Australia is likely to introduce lung cancer screening within five years but it must ensure high risk groups beyond smokers are targeted, researchers told COSA 2018.
People who have occupational exposure to asbestos have a high risk of lung cancer similar to smokers but they are not included in any current guidelines for lung cancer screening, said Dr Edward Harris a lung screening research fellow at Sir Charles Gairdner Hospital, Perth.
Dr Harris said the recently presented results from the NELSON study from Holland had confirmed the 20% reduction in lung cancer mortality seen in the 2012 US National Lung Screening Trial (NLST), and made it likely that Australia would adopt screening based on this robust evidence.
“I think it’s likely that CT screening for lung cancer will be adopted [in Australia] in the next three to five years on the back of these two large studies,” he said.
At the meeting he presented preliminary findings from five years of low dose CT screening (2012-2017) in Australians exposed to asbestos.
The study group comprised 1743 people in WA, of whom about one in ten participants (10.7%) had nodules on CT. Among this group 56% had exposure to asbestos from occupations other than mining and 33% were never smokers.
There were 18 (1%) people who developed lung cancers, 22% of whom were never smokers and smoking rates were modest among ex or current smokers.
Dr Harris says his research points to a gap in the current guidelines for lung cancer screening, as routine screening is not currently recommended in people exposed to asbestos who do not have a significant smoking history.
“The majority of our cohort would not have been eligible for screening under any of the current guidelines, despite the fact that the risk of 1% is similar to that in any other high-risk cohort,” he said.
The trial had identified that anyone with three months cumulative exposure to asbestos should be included in lung cancer screening recommendations, he said.
Also speaking at COSA 2018, Dr Annette McWilliams, head of respiratory medicine at Fiona Stanley Hospital, Perth, noted that the NELSON study results showed that CT screening in asymptomatic men at high risk for lung cancer led to a 26% (9-41%) reduction in lung cancer deaths at 10 years of study follow-up, with 86% compliance.
The findings also suggested that women may benefit even more than men from screening, with the rate-ratio of lung cancer mortality varying between 0.39 and 0.61 in different years of follow-up.
“No one was expecting the research results to be as convincing as they were – so there is now an increased interest in furthering our research in the Australian context to figure out what’s next,” she said
Both Dr McWilliams and Dr Harris encouraged more clinicians to refer Australians in high risk groups to participate in current ongoing lung screening pilot trials.