CT lung cancer screening is gaining momentum around the world, but one of the challenges providers face is how to manage incidental findings. It’s especially important given that a new study in JAMA Network Open suggests that incidental findings on screening exams are associated with a higher risk of cancer occurring outside the lung.
Incidental findings are suspicious areas discovered outside the target region being imaged, and are especially a concern with cancer screening exams.
- Incidental findings turn out to be normal most of the time, but pathology occurs often enough that most clinicians agree they’re worth investigating.
The problem is that many providers don’t have a robust system in place for alerting referring physicians to incidental findings and ensuring that patients get the follow-up exams they need.
The new study addresses incidental findings within the context of CT lung cancer screening, specifically in the National Lung Screening Trial, the landmark study that established low-dose CT’s lifesaving benefit.
- It’s an important question, because chasing down a large number of benign incidental findings would be a resource-intensive task that could alter the cost-benefit ratio of lung screening.
Researchers analyzed significant incidental findings unrelated to lung cancer in 26.4k people across three rounds of LDCT screening who were followed for a year, revealing…
- Cancer findings outside the lung occurred in 6.8% of people, and 13% of them had multiple cancers.
- Patients with significant incidental findings had a higher absolute risk of being diagnosed with extrapulmonary cancer within a year (16 per 1k participants).
- Study participants with incidental findings tended to be slightly older (62 vs. 61 years) and more likely to have a history of smoking-related disease (69% vs. 66%).
The findings confirm that having a plan to manage incidental findings should be an important part of any CT lung cancer screening program, especially given previous research showing that 23% of deaths in NLST were due to cancers outside the lung.
- In fact, an effective incidental finding program could enhance LDCT screening’s value, especially given that people eligible for screening have heavy smoking histories.
The Takeaway
The new study shows that incidental findings on CT lung screening exams are common and serious enough to warrant further investigation. Screening programs that are able to do so effectively will deliver even more value to their patients than lung screening alone.
