Emphysema detected with lung-density analysis software during low-dose CT lung cancer screening can be highly predictive of lung cancer risk, new research shows.
"Almost everyone has an incidental finding" — coronary artery disease, renal cell carcinoma, and arthritis are all commonly found — "but emphysema is the one we're concerned about," said investigator Humberto Choi, MD, from the Cleveland Clinic.
The prevalence is about 60%, but because "we don't know the threshold at which we should act on the emphysema," it is not clear how to proceed when it is detected, he told Medscape Medical News.
No protocol or care path exists, Choi explained. This is important because screening results that fall into categories that indicate higher risk for malignancy are associated with a higher incidence of cancer, he said. And more severe emphysema tends to be detected in these patients.
Choi presented results from the Cleveland Clinic lung cancer screening program, which uses automated lung density analysis software to detect emphysema, at the American Thoracic Society 2019 International Conference in Dallas.
Emphysema was detected in 125 (39%) of the 321 participants screened, indicated by a score that was greater than 0%. In the study cohort, 101 (31%) participants had previously been diagnosed with chronic obstructive pulmonary disease (COPD).
During the 12-month follow-up period, patients with emphysema detected made significantly more pulmonary outpatient visits than patients without emphysema (43.2% vs 27.0%; P = .01), and were more frequently prescribed treatment for COPD (47.2% vs 24.5%; P < .001).
However, the rate of visits to the emergency department was similar in the emphysema and no-emphysema groups (35.2% vs 29.6%; P = .32), as was the rate of hospitalization (7.2% vs 12.2%; P = .10).
"Patients with emphysema detected had more outpatient visits and more need for inhalers," Choi reported.
"We need to better understand which patients should see a pulmonologist and be treated," he added. Follow-up and treatment protocols are needed.
More Lung Nodules
Emphysema was also associated with a higher incidence of lung nodules in a separate study presented at the meeting by the same team.
Their retrospective analysis of 314 patients from the same Cleveland Clinic cohort assessed Lung-RADS assessment categories. Five patients were diagnosed with lung cancer during the 4-year follow-up period.
Correlation Between Lung-RADS Category and Emphysema
|Lung-RADS Category||n||Mean Rate of Emphysema, %|
"The emphysema itself causes benign risk nodules to look different, more irregular," Choi explained.
Both studies point to a need for review and follow-up when emphysema is detected, particularly because it can lead to other respiratory complications.
At the Cleveland Clinic, when a nodule is found, each scan is evaluated to determine the best procedure. "Bronchoscopy, surgical section, needle biopsy — we have to review carefully," Choi explained. When there is emphysema, there are greater risks, but currently there are no guidelines to follow.
Every program does follow-up differently, he said. A guideline that takes a multidisciplinary approach is needed.
"We should settle on a structured language for incidental findings," said Mark Spencer Godfrey, MD, from the Yale University School of Medicine in New Haven, Connecticut.
The program at his institution has developed its own internal process, but what is needed, he said, is "evidence-based reporting on how to proceed."
Currently, the Yale lung screening program simply classifies incidental findings with a yes or no. "It would be helpful to expand on that to give radiologists a way to report incidental findings the same way as nodules," said Spencer.
"To be honest, we get a lot of phone calls; with electronic medical records, everything is laid out for the patients to read about," he said.
At the Yale Union Hospital, they have their own internal template, but having different approaches in every screening program makes it hard to compare results.
"Severe emphysema may have a different definition here than somewhere else; we need a level playing field. As the program expands, this will become more of a headache," he predicted.
Choi and Godfrey have disclosed no relevant financial relationships.
American Thoracic Society (ATS) 2019 International Conference: Abstract A1123/212; presented May 19, 2019; abstract A4477/409, presented May 19, 2019.
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Cite this: Emphysema Frequently Found During Cancer Screening - Medscape - May 28, 2019.