Annual Lung Cancer Screening Adherence Poor After Initial Screening, Study Finds

Adherence to annual lung cancer screening (LCS) with low-dose CT (LDCT) imaging was only 22.3% among more than 1 million patients who underwent baseline screening between 2015 and 2019, according to study findings published in CHEST.

The study also explored outcomes and predictors of poor adherence to LCS.

For individuals at a high risk of lung cancer based on age and smoking history, an annual LDCT of the chest has been recommended by the United States Preventive Services Task Force (USPSTF) since 2013, the study authors noted. The American College of Radiology Lung Cancer Screening Registry (LCSR) began collecting data nationwide in 2015 after CMS made LCS a covered benefit and mandatory for facilities to report data on LCS to the national registry.

Researchers examined LCS data from the LCSR that encompassed 3625 facilities. Patient characteristics; examination information, including lung imaging reporting and data system (Lung-RADS) category; and cancer diagnosis and stage were captured. Because the study included data collected between 2015 to 2019, the authors assessed adherence and outcomes for individuals eligible for screening based on the 2013 USPSTF recommendations. This includes those aged 55 to 80 years who are either current smokers with a history of 30 or more pack-years of smoking or former smokers with at least 30 pack-years of smoking who have quit within the past 15 years.

A total of 1,052,591 people who were screened and met the eligibility criteria were included in the study. The researchers compared LDCT scan interpretations by Lung-RADS score, cancer detection rates (CDRs), and stage at diagnosis among the study cohort with findings of the National Lung Cancer Screening Trial (NLST), which was the catalyst to the initial 2013 USPSTF recommendation.

Of the overall population screened, 90.8% met the 2013 USPSTF eligibility criteria. The majority (83.1%) underwent screening between 2017 and 2019. Just over half (51.7%) of the screened population were men, 53% were 55 to 64 years old, and 61.4% were current smokers. Adherence was checked at 3 time points: T1 (11-15 months), T2 (16-24 months), and T3 (24 months or longer after baseline).

A total of 570,302 people were eligible for follow-up LCS at T1, although only 127,194 (22.3%) had follow-up examinations. The rate of adherence ranged from 20% to 30% across demographics, but it was particularly low among current smokers, Hispanic or Black individuals, and those with a lower reported education level.

Adjusted analyses showed that Black, Hispanic, and Asian individuals were significantly less likely to have at least 1 LCS examination following baseline screening, with adjusted odds ratios of 0.84, 0.73, and 0.79, respectively. Additionally, those in the West or South regions of the United States were less likely to adhere to LCS than those in the Northeast. An added 11.7% of people overall would have been considered adherent if repeat annual screening was extended to 24 months, and 5.9% more would have been adherent after 24 months.

Overall, 82.6% of patients had negative results at baseline screening, with 39.8% of those individuals falling into Lung-RADS category 1 and 42.8% considered Lung-RADS category 2; and 17.3% showed positive results, with 9.9% and 7.4% falling into Lung-RADS categories 3 and 4, respectively.

On repeat annual LCS, almost 90% of people showed negative results; 35.6% were Lung-RADS category 1 and 54.3% were Lung-RADS category 2. There were 9.7% with positive results, 5.2% were Lung-RADS category 3, and 4.5% were Lung-RADS category 4.

A total of 5882 lung cancers were diagnosed after 1,052,591 baseline LCS examinations in the study, making the overall CDR 0.56%. This is approximately half the rate reported in the NLST, the authors noted. A total of 760 cancers were detected in the 277,958 repeat annual screenings, for a CDR of 0.35%—67% less than in the first year of NLST follow-up.

The CDR at baseline was higher in positive Lung-RADS categories: 0.4% for Lung-RADS category 3, 2.6% for Lung-RADS category 4A, 11.1% for Lung-RADS category 4B, and 19.9% for Lung-RADS category 4X. Among patients with diagnosed cancer, the stage distribution in the study was similar to the distribution in the NLST.

The authors noted limitations, including potential underreporting in the registry and the fact that Veterans Health Administration and Department of Defense facilities are not required to report LCS data. The study was also only able to analyze adherence and outcomes for people who received baseline screening, so the low proportion of Asian and Hispanic individuals in the cohort may reflect disparities in screening rates.

Overall, the study shows poor annual screening adherence among patients considered to be at a high risk of lung cancer.

“Multilevel interventions that include policy, health system, provider, and patient education are needed both to improve uptake and to reduce the disparities associated with screening for lung cancer,” the authors concluded. “Because the new [2021] USPSTF criteria increase the number of individuals eligible, the lung cancer community should leverage this experience to work toward improving delivery, uptake, and adherence to target those who stand to benefit the most.

Reference

Silvestri GA, Goldman L, Tanner NT, et al. Outcomes from more than 1 million people screened for lung cancer with low-dose CT imaging. Chest. Published online February 10, 2023. doi:10.1016/j.chest.2023.02.003