There is currently no indication of nationwide public lung cancer screening (LCS) systems being widely adopted in Europe, but a reference model might soon become available, with recommendations from European radiological societies on how to implement LCS, explained an expert ahead of today’s New Horizons session on the subject.

LCS has been a worldwide effort for more than 20 years, but in Europe everything started about 15 years ago with the first European screening trial in Belgium and the Netherlands – the Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON) – which was followed by similar projects in Italy, Germany, Denmark and the UK.

The NELSON trial enrolled almost 16,000 people and its results were recently published in the New England Journal of Medicine1. “These data show that LCS with volume CT can reduce mortality by 24% in men, and potentially further in women,” said Mario Silva, a radiologist at the University Hospital of Parma and National Cancer Institute of Milan, Italy.

Variability in lung nodule measurement by manual caliper.

Most of the patients recruited in European and North American trials were aged between minimum 50–55 and maximum 75–80, with smoking habits over 15–20 pack years. That is the selection criteria now; however, more complex risk models may emerge. “There is the hypothesis that in 20 years we might also consider air pollution, as recently explored by researchers analysing regional data from Taiwan2,” Silva suggested.

Participants of European LCS trials were recruited through different channels, including public advertising, traditional mail and even email correspondence, as in Denmark. “Email contact would be the perfect setting for reaching out to the eligible population while minimising costs. For instance, Danish citizens have a governmental personal e-mail address,” he said.

These screening trials have taught researchers a lot about the profiles of the participants. “The responders usually smoke a bit less or quite frequently quit, are more educated and may have fewer risk factors or co-morbidities,” said Silva, who highlighted the need to involve the high-risk smoking population that might be hiding away from this setting of prevention.

A burning question that remains is whether LCS should be a national programme or not. “There is currently no answer,” he said.

A task force from the European Society of Radiology (ESR) and the European Respiratory Society (ERS) has just issued a document for imminent publication that has gathered experience on LCS from radiologists, pulmonologists and participants. Several milestones are detailed in the paper for every country that was approached, which might help local, regional and national entities set up their own screening programmes.

Ideally in the future, scientific societies will see LCS as a good practice to be implemented nationwide, although that task will not be easy. “For other cancers, it is gender and age. For LCS, nobody knows exactly the burden of risk factors, such as detailed smoking history,” said Silva.

Many LCS initiatives are ongoing in Europe, and Poland and Croatia are the first countries to have launched their national programmes.

The current trend is rather for local, cross-border initiatives. The group behind the NELSON trial, together with other groups from Europe, has launched a Horizon 2020 Project called ‘4-IN THE LUNG RUN’. The effort will recruit 26,000 people throughout Europe.

It may be a while before more countries adopt nationwide public systems, but things are moving forward, Silva explained. “It sounds like lung cancer screening is becoming more popular in the United States, where adherence to screening programmes is on the rise. Interest might also be sparked in Europe when screening practice becomes commonplace, with a mitigated and clear view of its pros and cons. Indeed, it is people’s engagement that still seems to be the utmost limit to implementation of lung cancer screening among those at highest risk,” he said.

Optimal approach by semi-automatic nodule volumetry.

Some degree of interest in screening is already experienced by every radiologist that faces opportunistic screening in clinical practice, i.e. when a smoker of a certain age wants to get a ‘lung check’ by CT.

Opportunistic screening is a dangerous approach because there might be no control of over-management of subtle clinically irrelevant CT findings, Silva insisted. Furthermore, some people are getting some control that may help, but that control is not taking place in the right setting.

“When you get a chest CT, depending on the expertise of the radiologist, you may get an examination using very low dose, which has been targeted to you, or you may be exposed to a very high dose, which may be unnecessary and potentially detrimental to your health,” he said.

Accuracy makes a difference, especially when very small findings are spotted on imaging that might trigger a risk of stress for the patient. Something screening has also shown is that no hurry is needed for small prevalent nodules.

“You will find a 7mm nodule and tell a patient that it needs to be taken out today, but the cancer risk may be low. And you would like to have a larger lesion to go for higher specificity and lower stress for the patient. If you tell patients they have a nodule, they will think it is cancer and will not understand that it does not need to be treated, but instead managed though a pre-specified algorithm for optimised work-up and characterisation,” he said.

LCS should therefore only be done in specialised facilities that are equipped with a new CT scanner to reduce dose to a minimum; good software to process images that improve efficiency and accuracy of reading sessions; and trained radiologists. The European Society of Thoracic Imaging (ESTI) has launched the LCS Certification Project, which provides radiologists with the literature, case-based workshops and lectures to teach about real threats and the best practice to do LCS.

1 De Koining et al, doi: 10.1056/NEJMoa1911793
2 Su SY et al, doi: 10.1186/s12889-019-7849-z

LIVE
New Horizons Session, Saturday, July 18, 16:00–17:00
NH 16 Lung cancer screening implementation in Europe: is it inevitable?

  • Chairperson’s introduction
    Mathias Prokop; Nijmegen/NL
  • NELSON trial latest results
    Harry J. de Koning; Rotterdam/NL
  • Lung cancer screening in Europe
    Mario Silva; Parma/IT
  • Challenges to implementing lung cancer screening: US experience
    Alexander A. Bankier; Worcester, MA/US
  • Lung cancer screening: will humans still be needed?
    Fergus Gleeson; Oxford/UK
  • Live Q&A: Lung cancer screening, from trial to practice 

FURTHER READING

Allen BD, Schiebler ML, Sommer G et al (2019) Cost-effectiveness of lung MRI in lung cancer screening. Eur Radiol. doi: 10.1007/s00330-019-06453-9: european-radiology.org/6453

Henschke CI, Yip R, Ma T et al (2019) CT screening for lung cancer: comparison of three baseline screening protocols. Eur Radiol. 29(10):5217-5226: european-radiology.org/5857

Meier-Schroers M, Homsi R, Gieseke J, Schild HH, Thomas D (2019) Lung cancer screening with MRI: Evaluation of MRI for lung cancer screening by comparison of LDCT- and MRI-derived Lung-RADS categories in the first two screening rounds. Eur Radiol. 29(2):898-905: european-radiology.org/5607

van Riel SJ, Jacobs C, Scholten ET et al (2019) Observer variability for Lung-RADS categorisation of lung cancer screening CTs: impact on patient management. Eur Radiol. 29(2):924-931: european-radiology.org/5599

Flors L, Kunin J, Hamid A et al (2019) Lung Cancer screening in a US state with the highest adult smoking rates: 4 years of experience. ECR 2019 / C-1741: myESR.org/191741