42% of nonsmokers have one or more solid lung nodules
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Key takeaways:
- A greater proportion of men vs. women nonsmokers had a lung nodule.
- Researchers found a higher prevalence of nodules in older vs. younger adults.
- A small proportion of individuals had an actionable nodule.
A lung nodule sized 30 mm3 or greater was found in 42% of adults in Northern Europe who reported either never smoking or former smoking, according to results published in Radiology.
“This study is newsworthy because it shows that solid lung nodules, including clinically relevant and even actionable ones, are present in a significant portion of the Northern European nonsmoking individuals — individuals who are traditionally thought to be low-risk for lung nodules and also for lung cancer,” Rozemarijn Vliegenthart, MD, PhD, radiologist and professor of cardiothoracic imaging at the University Medical Center Groningen and the University of Groningen in the Netherlands, told Healio.
Participants from the Lifelines population were invited for a chest CT as part of the Imaging in Lifelines study. Vliegenthart and colleagues evaluated 10,431 adults (median age, 60.4 years; 56.6% women; 98% white) aged 45 years or older who either reported never smoking (n = 4,812) or former smoking (n = 5,619) to determine how solid lung nodule prevalence and size on low-dose CT scans differs based on age and sex in this non-high-risk population.
A minimum of one lung nodule sized 30 mm3 or greater was found in 42% (n = 4,377; median volume, 69 mm3) of the total cohort (42.7% never smokers; 57.3% former smokers), according to researchers. When divided by sex, a greater proportion of men vs. women had a nodule (47.5% vs. 37.7%), and median nodule volume was larger among men (73 mm3 vs. 66 mm3).
In terms of age, researchers observed a higher prevalence of nodules in the oldest group (≥ 80 years) vs. the youngest group (45 to 49.9 years) for both men (60.7% vs. 39.4%) and women (50.9% vs. 27.7%).
A lung nodule measuring 100 mm3 or greater was classified as clinically relevant, meaning “according to guidelines, it would need follow-up or work-up,” Vliegenthart said. A nodule of this size was found in 11.1% of the population (median volume, 173 mm3).
“This was higher than we expected and similar to the rates seen in smokers in the context of lung cancer screening studies,” Vliegenthart told Healio.
Similar to above, a larger proportion of men vs. women met this nodule criteria (14% vs. 8.9%), as did those aged 80 years or older vs. those aged 45 to 49 years for men (24.4% vs. 8.5%). Additionally, the proportion of women with clinically relevant nodules was greater in the 75- to 79-year-old group vs. the 50- to 54-year-old group (15.6% vs. 3.7%).
Only a small proportion of individuals (2.3%) had an actionable nodule that was 300 mm3 or larger (median volume, 791 mm3). The proportion of men with this nodule size was close to the proportion of women (2.4% vs. 2.1%).
More older individuals had an actionable nodule than younger individuals, and this was true for both men (≥ 80 years vs. 45 to 49 years, 6.4% vs. 1.1%) and women (75 to 79 years vs. 50 to 54 years, 4.9% vs. 0.6%).
Notably, most of those with a nodule only had one (n = 2,430) or two (n = 975), with fewer individuals having three nodules (n = 433), four nodules (n = 224) or five or more (n = 315).
“It was unknown how common lung nodules are in Western general populations, and how large these nodules are,” Vliegenthart told Healio. “The prerequisite for understanding abnormalities and how to deal with them is to study what is normal and common in the general population, and we believe our work provides a reference point for this.
“As more chest CT scans are done for different clinical reasons and radiologists become more aware of lung nodules, we expect the need for follow-up scans will increase,” Vliegenthart added. “However, lung cancer is very rare in the studied group, suggesting that most lung nodules in nonsmokers are likely benign. Future data on lung cancer in this group could help improve how we manage these nodules for low-risk individuals.”
Reference:
- Lung nodules seen in a high percentage of non-smokers. https://www.eurekalert.org/news-releases/1053747. Published Aug. 13, 2024. Accessed Aug. 13, 2024.