Is Lung Cancer Screening as Effective Without Risk-Based Selection?

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Chinese study finds a high yield of screen-detected cancers in an all-comer middle-age population

by
Crystal Phend, Contributing Editor, MedPage Today
April 21, 2025 • 3 min read

Low-dose CT (LDCT) screening for lung cancer in an all-comer Chinese population ages 40 to 74 identified at least as many cases as would be expected from screening high-risk individuals, a study found.

One-time screening flagged 19.2% of participants in the prospective study and led to biopsy-proven lung cancer diagnosis in 1.7% (200 of 11,708), reported Wenhua Liang, MD, of the First Affiliated Hospital of Guangzhou Medical University in China, and colleagues in a research letter in JAMA.

This was in comparison with a rate of 1.1% in the high-risk population of the National Lung Screening Trial in the initial screening round and a 2.6% detection rate among never-smokers in Taiwan in a prior study.

“These findings highlight the necessity of prospective studies to evaluate efficacy of CT screening and the importance of identifying high-risk factors or prescreen-enriching biomarkers in populations not traditionally considered high risk,” Liang’s group wrote.

U.S. guidelines recommend LDCT screening annually for adults ages 50 to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years. “However, studies indicate increasing LC [lung cancer] cases among younger, nonsmoking populations, particularly in Asia,” Liang and colleagues noted.

The Guangzhou study challenges the conventional high-risk-only paradigm, said Jasleen Pannu, MBBS, of the Ohio State University Wexner Medical Center in Columbus, who was not involved in the study.

“The current study suggests that with a well-coordinated program, even non-risk-based screening can be executed effectively with reasonable uptake and diagnostic yield,” she told MedPage Today.

However, stigma, lack of awareness, insurance gaps, and provider unfamiliarity are all barriers to real-world screening, she added. “Even in risk-based models, uptake in the U.S. remains low (about 5-15%), especially in underserved and minority populations.”

Their Guangzhou Lung-Care Project offered one-time LDCT screening for all city residents ages 40 to 74 years from December 2015 through July 2021. The only exclusions were lung cancer diagnosis or treatment within the prior 5 years, chest CT within the past year, or significant cancer-related symptoms. The large majority of individuals assessed for eligibility completed screening.

Of these 11,708 screened individuals (median age 59), 16.1% met National Comprehensive Cancer Network (NCCN) high-risk criteria for screening, while 41.9% met Chinese consensus criteria for screening. Those not classified as high risk had a higher proportion of stage I cancer: 92% versus 60.5% among high-risk individuals per NCCN criteria and 93.2% versus 80.4% by Chinese consensus criteria. Detection rates of stage I cancer were 2% versus 1.6% and 2.3% versus 1.3%, respectively.

“Notably, stage I disease made up 82.5% of diagnosed cases — higher than U.S. trials — suggesting a favorable stage shift even in non-high-risk populations,” Pannu noted.

Notably, only 38 of the 200 screen- and biopsy-positive individuals would have met the NCCN criteria, yielding an 81% missed diagnosis rate for the criteria. The Chinese criteria would have missed 44%.

Overall, the one-time LDCT diagnostic performance in the non-risk-based screening population had a sensitivity of 96.6%, a specificity of 82.2%, a positive predictive value of 8.9%, a negative predictive value of 99.9%, and overall accuracy of 82.5%.

However, the researchers cautioned that “although only 7 cases were adenocarcinoma in situ, potential overdiagnosis concerns remain, given 21.5% minimally invasive adenocarcinoma.”

Biopsy complications occurred in 25.5% of participants (59 of 231 biopsied), including 21.6% minor to intermediate events and 3.9% (nine cases) major events, albeit without any procedural deaths within 60 days.

Study limitations included the “single-group, unrandomized design without mortality data from an unscreened comparison group, which prevents the assessment of the value of screening this population,” Liang and team noted.

“It is essential to test the generalizability of these findings in other regions and races,” including in the U.S., they acknowledged.

Pannu agreed, noting the “relatively healthy, urban, engaged population. Generalizing to the U.S. or Western countries is limited due to differences in demographics, lung cancer epidemiology, and healthcare infrastructure. For example, 69% of the population were never-smokers, which is atypical for U.S. lung cancer risk groups but increasingly relevant in East Asia.”

Before widespread adoption of a non-risk-based screening strategy, randomized controlled trials would need to demonstrate mortality benefit and cost-effectiveness in broader populations, she added. “Tailoring screening models to local epidemiology and health infrastructure is crucial for true generalizability.”