The biggest challenge of lung cancer screening

Lung cancer remains the deadliest cancer in Belgium. Not because treatments are lacking, but because tumours are often only detected once the disease is already at an advanced stage. With the ZORALCS study, Antwerp University Hospital, UAntwerp and the primary care zone ZORA are investigating whether systematic screening using low-dose CT scans is also feasible in Flanders. The technology already exists. The big question now is: how do you reach exactly those people who are most at risk?

Lung cancer often detected too late

Lung cancer often only causes symptoms once the disease is already at an advanced stage. ‘You can’t feel or see a lung,’ says radiologist and lead researcher Annemiek Snoeckx of Antwerp University Hospital. Together with Professors Guido Van Hal and Jan van Meerbeeck of UAntwerp (Faculty of Medicine and Health Sciences) and Professor Jan De Lepeleire, who chairs the primary care zone ZORA, she forms the core team of the ZORALCS study. ‘Tumours can grow for a long time without causing clear symptoms. People often only notice something when they start coughing up blood.’

‘International studies show that low-dose CT screening can reduce lung cancer mortality by at least 20%,’ says Snoeckx. ‘The scans often detect what are known as lung nodules: small spots in the lung tissue that are usually harmless, but can sometimes turn out to be an early form of cancer. That’s why follow-up is essential.’ Within ZORALCS, the images are assessed by radiologists supported by artificial intelligence. ‘It’s the first screening study in which AI is being used in daily practice, both for diagnosis and image reconstruction.’

More than a medical issue 

Still, broad screening remains complex. Alongside securing sufficient funding, one of the biggest challenges is the social stigma that surrounds smoking and lung cancer. ‘We sometimes received angry reactions from people who felt we shouldn’t spend money on screening people who had brought it upon themselves,’ says Snoeckx. ‘But addiction isn’t a matter of choice. What’s more, most participants had already quit smoking.’

According to Van Hal, that stigma also affects policymaking. ‘Prevention naturally remains important — and we also implemented a quit-smoking programme within the study — but if you focus only on that, you leave a large group of people out in the cold, namely those who have already quit.’

There are also the usual risks associated with screening. A scan may reveal abnormalities that ultimately prove harmless, leading to additional examinations and stress. Overdiagnosis also remains a concern: some tumours grow so slowly that they might never cause symptoms. ‘That trade-off exists in almost every population screening programme,’ says Van Hal. ‘The question is always: do the health benefits outweigh the disadvantages?'

From pilot project to policy

For now, ZORALCS remains a pilot project. Europe currently recommends carrying out trial studies before rolling out an official screening programme. Nevertheless, the researchers are closely following international developments. Several European countries already have successful national or large-scale screening programmes in place.

‘We may be slightly behind, but the work we’re doing here is exceptionally high-quality,’ Snoeckx believes. ‘We built the project according to the same standards as our other population screening programmes, such as breast and bowel cancer screening, and we now have an enormous amount of data. In addition, we score very highly on the patient-reported experience measures (PREMs). Participants were very satisfied.’ The researchers hope Flanders will be ready when Europe formulates further recommendations.