Screening for lung cancer. A critique of the Mayo Lung Project

Detection of lung cancer and stages via breath analysis using a self-made electronic nose device

BACKGROUND

Breathomics is an emerging area focusing on monitoring and diagnosing pulmonary diseases, especially lung cancer. This research aims to employ metabolomic methods to create a breathprint in human-expelled air to rapidly identify lung cancer and its stages.

RESEARCH DESIGN AND METHODS

An electronic nose (e-nose) system with five metal oxide semiconductor (MOS) gas sensors, a microcontroller, and machine learning algorithms was designed and developed for this application. The volunteers in this study include 114 patients with lung cancer and 147 healthy controls to understand the clinical potential of the e-nose system to detect lung cancer and its stages.

RESULTS

In the training phase, in discriminating lung cancer from controls, the XGBoost classifier model with 10-fold cross-validation gave an accuracy of 91.67%. In the validation phase, the XGBoost classifier model correctly identified 35 out of 42 patients with lung cancer samples and 44 out of 51 healthy control samples providing an overall sensitivity of 83.33% and specificity of 86.27%.

CONCLUSIONS

These results indicate that the exhaled breath VOC analysis method may be developed as a new diagnostic tool for lung cancer detection. The advantages of e-nose based diagnostics, such as an easy and painless method of sampling, and low-cost procedures, will make it an excellent diagnostic method in the future.

A population-based study of 15,000 people on Knowledge and awareness of lung cancer symptoms and risk factors in Saudi Arabia

Background

Lung cancer is currently the most fatal form of cancer worldwide, ranking as the fourth most prevalent type in Saudi Arabia, particularly among males. This trend is expected to increase with growing population, lifestyle changes, and aging population. Understanding the awareness of the Saudi population regarding the risk factors and symptoms of lung cancer is necessary to attenuate the predicted increase in cases.

Method

A cross-sectional, population-based survey was performed using a previously validated questionnaire (Lung CAM). Multiple linear regression analysis was used to assess variables associated with deficiency in knowledge and awareness of risk factors and symptoms of lung cancer.

Results

Majority of the 15,099 respondents were male (65%), aged between 18 and 30 years (53%), 50% of which were educated up to a bachelor's degree level. Overall awareness of lung cancer signs and symptoms was 53%, with painful cough and coughing up blood being the best-known symptoms. Conversely, persistent shoulder pain (44%) and clubbing fingers (47%) were the least known lung cancer symptoms. Also, 60% of the respondents showed low confidence in identifying the signs and symptoms of lung cancer. The overall awareness of the risk factors for lung cancer development was 74%, with first-hand (74%) and second-hand (68%) smoking being the most known risk factors. However, only ≤ 62% know the other non-smoking risk factors. Awareness of the risk factors and symptoms of lung cancer depended on age, gender, education, marital and employment status (p < 0.001).

Conclusion

Public awareness of the risk factors and symptoms of lung cancer in Saudi Arabia is inadequate and heavily dependent on education and socio-economic status. Awareness can be improved through campaigns to raise awareness about other lesser-known lung cancer risk factors and symptoms.

Cancer Screening, Incidental Detection, and Overdiagnosis

BACKGROUND

In the past, patients were only diagnosed with cancer because they had symptoms. Now, because of screening and incidental detection, some patients are diagnosed with cancer when they are asymptomatic. While this shift is typically viewed as desirable, it has produced an unfortunate side-effect: it is now possible to be diagnosed with a cancer not destined to cause symptoms or death-a phenomenon labeled as overdiagnosis.

CONTENT

We begin with a brief introduction to the heterogeneity of cancer progression: at one extreme, some cancers are already systemic by the time they are detectable; at the other, some grow extremely slowly or even regress. The ensuing sections describe the evidence that the pursuit of earlier detection has led to overdiagnosis. Although rarely confirmed in an individual, overdiagnosis is readily identifiable in a long-term follow-up of a randomized trial of screening. Furthermore, 2 population signatures for overdiagnosis exist: (a) rising incidence coupled with stable mortality and (b) rising early-stage incidence coupled with stable late-stage incidence. Finally, we review the misleading feedback produced by overdiagnosis-such as rising 5-year survival rates and more cancer survivors. This feedback is erroneously interpreted as reinforcing the value of early detection, encourages more screening/incidental detection and, ironically, promotes more overdiagnosis.

SUMMARY

Overdiagnosis is an unintended consequence of the desire to detect cancer early. Given the evolving understanding that tumor biology and host response are more relevant to prognosis than early vs late diagnosis, it is time to challenge the assertion that early diagnosis is always the best approach to curing cancer.

Ensemble Federated Learning Approach for Diagnostics of Multi-Order Lung Cancer

The early detection and classification of lung cancer is crucial for improving a patient's outcome. However, the traditional classification methods are based on single machine learning models. Hence, this is limited by the availability and quality of data at the centralized computing server. In this paper, we propose an ensemble Federated Learning-based approach for multi-order lung cancer classification. This approach combines multiple machine learning models trained on different datasets allowing for improvising accuracy and generalization. Moreover, the Federated Learning approach enables the use of distributed data while ensuring data privacy and security. We evaluate the approach on a Kaggle cancer dataset and compare the results with traditional machine learning models. The results demonstrate an accuracy of 89.63% with lung cancer classification.

Effective lung cancer control: An unaccomplished challenge in cancer research

Lung cancer has always been a burden to the society since its non-effective early detection and poor survival status. Different imaging modalities such as computed tomography scan have been practiced for lung cancer detection. This review focuses on the importance of sputum cytology for early lung cancer detection and biomarkers effective in sputum samples. Published articles were discussed in light of the potential of sputum cytology for lung cancer early detection and risk assessment across high-risk groups. Recent developments in sample processing techniques have documented a clear potential to improve or refine diagnosis beyond that achieved with conventional sputum cytology examination. The diagnostic potential of sputum cytology may be exploited better through the standardization and automation of sputum preparation and analysis for application in routine laboratory practices and clinical trials. The challenging aspects in sputum cytology as well as sputum-based molecular markers are to ensure appropriate standardization and validation of the processing techniques.

A Structured Program Maximizes Benefit of Lung Cancer Screening in an Area of Endemic Histoplasmosis

BACKGROUND

Lung cancer screening with low-dose computed tomography has demonstrated at least a 20% decrease in lung cancer-specific mortality, but has the potential harm of unnecessary invasive procedures due to false positive results. We report the outcomes of a structured multi-disciplinary lung cancer screening program in an area of endemic histoplasmosis.

METHODS

A retrospective review of patients undergoing lung cancer screening from December 2012 to March 2019 was conducted. Findings suspicious for lung cancer were presented at a multidisciplinary thoracic tumor board. Patients were assigned to interval imaging follow-up, additional diagnostic imaging, or referral for an invasive procedure. Invasive procedures were then compared between benign and malignant pathologies.

RESULTS

4087 scans were done on 2129 patients. 372 (9.1%) were suspicious and presented at a multidisciplinary thoracic tumor board. Ultimately 108 procedures were done: 55 bronchoscopies, seven percutaneous biopsies, and 46 operations. 25 patients (1.2%) underwent bronchoscopy resulting in benign pathology, significantly associated with an indication of an endobronchial lesion (p=0.01). All percutaneous biopsies revealed malignancy. Five patients (0.2%) who underwent resection had benign disease. Lung cancer was diagnosed in 67 patients (3.1% of the entire cohort), 46 of which were stage I/II.

CONCLUSIONS

Lung cancer screening in a structured, multidisciplinary program successfully identifies patients with early-stage lung cancer with limited unnecessary surgical interventions. Isolated endobronchial lesions should undergo short interval imaging follow up to avoid bronchoscopy for benign disease. Future studies to minimize unnecessary procedures could incorporate biomarkers and advanced imaging analysis into risk assessment models.

Lung cancer screening: who pays? Who receives? The European perspectives

Lung cancer is the leading cause of cancer-related death worldwide, and its early detection is critical to achieving a curative treatment and to reducing mortality. Low-dose computed tomography (LDCT) is a highly sensitive technique for detecting noninvasive small lung tumors in high-risk populations. We here analyze the current status of lung cancer screening (LCS) from a European point of view. With economic burden of health care in most European countries resting on the state, it is important to reduce costs of screening and improve its effectiveness. Current cost-effectiveness analyses on LCS have indicated a favorable economic profile. The most recently published analysis reported an incremental cost-effectiveness ratio (ICER) of €3,297 per 1 life-year gained adjusted for the quality of life (QALY) and €2,944 per life-year gained, demonstrating a 90% probability of ICER being below €15,000 and a 98.1% probability of being below €25,000. Different risk models have been used to identify the target population; among these, the PLCOM2012 in particular allows for the selection of the population to be screened with high sensitivity. Risk models should also be employed to define screening intervals, which can reduce the general number of LDCT scans after the baseline round. Future perspectives of screening in a European scenario are related to the will of the policy makers to implement policy on a large scale and to improve the effectiveness of a broad screening of smoking-related disease, including cardiovascular prevention, by measuring coronary calcium score on LDCT. The employment of artificial intelligence (AI) in imaging interpretation, the use of liquid biopsies for the characterization of CT-detected undetermined nodules, and less invasive, personalized surgical treatments, will improve the effectiveness of LCS.

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.

The promises and challenges of early non-small cell lung cancer detection: patient perceptions, low-dose CT screening, bronchoscopy and biomarkers

Lung cancer survival statistics are sobering with survival ranking among the poorest of all cancers despite the addition of targeted therapies and immunotherapies. However, improvements in tools for early detection hold promise. The Nederlands–Leuvens Longkanker Screenings Onderzoek (NELSON) trial recently corroborated the findings from the previous National Lung Screening Trial low‐dose Computerised Tomography (NLST) screening trial in reducing lung cancer mortality. Biomarker research and development is increasing at pace as the molecular life histories of lung cancers become further unravelled. Low‐dose CT screening (LDCT) is effective but targets only those at the highest risk and is burdensome on healthcare. An optimally designed CT screening programme at best will only detect a low proportion of overall lung cancers as only those at very high‐risk meet screening criteria. Biomarkers that help risk stratify suitable patients for LDCT screening, and those that assist in determining which LDCT detected nodules are likely to represent malignant disease are needed. Some biomarkers have been proposed as standalone lung cancer diagnosis tools. Bronchoscopy technology is improving, with better capacity to identify and obtain samples from early lung cancers. Clinicians need to be aware of each early lung cancer detection method’s inherent limitations. We anticipate that the future of early lung cancer diagnosis will involve a synergistic, multimodal approach, combining several early detection methods.

Predictive factors for the participation of general practitioners in lung cancer screening by low-dose CT scan in the Somme department in northern France

INTRODUCTION

A study on lung cancer screening using low-dose computed tomography (DEP KP80) was conducted in the Somme department in northern France between May 2016 and December 2018. We conducted a cross-sectional survey of family physicians in that department to identify potential predictive factors for their participation in this pilot study.

METHODS

A survey questionnaire was sent to the 545 general practitioners (GPs) of the Somme department. This survey rendered it possible to identify the investigators who were active in the DEP KP80 study. The questionnaire's content was focused on the socio-demographic conditions of GPs, their professional practices, and their medical practice situations.

RESULTS

The response rate was 38% (206 completed questionnaires). Active investigators in DEP KP80 accounted for 55% (n=113) of the GPs surveyed, and non-investigators for 45% (n=93). Age, gender, or medical practice situation were not related to the active GPs' participation in DEP KP80. A multivariate analysis revealed that two factors were correlated with active participation in organized screening: (1) prescription of nicotine replacement therapy; (2) smoking history of the GP.

CONCLUSIONS

Securing the active involvement of family physicians and of the French regional cancer screening coordination centers seems essential for the future organization of lung cancer screening on a regional or national level. Our results demonstrate that incorporating smoking cessation support structures into the program would maximize the mechanism's potential.

Performance of lung cancer screening with low-dose CT in Gejiu, Yunnan: A population-based, screening cohort study

Background

The performance of lung cancer screening with low‐dose computed tomography (CT) (LDCT) in China is uncertain. This study aimed to evaluate the performance of LDCT lung cancer screening in the Chinese setting.

Methods

In 2014, a screening cohort of lung cancer with LDCT was established in Gejiu, Yunnan Province, a screening center of the Lung Cancer Screening Program in Rural China (LungSPRC). Participants received a baseline screening and four rounds of annual screening with LDCT in two local hospitals until June 2019. We analyzed the rates of participation, detection, early detection, and the clinical characteristics of lung cancer.

Results

A total of 2006 participants had complete baseline screening results with a compliance rate of 98.4%. Of these, 1411 were high‐risk and 558 were nonhigh‐risk participants. During this period, 40 lung cancer cases were confirmed, of these, 35 were screen‐detected, four were post‐screening and one was an interval case. The positive rate of baseline and annual screening was 9.7% and 9.0%, while the lung cancer detection rate was 0.4% and 0.6%, respectively. The proportion of early lung cancer increased from 37.5% in T0 to 75.0% in T4. Adenocarcinoma was the most common histological subtype. Lung cancer incidence according to the criteria of LungSPRC and National Lung Cancer Screening Trial (NLST) was 513.31 and 877.41 per 100 000 person‐years, respectively.

Conclusions

The program of lung cancer screening with LDCT showed a successful performance in Gejiu, Yunnan. However, further studies are warranted to refine a high‐risk population who will benefit most from LDCT screening and reduce the high false positive results.

Key points

This study reports the results of lung cancer screening with LDCT in Gejiu, Yunnan, a high‐risk area of lung cancer, and it demonstrates that lung cancer screening with LDCT is effective in detecting early‐stage lung cancer. Our program provides an opportunity to explore the performance of LDCT lung cancer screening in the Chinese context.

Overdiagnosis of lung cancer with low-dose computed tomography screening: meta-analysis of the randomised clinical trials

In low-dose computed tomography (LDCT) screening for lung cancer, all three main conditions for overdiagnosis in cancer screening are present: 1) a reservoir of slowly or nongrowing lung cancer exists; 2) LDCT is a high-resolution imaging technology with the potential to identify this reservoir; and 3) eligible screening participants have a high risk of dying from causes other than lung cancer. The degree of overdiagnosis in cancer screening is most validly estimated in high-quality randomised controlled trials (RCTs), with enough follow-up time after the end of screening to avoid lead-time bias and without contamination of the control group. Nine RCTs investigating LDCT screening were identified. Two RCTs were excluded because lung cancer incidence after the end of screening was not published. Two other RCTs using active comparators were also excluded. Therefore, five RCTs were included: two trials were at low risk of bias, two of some concern and one at high risk of bias. In a meta-analysis of the two low risk of bias RCTs including 8156 healthy current or former smokers, 49% of the screen-detected cancers were overdiagnosed. There is uncertainty about this substantial degree of overdiagnosis due to unexplained heterogeneity and low precision of the summed estimate across the two trials.

Key points

Nine randomised controlled trials (RCTs) on low-dose computed tomography screening were identified; five were included for meta-analysis but only two of those were at low risk of bias.In a meta-analysis of recent low risk of bias RCTs including 8156 healthy current or former smokers from developed countries, we found that 49% of the screen-detected cancers may be overdiagnosed.There is uncertainty about the degree of overdiagnosis in lung cancer screening due to unexplained heterogeneity and low precision of the point estimate.If only high-quality RCTs are included in the meta-analysis, the degree of overdiagnosis is substantial.

Educational aims

To appreciate that low-dose computed tomography screening for lung cancer meets all three main conditions for overdiagnosis in cancer screening: a reservoir of indolent cancers exists in the population; the screening test is able to "tap" this reservoir by detecting biologically indolent cancers as well as biologically important cancers; and the population being screened is characterised by a relatively high competing risk of death from other causesTo learn about biases that might affect the estimates of overdiagnosis in randomised controlled trials in cancer screening.

Acquired Resistance in Lung Cancer

The last decade has witnessed a transformation in the treatment of advanced-stage lung cancer from a largely palliative approach to one where long-term durable remissions and even cures might be within reach. In this review, we discuss the current state of oncogene-directed precision medicine therapies in lung cancer and focus on the major cause of mortality for lung cancer patients: acquired resistance. We consider the multifaceted resistance mechanisms tumors utilize, often simultaneously. We then present areas for future scientific and clinical investigation with an emphasis on population dynamics, early detection, combinatorial therapies targeting resistance mechanisms, and understanding the drug-tolerant persister state.

Measuring the Effects of Education in Detecting Lung Cancer on Chest Radiographs: Utilization of a New Assessment Tool

This study was designed to evaluate the effect of group and individualized educational lectures to accurately interpret chest radiographs of lung cancer patients and to introduce a new educational tool in evaluating skills for reading chest radiographs. Utilizing "hotspot" technology will be instrumental in measuring the effect of education in interpreting chest radiographs. There were 48 participants in the study. Chest radiographs of 100 lung cancer patients and 11 healthy patients taken at various time points were used for evaluation. Using "hotspot" technology, lesions on each radiograph were outlined. Values were taken at baseline, after which the group received lectures. Several days later, they underwent exam 2. Exam 3 was conducted after individualized lectures. A final exam was taken after the participants underwent individualized training within 2 months. Scores significantly improved after the individual lessons (p < 0.001). This improvement in performance decreased in the final examination. Statistically significant differences were observed between exam 2 vs. exam 3 and exam 3 vs. the final exam (p < 0.001, p < 0.001). Participants demonstrated more improvement in detecting lesions in abnormal chest radiographs than in identifying normal ones. Although there was significant improvement in detecting abnormal radiographs by the end of the study (p < 0.001), no improvement was observed in detecting normal ones. We measured lung cancer detection rate using a new "hotspot" detection tool for chest radiographs. With the proposed scoring system, this tool could be objectively used in evaluating the educational effects.

Misclassification of the actual causes of death and its impact on analysis: A case study in non-small cell lung cancer

OBJECTIVES

Cumulative incidence of lung cancer deaths (LC-CID) is an important metric to understand cancer prognosis and to determine treatment options. However, credible estimates of LC-CID rely on accurate cause-of-death coding in death certificates. Results from lung cancer screening trials estimated 15% under-reporting and 1% over-reporting of lung cancer deaths due to misclassification. This study investigated the impact of cause-of-death misclassification on the estimation of LC-CID.

MATERIALS AND METHODS

Patients with stage I/II non-small cell lung cancer (NSCLC) from the Surveillance, Epidemiology, and End Results registry were included. LC-CID was estimated using the competing-risk approach in two ways: (1) reporting observed estimates that ignore potential cause-of-death misclassification and (2) correcting for plausible misclassification rates reported in the literature (15% under-reporting and 1% over-reporting). Bias was quantified as the difference between observed and corrected 10-year LC-CIDs: positive values indicated that observed LC-CID overestimated true LC-CID, whereas negative values indicated the opposite.

RESULTS

Among 66,179 patients, the impact of over-reporting on 10-year LC-CID was negligible across all age groups. In contrast, under-reporting resulted in substantial underestimation of 10-year LC-CID. The biases increased as age increased due to higher LC-CIDs: 10-year LC-CIDs among stage I patients 18-44, 45-59, 60-74 and ≥75 years were 25%, 32%, 41%, and 50%, respectively, and the corresponding biases given the plausible misclassification rates were -4.4%, -5.6%, -7.1%, and -8.6%. Because the observed LC-CIDs among patients with stage II disease were higher than those with stage I disease, the biases were greater among stage II patients, up to -12.5% in the oldest age group.

CONCLUSIONS

In lung cancer, LC-CID may be severely underestimated due to under-reporting of lung cancer deaths, particularly among older patients or those with late-stage disease. Future studies that involve such subpopulations should present the corrected LC-CIDs based on plausible misclassification rates alongside the observed LC-CIDs.

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.

Chest radiography surveillance for lung cancer: Results from a National Health Insurance database in South Korea

BACKGROUND

Lung cancer screening with low-dose computed tomography reduced mortality in selected high risk patients. However, the use of chest radiography for lung cancer screening in Asian populations is still controversial. We investigated the effectiveness of chest radiographic surveillance using a nationwide health service data in South Korea.

METHODS

Data from the Korean National Health Insurance Service examinee cohort of 2004 to 2013 were examined, and 63,228 patients with lung cancer were identified, 38,494 (57%) of whom underwent chest radiography screening. The others did not undergo lung cancer screening and were considered as a control group. Clinical data including age, smoking, screening intervals, lung cancer stages, treatments, and survival were collected. Survival gain from surveillance after adjustment for lead-time bias based on the sojourn time was calculated. Cox-proportional hazard analyses were performed to evaluate the effectiveness of screening and to determine the appropriate screening interval for chest radiography surveillance.

RESULTS

Early lung cancer was found in 38% of patients receiving chest radiography versus 26% of those without surveillance. A patient age of more than 65 years (hazard ratio [HR], 1.53; 95% confidence limits [CL], 1.50-1.56), male (HR, 1.66; 95% CL, 1.62-1.70), and high lung cancer stages at the time of diagnosis were independent factors associated with mortality (each, P < 0.001). Chest radiography surveillance was a factor for decreasing mortality in female (HR, 0.81; 95% CL, 0.77-0.84, P < 0.001), with mortality reduction of 10% at the 3- and 5-year survival time-points. In female patients, chest radiography surveillance at intervals of less than 3 years was an independent predictor of improved survival.

CONCLUSIONS

Surveillance chest radiography increased survival in a female screened population in South Korea. Chest radiography intervals of less than 3 years may help to detect lung cancer in female patients.

[China National Lung Cancer Screening Guideline with Low-dose Computed Tomography (2018 version)]

BACKGROUND

Lung cancer is the leading cause of cancer-related death in China. The 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. The aim of tihs study is to establish the China National lung cancer screening guidelines for clinical practice.

METHODS

The China lung cancer early detection and treatment expert group (CLCEDTEG) established the China National Lung Cancer Screening Guideline with multidisciplinary representation including 4 thoracic surgeons, 4 thoracic radiologists, 2 medical oncologists, 2 pulmonologists, 2 pathologist, and 2 epidemiologist. Members have engaged in interdisciplinary collaborations regarding lung cancer screening and clinical care of patients with at risk for lung cancer. The expert group reviewed the literature, including screening trials in the United States and Europe and China, and discussed local best clinical practices in the China. A consensus-based guidelines, China National Lung Cancer Screening Guideline (CNLCSG), was recommended by CLCEDTEG 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 recommended for the high-risk population in China. Additional research , including LDCT combined with biomarkers, is needed to optimize the approach to low-dose CT screening in the future.

Detection of sputum cofilin-1 as indicator of malignancy

Cofilin-1 (CFL1), a small protein of 18 kDa, has been studied as a biomarker due to its involvement in tumor cell migration and invasion. Our aim was to evaluate CFL1 as an indicator of malignancy and aggressiveness in sputum samples. CFL1 was analyzed by ELISA immunoassay in the sputum of 73 lung cancer patients, 13 cancer-free patients, and 6 healthy volunteers. Statistical analyses included ANOVA, ROC curves, Spearman correlation, and logistic regression. Sputum CFL1 levels were increased in cancer patients compared to cancer-free patients and volunteers (P<0.05). High expression of sputum CFL1 was correlated to T4 stage (P=0.01) and N stage (P=0.03), tobacco history (P=0.01), and squamous cell carcinoma histologic type (P=0.04). The accuracy of sputum CFL1 in discriminating cancer patients from cancer-free patients and healthy volunteers were 0.78 and 0.69, respectively. CFL1 at a cut-off value of 415.25 pg/mL showed sensitivity/specificity of 0.80/0.70 in differentiating between healthy volunteers and cancer patients. Sputum CFL1 was also able to identify cancer-free patients from patients with lung cancer. The AUC was 0.70 and, at a cut-off point ≥662.63 pg/mL, we obtained 60% sensitivity and 54% specificity. Logistic regression analysis controlled for tobacco history, histologic types, and N stage showed that cancer cell-associated CFL1 was an independent predictor of death. Smoker patients with squamous cell carcinoma, lymph node metastasis and sputum CFL1>1.475 pg/mL showed augmented chance of death, suggesting lung cancer aggressiveness. CFL1 presented diagnostic value in detecting lung cancer and was associated to tumor aggressiveness.

Utility of the National Lung Screening Trial Criteria for Estimation of Lung Cancer in the Korean Population

Purpose

Screening forlung cancerin high-risk patients using theNational Lung Screening Trial (NLST) criteria resulted in a decreased lung cancer-related mortality rate. However, whether these criteria are applicable to the Korean has not been investigated thus far. Therefore, we estimated the utility of the NLST criteria as a screening tool for lung cancer in the Korean population.

Materials and Methods

The total number of newly diagnosed lung cancer cases in 2013 was obtained from the Korea National Statistical Office. The proportion of newly diagnosed lung cancer cases that met the NLST criteria was calculated via a retrospective cohort of a tertiary referral hospital. We estimated the nationwide proportion of patients who met the NLST criteria using the 5th Korea National Health and Nutrition Examination Survey conducted during 2010-2012 (KNHANES V).

Results

Using KNHANES V data, we found that approximately 6.92% of the general population of Korea would meet the NLST criteria. In the tertiary referral hospital, 29.6% of the 2,689 newly diagnosed lung cancer patients met the NLST criteria. In 2013, the total number of newly diagnosed lung cancer cases in Korea was 23,177. The estimated nationwide proportions of lung cancer patients who met and did not meet the NLST criteria were 0.37% and 0.06%, respectively, yielding a ratio of 5.78.

Conclusion

The NLST criteria demonstrated sound clinical utility for lung cancer screening of high-risk patients in Korea.

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.

[Lung Nodules Assessment--Analysis of Four Guidelines]

近20年来，随着计算机断层扫描（computed tomography, CT）技术的提高和肺癌高危人群筛查的普及，越来越多的肺部小结节被发现，然而肺结节的定性诊断仍有很多困难。肺结节是临床上一种常见的现象，恶性结节早期发病比较隐匿，如果不进行早期干预，其病程迅速、恶性程度强、预后差。如果能在早期阶段对病灶进行手术切除，将会明显改善肺癌患者的预后。目前针对肺结节的处理指南层出不穷，但各大指南均未达成统一的共识。本文拟对在国内影响最大的四个指南：美国国家综合癌症网络非小细胞肺癌（non-small cell lung cancer, NSCLC）临床实践指南、美国胸科医师协会肺癌诊疗指南、Fleischner-Society肺结节处理策略指南、肺结节的评估亚洲共识指南所推荐的肺结节诊断和处理策略进行介绍和分析。

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.

[Lung cancer screening with low-dose thoracic CT-scan in the Somme area]

RATIONALE

This feasibility trial proposes to set up in the department of the Somme an annual screening for lung cancer with low-dose thoracic CT. It responds to the first objective of the third cancer plan and follows the publication of the results of the National Lung Screening Trial in 2011.

METHODS

The method of this study is to use the existing networks among and between healthcare professionals and the departmental cancer screening structure. The inclusion criteria will be those of the National Lung Screening Trial. Screening will be proposed by treating physicians and chest physicians. The CT-scan will be performed in radiological centers that adhere to the good practice charter for low radiation scanning. A copy of CT results will be sent to the departmental structure of cancer screening (ADEMA80) which will ensure traceability and will perform statistical analysis. The study received funding from the Agence régionale de santé de la Picardie and la ligue contre le cancer.

EXPECTED RESULTS

The primary endpoints of this screening will be the number of cancers diagnosed and the survival of the patients. The follow-up of positive examinations, delays in management and the level of participation will also be assessed.

Advancing and sharing the knowledge base of CT screening for lung cancer

CT screening for lung cancer is gaining in acceptance and is now moving from the research domain into standard clinical practice. Coincident with this, there is also increasing awareness of the usefulness of collecting large datasets obtained in the clinical domain and how this can be used to advance practice. Toward this end, in the United States, the Centers for Medicare and Medicaid Services (CMS) are requiring data from screening to be entered into certified registries. While this is still in its early stage and only limited datasets are required, this would be particularly relevant if images as well as clinical information were collected as it will allow for additional evaluation of all imaging findings including ancillary ones and understanding how they integrate into the screening process. All of this needs to be considered in the context of how this information can be shared with a person interested in being screened. In particular, the potential benefit of screening needs to be presented in terms of what is meaningful to the individual including their chances of having lung cancer and also their chance of being cured. This is very different then presenting it in terms of mortality reduction which was never meant to be used for that purpose. Also, how findings made on the CT scans, in addition to those related to lung cancer will be meaningful to them.

Early detection of lung cancer

Most patients with lung cancer are diagnosed when they present with symptoms, they have advanced stage disease, and curative treatment is no longer an option. An effective screening test has long been desired for early detection with the goal of reducing mortality from lung cancer. Sputum cytology, chest radiography, and computed tomography (CT) scan have been studied as potential screening tests. The National Lung Screening Trial (NLST) demonstrated a 20% reduction in mortality with low-dose CT (LDCT) screening, and guidelines now endorse annual LDCT for those at high risk. Implementation of screening is underway with the desire that the benefits be seen in clinical practice outside of a research study format. Concerns include management of false positives, cost, incidental findings, radiation exposure, and overdiagnosis. Studies continue to evaluate LDCT screening and use of biomarkers in risk assessment and diagnosis in attempt to further improve outcomes for patients with lung cancer.

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.

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.

Long-Term Follow-up Results of the DANTE Trial, a Randomized Study of Lung Cancer Screening with Spiral Computed Tomography

RATIONALE

Screening for lung cancer with low-dose spiral computed tomography (LDCT) has been shown to reduce lung cancer mortality by 20% compared with screening with chest X-ray (CXR) in the National Lung Screening Trial, but uncertainty remains concerning the efficacy of LDCT screening in a community setting.

OBJECTIVES

To explore the effect of LDCT screening on lung cancer mortality compared with no screening. Secondary endpoints included incidence, stage, and resectability rates.

METHODS

Male smokers of 20+ pack-years, aged 60 to 74 years, underwent a baseline CXR and sputum cytology examination and received five screening rounds with LDCT or a yearly clinical review only in a randomized fashion.

MEASUREMENTS AND MAIN RESULTS

A total of 1,264 subjects were enrolled in the LDCT arm and 1,186 in the control arm. Their median age was 64.0 years (interquartile range, 5), and median smoking exposure was 45.0 pack-years. The median follow-up was 8.35 years. One hundred four patients (8.23%) were diagnosed with lung cancer in the screening arm (66 by CT), 47 of whom (3.71%) had stage I disease; 72 control patients (6.07%) were diagnosed with lung cancer, with 16 (1.35%) being stage I cases. Lung cancer mortality was 543 per 100,000 person-years (95% confidence interval, 413-700) in the LDCT arm versus 544 per 100,000 person-years (95% CI, 410-709) in the control arm (hazard ratio, 0.993; 95% confidence interval, 0.688-1.433).

CONCLUSIONS

Because of its limited statistical power, the results of the DANTE (Detection And screening of early lung cancer with Novel imaging TEchnology) trial do not allow us to make a definitive statement about the efficacy of LDCT screening. However, they underline the importance of obtaining additional data from randomized trials with intervention-free reference arms before the implementation of population screening.

Positron emission tomography in the diagnostic work-up of screening-detected lung nodules

Low-dose computed tomography (CT) screening for lung cancer can reduce lung cancer mortality, but overdiagnosis, false positives and invasive procedures for benign nodules are worrying. We evaluated the utility of positron emission tomography (PET)-CT in characterising indeterminate screening-detected lung nodules. 383 nodules, examined by PET-CT over the first 6 years of the COSMOS (Continuous Observation of Smoking Subjects) study to diagnose primary lung cancer, were reviewed and compared with pathological findings (surgically-treated patients) or follow-up (negative CT for ⩾2 years, considered negative); 196 nodules were malignant. The sensitivity, specificity and accuracy of PET-CT for differentially diagnosing malignant nodules were, respectively, 64%, 89% and 76% overall, and 82%, 92% and 88% for baseline-detected nodules. Performance was lower for nodules found at repeat annual scans, with sensitivity ranging from 22% for nonsolid to 79% for solid nodules (p=0.0001). Sensitivity (87%) and specificity (73%) were high for nodules ⩾15 mm, better (sensitivity 98%) for solid nodules ⩾15 mm. PET-CT was highly sensitive for the differential diagnosis of indeterminate nodules detected at baseline, nodules ⩾15 mm and solid nodules. Sensitivity was low for sub-solid nodules and nodules discovered after baseline for which other methods, e.g. volume doubling time, should be used.

Lung cancer screening: subsequent evidences of national lung screening trial

The US National Lung Screening Trial (NLST) demonstrated a 20% reduction in lung cancer mortality and a 6.7% decrease in all-cause mortality. The NLST is the only trial showing positive results in a high-risk population, such as in patients with old age and heavy ever smokers. Lung cancer screening using a low-dose chest computed tomography might be beneficial for the high-risk group. However, there may also be potential adverse outcomes in terms of over diagnosis, bias and cost-effectiveness. Until now, lung cancer screening remains controversial. In this review, we wish to discuss the evolution of lung cancer screening and summarize existing evidences and recommendations.

Lung cancer screening

Lung cancer is the leading cause of cancer death. Although smoking prevention and cessation programs have decreased lung cancer mortality, there remains a large at-risk population. Dismal long-term survival rates persist despite improvements in diagnosis, staging, and treatment. Early efforts to identify an effective screening test have been unsuccessful. Recent advances in multidetector computed tomography have allowed screening studies using low-dose computed tomography (LDCT) to be performed. This set the stage for the National Lung Screening Trial that found that annual LDCT screening benefits individuals at high risk for lung cancer. An understanding of the harmful effects of lung cancer screening is required to help maximize the benefits and decrease the risks of a lung cancer screening program. Although many questions remain regarding LDCT screening, a comprehensive lung cancer screening program of high-risk individuals will increase detection of preclinical and potentially curable disease, creating a new model of lung cancer surveillance and management.

Evaluation and management of pulmonary nodules: state-of-the-art and future perspectives

INTRODUCTION

The imaging evaluation of pulmonary nodules, often incidentally detected on imaging examinations performed for other clinical reasons, is a frequently encountered clinical circumstance. With advances in imaging modalities, both the detection and characterization of pulmonary nodules continue to evolve and improve.

AREAS COVERED

This article will review the imaging modalities used to detect and diagnose benign and malignant pulmonary nodules, with a focus on computed tomography (CT), which continues to be the mainstay for evaluation. The authors discuss recent advances in the lung nodule management, and an algorithm for the management of indeterminate pulmonary nodules.

EXPERT OPINION

There are set of criteria that define a benign nodule, the most important of which are the lack of temporal change for 2 years or more, and certain benign imaging criteria, including specific patterns of calcification or the presence of fat. Although some indeterminate pulmonary nodules are immediately actionable, generally those approaching 1 cm or larger in diameter, at which size the diagnostic accuracy of tools such as positron emission tomography (PET)/CT, single photon emission CT (SPECT) and biopsy techniques are sufficient to warrant their use. The majority of indeterminate pulmonary nodules are under 1 cm, for which serial CT examinations through at least 2 years for solid nodules and 3 years for ground-glass nodules, are used to demonstrate either benign biologic behavior or otherwise. The management of incidental pulmonary nodules involves a multidisciplinary approach in which radiology plays a pivotal role. Newer imaging and postprocessing techniques have made this a more accurate technique eliminating ambiguity and unnecessary follow-up.

Overdiagnosis in low-dose computed tomography screening for lung cancer

IMPORTANCE

Screening for lung cancer has the potential to reduce mortality, but in addition to detecting aggressive tumors, screening will also detect indolent tumors that otherwise may not cause clinical symptoms. These overdiagnosis cases represent an important potential harm of screening because they incur additional cost, anxiety, and morbidity associated with cancer treatment.

OBJECTIVE

To estimate overdiagnosis in the National Lung Screening Trial (NLST).

DESIGN, SETTING, AND PARTICIPANTS

We used data from the NLST, a randomized trial comparing screening using low-dose computed tomography (LDCT) vs chest radiography (CXR) among 53 452 persons at high risk for lung cancer observed for 6.4 years, to estimate the excess number of lung cancers in the LDCT arm of the NLST compared with the CXR arm.

MAIN OUTCOMES AND MEASURES

We calculated 2 measures of overdiagnosis: the probability that a lung cancer detected by screening with LDCT is an overdiagnosis (PS), defined as the excess lung cancers detected by LDCT divided by all lung cancers detected by screening in the LDCT arm; and the number of cases that were considered overdiagnosis relative to the number of persons needed to screen to prevent 1 death from lung cancer.

RESULTS

During follow-up, 1089 lung cancers were reported in the LDCT arm and 969 in the CXR arm of the NLST. The probability is 18.5% (95% CI, 5.4%-30.6%) that any lung cancer detected by screening with LDCT was an overdiagnosis, 22.5% (95% CI, 9.7%-34.3%) that a non-small cell lung cancer detected by LDCT was an overdiagnosis, and 78.9% (95% CI, 62.2%-93.5%) that a bronchioalveolar lung cancer detected by LDCT was an overdiagnosis. The number of cases of overdiagnosis found among the 320 participants who would need to be screened in the NLST to prevent 1 death from lung cancer was 1.38.

CONCLUSIONS AND RELEVANCE

More than 18% of all lung cancers detected by LDCT in the NLST seem to be indolent, and overdiagnosis should be considered when describing the risks of LDCT screening for lung cancer.