Early Emphysema Detection on CT Scans Predicts Long-Term Mortality Risks in Smokers

A new long-term study published in Radiology, a journal of the Radiological Society of North America (RSNA), reveals that emphysema identified on initial low-dose chest CT (LDCT) scans is linked to a significantly increased risk of death from all causes, chronic obstructive pulmonary disease (COPD), and cardiovascular disease over a 25-year period. The findings, drawn from a cohort of over 9,000 asymptomatic adults enrolled in a lung cancer screening program, suggest that emphysema detection during screening can serve as a powerful predictor of long-term health outcomes.

Emphysema is a progressive lung disease marked by irreversible damage to the air sacs in the lungs, which hinders breathing. It is most often caused by prolonged exposure to airborne irritants such as cigarette smoke and air pollution. Despite its severity, emphysema is frequently underdiagnosed, especially in individuals without symptoms.

“Until now, we didn’t know if baseline visual emphysema scoring on LDCT in the lung cancer screening setting had any prognostic value,” said Dr. Claudia I. Henschke, the study’s senior author and a professor of radiology at the Icahn School of Medicine at Mount Sinai in New York. “Our study stands out for its long follow-up and comprehensive analysis of the causes of death in a large lung cancer screening cohort.”

The research analyzed data from 9,047 participants (aged 40–85, median age 65, 4,614 women), all of whom had a history of smoking and were enrolled in the International Early Lung Cancer Action Program (I-ELCAP). They underwent baseline LDCT scans between 2000 and 2008 and were monitored until death or through the end of 2024, with a median follow-up of 23.3 years.

Each CT scan was evaluated by an experienced chest radiologist who visually scored the severity of emphysema on a scale from 0 (none) to 3 (severe). Among the participants, 70.9% showed no emphysema, while 21.1% had mild, 5.7% had moderate, and 2.4% had severe emphysema. Notably, nearly 80% of those with emphysema on LDCT had no prior diagnosis, including 5% of individuals with moderate or severe disease.

“Lung cancer screening shouldn’t just be looking for nodules,” emphasized Dr. Henschke. “That’s a small part of what we see on the CT scan. As radiologists, we’re responsible for the entire image.”

By the end of the study period, 3,738 participants (41.3%) had died. The most frequent causes of death were cardiovascular disease (12.7%) and COPD (3.3%). Median age at death was approximately 81 years across all causes. Statistical analysis confirmed that emphysema presence and severity correlated with increased all-cause and COPD mortality, though not with cardiovascular-specific mortality.

“Clinically, these findings suggest emphysema is not merely an incidental CT finding, but a distinct disease entity associated with worst outcomes and increased mortality,” said Dr. Henschke. “The findings show an increased risk of all causes of death by the presence of emphysema and its severity, ranging from a 1.15-fold increase for mild disease and a 2.28-fold increase for severe emphysema. For deaths due to COPD, the increased risk ranged from a 2.07-fold for mild disease to 12.06-fold increase for severe emphysema.”

These results highlight the potential for CT-based visual assessment of emphysema to shape long-term, risk-based management strategies. Dr. Henschke believes this reflects a transformative moment in preventive care. “The amount of information you get and the ability to act on it in a meaningful way is something preventive health only dreamed of being just a few years ago,” she said.

She envisions an expanded lung screening approach that includes assessment of COPD and cardiovascular risks, calling for closer collaboration among pulmonologists, cardiologists, and radiologists. “We have to work towards solutions holistically,” she noted.

While current U.S. guidelines recommend annual LDCT screening for adults aged 50–80 with a 20 pack-year smoking history, Dr. Henschke advocates for broadening access to include non-smokers. “In the U.S., about 30,000 to 40,000 deaths each year are found in non-smokers,” she said. “That’s about a third of the total deaths due to lung cancer annually.”