Almost half of patients with high risk findings at CT screening for lung cancer are not returning in a timely fashion for the recommended follow-up, according to US data presented at the ATS 2022

A retrospective cohort study from Washington state included adults with baseline and  annual  lung cancer screening between 2012 and 2021 and  findings standardised as  Lung-RADS categories 3, 4A, 4B or 4X.

It identified 397 with high-risk findings of which 59 (15%) were ultimately diagnosed with lung cancer.

The study found the median delay time to follow up, including a second CT scan, other appropriate imaging, and/or specialty consultation or procedure, was 91 days overall.

By risk category, the delay was 181 days in Lung-RADS 3, 68 days in Lung RADS-4A, and 32 days for those at the highest risk Lung-RADS 4B and 4X.

Lung cancer diagnoses occurred in 1%, 10% and 15% of the groups respectively.

Of patient characteristics evaluated, current smoking was associated with higher levels of delay overall (p=0.008), independent of Lung-RADS.

“The fact that nearly half of all patients with abnormal findings in our study experienced delays in following up is alarming,” said the study’s presenting author Dr Alwiya Ahmed in a statement.

Dr Ahmed, from the Seattle Cancer Care Alliance and Fred Hutchinson Cancer Research Center, said participation in lung cancer screening was relatively low compared to that in more established breast and colorectal cancer screening programs.

He said most studies have focused on improving uptake of lung cancer screening and maintaining long-term engagement of people with normal screening findings rather than investigating follow-up in people with high-risk findings.

Dr Ahmed said interventions may be needed at both the provider and patient levels.

“Interventions may be needed to ensure adequate follow-up after high-risk Lung-RADS finding, and  further study is needed to evaluate the impact of delay in diagnosis after LCS  on lung cancer stage and survival. ”

The findings provide some insight into the complexities of designing an effective lung cancer screening program – a process which was well underway in Australia but for which there is currently no federal government funding commitment.

The Lung Foundation Australia continues to advocate for a $60 million pilot screening program that would allow people aged over 55 with a history of smoking to access low-dose CT screening.

It says such a program would prevent 10,000 lung cancer deaths over a decade.

“Tragically, at the moment, nearly 75% [of cases] are diagnosed at stage 3 and stage 4 where treatment options are much more limited than it would be if we were able to diagnose at stage 1 and 2,” Lung Foundation Australia CEO Mark Brooke told the ABC.