Design, recruitment and baseline results of the ITALUNG trial for lung cancer screening with low-dose CT. Lung Cancer. 2009;64:34-40. [PMID: 18723240 DOI: 10.1016/j.lungcan.2008.07.003]

A phantom study investigating the relationship between ground-glass opacity visibility and physical detectability index in low-dose chest computed tomography

In this study, the relationship between ground-glass opacity (GGO) visibility and physical detectability index in low-dose computed tomography (LDCT) for lung cancer screening was investigated. An anthropomorphic chest phantom that included synthetic GGOs with CT numbers of -630 Hounsfield units (HU; high attenuation GGO: HGGO) and -800 HU (low attenuation GGO: LGGO), and three phantoms for physical measurements were employed. The phantoms were scanned using 12 CT systems located in 11 screening centers in Japan. The slice thicknesses and CT dose indices (CTDI(vol)) varied over 1.0-5.0 mm and 0.85-3.30 mGy, respectively, and several reconstruction kernels were used. Physical detectability index values were calculated from measurements of resolution, noise, and slice thickness properties for all image sets. Five radiologists and one thoracic surgeon, blind to one another's observations, evaluated GGO visibility using a five-point scoring system. The physical detectability index correlated reasonably well with the GGO visibility (R² = 0.709, p < 0.01 for 6 mm HGGO and R² = 0.646, p < 0.01 for 10 mm LGGO), and was nearly proportional to the CTDI(vol). Consequently, the CTDI(vol) also correlated reasonably well with the GGO visibility (R² = 0.701, p < 0.01 for 6 mm HGGO and R² = 0.680, p < 0.01 for 10 mm LGGO). As a result, the CTDI(vol) was nearly dominant in the GGO visibility for image sets with different reconstruction kernels and slice thicknesses, used in this study.

The Solitary Pulmonary Nodule

Due to the high etiological diversity and the potential for malignancy, pulmonary nodules represent a clinical challenge, becoming increasingly frequent as the number of CT examinations rises. The topic gains even more importance as clear evidence for the effectiveness of CT screening was provided by the National Lung Screening Trial (NLST). Yet, the results were tempered by the high false-positive rate and the requirement of performing further diagnostic procedures. The management of those detected solitary pulmonary nodules is currently based on the individuals' risk of developing lung cancer, the pulmonary nodule characteristics and the capability of diagnostic and therapeutic approaches.

Selecting High-Risk Individuals for Lung Cancer Screening: A Prospective Evaluation of Existing Risk Models and Eligibility Criteria in the German EPIC Cohort

Lung cancer risk prediction models are considered more accurate than the eligibility criteria based on age and smoking in identification of high-risk individuals for screening. We externally validated four lung cancer risk prediction models (Bach, Spitz, LLP, and PLCO(M2012)) among 20,700 ever smokers in the EPIC-Germany cohort. High-risk subjects were identified using the eligibility criteria applied in clinical trials (NELSON/LUSI, DLCST, ITALUNG, DANTE, and NLST) and the four risk prediction models. Sensitivity, specificity, and positive predictive value (PPV) were calculated based on the lung cancers diagnosed in the first 5 years of follow-up. Decision curve analysis was performed to compare net benefits. The number of high-risk subjects identified by the eligibility criteria ranged from 3,409 (NELSON/LUSI) to 1,458 (NLST). Among the eligibility criteria, the DLCST produced the highest sensitivity (64.13%), whereas the NLST produced the highest specificity (93.13%) and PPV (2.88%). The PLCO(M2012) model showed the best performance in external validation (C-index: 0.81; 95% CI, 0.76-0.86; E/O: 1.03; 95% CI, 0.87-1.23) and the highest sensitivity, specificity, and PPV, but the superiority over the Bach model and the LLP model was modest. All the models but the Spitz model showed greater net benefit over the full range of risk estimates than the eligibility criteria. We concluded that all of the lung cancer risk prediction models apart from the Spitz model have a similar accuracy to identify high-risk individuals for screening, but in general outperform the eligibility criteria used in the screening trials.

Lung cancer screening: identifying the high risk cohort

Low dose computed tomography (LDCT) is a viable screening tool for early lung cancer detection and mortality reduction. In practice, the success of any lung cancer screening programme will depend on successful identification of individuals at high risk in order to maximise the benefit-harm ratio. Risk prediction models incorporating multiple risk factors have been recognised as a method of identifying individuals at high risk of developing lung cancer. Identification of individuals at high risk will facilitate early diagnosis, reduce overall costs and also improve the current poor survival from lung cancer. This review summarises the current methods utilised in identifying high risk cohorts for lung cancer as proposed by the Liverpool Lung Project (LLP) risk model, Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial risk models and the prediction model for lung cancer death using quintiles. In addition, the cost-effectiveness of CT screening and future perspective for selecting high risk individuals is discussed.

Coronary artery calcification detected in lung cancer screening predicts cardiovascular death

OBJECTIVES

It remains unknown whether non-electrocardiogram-gated coronary artery calcium (CAC) score in lung cancer screening provides incremental prognostic value. The aim of this study was to evaluate the prognostic value of CAC in the Danish Lung Cancer Screening Trial (DLCST), in addition to conducting a systematic review and meta-analysis including previously published studies regarding CAC in lung cancer screening.

DESIGN

In DLCST, we measured Agatston CAC scores in 1,945 current and former smokers. Causes of death were extracted from the Danish National Death Registry. We used Cox proportional hazards model to determine hazard ratios (HRs) of CAC scores. A weighted fixed-effects model was used for the meta-analysis.

RESULTS

Median follow-up in DLCST was 7.1 years, and 55% were men. Overall survival rates associated with CAC scores of 0, 1-400, and > 400 were 98%, 96%, and 92% (p < 0.001), respectively. Adjusted HR of cardiovascular death associated with CAC >400 was 3.8 (1.0-15) (p < 0.05). The meta-analysis included 28,045 asymptomatic participants. A high non-gated CAC score was associated with fatal or non-fatal cardiovascular events (p < 0.0001).

CONCLUSION

Assessment of non-electrocardiogram-gated CAC in lung cancer screening programs is a robust prognostic measure of fatal or non-fatal cardiovascular events in current and former smokers independent of traditional cardiovascular risk factors.

Long-term Oncologic and financial implications of lung cancer screening

Benefits and risks of computed tomography lung cancer screening are discussed with specific focus on oncologic and financial issues. Earlier disease stage at diagnosis implies that more patients are treated surgically, but the changes in oncologic treatment will not be dramatic. The crucial issue for implementation of screening will be that it is cost effective. Preliminary data from the National Lung Screening Trial indicate that it is cost effective and comparable to screening for other major malignancies. Some future modifications in the computed tomography screening methodology are discussed.

Lung cancer screening

The United States Preventive Services Task Force recommends lung cancer screening with low-dose computed tomography (LDCT) in adults of age 55 to 80 years who have a 30 pack-year smoking history and are currently smoking or have quit within the past 15 years. This recommendation is largely based on the findings of the National Lung Screening Trial. Both policy-level and clinical decision-making about LDCT screening must consider the potential benefits of screening (reduced mortality from lung cancer) and possible harms. Effective screening requires an appreciation that screening should be limited to individuals at high risk of death from lung cancer, and that the risk of harm related to false positive findings, overdiagnosis, and unnecessary invasive testing is real. A comprehensive understanding of these aspects of screening will inform appropriate implementation, with the objective that an evidence-based and systematic approach to screening will help to reduce the enormous mortality burden of lung cancer.

Computed tomographic screening for lung cancer: the Mayo Clinic experience

The Mayo Clinic has been involved in screening for lung cancer since the lung cancer project in 1971. The Mayo Clinic recently completed a study of more than 1500 patients with low-dose computed tomographic (CT) screening for lung cancer. Results showed that more than 75% of patients in the screening program had a lung nodule but only a small percentage had lung cancer. As others have found, screening with low-dose CT finds patients with lung cancer at an earlier stage and hopefully will increase the cure rate.

Surgeons and lung cancer screening: rules of engagement

To understand the challenges of screening for lung cancer, surgeons should be familiar with fundamental epidemiologic concepts pertaining to screening and have an understanding of the evidence regarding the various modalities used for screening lung cancer. One large, recent study has confirmed that screening for lung cancer with low-dose computed tomography decreases mortality in high-risk individuals. As a result of these findings, comprehensive screening programs are being developed. High-quality programs should be safe, cost-effective, accessible to high-risk patients, and involve the participation of a multidisciplinary team. Surgeons should be engaged in the implementation of screening programs for lung cancer.

A meta-analysis: is low-dose computed tomography a superior method for risky lung cancers screening population?

BACKGROUND AND AIMS

Low-dose computed tomography (LDCT) has been proposed to be a new screening method to discover lung cancers in an early stage, especially those patients who are in a high risk of lung cancer. The primary objective of this meta-analysis is to systematically review the effect of LDCT on screening for lung cancers among the risky population who are older than 49 years old and with smoking exposure.

METHODS

We searched randomized controlled clinical trials (RCTs) about comparing LDCT and chest X-ray or usual caring from MEDLINE, EMBASE, and the Cochrane Library, Web of Knowledge and SpringerLink databases (January 1994 to September 2013).

RESULTS

Nine RCTs met criteria for inclusion. Screening for lung cancer using LDCT resulted in a significantly higher number of stage I lung cancers [odds ratio (OR) 2.15, 95% confidence interval (CI) 1.88-2.47], higher number of total lung cancers (OR 1.31, 95% CI 1.20-1.43) than the control. Four of the nine studies indicated that the screening method did not decrease all-cause mortality (OR 0.96, 95% CI 0.90-1.02), but decreased lung cancer-specific mortality (OR 0.84, 95% CI 0.74-0.96). Five studies showed that LDCT had higher false-positive rates (OR 8.7, 95% CI 7.43-10.19) than the group of control.

CONCLUSION

Among the risky population, LDCT screening find out more stage I lung cancers and total lung cancers compared with chest X-ray or no screening, and also shows advantages in decreasing lung cancer-specific mortality, but the screening method does not decrease all-cause mortality and have a higher false-positive rates in diagnosis.

CT screening for lung cancer: value of expert review of initial baseline screenings

OBJECTIVE. Appropriate radiologic interpretation of screening CT can minimize unnecessary workup and intervention. This is particularly challenging in the baseline round. We report on the quality assurance process we developed for the International Early Lung Cancer Action Program. MATERIALS AND METHODS. After initial training at the coordinating center, radiologists at 10 participating institutions and at the center independently interpreted the first 100 baseline screenings. The radiologist at the institutions had access to the center interpretations before issuing the final reports. After the first 100 screenings, the interpretations were jointly discussed. This report summarizes the results of the initial 100 dual interpretations at the 10 institutions. RESULTS. The final institution interpretations agreed with the center in 895 of the 1000 interpretations. Compared with the center, the frequency of positive results was higher at eight of the 10 institutions. The most frequent reason of discrepant interpretations was not following the protocol (n = 55) and the least frequent was not identifying a nodule (n = 3). CONCLUSION. The quality assurance process helped focus educational programs and provided an excellent vehicle for review of the protocol with participating physicians. It also suggests that the rate of positive results can be reduced by such measures.

Lung cancer screening: advantages, controversies, and applications

BACKGROUND

Lung cancer is the leading cause of cancer death in the United States. Results from the National Lung Screening Trial (NLST) have shown that low-dose computed tomography (CT) is capable of detecting lung neoplasms in individuals at high risk. However, whether it is advantageous to perform lung cancer screening on these patients is a significant concern, as are the potential adverse outcomes from screening.

METHODS

A review of several randomized clinical trials, focusing on the NLST, was undertaken. Adverse outcomes and costs related to lung cancer screening were also examined.

RESULTS

Lung cancer screening using low-dose CT in high-risk individuals reduced lung cancer deaths by more than 20% when compared with those screened by chest radiography. False-positive results were seen in both groups, but the number of adverse events from the screening test and subsequent diagnostic procedures was low.

CONCLUSIONS

Lung cancer screening is controversial, but the NLST has demonstrated that such testing may reduce lung cancer deaths in high-risk individuals when performed with low-dose CT rather than chest radiography. Guidelines should be established to not only help identify an appropriate screening population, but also develop standards for radiological testing.

Screening for lung cancer

PURPOSE OF REVIEW

The purpose of this review is to provide an update on the current data about low-dose computed tomography (LD-CT) lung cancer screening.

RECENT FINDINGS

The National Lung Screening Trial (NLST) was the first study that provided statistical evidence that LD-CT screening for lung cancer significantly reduces lung cancer mortality by 20%. Three statistically underpowered European trials could not confirm the positive effect of LD-CT screening on lung cancer mortality. Major obstacles in lung cancer screening are overdiagnosis and the large number of false-positive results. In the NLST, more than 24% of the screens were positive, most of which (96.4%) proved to be benign in nature. Optimized protocols for the workup of detected nodules may help to reduce the number of false-positive screens.

SUMMARY

Currently, the NLST is the only sufficiently powered trial to report a lower mortality rate with LD-CT screening. Long-term follow-up data are still anticipated on the European screening trials. Furthermore, data on the extent of the potential dangers of LD-CT screening, such as overdiagnosis, false-positive results, and the effect of cumulative radiation dose, have yet to be investigated thoroughly.

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.

How to follow up patients after curative resection of lung cancer

Survivors of lung cancer surgery are among the highest-risk patients for developing another lung cancer, yet there is no clear consensus on the method of surveillance for patients after curative surgical resection. Surveillance is no longer futile because the emergence of computed tomography screening has allowed the detection of recurrences and new metachronous cancers at an early stage. In selected patients, lung cancer identified recently on routine computed tomography scan is amenable to curative treatment and is associated with longer survival.

Initial LDCT appearance of incident lung cancers in the ITALUNG trial

OBJECTIVES

To characterize early features of lung cancers detected with low-dose computed tomography (LDCT) screening.

MATERIALS AND METHODS

Two radiologists reviewed prior LDCTs in 20 incident cancers diagnosed at annual repeat screening rounds and 83 benign nodules observed in the ITALUNG trial.

RESULTS

No abnormality was observed in 3 cancers. Focal abnormalities in prior LDCT were identified in 17(85%) cancers (14 adenocarcinomas; 14 stage I). Initial abnormalities were intra-pulmonary in 10, subpleural in 4 and perifissural in 3. Average mean diameter was 9mm (range 4.5-18mm). Nine exhibited solid, 4 part-solid and 4 non-solid density. The margins were smooth and regular in 5 cases, lobulated in 6, irregular with spiculations in 3 and blurred in 3. Ten (59%) initial focal abnormalities had a round or oval nodular shape, but 7(41%) had a non-nodular complex (n=5) or "stripe-like" (n=2) shape. Bronchus sign was observed in 3 cases and association with cystic airspace in 2 cases. Non-solid density, complex or "stripe-like" shape, bronchus sign and association with cystic airspace had a specificity higher than 90%, but positive predictive value of every feature of incident lung cancers was low (range 10.4-50%).

CONCLUSIONS

The vast majority of cancers diagnosed at annual repeat show corresponding focal lung abnormalities in prior LDCTs. Perifissural location and non-nodular shape do not exclude the possibility of early lung cancer. Since specificity of the early features of incident lung cancer is incomplete and their positive predictive value is low, all focal pulmonary abnormalities detected in screened subjects should be re-evaluated in subsequent LDCTs.

CT lung cancer screening: where are we heading to?

SUMMARY 

Lung cancer screening has been the subject of controversies since the 1970s. After failure of chest x-ray and sputum cytology examination to decrease lung cancer mortality, there was a 15-year period of disillusion. Low-dose CT scan of the thorax provided a renewal of interest with prospective studies followed by randomized trials of which four have been published. Only one, the NLST trial involving 53,000 participants is positive with a 20% reduction in lung cancer specific mortality rate. The European studies are by far smaller, the largest being the Nelson study with 15,000 participants. There are some shortcomings and biases that must be known and well explained to the future participants to a lung cancer screening program. The cost/benefit ratio remains to be better analyzed.

The assessment of the role of baseline low-dose CT scan in patients at high risk of lung cancer

BACKGROUND

Despite the progress in contemporary medicine comprising diagnostic and therapeutic methods, lung cancer is still one of the biggest health concerns in many countries of the world. The main purpose of the study was to evaluate the detection rate of pulmonary nodules and lung cancer in the initial, helical low-dose CT of the chest as well as the analysis of the relationship between the size and the histopathological character of the detected nodules.

MATERIAL/METHODS

We retrospectively evaluated 1999 initial, consecutive results of the CT examinations performed within the framework of early lung cancer detection program initiated in Szczecin. The project enrolled persons of both sexes, aged 55-65 years, with at least 20 pack-years of cigarette smoking or current smokers. The analysis included assessment of the number of positive results and the evaluation of the detected nodules in relationship to their size. All of the nodules were classified into I of VI groups and subsequently compared with histopathological type of the neoplastic and nonneoplastic pulmonary lesions.

RESULTS

Pulmonary nodules were detected in 921 (46%) subjects. What is more, malignant lesions as well as lung cancer were significantly, more frequently discovered in the group of asymptomatic nodules of the largest dimension exceeding 15 mm.

CONCLUSIONS

The initial, low-dose helical CT of the lungs performed in high risk individuals enables detection of appreciable number of indeterminate pulmonary nodules. In most of the asymptomatic patients with histopathologically proven pulmonary nodules greater than 15 mm, the mentioned lesions are malignant, what warrants further, intensified diagnostics.

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

Screening using low-dose computed tomography (CT) represents an exciting new development in the struggle to improve outcomes for people with lung cancer. Randomised controlled evidence demonstrating a 20% relative lung cancer mortality benefit has led to endorsement of screening by several expert bodies in the US and funding by healthcare providers. Despite this pivotal result, many questions remain regarding technical and logistical aspects of screening, cost-effectiveness and generalizability to other settings. This review discusses the rationale behind screening, the results of on-going trials, potential harms of screening and current knowledge gaps.

Small irregular pulmonary nodules in low-dose CT: observer detection sensitivity and volumetry accuracy

OBJECTIVE

The purpose of this study is to evaluate observer detection and volume measurement of small irregular solid artificial pulmonary nodules on 64-MDCT in an anthropomorphic thoracic phantom.

MATERIALS AND METHODS

Forty in-house-made solid pulmonary nodules (lobulated and spiculated; actual volume, 5.1-88.4 mm3; actual CT densities, -51 to 157 HU) were randomly placed inside an anthropomorphic thoracic phantom with pulmonary vasculature. The phantom was examined on two 64-MDCT scanners, using a scan protocol as applied in lung cancer screening. Two independent blinded observers screened for pulmonary nodules. Nodule volume was evaluated semiautomatically using dedicated software and was compared with the actual volume using an independent-samples t test. The interscanner and interobserver agreement of volumetry was assessed using Bland-Altman analysis.

RESULTS

Observer detection sensitivity increased along with increasing size of irregular nodules. Sensitivity was 100% when the actual volume was at least 69 mm3, regardless of specific observer, scanner, nodule shape, and density. Overall, nodule volume was underestimated by (mean±SD) 18.9±11.8 mm3 (39%±21%; p<0.001). The relative interscanner difference of volumetry was 3.3% (95% CI, -33.9% to 40.4%). The relative interobserver difference was 0.6% (-33.3% to 34.5%).

CONCLUSION

Small irregular solid pulmonary nodules with an actual volume of at least 69 mm3 are reliably detected on 64-MDCT. However, CT-derived volume of those small nodules is largely underestimated, with considerable variation.

A systematic review of the characteristics associated with recall rates, detection rates and positive predictive values of computed tomography screening for lung cancer

BACKGROUND

Low-dose computed tomography (LDCT) screening has been shown to reduce mortality from lung cancer but at a substantial cost in diagnostic activity. The objective of this study was to investigate the characteristics of screening programmes associated with recall rates, detection rates and positive predictive values (PPVs).

DESIGN

We conducted a systematic review of randomised trials and observational studies on LDCT screening for lung cancer. A meta-regression using random-effect logistic regressions was carried out to assess factors influencing recall rates for further investigation, cancer detection rates and PPVs of recall.

RESULTS

We used data from 63 372 prevalent screens from 16 studies of LDCT screening for lung cancer and 79 302 incident screens from nine studies. In univariable analysis, the use of a cut-off size to define nodules warranting further investigation at prevalent screens reduced recall rates [odds ratio (OR) = 0.44, 95% confidence interval (CI) 0.24-0.82 and OR = 0.42, 95% CI 0.21-0.84 for cut-off sizes of 3-4 and 5-8 mm, respectively], without significant changes in detection rates and PPVs. The number of readers (1 or ≥2) was not associated with changes in recall rates, detection rates and PPVs at prevalent and incident screens. Using the volumetry software at incident screens significantly increased the PPV (OR = 5.02, 95% CI 1.65-15.28) as a result of a decrease in recall rates (OR = 0.25, 95% CI 0.12-0.51), without significant changes in detection rates.

CONCLUSION

These results highlight the value of using a cut-off size for nodules warranting further investigation with lower recall rates at prevalent screens, whereas the volumetric assessment software at incident screens results in lower recall rates and higher PPVs. The presence of positron emission tomography in the work-up protocol might be associated with lower rates of surgical procedures for benign findings, although this hypothesis deserves further investigation.

Lung cancer screening with low-dose computed tomography for primary care providers

This review provides an update on lung cancer screening with low-dose computed tomography (LDCT) and its implications for primary care providers. One of the unique features of lung cancer screening is the potential complexity in patient management if an LDCT scan reveals a small pulmonary nodule. Additional tests, consultation with multiple specialists, and follow-up evaluations may be needed to evaluate whether lung cancer is present. Primary care providers should know the resources available in their communities for lung cancer screening with LDCT and smoking cessation, and the key points to be addressed in informed and shared decision-making discussions with patients.

Would screening for lung cancer benefit 75- to 84-year-old residents of the United States?

Background: The National Lung Screening Trial demonstrated that screening for lung cancer improved overall survival (OS) and reduced lung cancer mortality in the 55- to 74-year-old age group by increasing the proportion of cancers detected at an early stage. Because of the increasing life expectancy of the American population, we investigated whether screening for lung cancer might benefit men and women aged 75–84 years.

Materials/Methods: Rates of non-small cell lung cancer (NSCLC) from 2000 to 2009 were calculated in both younger and older age groups using the surveillance epidemiology and end reporting database. OS and lung cancer-specific survival (LCSS) in patients with Stage I NSCLC diagnosed from 2004 to 2009 were analyzed to determine the effects of age and treatment.

Results: The per capita incidence of NSCLC decreased in the 55–74 cohort, but increased in the 75–84 cohort over the study period. Crude lung cancer death rates in the two age groups who had no specific treatment were 39.5 and 44.9%, respectively. These rates fell in both age groups when increasingly aggressive treatment was used. Rates of OS and LCSS improved significantly with increasingly aggressive treatment in the 75–84 age group. The survival benefits of increasingly aggressive treatment in 75- to 84-year-old females did not differ from their counterparts in the younger cohort.

Conclusion: Screening for lung cancer might be of benefit to individuals at increased risk of lung cancer in the 75–84 age group. The survival benefits of aggressive therapy are similar in females between 55–74 and 75–84 years old.

CT screening for lung cancer: countdown to implementation

Implementation of lung cancer CT screening is currently the subject of a major policy decision within the USA. Findings of the US National Lung Screening Trial showed a 20% reduction in lung cancer mortality and a 6·7% decrease in all-cause mortality; subsequently, five US professional and clinical organisations and the US Preventive Services Task Force recommended that screening should be implemented. Should national health services in Europe follow suit? The European community awaits mortality and cost-effectiveness data from the NELSON trial in 2015-16 and pooled findings of European trials. In the intervening years, a recommendation is proposed that a demonstration trial is done in the UK. In this Review, we summarise the existing evidence and identify questions that remain to be answered before the implementation of international lung cancer screening programmes.

Features of resolving and nonresolving indeterminate pulmonary nodules at follow-up CT: the NELSON study

PURPOSE

To retrospectively identify features that allow prediction of the disappearance of solid, indeterminate, intraparenchymal nodules detected at baseline computed tomographic (CT) screening of individuals at high risk for lung cancer.

MATERIALS AND METHODS

The study was institutional review board approved. Participants gave informed consent. Participants with at least one noncalcified, solid, indeterminate, intraparenchymal nodule (volume range, 50-500 mm(3)) at baseline were included (964 nodules in 750 participants). According to protocol, indeterminate nodules were re-examined at a 3-month follow-up CT examination. Repeat screening was performed at years 2 and 4. A nodule was defined as resolving if it did not appear at a subsequent CT examination. Nodule resolution was regarded as spontaneous, not the effect of treatment. CT features of resolving and nonresolving (stable and malignant) nodules were compared by means of generalized estimating equations analysis.

RESULTS

At subsequent screening, 10.1% (97 of 964) of the nodules had disappeared, 77.3% (n = 75) of these at the 3-month follow-up CT and 94.8% (n = 92) at the second round of screening. Nonperipheral nodules were more likely to resolve than were peripheral nodules (odds ratio: 3.16; 95% confidence interval: 1.76, 5.70). Compared with smooth nodules, nodules with spiculated margins showed the highest probability of disappearance (odds ratio: 4.36; 95% confidence interval: 2.24, 8.49).

CONCLUSION

Approximately 10% of solid, intermediate-sized, intraparenchymal pulmonary nodules found at baseline screening for lung cancer resolved during follow-up, three-quarters of which had disappeared at the 3-month follow-up CT examination. Resolving pulmonary nodules share CT features with malignant nodules.

Current status of lung cancer screening

Low-dose CT (LDCT) is effective in the early detection of lung cancer, providing higher resectability and long-term survival rates. The National Lung Screening Trial shows a statistically significant mortality reduction in LDCT compared with chest radiography. The efficacy and safety of annual LDCT screening in heavy smokers must be explored, and the magnitude of benefit compared with the cost of large-scale screening. Trials in Europe have different study designs and an observational arm. Strategies to reduce lung cancer mortality should combine early detection with primary prevention and innovative biologic approaches.

[Advance of lung cancer screening with low-dose spiral CT]

Lung cancer has become the leading cause of cancer mortality globally, and 5-year survival rate is very poor. Screening and early detection are vital to improve survival and decrease mortality of lung cancer. In recent 20 years, low-dose spiral CT (LDCT) screening has become a research focus in this area. Randomized controlled trials have confirmed that LDCT can decrease lung cancer mortality. However, there are still some problems of LDCT. In this paper, we summarized the controversy that whether low-dose helical CT screening can reduce lung cancer mortality or not before its effectiveness was been confirmed, the results and problems in the randomized controlled trials and gave a prospect of low-dose helical CT screening's future application.

Diagnostic work-up and surgery in participants of the Gdansk lung cancer screening programme: the incidence of surgery for non-malignant conditions

OBJECTIVES

Low-dose computed tomography (LDCT) screening improves lung cancer prognosis but also results in diagnostic work-up and surgical treatment in many individuals without cancer. Therefore, we analysed the procedures that screening participants underwent to better understand the extent of overdiagnosis.

METHODS

Between 2009 and 2011, 8649 healthy volunteers aged 50-75 years with a 20 pack-year smoking history underwent LDCT screening, of whom individuals with detected lung nodules had 2 years control. Participants with a nodule >10 mm in diameter or with suspected tumour morphology underwent diagnostic work-up: 283 (6%)/4694 (54%) screened participants had detected lung nodules. One hundred and four individuals underwent surgery, 27 underwent oncological treatment and 152 without a cancer diagnosis underwent further follow-up with LDCT.

RESULTS

In 75% of participants accepted for diagnostic work-up and 25% of surgical patients, the procedures were unnecessary. In 70 (24.7%) participants, a specific diagnosis was obtained mainly due to the low efficacy of fine needle aspiration biopsy [sensitivity, 65.2%; negative predictive value (NPV), 95.9%] and bronchofiberoscopy (sensitivity, 71.4%; NPV, 50%) caused by overinterpretation of LDCT [positive predictive value (PPV), 2%]. Of 104 (36.7%) surgical patients, 43 (41.4%) had a preoperative cancer diagnosis, and 61 (58.6%) underwent surgery without pathological examination. In the latter group, intervention was justified in 35 (57.3%) patients. Complications occurred in 49 (17.3%) participants subjected to diagnostic work-up. In surgical patients, 67 (64.4%) malignant and 37 (35.6%) benign lesions were resected. In the latter group, intervention was justified in only 11 (29.7%) patients. No patient died because of diagnostic or treatment procedures during the study. The complication rate was 14.5% in the malignant and 10.8% in the benign groups. A neoplasm was found in 94 screening participants, of whom 67 (71.3%) underwent surgery; the remaining 27 (28.7%) patients were not surgical candidates. Adenocarcinoma accounted for 49/67 (73%) patients who underwent surgery for non-small-cell lung cancer (NSCLC); 56/67 (84%) patients had stage I NSCLC, and 26/67 (38%) underwent video-assisted thoracoscopic surgery lobectomy.

CONCLUSIONS

Futile diagnostic work-ups and operations must be reduced before LDCT screening can be broadly used. Stage I adenocarcinoma dominated in the NSCLC patients who underwent surgery.

Prospects for population screening and diagnosis of lung cancer

Deaths from lung cancer exceed those from any other type of malignancy, with 1·5 million deaths in 2010. Prevention and smoking cessation are still the main methods to reduce the death toll. The US National Lung Screening Trial, which compared CT screening with chest radiograph, yielded a mortality advantage of 20% to participants in the CT group. International debate is ongoing about whether sufficient evidence exists to implement CT screening programmes. When questions about effectiveness and cost-effectiveness have been answered, which will await publication of the largest European trial, NELSON, and pooled analysis of European CT screening trials, we discuss the main topics that will need consideration. These unresolved issues are risk prediction models to identify patients for CT screening; radiological protocols that use volumetric analysis for indeterminate nodules; options for surgical resection of CT-identified nodules; screening interval; and duration of screening. We suggest that a demonstration project of biennial screening over a 4-year period should be undertaken.