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by Mélisande Rouger

Momentum for lung cancer screening is building in Europe, as projects to boost the implementation of national programs are underway and emerging research suggests that women might be two to three times more at risk of developing the disease than men.

A long awaited response to the global burden of lung cancer may soon be given, as evidence that low dose CT screening could drastically reduce mortality is piling up, especially in women with a history of smoking. Initial results from the CASCADE clinical trial in France 1 indicate that the risk of developing lung cancer is much higher than expected in female smokers, according to Prof. Marie Pierre Revel, head of the radiology department at Cochin Hospital, University of Paris. 

“One year into the study we observe that, at equal tobacco consumption, cancer prevalence in women is two to three times higher than in men, and more than double to results obtained in previous trials like NELSON,” said Revel, who is the principal investigator of the CASCADE (lung CAncer SCreening in French women using low-dose CT and Artificial intelligence for DEtection) trial. 

The emerging data demands a prompt response in reaching out to potential candidates, i. e. women between 55 and 74 years old who have smoked at least one pack of 20 cigarettes per day for 20 years. “If our study confirms that the risk to develop lung cancer is three times higher in women, then we need to do everything we can to target this population,” she said.

CASCADE, which is funded by the French Ministry of Health and the French Cancer Institute, was launched to obtain so far lacking data on women, as these were under represented in most lung cancer screening studies, she explained. 

“We have a very worrying epidemiological situation in France because women now represent 35 percent of lung cancer patients, compared with 16 percent in 2000. So it’s very likely that lung cancer is the leading cause of cancer death before breast cancer in French women (…) It kills too many women and the lack of perception of the risk is distressing.”

Positive screening result in a 62-year-old former smoker with a 25 pack-year smoking history. This early stage lung adenocarcinoma was surgically treated and did not require any other postoperative treatment. 

Building awareness among healthcare professionals that lung cancer is not just a male disease is paramount to improve patient outcome. 

Lung cancer screening in women could be run in parallel to breast cancer screening, Revel suggested. “We would benefit from our collaboration with screening centers and include an invitation letter to the recipients. If they are smokers, we could check their eligibility and decide if they should also be screened for lung cancer.” 

Immediate action must be taken to adequately implement lung can- cer screening in France, as a large pilot study to recruit all smokers will be launched by the French National Cancer Institute (INCa) in 2024. The CT scan reading modalities will be based on the recommendations from Revel’s research group. 

“I want to urge centers taking part in the program to organize a double reading validated by AI instead of another expert radiologist,” she said. “It’s easier to screen a population using a single general radiologist trained in lung cancer screening rather than to rely on the barely 200 thoracic radiologists in France.” 

The SOLACE project 

Lung cancer has the highest mortality of all cancers, more than colon and breast cancer together. The key to improving outcomes is to diagnose patients early, when curative therapy is still an option. 

The recommendation from the European Council to explore the feasibility and effectiveness of low-dose CT to screen individuals at high risk for lung cancer, including heavy smokers and ex-smokers, was a big step in that direction, according to Prof. Hans Ulrich Kauczor, medical director of the diagnostic and interventional radiology department at Heidelberg University Hospital, Germany. 

“Now we have the opportunity to take all the accumulated evidence on low dose CT screening and really do something,” said Kauczor, who is the scientific coordinator of the Strengthening screening Of Lung cAnCer in Europe (SOLACE) initiative, an EU4Health project launched under the Europe’s Beating Cancer Plan to facilitate the implementation of screening programs across Europe. 

The initiative is in “an exciting phase”, with increased recruiting rates and a pilot project underway in ten countries. “We have a lot of activity in Hungary, Poland, Estonia, Czech Republic, France, and Germany. In Croatia, the national lung cancer screening program is living up to its reputation,” he said. “In Ireland things are moving a bit slower and Spain is taking steps. Greece and Romania are still a little behind, but there’s definitely some progress. Further away, Australia has just recently decided to launch a national screening program.” 

Screening can help reduce the burden of lung cancer on health care systems, especially those who cannot afford expensive treatments such as immunotherapy. “It’s easier to address these countries by showing that lung cancer screening in smokers is cost efficient,” he said. 

With current CT scanners, radiation exposure is no longer an issue, he added. “Dose is going down tremendously with new equipment, below 1 mSv, so we will come to a point where radiation exposure in lung cancer screening becomes negligible.“ 

Successfully implementing screening programs will mean being able to reach out to the populations who are at the highest risk but have traditionally remained far from the healthcare system. 

“We will release flyers and messages in the media to reach out to everyone, whether they live in city centers, remote areas or are part of isolated ethnic minorities,” Kauczor said. “We also plan to find ambassadors, i. e. patients who have benefited from lung cancer screening and can talk about it positively to raise awareness among their communities.” 

The gender issue is key and screening is expected to reduce mortality more among women than men, early research shows. “Lung cancer screening may reduce mortality by 30 percent in women and below 20 percent in men,” he said. “The holy grail is trying to reduce general mortality with these programs, and hopefully we will. But we need European guidelines that national policy makers can use to implement these programs, so we have to have a common ground of quality level.”



Marie-Pierre Revel is professor of radiology and head of the radiology department at Cochin Hospital, University of Paris, France. She is past president of the European Society of Thoracic Imaging and in charge of the Lung Cancer Screening Certification Program, which is endorsed by the European Society of Radiology (ESR), where she now serves as chair of the communication and external affairs committee. She is the scientific director of the lung CAncer SCreening in French women using low-dose CT and Artificial intelligence for DEtection (CASCADE), a study funded by the French Ministry of Health.

Hans Ulrich Kauczor is professor of radiology and chairman of radiology at the University of Heidelberg, Germany. He is also medical director of its department of diagnostic and interventional radiology. He is the scientific coordinator of the Strengthening the screening of Lung Cancer in Europe (SOLACE) project and first author of both joint statement papers from the ESR and the European Respiratory Society (ERS) on lung cancer screening.