had improved OS (79.7% [95% CI, 64.4-88.9%], P < .0001 and 95.4% [95% CI, 89.2-98.0%], P < .0001, respectively) and FFP (85.8% [95% CI, 70.7-93.5], P = .03 and 95.4% [95% CI, 89.2-98.0%], P < .0001, respectively). Patients receiving synchronous SBRT had similar OS (46.4% [95% CI, 19.3-69.9%], P = .75) and similar FFP (57.5% [95% CI, 25.3-80.0%], P = .17) as single-course patients. There were no significant differences in rates of grade 3 or higher toxicity or of grade 1 or higher toxicity between single-course patients and the other groups.

CONCLUSION

Patients who received either synchronous or metachronous SBRT had no significant detriment in OS or toxicity compared to single-course patients. This supports the use of SBRT in patients with multiple primary lung cancers.

Novel non-invasive early detection of lung cancer using liquid immunobiopsy metabolic activity profiles

Lung cancer is the leading cause of cancer death worldwide. Survival is largely dependent on the stage of diagnosis: the localized disease has a 5-year survival greater than 55%, whereas, for spread tumors, this rate is only 4%. Therefore, the early detection of lung cancer is key for improving prognosis. In this study, we present an innovative, non-invasive, cancer detection approach based on measurements of the metabolic activity profiles of immune system cells. For each Liquid ImmunoBiopsy test, a 384 multi-well plate is loaded with freshly separated PBMCs, and each well contains 1 of the 16 selected stimulants in several increasing concentrations. The extracellular acidity is measured in both air-open and hermetically-sealed states, using a commercial fluorescence plate reader, for approximately 1.5 h. Both states enable the measurement of real-time accumulation of 'soluble' versus 'volatile' metabolic products, thereby differentiating between oxidative phosphorylation and aerobic glycolysis. The metabolic activity profiles are analyzed for cancer diagnosis by machine-learning tools. We present a diagnostic accuracy study, using a multivariable prediction model to differentiate between lung cancer and control blood samples. The model was developed and tested using a cohort of 200 subjects (100 lung cancer and 100 control subjects), yielding 91% sensitivity and 80% specificity in a 20-fold cross-validation. Our results clearly indicate that the proposed clinical model is suitable for non-invasive early lung cancer diagnosis, and is indifferent to lung cancer stage and histological type.

Population impact of lung cancer screening in the United States: Projections from a microsimulation model

BACKGROUND

Previous simulation studies estimating the impacts of lung cancer screening have ignored the changes in smoking prevalence over time in the United States. Our primary rationale was to perform, to our knowledge, the first simulation study that estimates the health outcomes of lung cancer screening with explicit modeling of smoking trends for the whole US population.

METHODS/FINDINGS

Utilizing a well-validated microsimulation model, we estimated the benefits and harms of an annual low-dose computed tomography screening scenario with a realistic screening adherence rate versus a no-screening scenario for the US population from 2016-2030. The Centers for Medicare and Medicaid Services (CMS) eligibility criteria were applied: age 55-77 years at time of screening, history of at least 30 pack-years of smoking, and current smoker or former smoker with fewer than 15 years since quitting. In the screened population, cumulative mortality reduction was projected to reach 16.98% (95% CI 16.90%-17.07%). Cumulative mortality reduction was estimated to be 3.52% (95% CI 3.50%-3.53%) for the overall study population, with annual mortality reduction peaking at 4.38% (95% CI 4.36%-4.41%) in 2021 and falling to 3.53% (95% CI 3.50%-3.56%) by 2030. Lung cancer screening would save a projected 148,484 life-years (95% CI 147,429-149,540) across the total population through 2030. There were estimated to be 9,054 (95% CI 9,011-9,098) overdiagnosed cases among the 252,429 (95% CI 251,208-253,649) screen-detected lung cancer diagnoses, yielding an overdiagnosis rate of 3.59%. The limitations of our study are that we do not explicitly model race or socioeconomic status and our model was calibrated to data from studies performed in academic centers, both of which may impact the generalizability of our results. We also exclusively model the effects of the CMS guidelines for lung cancer screening and not any other screening strategies.

CONCLUSIONS

The mortality reduction and life-years gained estimated by this study are lower than those of single birth cohort studies. Single cohort studies neglect the changing dynamics of smoking behavior across generations, whereas this study reflects the trend of decreasing smoking prevalence since the 1960s. Maximum benefit could be derived from lung cancer screening through 2021; in later years, mortality reduction due to screening will decline. If a comprehensive screening program is not implemented in the near future, the opportunity to achieve these benefits will have passed.

Current and Prospective Protein Biomarkers of Lung Cancer

Lung cancer is a malignant lung tumor with various histological variants that arise from different cell types, such as bronchial epithelium, bronchioles, alveoli, or bronchial mucous glands. The clinical course and treatment efficacy of lung cancer depends on the histological variant of the tumor. Therefore, accurate identification of the histological type of cancer and respective protein biomarkers is crucial for adequate therapy. Due to the great diversity in the molecular-biological features of lung cancer histological types, detection is impossible without knowledge of the nature and origin of malignant cells, which release certain protein biomarkers into the bloodstream. To date, different panels of biomarkers are used for screening. Unfortunately, a uniform serum biomarker composition capable of distinguishing lung cancer types is yet to be discovered. As such, histological analyses of tumor biopsies and immunohistochemistry are the most frequently used methods for establishing correct diagnoses. Here, we discuss the recent advances in conventional and prospective aptamer based strategies for biomarker discovery. Aptamers like artificial antibodies can serve as molecular recognition elements for isolation detection and search of novel tumor-associated markers. Here we will describe how these small synthetic single stranded oligonucleotides can be used for lung cancer biomarker discovery and utilized for accurate diagnosis and targeted therapy. Furthermore, we describe the most frequently used in-clinic and novel lung cancer biomarkers, which suggest to have the ability of differentiating between histological types of lung cancer and defining metastasis rate.

Lung cancer screening with ultra-low dose CT using full iterative reconstruction

PURPOSE

To investigate the diagnostic capability of ultra-low-dose CT (ULDCT) with full iterative reconstruction (f-IR) for lung cancer screening.

MATERIALS AND METHODS

All underwent ULDCT and/or low-dose CT (LD-CT) on a 320-detector scanner. ULDCT images were reconstructed with f-IR. We qualitatively and quantitatively studied 95 nodules in 69 subjects. Two radiologists classified the nodules on ULDCT images as solid-, part-solid-, and pure ground-glass (PGG) and recorded their mean size. Their findings were compared with the reference standard. The observer performance study included 7 other radiologists and 35 subjects with- and 15 without nodules. The results were analyzed by AFROC analysis.

RESULTS

In the qualitative study, the kappa values between observers 1 and 2, respectively, and the reference standard were 0.70 and 0.83; the intra-class correlation coefficients for the nodule diameter between the reference standard and their measurements were 0.84 and 0.90. The 95% confidence interval (CI) for the area under the curve (AUC) difference for nodule detection on LDCT and ULDCT was -0.03 to 0.07. The 95% CI crossed the 0 difference in the AUC but not the pre-defined non-inferiority margin of -0.08.

CONCLUSION

The diagnostic ability of ULDCT using f-IR is comparable to LDCT.

Comparison between endobronchial ultrasound-guided transbronchial biopsy and CT-guided transthoracic lung biopsy for the diagnosis of peripheral lung cancer: a systematic review and meta-analysis

BACKGROUND

With the release of the National Lung Screening Trial results, the detection of peripheral pulmonary lesions (PPLs) is likely to increase. Computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) and radial probe endobronchial ultrasound (r-EBUS)-guided transbronchial lung biopsy (TBLB) are recommended for tissue diagnosis of PPLs.

METHODS

A systematic review of published literature evaluating the accuracy of r-EBUS-TBLB and CT-PTNB for the diagnosis of PPLs was performed to determine point sensitivity and specificity, and to construct a summary receiver-operating characteristic curve.

RESULTS

This review included 31 publications dealing with EBUS-TBLB and 14 publications dealing with CT-PTNB for the diagnosis of PPLs. EBUS-TBLB had point sensitivity of 0.69 (95% CI: 0.67-0.71) for the diagnosis of peripheral lung cancer (PLC), which was lower than the sensitivity of CT-PTNB (0.94, 95% CI: 0.94-0.95). However, the complication rates observed with EBUS-TBLB were lower than those reported for CT-PTNB.

CONCLUSIONS

This meta-analysis showed that EBUS-TBLB is a safe and relatively accurate tool in the investigation of PLC. Although the yield remains lower than that of CT-PTNB, the procedural risks are lower.

Differential Serum Cytokine Levels and Risk of Lung Cancer Between African and European Americans

BACKGROUND

African Americans have a higher risk of developing lung cancer than European Americans. Previous studies suggested that certain circulating cytokines were associated with lung cancer. We hypothesized that variations in serum cytokine levels exist between African Americans and European Americans, and increased circulating cytokine levels contribute to lung cancer differently in the two races.

METHODS

Differences in 10 serum cytokine levels, IL1β, IL4, IL5, IL6, IL8, IL10, IL12, granulocyte macrophage colony-stimulating factor, IFNγ, and TNFα, between 170 African-American and 296 European-American controls from the National Cancer Institute-Maryland (NCI-MD) case-control study were assessed. Associations of the serum cytokine levels with lung cancer were analyzed. Statistically significant results were replicated in the prospective Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and the Wayne State University Karmanos Cancer Institute case-control study.

RESULTS

Six cytokines, IL4, IL5, IL8, IL10, IFNγ, and TNFα, were significantly higher among European-American as compared with African-American controls. Elevated IL6 and IL8 levels were associated with lung cancer among both races in all three studies. Elevated IL1β, IL10, and TNFα levels were associated with lung cancer only among African Americans. The association between elevated TNFα levels and lung cancer among European Americans was significant after adjustment for additional factors.

CONCLUSIONS

Serum cytokine levels vary by race and might contribute to lung cancer differently between African Americans and European Americans.

IMPACT

Future work examining risk prediction models of lung cancer can measure circulating cytokines to accurately characterize risk within racial groups.

Improved Classification of Lung Cancer Using Radial Basis Function Neural Network with Affine Transforms of Voss Representation

Lung cancer is one of the diseases responsible for a large number of cancer related death cases worldwide. The recommended standard for screening and early detection of lung cancer is the low dose computed tomography. However, many patients diagnosed die within one year, which makes it essential to find alternative approaches for screening and early detection of lung cancer. We present computational methods that can be implemented in a functional multi-genomic system for classification, screening and early detection of lung cancer victims. Samples of top ten biomarker genes previously reported to have the highest frequency of lung cancer mutations and sequences of normal biomarker genes were respectively collected from the COSMIC and NCBI databases to validate the computational methods. Experiments were performed based on the combinations of Z-curve and tetrahedron affine transforms, Histogram of Oriented Gradient (HOG), Multilayer perceptron and Gaussian Radial Basis Function (RBF) neural networks to obtain an appropriate combination of computational methods to achieve improved classification of lung cancer biomarker genes. Results show that a combination of affine transforms of Voss representation, HOG genomic features and Gaussian RBF neural network perceptibly improves classification accuracy, specificity and sensitivity of lung cancer biomarker genes as well as achieving low mean square error.

Is chest X-ray screening for lung cancer in smokers cost-effective? Evidence from a population-based study in Italy

Background

After implementation of the PREDICA annual chest X-ray (CXR) screening program in smokers in the general practice setting of Varese-Italy a significant reduction in lung cancer-specific mortality (18 %) was observed. The objective of this study covering July 1997 through December 2006 was to estimate the cost-effectiveness of this intervention.

Methods

We examined detailed information on lung cancer (LC) cases that occurred among smokers invited to be screened in the PREDICA study (Invitation-to-screening Group, n = 5815 subjects) to estimate costs and quality-adjusted life-years (QALYs) from LC diagnosis until death. The control group consisted of 156 screening-eligible smokers from the same area, uninvited and unscreened, who developed LC and were treated by usual care. We calculated the incremental net monetary benefit (INMB) by comparing LC management in screening participants (n = 1244 subjects) and in the Invitation-to-screening group versus control group.

Results

The average number of QALYs since LC diagnosis was 1.7, 1.49 and 1.07, respectively, in screening participants, the invitation-to-screening group, and the control group. The average total cost (screening + management) per LC case was higher in screening participants (€17,516) and the Invitation-to-screening Group (€16,167) than in the control group (€15,503). Assuming a maximum willingness to pay of €30,000/QALY, we found that the intervention was cost-effective with high probability: 79 % for screening participation (screening participants vs. control group) and 95 % for invitation-to-screening (invitation-to-screening group vs. control group).

Conclusions

Based on the PREDICA study, annual CXR screening of high-risk smokers in a general practice setting has high probability of being cost-effective with a maximum willingness to pay of €30,000/QALY.

CYP1A2 rs2069514 polymorphism and lung cancer susceptibility: a meta-analysis

Many studies have examined the association between the CYP1A2 rs2069514 polymorphism gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent. The PubMed was searched for case-control studies published up to Sep 01, 2014. Data were extracted and pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated. In this meta-analysis, we assessed six published studies involving comprising 1,168 cases and 1,598 controls of the association between CYP1A2 rs2069514 polymorphism and lung cancer risk. For the homozygote A/A and A allele carriers (G/A + A/A), the pooled ORs were 1.47 (95% CI, 1.15-1.99; P=0.007 for heterogeneity) and 1.43 (95% CI, 1.07-1.90; P=0.000 for heterogeneity), when compared with the homozygous wild-type genotype (G/G). In the stratified analysis by ethnicity, the significantly risks were found among non-Asians for both the A allele carriers and homozygote A/A. However, no significant associations were found in Asian population all genetic models. These results from the meta-analysis suggest that CYP1A2 rs2069514 polymorphism contributes to risk of lung cancer among non-Asian population.

Characterization of Individuals Taking Part in Low Dose Computed Tomography (LDCT) Screening Program

In the past years the participation rate in conventional voluntary x-ray lung screening has been around 22 % in Somogy County in Hungary. Due to the high morbidity and mortality rates of lung cancer, low participation rate of the high risk individuals on the screening is a primary question in Hungary. To obtain an effectively high level of participation in our ongoing low dose CT screening program, we had to emphasize the benefits of participation for the targeted individuals. As a first step, our aim was to gather information on the aspects affecting the individuals' will for participation. We used the most accessible source of information: individuals over the age of 50, who attended the conventional voluntary lung screening, were approached to fill a questionnaire on their habits relating to smoking, health issues and their prior participation of lung screening. 1080 adults anonymously completed the questionnaire. Analyzing the results, beside other findings, we found a unique variable factor, which altered negatively the compliance for the screening: older individuals, who started participating in the screening in obligation to the health regulations, took part in the voluntary screening programs at a significantly lower rate. Our findings led us to better understanding the complexity of decision making affecting the individual's participation and attitudes toward health issues.

TRIAL REGISTRATION

IG/03833/2012.

ESR/ERS white paper on lung cancer screening

Abstract

Lung cancer is the most frequently fatal cancer, with poor survival once the disease is advanced. Annual low-dose computed tomography has shown a survival benefit in screening individuals at high risk for lung cancer. Based on the available evidence, the European Society of Radiology and the European Respiratory Society recommend lung cancer screening in comprehensive, quality-assured, longitudinal programmes within a clinical trial or in routine clinical practice at certified multidisciplinary medical centres. Minimum requirements include: standardised operating procedures for low-dose image acquisition, computer-assisted nodule evaluation, and positive screening results and their management; inclusion/exclusion criteria; expectation management; and smoking cessation programmes. Further refinements are recommended to increase quality, outcome and cost-effectiveness of lung cancer screening: inclusion of risk models, reduction of effective radiation dose, computer-assisted volumetric measurements and assessment of comorbidities (chronic obstructive pulmonary disease and vascular calcification). All these requirements should be adjusted to the regional infrastructure and healthcare system, in order to exactly define eligibility using a risk model, nodule management and a quality assurance plan. The establishment of a central registry, including a biobank and an image bank, and preferably on a European level, is strongly encouraged.

Key points

• Lung cancer screening using low dose computed tomography reduces mortality.

• Leading US medical societies recommend large scale screening for high-risk individuals.

• There are no lung cancer screening recommendations or reimbursed screening programmes in Europe as of yet.

• The European Society of Radiology and the European Respiratory Society recommend lung cancer screening within a clinical trial or in routine clinical practice at certified multidisciplinary medical centres.

• High risk, eligible individuals should be enrolled in comprehensive, quality-controlled longitudinal programmes.

ESR/ERS white paper on lung cancer screening

Lung cancer is the most frequently fatal cancer, with poor survival once the disease is advanced. Annual low dose computed tomography has shown a survival benefit in screening individuals at high risk for lung cancer. Based on the available evidence, the European Society of Radiology and the European Respiratory Society recommend lung cancer screening in comprehensive, quality-assured, longitudinal programmes within a clinical trial or in routine clinical practice at certified multidisciplinary medical centres. Minimum requirements include: standardised operating procedures for low dose image acquisition, computer-assisted nodule evaluation, and positive screening results and their management; inclusion/exclusion criteria; expectation management; and smoking cessation programmes. Further refinements are recommended to increase quality, outcome and cost-effectiveness of lung cancer screening: inclusion of risk models, reduction of effective radiation dose, computer-assisted volumetric measurements and assessment of comorbidities (chronic obstructive pulmonary disease and vascular calcification). All these requirements should be adjusted to the regional infrastructure and healthcare system, in order to exactly define eligibility using a risk model, nodule management and quality assurance plan. The establishment of a central registry, including biobank and image bank, and preferably on a European level, is strongly encouraged.

Screening tests: a review with examples

Screening tests are widely used in medicine to assess the likelihood that members of a defined population have a particular disease. This article presents an overview of such tests including the definitions of key technical (sensitivity and specificity) and population characteristics necessary to assess the benefits and limitations of such tests. Several examples are used to illustrate calculations, including the characteristics of low dose computed tomography as a lung cancer screen, choice of an optimal PSA cutoff and selection of the population to undergo mammography. The importance of careful consideration of the consequences of both false positives and negatives is highlighted. Receiver operating characteristic curves are explained as is the need to carefully select the population group to be tested.

Downregulation of PEBP4, a target of miR-34a, sensitizes drug-resistant lung cancer cells

The aim of this study was to determine the relationship and underlying mechanisms between ectopic expression of phosphatidylethanolamine-binding protein 4 (PEBP4) and cisplatin (DDP)-induced cytotoxicity in the lung cancer cell line A549 to provide an experimental basis for future chemotherapeutic applications involving PEBP4 in human lung cancer. A recombinant plasmid, pcDNA3-PEBP4, and a PEBP4-targeting small hairpin RNA (shRNA) were transfected into the lung cancer cell line A549. The PEBP4 protein expression levels were determined for each group by Western blot, and after 48 h of cisplatin (DDP) treatment, the viability of cells in the treatment and control groups was determined by 3-[4,5-dimethylthiazol-2-yl]-3,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis in each treatment group was determined using flow cytometry. Western blotting was used to examine expression of the p53 protein in A549 cells from each group. We employed a luciferase reporter-gene assay to confirm PEBP4 as a target gene of miR-34a. Western blotting was used to determine the effects of miR-34a on PEBP4 protein expression in A549 cells. Following transfection of A549 cells with either the recombinant plasmid pcDNA3-PEBP4 or a PEBP4-targeting shRNA, Western blotting analyses showed PEBP4 protein expression was significantly higher in the pcDNA3-PEBP4-transfected group compared with the control or PEBP4-shRNA-transfected groups (p < 0.01). Furthermore, PEBP4 protein expression was significantly reduced in the PEBP4-shRNA-transfected group (p < 0.01). After 48 h of DDP treatment, MTT assays indicated that A549 cell viability was significantly lower in the DDP-treated group compared with the control group (p < 0.01). The viability of A549 cells in the pcDNA3-PEBP4-transfected group was lower than that in the control group (p < 0.05) but higher than that in either the DDP-treated or PEBP4-shRNA-transfected groups (p < 0.05). Moreover, the viability of A549 cells in the PEBP4-shRNA-transfected group was significantly lower than that in either the control (p < 0.01) or DDP-treated (p < 0.05) groups. Flow cytometry and Western blotting analyses indicated that the number of apoptotic cells and p53 protein expression were significantly higher in the DDP-treated group compared with the control group (p < 0.01). In the pcDNA3-PEBP4-transfected group, the number of apoptotic cells and p53 protein expression level were higher than those in the control group (p < 0.05) but lower than those in the DDP-treated and PEBP4-shRNA-transfected groups (p < 0.05). The number of apoptotic cells and p53 protein expression level in the PEBP4-shRNA-transfected group were higher than those in the control (p < 0.01) and DDP-treated (p < 0.05) groups. The luciferase reporter-gene assay showed that the relative luciferase activity after transfection with a miR-34a mimic was significantly reduced compared with the control group (p < 0.01). Western blotting analysis demonstrated that PEBP4 protein expression was significantly decreased in A549 cells 48 h after transfection with a miR-34a mimic compared with the control group (p < 0.01). In conclusion, overexpression of PEBP4 reduced the sensitivity of A549 cells to DDP-induced cytotoxicity, mainly through the altered expression of the p53 protein or the modulation of miR-34a.

Management strategy of solitary pulmonary nodules

Solitary pulmonary nodules (SPNs) are increasingly detected with the widespread use of chest computed tomography (CT) scans. The management of patients with SPN should begin with estimating the probability of cancer from the patient's clinical risk factors and CT characteristics. The decision-making process need to incorporate the probability of cancer, the potential benefits and harms of surgery, the accuracy of the available diagnostic tests and patient preferences. For patients with a very low probability of cancer, careful observation with serial CT is warranted. For patients in the intermediate range of probabilities, either CT-guided fine-needle aspiration biopsy (FNAB) or positron emission tomography (PET), is recommended. For those with a high probability of cancer, surgical diagnosis is warranted.

Diagnostic value of computed tomography scanning in differentiating malignant from benign solitary pulmonary nodules: a meta-analysis

An early diagnosis of lung cancer is crucial for early treatment and management. The objective of this systematic review was to assess the overall diagnostic accuracy of chest computed tomography (CT) scanning in differentiating malignant from benign solitary pulmonary nodules (SPNs) with meta-analysis. The PubMed and China National Knowledge Infrastructure (CNKI) database were searched for eligible studies published up to March 2014. The sensitivity, specificity, and other measures of accuracy of chest CT scanning in the diagnosis of SPNs were pooled along with 95 % confidence intervals (CI). Summary receiver operating characteristic (ROC) curves were used to summarize overall test performance. Thirty-two studies met our inclusion criteria. The summary estimates for chest CT scanning in the diagnosis of SPNs in the meta-analysis were as follows: pooled sensitivity, 0.89 (95 % CI, 0.88 to 0.91); pooled specificity, 0.70 (95 % CI, 0.68 to 0.73); positive likelihood ratio, 2.88 (95 % CI, 2.46 to 3.37); negative likelihood ratio, 0.16 (95 % CI, 0.12 to 0.21); and diagnostic odds ratio, 23.83 (95 % CI, 16.18 to 35.11). The results indicate that CT scanning has relatively high sensitivity and moderate specificity for the diagnosis of SPNs. Given the low cost and growing prevalence of the technology, CT scanning should be recommended as the initial test for the evaluation of SPNs.