Experts call for Lung-RADS updates amid concern about certain incidental findings
New findings from a large CT lung cancer screening dataset reveal that a significant number of patients have significant incidental findings visible on their scans.
Researchers from Brown University recently retrospectively reviewed data from over 26,000 people who took part in the landmark National Lung Screening Trial. They sought to determine whether these incidental findings—potentially indicative of extrapulmonary cancer—were routinely identified on screening exams. The group focused specifically on identifying significant incidental findings that preceded a diagnosis of cancer within one year of the exam, sharing their results Tuesday in JAMA Network Open.
Prior research has indicated that about 1 out of every 3 low-dose lung cancer CT scans contain some sort of incidental finding. But not all warrant further investigation, which makes quantifying their risk challenging.
“The goal is to give physicians and patients better data so that they can make more informed choices about those abnormalities that should be considered for follow-up and those that most likely can be ignored,” said Ilana F. Gareen, PhD, a professor of epidemiology at Brown. “While current recommendations exist for reporting and addressing [significant incidental findings], the evidence base examining the association between SIFs detected at LDCT lung cancer screening with an extrapulmonary cancer diagnosis is limited.”
More than 75,000 screenings were included in the analysis. Of those, around 7% of participants had cancerous significant incidental findings on one of their exams; around 3% of those were diagnosed within one year of a screening.
The group classified each extrapulmonary cancer using Surveillance, Epidemiology, and End Results (SEER) Program organ system categories. They determined that the risk of urinary cancers was the highest among the cohort, followed by lymphoma and leukemia.
These findings, the group contends, suggest that the Lung-RADs S modifier—which notates the presence of an incidental finding potentially suspicious for malignancy—should be updated.
“Our findings may serve as an impetus for revising the Lung-RADS S modifier to include more specificity on classification of [significant incidental findings],” the authors suggested. “Although the number of extrapulmonary cancers potentially associated with SIF detection in the [National Lung Screening Trial] seem relatively small, when considered in context of the nearly 14 million people who now qualify for lung cancer screening in the U.S., the potential impact is large.”
Read more about the findings here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.