Screening tsunami coming for GPs

Lung cancer screening could bring as many as 2.4 million extra consults to general practice in 2025.

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GPs could face an extra 2.4 million consultations in the first year of Australia’s lung cancer screening program, according to experts who crunched the numbers.

And the practicalities of the scheme are still up in the air, they say, citing a lack of clarity around who will be responsible for following up incidental findings and who will bear the cost of further tests, the WONCA conference in Sydney heard last month. 

Around three million smokers or former smokers aged 55 to 74 years would be eligible for risk assessment, and under two million are expected to choose to opt in, according to modelling late last year by Deakin University.

After undertaking the risk assessment, the modelling predicts that half a million people would have a low-dose CT scan in the first year of the program, which is set to launch July 2025.

Participants with no signs of malignancy will be asked to screen again in two years, those with moderate risk nodules asked to return for a three-month follow-up scan and low risk results to return for a 12-month follow-up.

This could result in 2.4 million extra GP consults in the “worst-case scenario”, Associate Professor Nicole Rankin, a behavioural scientist at University of Melbourne, told WONCA delegates.

This is made up of the initial number of patients expected to take up a risk assessment consultation, and the remainder are those patients who chose to have a CT scan and required follow-up GP consultations. Professor Rankin told TMR it was difficult to accurately predict this number, hence the “worst-case scenario” forecast.

Several important questions about the rollout were still unanswered, she said.

For example, it was still unclear how patients would be contacted about the screening program and whether a medical practitioner would have to order the CT scan. 

There were also questions about who would be responsible for following up patients with incidental findings, and who would pay for the additional investigations and consultations to manage findings.

The federal government estimated up to 5000 lives will be saved by the $264 million national program in the first few years, Professor Rankin said.

International trials have shown low dose CT screening significantly improves the detection of early-stage disease and reduces lung cancer mortality.

The US National Lung Cancer Screening Trial, which compared low-dose CT scans with x-rays, found that the CT screening led to a 20% reduction in lung cancer deaths as well as all-cause mortality. 

“The really exciting part of the lung cancer screening story is that when you look at how you move from these rigorously highly controlled trials into real-world settings, you find an even better outcome in terms of the number of people who are being identified with stage one disease,” Professor Rankin said.

“In the US, the UK and Canada we see great mortality outcomes and people being diagnosed at stage one and stage two. The challenge when you’re moving from trials to real practice, you want to know ‘Is this actually going to work?’, and we have very good indication that it does.”

Dr Emily Stone, a Sydney respiratory physician, told the GP audience her colleagues were expecting to be inundated in July 2025.

“It’s ramping up and we’re going to get smashed, let alone you guys,” said the clinical researcher from Sydney’s St Vincent’s Hospital and the University of NSW.

“The system is not going to provide us with navigations. We are not going to perform as well as the breast screening in terms of referral pathways and packages.

“A lot of the nodules will not need rapid intervention and rapid biopsy. But the point is getting that decision made.”

Dr Stone said smoking cessation should be integrated into the lung cancer screening program because it took an average of 33 conversations for a patient to stop smoking.

“We need to get those 33 conversations happening,” said Dr Stone.

Professor Rankin said 11% of Australians currently smoke and lung cancer was the number one cause of cancer death, with 14,500 people diagnosed and almost 9000 dying from the disease each year. 

“In terms of the death rate, we have some serious work to do with nearly 9000 people each year dying from lung cancer,” she said.

“The majority of those people will be diagnosed with an advanced stage of disease and so their options for treatment are very limited.”

Detecting lung cancer earlier gave a much higher chance of survival, Dr Rankin said, with research showing that two in three people would still be alive after five years if their cancer was detected at stage I. 

When lung cancer is detected at stage III or IV, five-year survival ranged from 3% to 17%, she said.

“That’s where we need to improve screening because that’s where we see the shift between people being detected with early-stage disease,” she said.

Professor Rankin said the screening program would use “older” criteria – recommended by the Medical Services Advisory Council – which is based on age and smoking history, rather than the newer PLCOm2012 assessment tool which includes more risk factors such as family history, BMI, education, race and ethnicity.