Screening for lung cancer can also accelerate diagnosis of interstitial lung disease (ILD), potentially improving outcomes through earlier access to treatment, a study has concluded.
A UK research team found that at least 1.5% of people attending for lung cancer screening had undiagnosed ILD, around half of whom had idiopathic pulmonary fibrosis (IPF).
The screening program also provided the opportunity to capture and monitor patients with interstitial lung abnormalities (ILA), who then progressed to IPF during follow-up, the researchers noted.
The findings, published in Thorax, showed that IPF was “highly represented in this high-risk cohort”, and 19% of all patients referred for evaluation were started on antifibrotic therapy.
“Lung cancer screening, therefore, provides an opportunity to detect and treat ILD early, potentially improving patient outcomes,” concluded the researchers led by Dr Richard Hewitt of the Interstitial Lung Disease Unit, Royal Brompton & Harefield Hospitals, London.
The retrospective study was carried out at the Royal Brompton Hospital between August 2018 and April 2021 as part of a lung cancer screening pilot in which 1,853 subjects underwent low-dose CT screening. ILA with a greater than 5% extent on CT were identified in 4.2% of the cohort, of which 43 subjects (2.3%) underwent ILD assessment.
ILD was diagnosed in 65.1% of people assessed, with the remainder categorised as having ILA.
IPF was the most common ILD (30.2%), followed by smoking-related ILD (11.6%), hypersensitivity pneumonitis (9.3%) and pleuroparenchymal fibroelastoses (4.7%).
Treatment with pirfenidone or nintedanib for IPF was initiated in 18.6% subjects who met the UK National Institute for Health and Care Excellence criteria with an FVC between 50% and 80%, while immunomodulatory therapies were started in three patients.
The researchers also noted that there weren’t any significant variations in age, gender or smoking pack-years between those with a final MDT diagnosis of ILD versus those with ILA.
It was however shown that “individuals diagnosed with ILD had a greater extent of abnormality on CT; ≥10% extent ILA was reported in 89.3% of individuals with ILD compared with 46.7% of those with ILA,” according to the authors.
Respiratory symptoms were more frequently reported in the ILA group (73.3%) versus the ILD group (42.9%), “potentially reflective of the comorbid nature of this population”, they added.
There were some key limitations to the study, including that the final cohort of patients diagnosed with ILD via the screening program came from one region of the UK, and that the pre-selected population at high risk of lung cancer excluded non-smokers and younger people.
The study’s findings “demonstrate the value of targeted ILD case-finding in lung cancer screening programmes”, but “require confirmation across other screening populations and ILD centres”, the authors concluded.