Results of an open-access lung cancer screening program with low-dose computed tomography: the Gdańsk experience

Lung cancers and pulmonary nodules detected by computed tomography scan: a population-level analysis of screening cohorts

Background

An increasing number and proportion of younger lung cancer patients have been observed worldwide, raising concerns on the optimal age to begin screening. This study aimed to investigate the association between age and findings in initial CT scans.

Methods

We searched for low-dose CT screening cohorts from electronic databases. Single-arm syntheses weighted by sample size were performed to calculate the detection rates of pulmonary nodules, lung cancers (all stages and stage I), and the proportion of stage I diseases in lung cancers. In addition, we included patients who underwent chest CT in our center as a supplementary cohort. The correlation between the detection rates and age was evaluated by the Pearson Correlation Coefficient.

Results

A total of 37 studies involving 163,442 participants were included. We found the detection rates of pulmonary nodules and lung cancers increased with age. However, the proportion of stage I diseases in lung cancers declined with increased starting age and was significantly higher in the 40-year group than in other groups (40 vs. 45, 50, 55, P<0.001). In addition, the ratio of early-stage lung cancer to the number of nodules declined with age. Similarly, in our center, the detection rates of nodules (R²=0.86, P≤0.001), all lung cancer (R²=0.99, P≤0.001) and stage I diseases (R²=0.87, P=0.001) increased with age, while the proportion of stage I diseases consistently declined with age (R²=0.97, P≤0.001).

Conclusions

Starting lung cancer screening at an earlier age is associated with a higher probability of identifying a curable disease, urging future research to determine the optimal starting age.

Performance of various risk prediction models in a large lung cancer screening cohort in Gdańsk, Poland-a comparative study

Background

Optimal selection criteria for the lung cancer screening programme remain a matter of an open debate. We performed a validation study of the three most promising lung cancer risk prediction models in a large lung cancer screening cohort of 6,631 individuals from a single European centre.

Methods

A total of 6,631 healthy volunteers (aged 50-79, smoking history ≥30 pack-years) were enrolled in the MOLTEST BIS programme between 2016 and 2018. Each participant underwent a low-dose computed chest tomography scan, and selected participants underwent a further diagnostic work-up. Various lung cancer prediction models were applied to the recruited screenees, i.e., (I) Tammemagi's Prostate, Colorectal, and Ovarian Cancer Screening Trial 2012 (PLCO_m2012), (II) Liverpool Lung Project (LLP) model, and (III) Bach's lung cancer risk model. Patients (I) with 6-year lung cancer probability ≥1.3% were considered as high risk in PLCO_m2012 model, (II) in LLP model with 5-year lung cancer probability ≥5.0%, and (III) in Bach's model with 5-year lung cancer probability ≥2.0%. The particular model cut-off values were employed to the cohort to evaluate each model's performance in the screened population.

Results

Lung cancer was diagnosed in 154 (2.3%) participants. Based on the risk estimates by PLCO_m2012, LLP and Bach's models there were 82.4%, 50.3% and 19.8% of the MOLTEST BIS participants, respectively, who fulfilled the above-mentioned threshold criteria of a lung cancer development probability. Of those detected with lung cancer, 97.4%, 74.0% and 44.8% were eligible for screening by PLCO_m2012, LLP and Bach's model criteria, respectively. In Tammemagi's risk prediction model only four cases (2.6%) would have been missed from the group of 154 lung cancer patients primarily detected in the MOLTEST BIS.

Conclusions

Lung cancer screening enrollment based on the risk prediction models is superior to NCCN Group 1 selection criteria and offers a clinically significant reduction of screenees with a comparable proportion of detected lung cancer cases. Tammemagi's risk prediction model reduces the proportion of patients eligible for inclusion to a screening programme with a minimal loss of detected lung cancer cases.

A narrative review of invasive diagnostics and treatment of early lung cancer

The diagnosis and treatment of early-stage lung cancer remains a clinical challenge. The broadening implementation of lung cancer screening has resulted in positive findings in numerous patients that are mostly non-malignant. Many other patients have indeterminate nodules that are difficult to assess through simple observation. The critical interpretation of such screening results remains a challenge for radiologists and multidisciplinary teams involved in screening for lung cancer. The evaluation and diagnosis of each participant suspected for malignancy should be based on the basic clinical principles such as a carefully collected medical history, physical examination, and detailed analysis of all imaging tests performed. Indeed, the decision to go ahead with more invasive diagnostics requires consideration of the both the risks and benefits, with reflection upon the complete clinical and radiological picture. Although transthoracic needle aspiration biopsy remains the first-choice method of diagnosis, several newer technologies have slowly begun to emerge as potential replacements. The guiding strategy for method selection is to choose the least harmful approach that offers the most relevant potential insights. Transthoracic biopsy is an effective method that allows the collection of cytological and tissue material from small, peripheral tumors, but it carries a moderate risk of complications. Bronchofiberoscopy, especially in combination with electromagnetic navigation, fluoroscopy or radial EBUS, also allows effective diagnosis of the peripheral pulmonary nodules. One of the most important diagnostic methods is the EBUS examination, which allows determining of staging in addition to diagnosis. Anatomical lung lobe resection and lymphadenectomy or sampling of the hilar and mediastinal lymph nodes is currently the treatment of choice for patients with stage I and II non-small cell lung cancer (NSCLC), but sublobar resections are recommended when a patient has limited pulmonary function or other significant comorbidities. Notably, several studies have highlighted the potential utility of more limited resections in small malignant lesions less than 2cm in diameter, with pure AIS histology, when more than 50% of the diameter of pulmonary nodule has ground-glass opacity (GGO) attenuation on CT, or long volume doubling time (VDT). Videothoracoscopy is the preferred surgical approach for resection of early-stage lung cancer. Patients who are not candidates for surgery or do not agree to surgery can be offered radical radiotherapy. Stereotactic body radiation therapy (SBRT) is a type of radical radiotherapy with proven effectiveness, a high rate of local control and an acceptable risk of the development of later complications. Future trials are expected to define the role of SBRT in the treatment of early lung cancer in healthy subjects.

Emphysema - The review of radiological presentation and its clinical impact in the LDCT screening era

Emphysema is one of three main lung pathologies in Chronic Obstructive Pulmonary Disease, along with chronic bronchitis and small airway obstruction. The diagnosis is based on detection of low attenuation areas in lung tissue on chest Computed Tomography, either visual by a radiologist, or automatic by the applied Computed Tomography software. Results of the studies on the association between emphysema and lung cancer incidence are mixed. Many studies have demonstrated, that chronic lung diseases, like Chronic Obstructive Pulmonary Disease, are associated with lung cancer morbidity. There is also evidence, that emphysema can be related with worse prognosis in patients with detected lung cancer. In this review article we aim to summarize current knowledge about emphysema detection and evaluation on Computed Tomography, both quantitative and qualitative. We also summarize current data on correlation between emphysema and lung cancer, as well as its potential use in selecting patients, who would most benefit from lung cancer screening.

Implementation of lung cancer screening at the national level: Polish example

In Poland the national demonstration lung cancer screening program is about to be started in 2019. We share our concerns and discussing most important topics to be resolved while preparing such a program. The decisions made are virtually based on available scientific data and the results of two randomized controlled trials but also on the personal experience gained during the lung cancer screening studies performed in Poland. The most important and comprehensive guidelines and statements, both European and American, have been searched to find an optimal solution adjusted to the Polish national circumstances-as we assume that should be done in each country implementing such a program.

Low-dose computed tomography screening reduces lung cancer mortality

Lung cancer causes an estimated 1.6 million deaths each year, being the leading cause of cancer-related deaths in the world. Late diagnosis and, in some cases, the high aggressiveness of the tumour result in low overall five-year survival rates of 12% among men and 7% among women. The cure is most likely in early-stage disease. The poor outcomes of treatment in lung cancer resulting from the fact that most cases are diagnosed in the advanced stage of the disease justify the implementation of an optimal lung cancer prevention in the form of smoking cessation and screening programmes that would offer a chance to detect early stages of the disease, while fitting within specific economic constraints. The National Lung Screening Trial (NLST) - the largest and most expensive randomised, clinical trial in the USA demonstrated a 20% mortality rate reduction in patients who had undergone chest low-dose computed tomography (LDCT) screening, as compared to patients screened with a conventional chest X-ray. Results of the NLST enabled the implementation of lung cancer screening programme among highrisk patients in the USA and parts of China. In 2017, recommendations of the European Society of Thoracic Surgeons also strongly recommend an implementation of a screening programme in the EU. Further studies of improved lung cancer risk assessment scores and of effective molecular markers should intensify in order to reduce all potential harms to the high-risk group and to increase cost-effectiveness of the screening.

Screen-detected multiple primary lung cancers in the ITALUNG trial

Occurrence of multiple primary lung cancers (MPLC) in individuals undergoing low-dose computed tomography (LDCT) screening has not been thoroughly addressed. We investigated MPLC in subjects recruited in the ITALUNG randomized clinical trial. Cases of cytologically/histologically proven MPLC detected at screening LDCT or follow-up CT were selected and pathologically re-evaluated according to the WHO 2015 classification. Overall 16 MPLC were diagnosed at screening LDCT (n=14, all present at baseline) or follow-up CT (n=2) in six subjects (4 in one subject, 3 in two and 2 in three subjects), representing 0.43% of the 1,406 screenees and 15.8% of the 38 subjects with at least one screen-detected primary lung cancer. MPLC included 9 adenocarcinomas in three subjects and a combination of 7 different tumour histotypes in three subjects. MPLC, mostly adenocarcinomas, are not uncommon in smokers and ex-smokers with at least one LDCT screen detected primary lung cancer.

Can CT Screening Give Rise to a Beneficial Stage Shift in Lung Cancer Patients? Systematic Review and Meta-Analysis

Objectives

To portray the stage characteristics of lung cancers detected in CT screenings, and explore whether there’s universal stage superiority over other methods for various pathological types using available data worldwide in a meta-analysis approach.

Materials and Methods

EMBASE and MEDLINE were searched for studies on lung cancer CT screening in natural populations through July 2015 without language or other filters. Twenty-four studies (8 trials and 16 cohorts) involving 1875 CT-detected lung cancer patients were enrolled and assessed by QUADAS-2. Pathology-confirmed stage information was carefully extracted by two reviewers. Stage I or limited stage proportions were pooled by random effect model with Freeman-Tukey double arcsine transformation.

Results

Pooled stage I cancer proportion in CT screenings was 73.2% (95% confidence interval: 68.6%, 77.5%), with a significant rising trend (P_trend<0.05) from baseline (64.7%) to ≥5 repeat rounds (87.1%). Relative to chest radiograph and usual care, the increased stage I proportions in CT were 12.2% (P>0.05), and 46.5% (P<0.05), respectively. Pathology-specifically, adenocarcinomas (66%) and squamous cell lung cancers (17%) composed the majority of CT-detected lung cancers, and had significantly higher stage I proportions relative to chest radiograph (bronchioloalveolar adenocarcinomas, 80.9% vs 51.4%; other adenocarcinomas, 58.8% vs 38.3%; squamous cell lung cancers, 52.3% vs 38.3%; all P<0.05). However, the percentage of small cell lung cancer was lower using CT than other detection routes, and no significant difference in limited stage proportion was observed (6.8% vs 10.8%, P>0.05).

Conclusion

CT screening can detect more early stage non-small cell lung cancers, but not all of them could be beneficial as there are a considerable number of indolent ones such as bronchioloalveolar adenocarcinomas. Still, current evidence is lacking regarding small cell lung cancers.