Lung Cancer Screening Results Influence Follow-Up Adherence

A patient’s Lung Computed Tomography Screening Reporting & Data System (Lung-RADS) score was the factor most strongly associated with adherence to recommended screening follow-up, a single-center study showed.

The higher risk the initial Lung-RADS score, the better the odds of adherence to subsequent screening, researchers led by Yannan Lin, MD, MPH, of the University of California Los Angeles, reported in JAMA Network Open.

Higher-risk groups (Lung-RADS 3-4X), where more aggressive follow-up is recommended, were 65-90% more likely to be adherent than individuals with a baseline Lung-RADS score of 1 or 2, a group still advised to continue annual low-dose CT screening.

Low-risk findings on consecutive screenings were also tied to diminished adherence, while other factors associated with adherence included a family history of lung cancer, the type of provider that referred the patient for screening, as well as income and education level.

The findings might help resource-constrained health systems to target their outreach efforts and emphasize the need for ongoing patient education and reminders, as well as reinforcing the benefits of screening, the researchers suggested. Other interventions to facilitate adherence might include ensuring availability of screening locations near the patient and minimize patient inconvenience through timely scheduling and efficient patient throughput, the group suggested.

Clinical lung cancer screening (LCS) programs have reported adherence of about 57-65% to the Lung-RADS guidelines. Those recommendations, initially released in 2014, call for yearly low-dose CT (LDCT) screenings with a Lung-RADS score of 1 or 2, while those with scores of 3 or 4 should have more frequent follow-up screening, based on their score, tissue samples, chest CT, and more.

Clinical trials have shown that CT screening can help reduce lung cancer mortality by potentially up to 20%, but that benefit was in the context of better than 90% follow-up screening adherence.

“Failing to maintain annual adherence to LCS recommendations may diminish the ability of clinical screening programs to achieve the same mortality benefits found in large clinical trials,” Lin’s group wrote. “Interval lung cancers, diagnosed between screening episodes following a preceding negative screening result (Lung-RADS score, 1 or 2), are more likely to be aggressive, emphasizing the importance of regular screening intervals.”

“Lung cancer screening is nascent as a preventive measure in the U.S.; as such, barriers to LCS have been incompletely investigated,” the group wrote.

To explore those factors, Lin and colleagues examined data from their academic medical center’s patients across 10 geographically distributed sites where lung cancer screening is offered.

From July 31, 2013, to Nov. 30, 2021, 1,979 patients received at least one LDCT screening in the program. Participants had an average age of 65.3 years, and 40.6% were female. The majority of patients were white (77.1%), followed by Asian patients (8.5%), Black patients (6.6%), Hispanic or Latino patients (5.6%), and patients of another race (2.2%).

Compared with individuals with a negative initial Lung-RADS score of 1-2, indicating no or benign nodules, the adjusted likelihood of adherence to the first subsequent screening was a relative 65% higher if the patient’s initial score was 3 to 79% if that initial score was 4A, and to 90% if the initial score was 4B/X (adjusted ORs of 0.35, 0.21, and 0.10 for nonadherence, respectively; P<0.001 for all).

Nonadherence risk increased with a second consecutive negative Lung-RADS score (adjusted OR 1.38, 95% CI 1.12-1.69) or negative score following a positive result at baseline (aOR 5.08, 95% CI 1.28-20.1), but decreased if the subsequent test showed higher risk features than initially seen (aOR 0.29, 95% CI 0.14-0.60).

Other factors linked to a lower risk for nonadherence to guideline-recommended screening included:

• A familial history of lung cancer (aOR 0.74, 95% CI 0.59-0.93)
• High- vs low-income status (aOR 0.79, 95% CI 0.65-0.98)
• Referral by a provider in pulmonary or thoracic-related departments versus other departments (aOR 0.56, 95% CI 0.44-0.73)
• Age-adjusted Charlson Comorbidity Index score of 4 or above vs scores of 0-1 (aOR 0.67, 95% CI 0.46-0.98)
• Greater education level (aOR 0.70 for postgraduate vs college degree, 95% CI 0.53-0.92)

Study limitations included the fact that social determinants of health, social, environmental, cognitive, and psychological factors, alongside provider recommendations, were not considered.

“Given that patient characteristics in clinical LCS programs vary across institutions, clinical risk stratification models that aid in the identification of potentially nonadherent patients may result in more aggressive, tailored approaches and thus improve the mortality benefit of screening,” the researchers wrote. “Our study provides evidence that may be used as the basis of a decision-support tool to estimate nonadherence across multiple time points and inform future outreach interventions designed to improve patient adherence to LCS.”