Screening for early lung cancer. Results of the Memorial Sloan-Kettering study in New York

Asian Perspective on Lung Cancer Screening

Lung cancer is the leading cause of cancer-related mortality in Japan and worldwide. Early detection of lung cancer is an important strategy for decreasing mortality. Advances in diagnostic imaging have made it possible to detect lung cancer at an early stage in medical practice. Conversely, screening of asymptomatic healthy populations is recommended only when the evidence shows the benefits of regular intervention. Due to a variety of evidence and racial differences, screening methods vary from country to country. This article focused on the perspective of lung cancer screening in Japan.

Imaging of lung cancer

Lung cancer is the leading cause of cancer-related mortality globally. Imaging is essential in the screening, diagnosis, staging, response assessment, and surveillance of patients with lung cancer. Subtypes of lung cancer can have distinguishing imaging appearances. The most frequently used imaging modalities include chest radiography, computed tomography, magnetic resonance imaging, and positron emission tomography. Artificial intelligence algorithms and radiomics are emerging technologies with potential applications in lung cancer imaging.

Artificial Intelligence for Cardiothoracic Imaging: Overview of Current and Emerging Applications

Artificial intelligence algorithms can learn by assimilating information from large datasets in order to decipher complex associations, identify previously undiscovered pathophysiological states, and construct prediction models. There has been tremendous interest and increased incorporation of artificial intelligence into various industries, including healthcare. As a result, there has been an exponential rise in the number of research articles and industry participants producing models intended for a variety of applications in medical imaging, which can be challenging to navigate for radiologists. In thoracic imaging, multiple applications are being evaluated for chest radiography and computed tomography and include applications for lung nodule evaluation and cancer imaging, quantifying diffuse lung disorders, and cardiac imaging, to name a few. This review aims to provide an overview of current clinical AI models, focusing on the most common clinical applications of AI in cardiothoracic imaging.

Implementing physician education to increase lung cancer screening uptake

Aim

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. The US Preventive Services Task Force and National Comprehensive Cancer Network recommend annual low-dose computed tomography (LDCT) for eligible adults. We conducted a study to assess physician LDCT referral patterns.

Methods

The study was divided into a pre-, intervention, and post-intervention periods. The intervention was a LC screening educational series. We evaluated rates of LDCT screening referrals during pre- and post-intervention periods.

Results

In the pre-intervention period, 75 patients fulfilled US Preventive Services Task Force and/or National Comprehensive Cancer Network criteria and 27% underwent LDCT. In the post-intervention period, 135 patients fulfilled either screening criteria of whom 61.5% underwent LDCT.

Conclusion

In our study, educational lectures improved compliance significantly and should be used as tool for primary care providers to effectively increase LDCT screening referrals.

Lung Cancer Screening

Lung cancer screening with low-dose computed tomography (LDCT) reduces lung cancer deaths by early detection. The United States Preventive Services Task Force recommends lung cancer screening with LDCT in adults of age 50 years to 80 years who have at least a 20 pack-year smoking history and are currently smoking or have quit within the past 15 years. The implementation of a lung-cancer-screening program is complex. High-quality screening requires the involvement of a multidisciplinary team. The aim of a screening program is to find balance between mortality reduction and avoiding potential harms related to false-positive findings, overdiagnosis, invasive procedures, and radiation exposure. Components and processes of a high-quality lung-cancer-screening program include the identification of eligible individuals, shared decision-making, performing and reporting LDCT results, management of screen-detected lung nodules and non-nodule findings, smoking cessation, ensuring adherence, data collection, and quality improvement.

Artificial Intelligence in Lung Cancer Imaging: Unfolding the Future

Lung cancer is one of the malignancies with higher morbidity and mortality. Imaging plays an essential role in each phase of lung cancer management, from detection to assessment of response to treatment. The development of imaging-based artificial intelligence (AI) models has the potential to play a key role in early detection and customized treatment planning. Computer-aided detection of lung nodules in screening programs has revolutionized the early detection of the disease. Moreover, the possibility to use AI approaches to identify patients at risk of developing lung cancer during their life can help a more targeted screening program. The combination of imaging features and clinical and laboratory data through AI models is giving promising results in the prediction of patients’ outcomes, response to specific therapies, and risk for toxic reaction development. In this review, we provide an overview of the main imaging AI-based tools in lung cancer imaging, including automated lesion detection, characterization, segmentation, prediction of outcome, and treatment response to provide radiologists and clinicians with the foundation for these applications in a clinical scenario.

The 50-Year Journey of Lung Cancer Screening: A Narrative Review

Early diagnosis and treatment are associated with better outcomes in oncology. We reviewed the existing literature using the search terms “low dose computed tomography” and “lung cancer screening” for systematic reviews, metanalyses, and randomized as well as non-randomized clinical trials in PubMed from January 1, 1963 to April 30, 2022. The studies were heterogeneous and included people with different age groups, smoking histories, and other specific risk scores for lung cancer screening. Based on the available evidence, almost all the guidelines recommend screening for lung cancer by annual low dose CT (LDCT) in populations over 50 to 55 years of age, who are either current smokers or have left smoking less than 15 years back with more than 20 to 30 pack-years of smoking. “LDCT screening” can reduce lung cancer mortality if carried out judiciously in countries with adequate resources and infrastructure.

Advances in lung cancer screening and early detection

Lung cancer is associated with a heavy cancer-related burden in terms of patients' physical and mental health worldwide. Two randomized controlled trials, the US-National Lung Screening Trial (NLST) and Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON), indicated that low-dose CT (LDCT) screening results in a statistically significant decrease in mortality in patients with lung cancer, LDCT has become the standard approach for lung cancer screening. However, many issues in lung cancer screening remain unresolved, such as the screening criteria, high false-positive rate, and radiation exposure. This review first summarizes recent studies on lung cancer screening from the US, Europe, and Asia, and discusses risk-based selection for screening and the related issues. Second, an overview of novel techniques for the differential diagnosis of pulmonary nodules, including artificial intelligence and molecular biomarker-based screening, is presented. Third, current explorations of strategies for suspected malignancy are summarized. Overall, this review aims to help clinicians understand recent progress in lung cancer screening and alleviate the burden of lung cancer.

Application of Artificial Intelligence in Lung Cancer

Simple Summary

Lung cancer is the leading cause of malignancy-related mortality worldwide. AI has the potential to help to treat lung cancer from detection, diagnosis and decision making to prognosis prediction. AI could reduce the labor work of LDCT, CXR, and pathology slides reading. AI as a second reader in LDCT and CXR reading reduces the effort of radiologists and increases the accuracy of nodule detection. Introducing AI to WSI in digital pathology increases the Kappa value of the pathologist and help to predict molecular phenotypes with radiomics and H&E staining. By extracting radiomics from image data and WSI from the histopathology field, clinicians could use AI to predict tumor properties such as gene mutation and PD-L1 expression. Furthermore, AI could help clinicians in decision-making by predicting treatment response, side effects, and prognosis prediction in medical treatment, surgery, and radiotherapy. Integrating AI in the future clinical workflow would be promising.

Abstract

Lung cancer is the leading cause of malignancy-related mortality worldwide due to its heterogeneous features and diagnosis at a late stage. Artificial intelligence (AI) is good at handling a large volume of computational and repeated labor work and is suitable for assisting doctors in analyzing image-dominant diseases like lung cancer. Scientists have shown long-standing efforts to apply AI in lung cancer screening via CXR and chest CT since the 1960s. Several grand challenges were held to find the best AI model. Currently, the FDA have approved several AI programs in CXR and chest CT reading, which enables AI systems to take part in lung cancer detection. Following the success of AI application in the radiology field, AI was applied to digitalized whole slide imaging (WSI) annotation. Integrating with more information, like demographics and clinical data, the AI systems could play a role in decision-making by classifying EGFR mutations and PD-L1 expression. AI systems also help clinicians to estimate the patient’s prognosis by predicting drug response, the tumor recurrence rate after surgery, radiotherapy response, and side effects. Though there are still some obstacles, deploying AI systems in the clinical workflow is vital for the foreseeable future.

Nationwide lung cancer screening with low-dose computed tomography: implementation and first results of the HUNCHEST screening program

OBJECTIVES

Lung cancer (LC) kills more people than any other cancer in Hungary. Hence, there is a clear rationale for considering a national screening program. The HUNCHEST pilot program primarily aimed to investigate the feasibility of a population-based LC screening in Hungary, and determine the incidence and LC probability of solitary pulmonary nodules.

METHODS

A total of 1890 participants were assigned to undergo low-dose CT (LDCT) screening, with intervals of 1 year between procedures. Depending on the volume, growth, and volume doubling time (VDT), screenings were defined as negative, indeterminate, or positive. Non-calcified lung nodules with a volume > 500 mm³ and/or a VDT < 400 days were considered positive. LC diagnosis was based on histology.

RESULTS

At baseline, the percentage of negative, indeterminate, and positive tests was 81.2%, 15.1%, and 3.7%, respectively. The frequency of positive and indeterminate LDCT results was significantly higher in current smokers (vs. non-smokers or former smokers; p < 0.0001) and in individuals with COPD (vs. those without COPD, p < 0.001). In the first screening round, 1.2% (n = 23) of the participants had a malignant lesion, whereas altogether 1.5% (n = 29) of the individuals were diagnosed with LC. The overall positive predictive value of the positive tests was 31.6%. Most lung malignancies were diagnosed at an early stage (86.2% of all cases).

CONCLUSIONS

In terms of key characteristics, our prospective cohort study appears consistent to that of comparable studies. Altogether, the results of the HUNCHEST pilot program suggest that LDCT screening may facilitate early diagnosis and thus curative-intent treatment in LC.

KEY POINTS

• The HUNCHEST pilot study is the first nationwide low-dose CT screening program in Hungary. • In the first screening round, 1.2% of the participants had a malignant lesion, whereas altogether 1.5% of the individuals were diagnosed with lung cancer. • The overall positive predictive value of the positive tests in the HUNCHEST screening program was 31.6%.

Missed Opportunities? An Observational Analysis of Lung Cancer Screening Utilization Amongst Patients With Lung Cancer

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. The U.S. Preventive Services Task Force (USPSTF) and National Comprehensive Cancer Network (NCCN) recommend annual low-dose CT chest (LDCT) for LC screening in high-risk adults who meet appropriate criteria, which primarily focus on age and smoking history. Despite this, screening rates remain low and patients with LC are typically diagnosed at a later stage.

We conducted a single-center retrospective analysis of patients with an established diagnosis of lung cancer to evaluate if screening guidelines were appropriately followed before the cancer diagnosis.

Patients diagnosed with LC between 2016 and 2019 were included in the analysis. Charts were reviewed for demographics, detailed smoking history, as well as histology and stage of LC. Associations between categorical factors and screening were examined using the chi-square test. Associations between continuous and ordinal factors and screening were examined using the Mann–Whitney test.

A total of 530 charts were reviewed, of which 52% met NCCN criteria and 35% met USPSTF criteria. Only 4.0% and 4.8% of patients who met NCCN and USPSTF criteria, respectively, underwent screening. There was a significant association between staging at diagnosis and screening with LDCT. All the patients who had screening CT scans were diagnosed at localized stages of lung cancer in both NCCN and USPSTF groups compared to 49.1% and 48% in eligible subjects that did not undergo screening, respectively.

Our study showed that despite established guidelines for LC screening and insurance coverage, a vast majority of screening-eligible LC patients have never had LDCT. We found that patients who underwent screening as per guidelines were diagnosed at earlier stages of the disease. Ongoing efforts to increase awareness and adherence to LC screening guidelines are needed to improve early detection and reduce LC mortality.

Lung cancer screening: a critical appraisal

PURPOSE OF REVIEW

The recently published large-scale NELSON trial showed a reduction in lung cancer (LC) mortality with the use of low-dose computed tomography (LDCT) in high-risk patients. This is the first such European-based trial to mirror the results of the US National Lung Screening Trial (NLST). The NLST was responsible for nationwide implementation of LC screening protocols which has shown a decrease in LC mortality. However, the implementation of such screening in Europe has been challenging. With the findings from the NELSON trial, implementation of LC screening throughout Europe should once again be evaluated.

RECENT FINDINGS

This review article further elaborates on the advantages of LDCT in LC screening. It also discusses promising future approaches that can supplement the current LC screening guidelines.

SUMMARY

Implementation of LC screening with LDCT should again be evaluated throughout Europe as it could substantially decrease LC-related mortality.

Long-term Lung Cancer Risk Associated with Sputum Atypia: A 27-Year Follow-up Study of an Occupational Lung Screening Cohort in Yunnan, China

BACKGROUND

Sputum cytologic atypia is associated with increased lung cancer risk. However, little is known about the long-term magnitude and temporal trend of this risk.

METHODS

An extended follow-up was conducted in a prospective screening cohort among occupational tin miners in Yunnan, China. Sputum samples were collected prospectively at baseline and 7 annual screenings since enrollment. The associations between sputum cytologic results from baseline screening, the first 4 consecutive rounds of sputum screening, and lung cancer risk were analyzed by time-varying covariate Cox regression model.

RESULTS

A moderate or worse cytologic result was associated with a significantly increased lung cancer risk. This relative hazard significantly decreased over time. Compared with negative screening results, the adjusted hazard ratios of baseline-moderate or worse atypia, at least one moderate or worse atypia in the first 4 consecutive screening rounds during the first 10 years of follow-up were 3.11 [95% confidence interval (CI): 2.37-4.07], 3.25 (95% CI: 2.33-4.54) respectively. This association was stronger for persistent atypia (adjusted hazard ratio = 17.55, 95% CI: 8.32-37.03); atypia identified in the recent screening rounds (adjusted HR = 4.14, 95% CI: 2.70-6.35), and those were old in age, had higher level of smoking, occupational radon, and arsenic exposure. In terms of histology, this increased risk was significant for squamous cell carcinoma and small cell lung cancer.

CONCLUSIONS

Although decreasing over time, an increased lung cancer risk concerning moderate or worse sputum atypia can continue at least for 10 years.

IMPACT

Sputum atypia might be helpful for identifying high-risk individuals for screening, surveillance, or chemoprevention of lung cancer.

Sputum-Based Tumor Fluid Biopsy: Isolation and High-Throughput Single-Cell Analysis of Exfoliated Tumor Cells for Lung Cancer Diagnosis

Timely and effective diagnosis is of great significance for improving the survival rate of lung cancer patients. Although histopathology is the main diagnostic tool among the existing methods for lung cancer diagnosis, it is not suitable for high-risk groups, early lung cancer patients, patients with advanced-stage disease, and other situations wherein tumor tissues cannot be obtained. In view of this, we proposed an innovative lung cancer diagnosis method employing for the first time a microfluidic technology for high-efficiency isolation and high-throughput single-cell analysis of exfoliated tumor cells (ETCs) in sputum. This method fully combines the advantages of traditional sputum cytology and microfluidic technology and realizes the diagnosis of lung cancer by using a small amount of repeatable ETCs instead of the tumor tissue. This method is expected to provide a practical strategy for the non-invasive detection of lung cancer patients and lung cancer screening for high-risk groups.

The 100 most cited articles on lung cancer screening: a bibliometric analysis

Background

The number of citations of an article reflects its impact on the scientific community. The aim of this study was to identify and characterize the 100 most cited articles on lung cancer screening.

Methods

The 100 most cited articles on lung cancer screening published in all scientific journals were identified using the Web of Science database. Relevant data, including the number of citations, publication year, publishing journal and impact factor (IF), authorship and country of origin, article type and study design, screening modality, and main topic, were collected and analyzed.

Results

The 100 most cited articles were all English and published between 1973 and 2017, with 81 published after 2000. The mean number of citations was 292.90 (range 100–3,910). Sixty articles originated from the United States. These articles were published in 32 journals; there was a statistically significant positive correlation between journal IF and the number of citations (r=0.238, P=0.018). Seventy-nine articles were original research of which 37.9% were about results from randomized controlled trials (RCTs). The most common screening modalities in these articles were low-dose computed tomography (LDCT) (n=78), followed by chest X-ray radiography (CXR) and sputum cytology (n=11). The most common topic in these articles was screening test effectiveness.

Conclusions

Our study presents a detailed list and analysis of the 100 most cited articles published about lung cancer screening which provides insight into the historical developments and key contributions in this field.

Primary care and pulmonary physicians' knowledge and practice concerning screening for lung cancer in Lebanon, a middle-income country

Background

Screening for lung cancer with low‐dose computed tomography (LDCT) was shown to reduce lung cancer incidence and overall mortality, and it has been recently included in international guidelines. Despite the rising burden of lung cancer in low and middle‐income countries (LMICs) such as Lebanon, little is known about what primary care physicians or pulmonologists know and think about LDCT as a screening procedure for lung cancer, and if they recommend it.

Objectives

Evaluate the knowledge about LDCT and implementation of international guidelines for lung cancer screening among Lebanese primary care physicians (PCPs) and pulmonary specialists.

Methodology

PCPs and PUs based in Lebanon were surveyed concerning knowledge and practices related to lung cancer screening by self‐administered paper questionnaires.

Results

73.8% of PCPs and 60.7% of pulmonary specialists recognized LDCT as an effective tool for lung cancer screening, with 63.6% of PCPs and 71% of pulmonary specialists having used it for screening. However, only 23.4% of PCPs and 14.5% of pulmonary specialists recognized the eligibility criteria for screening. Chest X‐ray was recognized as ineffective by only 55.8% of PCPs and 40.7% of pulmonary specialists; indeed, 30.2% of PCPs and 46% of pulmonary specialists continue using it for screening. The majority have initiated a discussion about the risks and benefits of lung cancer screening.

Conclusion

PCPs and pulmonary specialists are initiating discussions and ordering LDCT for lung cancer screening. However, a significant proportion of both specialties are still using a non‐recommended screening tool (chest x‐ray); only few PCPs and pulmonary specialists recognized the population at risk for which screening is recommended. Targeted provider education is needed to close the knowledge gap and promote proper implementation of guidelines for lung cancer screening.

Duration of lead time in screening for lung cancer

BACKGROUND

Screening for lung cancer has used chest radiography (CR), low dose computed tomography (LDCT) and sputum cytology (SC). Estimates of the lead time (LT), i.e., the time interval from detection of lung cancer by screening to the development of symptoms, have been derived from longitudinal studies of populations at risk, tumor doubling time (DT), the ratio between its prevalence at the first round of screening and its annual incidence during follow-up, and by probability modeling derived from the results of screening trials.

OBJECTIVE

To review and update the estimates of LT of lung cancer.

METHODS

A non-systematic search of the literature for estimates of LT and screening trials. Search of the reference sections of the retrieved papers for additional relevant studies. Calculation of LTs derived from these studies.

RESULTS

LT since detection by CR was 0.8-1.1 years if derived from longitudinal studies; 0.6-2.1 years if derived from prevalence / incidence ratios; 0.2 years if derived from the average tumor DT; and 0.2-1.0 if derived from probability modeling. LT since detection by LDCT was 1.1-3.5 if derived from prevalence / incidence ratios; 3.9 if derived from DT; and 0.9 if derived from probability modeling. LT since detection of squamous cell cancer by SC in persons with normal CR was 1.3-1.5 if derived from prevalence/incidence ratios; and 2.1 years if derived from the DT of squamous cell cancer.

CONCLUSIONS

Most estimates of the LT yield values of 0.2-1.5 years for detection by CR; of 0.9-3.5 years for detection by LDCT; and about 2 years or less for detection of squamous cell cancer by SC in persons with normal CR. The heterogeneity of the screening trials and methods of derivation may account for the variability of LT estimates.

Artificial Intelligence Tools for Refining Lung Cancer Screening

Nearly one-quarter of all cancer deaths worldwide are due to lung cancer, making this disease the leading cause of cancer death among both men and women. The most important determinant of survival in lung cancer is the disease stage at diagnosis, thus developing an effective screening method for early diagnosis has been a long-term goal in lung cancer care. In the last decade, and based on the results of large clinical trials, lung cancer screening programs using low-dose computer tomography (LDCT) in high-risk individuals have been implemented in some clinical settings, however, this method has various limitations, especially a high false-positive rate which eventually results in a number of unnecessary diagnostic and therapeutic interventions among the screened subjects. By using complex algorithms and software, artificial intelligence (AI) is capable to emulate human cognition in the analysis, interpretation, and comprehension of complicated data and currently, it is being successfully applied in various healthcare settings. Taking advantage of the ability of AI to quantify information from images, and its superior capability in recognizing complex patterns in images compared to humans, AI has the potential to aid clinicians in the interpretation of LDCT images obtained in the setting of lung cancer screening. In the last decade, several AI models aimed to improve lung cancer detection have been reported. Some algorithms performed equal or even outperformed experienced radiologists in distinguishing benign from malign lung nodules and some of those models improved diagnostic accuracy and decreased the false-positive rate. Here, we discuss recent publications in which AI algorithms are utilized to assess chest computer tomography (CT) scans imaging obtaining in the setting of lung cancer screening.

Lung Cancer Screening

Lung cancer is the leading cause of US cancer-related deaths. Lung cancer screening with a low radiation dose chest computed tomography scan is now standard of care for a high-risk eligible population. It is imperative for clinicians and surgeons to evaluate the trade-offs of benefits and harms, including the identification of many benign lung nodules, overdiagnosis, and complications. Integration of smoking cessation interventions augments the clinical benefits of screening. Screening programs must develop strategies to manage screening-detected findings to minimize potential harms. Further research should focus on how to improve patient selection, minimize harms, and facilitate access to screening.

Molecular testing on bronchial washings for the diagnosis and predictive assessment of lung cancer

Cytopathological analyses of bronchial washings (BWs) collected during fibre‐optic bronchoscopy are often inconclusive for lung cancer diagnosis. To address this issue, we assessed the suitability of conducting molecular analyses on BWs, with the aim to improve the diagnosis and outcome prediction of lung cancer. The methylation status of RASSF1A, CDH1, DLC1 and PRPH was analysed in BW samples from 91 lung cancer patients and 31 controls, using a novel two‐colour droplet digital methylation‐specific PCR (ddMSP) technique. Mutations in ALK, BRAF, EGFR, ERBB2, KRAS, MAP2K1, MET, NRAS, PIK3CA, ROS1 and TP53 and gene fusions of ALK, RET and ROS1 were also investigated, using next‐generation sequencing on 73 lung cancer patients and 14 tumour‐free individuals. Our four‐gene methylation panel had significant diagnostic power, with 97% sensitivity and 74% specificity (relative risk, 7.3; odds ratio, 6.1; 95% confidence interval, 12.7–127). In contrast, gene mutation analysis had a remarkable value for predictive, but not for diagnostic, purposes. Actionable mutations in EGFR, HER2 and ROS1 as well as in other cancer genes (KRAS, PIK3CA and TP53) were detected. Concordance with gene mutations uncovered in tumour biopsies was higher than 90%. In addition, bronchial‐washing analyses permitted complete patient coverage and the detection of additional actionable mutations. In conclusion, BWs are a useful material on which to perform molecular tests based on gene panels: aberrant gene methylation and mutation analyses could be performed as approaches accompanying current diagnostic and predictive assays during the initial workup phase. This study establishes the grounds for further prospective investigation.

CT screening for lung cancer: Are we ready to implement in Europe?

Lung cancer screening with low-dose CT (LDCT) is already available in certain parts of the world, such as the United States, but not yet in Europe. The recently published European position statement on lung cancer screening has recommended planning for implementation of screening to start within 18-months [1]. Pilot European programmes are already underway, primarily in the United Kingdom (UK), delivering lung cancer screening to their local populations. This review article acknowledges the evidence base for LDCT screening and will discuss the challenges that still need to be overcome in an attempt to answer the question: are we ready to implement in Europe?

Update on screening for lung cancer

As the leading cause of cancer related death world wide, lung cancer is responsible for an enormous amount of suffering and disability. Detection of disease when it is surgically curable is associated with far greater odds of cure, and therefore it is a disease for which mass screening of high-risk populations has significant potential benefit. Starting in 2011, with the publication of the National Lung Screening Trial from United States (U.S.), mass screening programs have emerged throughout the U.S., as well as in other countries. More recently, large European screening trials have confirmed the potential mortality benefit of lung cancer screening. This invited non-systematic review paper covers the trial that data justify mass-screening, for lung cancer and proposes strategies for maximizing benefits and minimizing harms in the context of a mass public health lung cancer screening program.

Feasibility of lung cancer screening in developing countries: challenges, opportunities and way forward

Lung cancer is the leading cause of all cancer deaths worldwide, comprising 18.4% of all cancer deaths. Low-dose computed tomography (LDCT) has shown mortality benefit in various trials and now a standard tool for lung cancer screening. Most researches have been carried out in developed countries where lung cancer incidence and mortality is very high. There is an increasing trend in lung cancer incidence in developing countries attributed to tobacco smoking and various environmental and occupational risk factors. Implementation of lung cancer screening is challenging, so organised lung cancer screening is practically non-existent. There are numerous challenges in implementing such programs ranging from infrastructure, trained human resources, referral algorithm to cost and psychological trauma due to over-diagnosis. Pulmonary tuberculosis and other chest infections are important issues to be addressed while planning for lung cancer screening in developing countries. Burden of these diseases is very high and can lead to over-diagnosis in view of cut off of lung nodule size in various studies. Assessment of high risk cases for lung cancer is difficult as various forms of smoking make quantification non-uniform and difficult. Lung cancer screening targets only high risk population unlike screening programs for other cancers where entire population is targeted. There is a need of lung cancer screening for high risk cases as it saves life. Tobacco control and smoking cessation remain the most important long term intervention to decrease morbidity and mortality from lung cancer in developing countries. There is no sufficient evidence supporting the introduction of population-based screening for lung cancer in public health services.

ACR Appropriateness Criteria® Lung Cancer Screening

Lung cancer remains the leading cause of cancer death in both men and women. Smoking is the single greatest risk factor for the development of lung cancer. For patients between the age of 55 and 80 with 30 or more pack years smoking history who currently smoke or who have quit within the last 15 years should undergo lung cancer screening with low-dose CT. In patients who do not meet these criteria but who have additional risk factors for lung cancer, lung cancer screening with low-dose CT is controversial but may be appropriate. Imaging is not recommended for lung cancer screening of patient younger than 50 years of age or patients older than 80 years of age or patients of any age with less than 20 packs per year history of smoking and no additional risk factor (ie, radon exposure, occupational exposure, cancer history, family history of lung cancer, history of COPD, or history of pulmonary fibrosis). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Identifying lung cancer in patients with active pulmonary tuberculosis

The diagnosis of lung cancer can be delayed in patients with a history of infection with pulmonary tuberculosis that present with new lesions on chest imaging, due to a high initial index of suspicion for mycobacterium tuberculosis complex rather than malignancy. This may lead to diagnosis of malignancy at a more advanced stage of the disease with subsequent increased morbidity and mortality. We reviewed the current literature to evaluate various methods of differentiating between a diagnosis of lung cancer and tuberculosis including radiography, computerized tomography (CT), positron emission tomography (PET) and various biological markers. We included only papers published in English. Based on current data, we recommend that patients established as high risk, according to the American Association of Thoracic Surgery, patients with age greater than or equal to 55 years and a smoking history of greater than or equal to 30 pack years, should be assessed with CT for underlying malignancy prior to beginning tuberculosis treatment, even in the presence of a clinical or microbiologic diagnosis of tuberculosis. In patients with equivocal CT findings, we recommend examination of tumor markers miR128, miR210, miR126 along with CEA, if these tests are at the clinician's disposal.

Challenges in Lung Cancer Screening in Latin America

Lung cancer is the deadliest cancer worldwide and is of particular concern for Latin America. Its rising incidence in this area of the world poses myriad challenges for the region's economies, which are already struggling with limited resources to meet the health care needs of low- and middle-income populations. In this environment, we are concerned that regional governments are relatively unaware of the pressing need to implement effective strategies for the near future. Low-dose chest computed tomography (LDCT) for screening, and routine use of minimally invasive techniques for diagnosis and staging remain uncommon. According to results of the National Lung Screening Trial, LDCT lung cancer screening provided a 20% relative reduction in mortality rates among at-risk individuals. Nevertheless, this issue is still a matter of debate, particularly in developing countries, and it is not fully embraced in developing countries. The aim of this article is to provide an overview of what the standard of care is for lung cancer computed tomography screening around the world and to aid understanding of the challenges and potential solutions that can help with the implementation of LDCT in Latin America.

Screening for Lung Cancer

Lung cancer is a global health burden and is among the most common and deadliest of all malignancies worldwide. The goal of screening programs is to detect tumors in earlier, curable stages, consequently reducing disease-specific mortality. The issue of screening has great relevance to thoracic surgeons, who should play a leading role in the debate over screening and its consequences. The burden is on thoracic surgeons to work in a multidisciplinary setting to guide and treat these patients safely and responsibly, ensuring low morbidity and mortality of potential diagnostic or therapeutic interventions.

Lung cancer screening

PURPOSE OF REVIEW

Lung cancer screening with low-dose chest computed tomography is now recommended for high-risk individuals by the US Preventive Services Task Force. This recommendation was informed by several randomized controlled trials, the largest of which, the National Lung Screening Trial, demonstrated a 20% relative reduction in lung cancer mortality with annual low-dose chest computed tomography compared with chest radiography.

RECENT FINDINGS

The benefit of lung cancer screening must be balanced against potential harms, including a high false-positive rate with consequent further evaluative studies and invasive testing. It is critical that harms be minimized as screening generalizes to the broad community. Informed decision making between providers and patients should include individualized risk assessment, a discussion of both potential benefit and harm, and tobacco treatment. Given the multiple components required for high quality, screening should ideally occur in the context of a multidisciplinary program.

SUMMARY

We are in the early days of lung cancer screening, still with much to learn. Ongoing studies are necessary to refine the definition of a positive screen and develop better methods of distinguishing between true positive and false-positive results. Novel approaches, including the development of multicomponent lung cancer biomarkers, will likely inform and improve our future screening practice.

[Effect of Scanning and Reconstruction Parameters on Three Dimensional Volume and CT Value Measurement of Pulmonary Nodules: A Phantom Study]

具有表皮生长因子受体（epidermal growth factor receptor, EGFR）敏感突变的非小细胞肺癌患者对酪氨酸激酶抑制剂（tyrosine kinase inhibitors, TKIs）具有良好反应，但是即使存在相同突变，不同患者对TKIs的反应也不一致。推测突变分子含量的不同是TKIs反应不一的部分原因，具有更高EGFR突变“丰度”的肿瘤患者可能从TKIs中获益更多。EGFR突变可根据检测方法敏感性的不同，定量检测突变分子比例以及突变蛋白表达等进行半定量或定量检测。EGFR突变丰度可能有助于反映肿瘤异质性，评估疾病进程，预测TKIs药物敏感性，早期发现耐药，具有重要的临床意义。

Progress and prospects of early detection in lung cancer

Lung cancer is the leading cause of cancer-related death in the world. It is broadly divided into small cell (SCLC, approx. 15% cases) and non-small cell lung cancer (NSCLC, approx. 85% cases). The main histological subtypes of NSCLC are adenocarcinoma and squamous cell carcinoma, with the presence of specific DNA mutations allowing further molecular stratification. If identified at an early stage, surgical resection of NSCLC offers a favourable prognosis, with published case series reporting 5-year survival rates of up to 70% for small, localized tumours (stage I). However, most patients (approx. 75%) have advanced disease at the time of diagnosis (stage III/IV) and despite significant developments in the oncological management of late stage lung cancer over recent years, survival remains poor. In 2014, the UK Office for National Statistics reported that patients diagnosed with distant metastatic disease (stage IV) had a 1-year survival rate of just 15-19% compared with 81-85% for stage I.

Improvement of survival for non-small cell lung cancer over time

Non-small cell lung cancer (NSCLC) is the main histological subtype of lung cancer, which is the leading cause of cancer death. It is unclear whether the improved survival seen at high-volume centers applies to the general population and, more importantly, whether the improvement in lung cancer survival was just a consequence of improved screening work. Data from the Surveillance, Epidemiology, and End Results (SEER) registry was used to identify 405,580 patients with NSCLC diagnosed from 1988 to 2008. The patients were divided into four groups according to the year of diagnosis. Trends of clinical characteristics were analyzed to reflect the progress of screening work. Five-year relative survivals in various subgroups were compared. The results indicated that proportion of aged, advanced, and non-surgical patients increased, whereas patients with lymph node metastasis and high histology grade decreased. Improvements in all stages of NSCLC patients were demonstrated, with relatively more significant gains for patients with localized and regional disease. After potentially curative surgical resection, remarkable improvements were observed in both cohorts with time (surgical: 52.00%–63.00%; non-surgical: 6.10%–13.50%). Specifically, patients who underwent pneumonectomy, lobectomy/bilobectomy, and partial/wedge/segmental resection all presented better survival rates. Our SEER analysis demonstrated improvements among patients in all stages of NSCLC that were deemed attributable to improved therapy and medical care for NSCLC rather than improved screening work.

AJRCCM: 100-Year Anniversary. The Shifting Landscape for Lung Cancer: Past, Present, and Future

The past century has witnessed a transformative shift in lung cancer from a rare reportable disease to the leading cause of cancer death among men and women worldwide. This historic shift reflects the increase in tobacco consumption worldwide, spurring public health efforts over the past several decades directed at tobacco cessation and control. Although most lung cancers are still diagnosed at a late stage, there have been significant advances in screening high-risk smokers, diagnostic modalities, and chemopreventive approaches. Improvements in surgery and radiation are advancing our ability to manage early-stage disease, particularly among patients considered unfit for traditional open resection. Arguably, the most dramatic progress has occurred on the therapeutic side, with the development of targeted and immune-based therapy over the past decade. This article reviews the major shifts in the lung cancer landscape over the past 100 years. Although many ongoing clinical challenges remain, this review will also highlight emerging molecular and imaging-based approaches that represent opportunities to transform the prevention, early detection, and treatment of lung cancer in the years ahead.

Screening for lung cancer

This review will comprise a general overview of the epidemiology of lung cancer, as well as lung cancer risk factors, screening modalities, current guideline recommendations for screening, and our approach to lung cancer screening.

Chaperonin (HSP60) and annexin-2 are candidate biomarkers for non-small cell lung carcinoma

BACKGROUND

Lung cancer is responsible of 12.4% and 17.6% of all newly diagnosed cancer cases and mortality due to cancer, respectively, and 5-year survival rate despite all improved treatment options is 15%. This survival rate reaches 66% in the Stage 1 and surgically treated patients. Early diagnosis which could not be definitely and commonly achieved yet is extremely critical in obtaining high survival rate in this disease. For this reason; proteomic differences were evaluated using matrix assisted laser desorption ionization (MALDI) mass spectrometry in the subgroups of lung adenocarcinoma and squamous cell carcinoma.

METHODS

Fresh tissue samples of 36 malignant cases involving 83.3% (n = 30) men and 16.7% (n = 6) women patients were distributed into 2 groups as early and end stage lung cancer and each group were composed of subgroups including 18 squamous cell carcinoma (9 early stage cases, 9 end stage cases) and 18 adenocarcinoma cases (9 early stage cases, 9 end stage cases). The fresh tissues obtained from the tumoral and matched normal sites after surgical intervention. The differences in protein expression levels were determined by comparing proteomic changes in each patient.

RESULTS

In the subgroups of advanced stage adenocarcinoma; tumoral tissue revealed differences in expression of 2 proteins compared with normal parenchymal tissue. Of those; difference in protein expression in heat shock protein 60 (HSP60) was found statistically significant (P = 0.0001). Subgroups of early and advanced stage squamos cell carcinoma have differed in certain 20 protein expression of normal tissue and diseased squamos cell carcinoma. Of those, increased protein expression level of only annexin-2 protein was found statistically significant (P = 0.002). No significant difference was detected in early and advanced stage protein expressions of the tumoral tissues in the subgroups of adenocarcinoma and squamous cell carcinoma.

CONCLUSIONS

We conclude that with respect to early diagnosis of lung cancer that HSP60 and annexin-2 proteins are the important biomarkers in the subgroups of adenocarcinoma and squamous cell carcinoma. We also consider that these 2 proteins are molecules which may provide critical contribution in evaluation of prognosis, metastatic potential, response to treatment, and in establishment of differential diagnosis between adenocarcinoma and squamous cell carcinoma.

Noncompliance in cancer screening trials

Background Randomized trials evaluating new cancer screening technologies may underestimate the efficacy of screening to reduce cancer mortality if study participants are noncompliant. Participants may fail to comply with the screening itself or fail to obtain appropriate diagnostic follow-up and treatment. Noncompliance with screening has drawn wide attention, but little attention has been paid to noncompliance with diagnostic follow-up and treatment.

Purpose To examine the importance of noncompliance with screening, follow-up, and treatment in cancer screening trials.

Methods The unique problems associated with noncompliance in screening trials are described and provide an example illustrating the potential impact of noncompliance in a screening trial. I discuss issues that arise with measurement of follow-up and therapeutic noncompliance, and the benefit of collecting information on health system and participant characteristics associated with noncompliance.

Results The estimate of the efficacy of a screening program on cancer mortality can be adjusted for screening, follow-up, and treatment noncompliance. Noncompliance needs to be measured in a rigorous, systematic manner across all arms of the trial. Information on health system and participant characteristics associated with compliance may also be incorporated into statistical models to estimate screening effects with full compliance, plan interventions to increase compliance, and extrapolate results of screening trials from one population to another.

Limitations Measuring compliance with follow-up and treatment can be difficult when these occur outside the trial, and when there is variation among providers in follow-up and treatment practices.

Conclusions Noncompliance may alter the estimate of a screening effect on cancer mortality in clinical trials. It is possible to adjust screening efficacy estimates for noncompliance using existing statistical techniques. It is important that data describing compliance with screening, follow-up, and treatment are collected as part of standard data collection in cancer screening trials. Clinical Trials 2007; 4: 341—349. http://ctj.sagepub.com

Lung cancer screening: promise and pitfalls

The results of the National Lung Screening Trial (NLST) have provided the medical community and American public with considerable optimism about the potential to reduce lung cancer mortality with imaging-based screening. Designed as a randomized trial, the NLST has provided the first evidence of screening benefit by showing a 20% reduction in lung cancer mortality and a 6.7% reduction in all-cause mortality with low dose helical computed tomography (LDCT) screening relative to chest X-ray. The major harms of LDCT screening include the potential for radiation-induced carcinogenesis; high false-positivity rates in individuals without lung cancer, and overdiagnosis. Following the results of the NLST, the National Comprehensive Cancer Network (NCCN) published the first of multiple lung cancer screening guidelines under development by major medical organizations. These recommendations amalgamated screening cohorts, practices, interpretations, and diagnostic follow-up based on the NLST and other published studies to provide guidance for the implementation of LDCT screening. There are major areas of opportunity to optimize implementation. These include standardizing practices in the screening setting, optimizing risk profiles for screening and for managing diagnostic evaluation in individuals with indeterminate nodules, developing interdisciplinary screening programs in conjunction with smoking cessation, and approaching all stakeholders systematically to ensure the broadest education and dissemination of screening benefits relative to risks. The incorporation of validated biomarkers of risk and preclinical lung cancer can substantially enhance the effectiveness screening programs.

Pulmonary nodules and CT screening: the past, present and future

Lung cancer screening has come a long way since the early studies with chest X-ray. Advancing technology and progress in the processing of images have enabled low dose CT to be tried and tested, and evidence suggests its use can result in a significant mortality benefit. There are several issues that need refining in order to successfully implement screening in the UK and elsewhere. Some countries have started patchy implementation of screening and there is increased recognition that the appropriate management of pulmonary nodules is crucial to optimise benefits of early detection, while reducing harm caused by inappropriate medical intervention. This review summarises and differentiates the many recent guidelines on pulmonary nodule management, discusses screening activity in other countries and exposes the present barriers to implementation in the UK.

Lung cancer screening: a systematic review of clinical practice guidelines

BACKGROUND

Lung cancer screening using low-dose computed tomography presents an exciting development for high-risk individuals. Several expert bodies and governments have recently issued and updated their clinical practice guidelines (CPGs) for lung cancer screening. We evaluate the CPGs and compare and contrast the recommendations between them.

METHODS

We searched seven databases (MEDLINE, EMBASE, TRIP, NGC, SIGN, GIN, CMA Infobase) to find CPGs, and used the appraisal of guidelines for research and evaluation instrument (AGREE-II) to evaluate them. We also assessed the recommendations within each CPG.

RESULTS

Of the eight CPGs included, four guidelines were regarded as high in quality (60%) based on rigour of development and effectively targeting 4-5 of the six domains according to the AGREE-II criteria. Most CPGs' recommendations for the lung cancer screening of high-risk individuals, the associated screening parameters and the benefit vs. harm of screening were consistent. However, there is still variation among the CPGs reviewed in this study.

CONCLUSIONS

The qualities of the selected CPGs vary and there is potential to improve the qualities among and between each. Specifically, more evidence is needed to support the recommendations such as a larger cohort of high-risk participants, and further analysis of the lung cancer screening interval, the benefit vs. harm of lung cancer screening, the timing and rigour of follow-up and availability of effective treatments.

Lung Cancer Screening

Lung cancer is the leading cause of cancer mortality in the United States and worldwide. Since lung cancer outcomes are dependent on stage at diagnosis with early disease resulting in longer survival, the goal of screening is to capture lung cancer in its early stages when it can be treated and cured. Multiple studies have evaluated the use of chest X-ray (CXR) with or without sputum cytologic examination for lung cancer screening, but none has demonstrated a mortality benefit. In contrast, the multicenter National Lung Screening Trial (NLST) from the United States found a 20 % reduction in lung cancer mortality following three consecutive screenings with low-dose computed tomography (LDCT) in high-risk current and former smokers. Data from European trials are not yet available. In addition to a mortality benefit, lung cancer screening with LDCT also offers a unique opportunity to promote smoking cessation and abstinence and may lead to the diagnoses of treatable chronic diseases, thus decreasing the overall disease burden. The risks of lung cancer screening include overdiagnosis, radiation exposure, and false-positive results leading to unnecessary testing and possible patient anxiety and distress. However, the reduction in lung cancer mortality is a benefit that outweighs the risks and major health organizations currently recommend lung cancer screening using age, smoking history, and quit time criteria derived from the NLST. Although more research is needed to clearly define and understand the application and utility of lung cancer screening in the general population, current data support that lung cancer screening is effective and should be offered to eligible beneficiaries.

Lung cancer screening: history, current perspectives, and future directions

Lung cancer has remained the leading cause of death worldwide among all cancers. The dismal 5-year survival rate of 16% is in part due to the lack of symptoms during early stages and lack of an effective screening test until recently. Chest X-ray and sputum cytology were studied extensively as potential screening tests for lung cancer and were conclusively proven to be of no value. Subsequently, a number of studies compared computed tomography (CT) with the chest X-ray. These studies did identify lung cancer in earlier stages. However, they were not designed to prove a reduction in mortality. Later trials have focused on low-dose CT (LDCT) as a screening tool. The largest US trial - the National Lung Screening Trial (NLST) - enrolled approximately 54,000 patients and revealed a 20% reduction in mortality. While a role for LDCT in lung cancer screening has been established, the issues of high false positive rates, radiation risk, and cost effectiveness still need to be addressed. The guidelines of the international organizations that now include LDCT in lung cancer screening are reviewed. Other methods that may improve earlier detection such as positron emission tomography, autofluorescence bronchoscopy, and molecular biomarkers are also discussed.

Lung cancer screening: Computed tomography or chest radiographs?

Worldwide, lung cancer is the leading cause of mortality due to malignancy. The vast majority of cases of lung cancer are smoking related and the most effective way of reducing lung cancer incidence and mortality is by smoking cessation. In the Western world, smoking cessation policies have met with limited success. The other major means of reducing lung cancer deaths is to diagnose cases at an earlier more treatable stage employing screening programmes using chest radiographs or low dose computed tomography. In many countries smoking is still on the increase, and the sheer scale of the problem limits the affordability of such screening programmes. This short review article will evaluate the current evidence and potential areas of research which may benefit policy making across the world.

China national lung cancer screening guideline with low-dose computed tomography (2015 version)

BACKGROUND

Lung cancer is the leading cause of cancer-related death in China. Results from a randomized controlled trial using annual low-dose computed tomography (LDCT) in specific high-risk groups demonstrated a 20% reduction in lung cancer mortality.

METHODS

A China national lung cancer screening guideline was developed by lung cancer early detection and treatment expert group appointed by the National Health and Family Planning Commission, based on results of the National Lung Screening Trial, systematic review of evidence related to LDCT screening, and protocol of lung cancer screening program conducted in rural China.

RESULTS

Annual lung cancer screening with LDCT is recommended for high risk individuals aged 50-74 years who have at least a 20 pack-year smoking history and who currently smoke or have quit within the past five years. Individualized decision making should be conducted before LDCT screening. LDCT screening also represents an opportunity to educate patients as to the health risks of smoking; thus, education should be integrated into the screening process in order to assist smoking cessation.

CONCLUSIONS

A lung cancer screening guideline is provided for the high-risk population in China.