Lung Cancer Screening Using Low Dose CT Scanning in Germany. Extrapolation of results from the National Lung Screening Trial

Lung Cancer Screening With Low-Dose Computed Tomography

BACKGROUND

Approximately 21 900 women and 35 300 men developed lung cancer in Germany in 2018, and 16 514 women and 28 365 men died of it. The outcome mainly depends on the tumor stage. In early stages (stage I or II), treatment can be curative; unfortunately, because early-stage lung cancers are generally asymptomatic, 74% of women and 77% of men already have advanced-stage disease (stage III or IV) at the time of diagnosis. Screening with low-dose computed tomography is an option enabling early diagnosis and curative treatment.

METHODS

This review is based on pertinent articles retrieved by a selective search of the literature on screening for lung cancer.

RESULTS

In the studies of lung cancer screening that have been published to date, sensitivity ranged from 68.5% to 93.8%, and specificity from 73.4% to 99.2%. A meta-analysis by the German Federal Office for Radiation Protection revealed a 15% reduction in lung cancer mortality when low-dose computed tomography was used in persons who were judged to be at high risk for lung cancer (risk ratio [RR] 0.85, 95% confidence interval [0.77; 0.95]). 1.9% of subjects died in the screening arm of the metaanalysis, and 2.2% in the control group. The observation periods ranged from 6.6 to 10 years; false-positive rates ranged from 84.9% to 96.4%. Malignant findings were confirmed in 45% to 70% of the biopsies or resective procedures that were performed.

CONCLUSION

Systematic lung cancer screening with low-dose CT lowers mortality from lung cancer in (current or former) heavy smokers. This benefit must be weighed against the high rate of false-positive findings and overdiagnoses.

Prognostic Impact of the Angiogenic Gene POSTN and Its Related Genes on Lung Adenocarcinoma

Background

The function of angiogenesis-related genes (ARGs) in lung adenocarcinoma (LUAD) remains poorly documented. This study was designed to reveal ARGs in LUAD and related networks.

Methods

We worked with sequencing data and clinical information pertaining to LUAD from public databases. ARGs were retrieved from the HALLMARK_ANGIOGENESIS gene set. Differential analysis and Kaplan–Meier (K–M) analysis were performed to authenticate the ARGs associated with LUAD. Weighted gene correlation network analysis was performed on the mining hub genes linked to the abovementioned genes, and functional enrichment analysis was done. Subsequently, Cox regression analyses were used to construct the prognostic gene. POSTN and microvessel density were detected using immunohistochemistry.

Results

POSTN, an ARG that was highly expressed in patients with LUAD and was closely associated with their weak overall survival was identified. Differentially expressed genes associated with POSTN were mainly enriched in entries related to the tubulointerstitial system, immune response, and epithelial cells. A positive correlation was demonstrated between POSTN expression and tumor microvessel density in LUAD. Subsequently, a prognostic gene signature was constructed and revealed that 4 genes may predict the survival of LUAD patients. Furthermore, the ESTIMATE and CIBERSORT analyses suggested that our risk scoring system may be implicated in altering the immune microenvironment of patients with LUAD. Finally, a ceRNA network was constructed based on the prognostic genes, and the regulatory networks were examined.

Conclusion

POSTN, a novel prognostic gene signature associated with ARGs, was constructed for the prognosis of patients with LUAD. This signature may alter the immune microenvironment by modulating the activation of the tubulointerstitial system, epithelial cells, and immune cells, ultimately affecting patient survival.

HRCT features between lepidic-predominant type and other pathological subtypes in early-stage invasive pulmonary adenocarcinoma appearing as a ground-glass nodule

Background

Different pathological subtypes of invasive pulmonary adenocarcinoma (IPA) have different surgical methods and heterogeneous prognosis. It is essential to clarify IPA subtypes before operation and high-resolution computed tomography (HRCT) plays a very important role in this regard. We aimed to investigate the HRCT features of lepidic-predominant type and other pathological subtypes of early-stage (T1N0M0) IPA appearing as a ground-glass nodule (GGN).

Methods

We performed a retrospective analysis on clinical data and HRCT features of 630 lesions in 589 patients with pathologically confirmed IPA (invasive foci > 5 mm) appearing as pure GGN (pGGN) and mixed GGN (mGGN) with consolidation-to-tumor ratio (CTR) ≤0.5 from January to December 2019. All GGNs were classified as lepidic-predominant adenocarcinoma (LPA) and nonlepidic-predominant adenocarcinoma (n-LPA) groups. Univariate analysis was performed to analyze the differences of clinical data and HRCT features between the LPA and n-LPA groups. Multivariate analysis was conducted to determine the variables to distinguish the LPA from n-LPA group independently. The diagnostic performance of different parameters was compared using receiver operating characteristic curves.

Results

In total, 367 GGNs in the LPA group and 263 GGNs in the n-LPA group were identified. In the univariate analysis, the CTR, mean CT values, and mean diameters as well as mixed GGN, deep lobulation, spiculation, vascular change, bronchial change, and tumor–lung interface were smaller in the LPA group than in the n-LPA group (P <  0.05). Logistic regression model was reconstructed including the mean CT value, CTR, deep lobulation, spiculation, vascular change, and bronchial change (P <  0.05). Area under the curve of the logistic regression model for differentiating LPA and n-LPA was 0.840 (76.4% sensitivity, 78.7% specificity), which was significantly higher than that of the mean CT value or CTR.

Conclusions

Deep lobulation, spiculation, vascular change, and bronchial change, CT value > − 472.5 HU and CTR > 27.4% may indicate nonlepidic predominant invasive pulmonary adenocarcinoma in GGNs.

Lung Cancer Screening with Low-Dose CT in Smokers: A Systematic Review and Meta-Analysis

Lung cancer continues to be one of the main causes of cancer death in Europe. Low-dose computed tomography (LDCT) has shown high potential for screening of lung cancer in smokers, most recently in two European trials. The aim of this review was to assess lung cancer screening of smokers by LDCT with respect to clinical effectiveness, radiological procedures, quality of life, and changes in smoking behavior. We searched electronic databases in April 2020 for publications of randomized controlled trials (RCT) reporting on lung cancer and overall mortality, lung cancer morbidity, and harms of LDCT screening. A meta-analysis was performed to estimate effects on mortality. Forty-three publications on 10 RCTs were included. The meta-analysis of eight studies showed a statistically significant relative reduction of lung cancer mortality of 12% in the screening group (risk ratio = 0.88; 95% CI: 0.79-0.97). Between 4% and 24% of screening-LDCT scans were classified as positive, and 84-96% of them turned out to be false positive. The risk of overdiagnosis was estimated between 19% and 69% of diagnosed lung cancers. Lung cancer screening can reduce disease-specific mortality in (former) smokers when stringent requirements and quality standards for performance are met.

Evidence-Based Follow-up for Adults With Cancer

BACKGROUND

The objectives of follow-up care for cancer patients include psycho- social assistance and the detection of health problems. The concept of follow-up care rests on the assumption that the early detection of cancer recurrences and disease- or treatment-related complications is beneficial to patients. In this article, we provide an overview of the scientific evidence supporting current recommen- dations for the follow-up care of patients with colorectal cancer, lung cancer, and lymphoma.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in PubMed, supplemented by the authors' own experience in patient care and guideline creation.

RESULTS

As recurrences usually arise soon after initial treatment, the recommended follow-up interval is shorter in the first two years (3-6 months) and longer thereafter (6-12 months). The question of which particular follow-up studies should be per- formed has only been systematically analyzed in a few cases. For patients with colorectal cancer, colonoscopy is the most important study. Intensive follow-up care is associated with a statistically non-significant increase in the survival rate compared to minimal follow-up care (77.5% versus 75.8%). Intensive diagnostic follow-up studies have been found to lead to a doubling of the frequency of operations for recurrence with curative intent, yet without any effect on the average survival time. The findings in lung cancer are similar. However, after tumor resection with curative intent, regularly repeated CT scanning leads to a survival advantage. In lymphoma patients, the longer the interval from primary treatment, the greater the likelihood of treatment-related secondary illnesses. It is not yet known how follow-up care should be provided to these patients in order to help them best.

CONCLUSION

The evidence supporting the efficacy of currently recommended modalities of follow-up care for cancer patients is weak. Until more data from clinical studies become available, the current guidelines should be followed.

Challenges in Lung Cancer Screening in Latin America

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

High-resolution computed tomography features and CT-guided microcoil localization of subcentimeter pulmonary ground-glass opacities: radiological processing prior to video-assisted thoracoscopic surgery

Background

With the rapid development of high-resolution computed tomography (HRCT), low-dose CT scanning and video-assisted thoracoscopic surgery (VATS), smaller pulmonary nodules can be detected. Subcentimeter ground-glass opacities (GGOs) are extremely difficult to diagnose and accurately locate during VATS and in surgically resected specimens.

Methods

From September 2013 to September 2017, 42 subcentimeter GGO lesions (≤1 cm) in 31 patients who underwent CT-guided microcoil insertion followed by VATS resection were included. All HRCT images were assessed by two experienced radiologists, and CT-guided microcoil localization procedures were performed by two experienced interventional radiologists.

Results

A total of 42 subcentimeter GGOs included 28 malignancies (66.7%) and 14 benign lesions (33.3%). The diameter of malignant GGOs (8.52±1.46 mm) was significantly larger than that of benign lesions (7.04±1.52 mm) (P<0.05). Seven patients had more than one GGO nodule. There were no significant differences in the location, composition, shape, margins, presence of air bronchograms, presence of the pleural indentation sign and presence of the vascular convergence sign between benign and malignant GGOs (P>0.05). All the localization procedures were performed successfully. A small pneumothorax occurred in 9 patients (21.4%), and minor hemorrhage in the lung parenchyma occurred in 8 patients (19.0%). All GGOs were easily identified during VATS and were definitively diagnosed.

Conclusions

Common HRCT features cannot be used as criteria for the differential diagnosis of subcentimeter benign and malignant pulmonary GGOs. CT-guided microcoil marking of these lesions prior to VATS is a feasible, safe, and effective procedure for the localization of subcentimeter pulmonary GGOs.

Necessity of organized low-dose computed tomography screening for lung cancer: From epidemiologic comparisons between China and the Western nations

OBJECTIVES

To compare the proportion of stage I lung cancer and population mortality in China to those in U.S. and Europe where lung cancer screening by low-dose computed tomography (LDCT) has been already well practiced.

METHODS

The proportions of stage I lung cancer in LDCT screening population in U.S. and Europe were retrieved from NLST and NELSON trials. The general proportion of stage I lung cancer in China was retrieved from a rapid meta-analysis, based on a literature search in the China National Knowledge Infrastructure database. The lung cancer mortality and prevalence of China, U.S. and Europe was retrieved from Globocan 2012 fact sheet. Mortality-to-prevalence ratio (MPR) was applied to compare the population survival outcome of lung cancer.

RESULTS

The estimated proportion of stage I lung cancer in China is merely 20.8% among hospital-based cross-sectional population, with relative ratios (RRs) being 2.40 (95% CI 2.18-2.65) and 2.98 (95% CI 2.62-3.38) compared by LDCT-screening population in U.S. and Europe trials, respectively. MPR of lung cancer is as high as 58.9% in China, with RRs being 0.46 (95% CI 0.31-0.67) and 0.58 (95% CI 0.39-0.85) compared by U.S. and Europe, respectively.

CONCLUSIONS

By the epidemiological inference, the LDCT mass screening might be associated with increasing stage I lung cancer and therefore improving population survival outcome. How to translate the experiences of lung cancer screening by LDCT from developed counties to China in a cost-effective manner needs to be further investigated.

Recommendations from the European Society of Thoracic Surgeons (ESTS) regarding computed tomography screening for lung cancer in Europe

In order to provide recommendations regarding implementation of computed tomography (CT) screening in Europe the ESTS established a working group with eight experts in the field. On a background of the current situation regarding CT screening in Europe and the available evidence, ten recommendations have been prepared that cover the essential aspects to be taken into account when considering implementation of CT screening in Europe. These issues are: (i) Implementation of CT screening in Europe, (ii) Participation of thoracic surgeons in CT screening programs, (iii) Training and clinical profile for surgeons participating in screening programs, (iv) the use of minimally invasive thoracic surgery and other relevant surgical issues and (v) Associated elements of CT screening programs (i.e. smoking cessation programs, radiological interpretation, nodule evaluation algorithms and pathology reports). Thoracic Surgeons will play a key role in this process and therefore the ESTS is committed to providing guidance and facilitating this process for the benefit of patients and surgeons.

Canine scent detection for the diagnosis of lung cancer in a screening-like situation

The prognosis in lung cancer depends largely on early stage detection, and thus new screening methods are attracting increasing attention. Canine scent detection has shown promising results in lung cancer detection, but there has only been one previous study that reproduces a screening-like situation. Here breath samples were collected from 122 patients at risk for lung cancer (smokers and ex-smokers); 29 of the subjects had confirmed diagnosis of lung cancer but had not yet been treated and 93 subjects had no signs or symptoms of lung cancer at the time of inclusion. The breath samples were presented to a trained sniffer dog squadron in a double-blind manner. A rigid scientific protocol was used with respect to earlier canine scent detection studies, with one difference: instead of offering one in five positive samples to the dogs, we offered a random number of positive samples (zero to five). The final positive and negative predictive values of 30.9% and 84.0%, respectively, were rather low compared to other studies. The results differed from those of previous studies, indicating that canine scent detection might not be as powerful as is looked for in real screening situations. One main reason for the rather poor performance in our setting might be the higher stress from the lack of positive responses for dogs and handlers.

Implementation and organization of lung cancer screening

CT screening for lung cancer is now being implemented in the US and China on a widespread national scale but not in Europe so far. The review gives a status for the implementation process and the hurdles to overcome in the future. It also describes the guidelines and requirements for the structure and components of high quality CT screening programs. These are essential in order to achieve a successful program with the fewest possible harms and a possible mortality benefit like that documented in the American National Lung Screening Trial (NLST). In addition the importance of continued research in CT screening methods is described and discussed with focus on the great potential to further improve this method in the future for the benefit of patients and society.

Thoracic Malignancies and Pulmonary Nodules in Patients under Evaluation for Transcatheter Aortic Valve Implantation (TAVI): Incidence, Follow Up and Possible Impact on Treatment Decision

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has become the treatment of choice in patients with severe aortic valve stenosis who are not eligible for operative replacement and an alternative for those with high surgical risk. Due to high age and smoking history in a high proportion of TAVI patients, suspicious findings are frequently observed in pre-procedural chest computer tomography (CCT).

METHODS

CCT scans of 484 consecutive patients undergoing TAVI were evaluated for incidentally discovered solitary pulmonary nodules (SPN).

RESULTS

In the entire study population, SPN ≥ 5 mm were found in 87 patients (18%). These patients were compared to 150 patients who were incidentally collected from the 397 patients without SPN or with SPN < 5 mm (control group). After a median follow-up of 455 days, lung cancer was diagnosed in only two patients. Neither SPN ≥ 5 mm (p = 0.579) nor SPN > 8 mm (p = 0.328) were significant predictors of overall survival.

CONCLUSIONS

Despite the high prevalence of SPNs in this single center TAVI cohort lung cancer incidence at midterm follow-up seems to be low. Thus, aggressive diagnostic approaches for incidentally discovered SPN during TAVI evaluation should not delay the treatment of aortic stenosis. Unless advanced thoracic malignancy is obvious, the well documented reduction of morbidity and mortality by TAVI outweighs potentially harmful delays regarding further diagnostics. Standard guideline-approved procedure for SPN can be safely performed after TAVI.