Lung Cancer Screening Adherence Decreases Across Subsequent Testing

"The finding that annual LCS adherence rates decreased across subsequent rounds of screening supports the use of annual adherence as a quality metric for LCS programs seeking to maximize the benefits of LCS for early lung cancer detection and, ultimately, reduced lung cancer-related deaths," according to the study authors.

Although adherence to lung cancer screening (LCS) improved overall and early-stage lung cancer detection incidence, adherence to these measures decreased annually following baseline screening, according to findings from a multicenter cohort study published in JAMA Network Open.1

Of 10,033 individuals eligible to undergo round T1 LCS, 61.2% (n = 6141; 95% CI, 60.2%-62.2%) showed adherence; among 9966 who were eligible for T2 LCS, adherence was reported in 50.5% (n = 5028; 95% CI, 49.5%-51.4%). Those who exhibited adherence for round T1 of screening had a higher likelihood of undergoing screening for round T2 than those who did not adhere to round T1 (adjusted relative risk [ARR], 2.40; 95% CI, 2.06-2.79).

Of 10,170 individuals who completed baseline LCS, 2.7% (n = 279; 95% CI, 2.4%-3.1%) had a lung cancer diagnosis; the rates of diagnosis were 12.1% (n = 191/1578; 95% CI, 10.5%-13.8%) for those with a positive result vs 1.0% (n = 88/8592; 95% CI, 1.1%-1.6%) for those with a negative result (P <.001). The diagnosis rate was 1.0% (n = 59/6141) for people who were adherent during round T1 of screening vs 0.2% (n = 8/3892) for those without adherence to T1 screening (P <.001). Regarding round T2 screening, the lung cancer diagnosis rates were 1.3% (n = 63/5028; 95% CI, 1.0%-1.6%) and 0.2% (n = 12/4938; 95% CI, 0.1%-0.4%) among individuals with and without adherence, respectively (P <.001). Screening adherence correlated with diagnoses during rounds T1 (ARR, 4.64; 95% CI, 2.57-8.37) and T2 per multivariate analyses (ARR, 5.90; 95% CI, 3.34-10.43).

Adherence to T1 screening did not correlate with lung cancer diagnosis during round T2 (ARR, 0.86; 95% CI, 0.60-1.23). Of 2928 individuals who did show adherence to screening rounds T1 and T2, 0.1% (n = 4; 95% CI, 0.04%-0.3%) had lung cancer diagnoses during round T2.

Regarding 279 lung cancer diagnoses determined within 36 months of baseline LCS, 73.1% (n = 204; 95% CI, 67.5%-78.2%) related to early-stage disease, 13.6% (n = 38; 95% CI, 9.8%-18.2%) were associated with stage III or regional disease, and 8.6% (n = 24; 95% CI, 5.6%-12.5%) related to stage IV or distant disease. Between individuals with and without adherence to T2 screening, respectively, the former were more likely to have early-stage disease (73.0% vs 25.0%) but less likely to have stage III or IV disease (20.6% vs 58.3%; P = .006).

“In this multicenter cohort study of adults who received baseline LCS between 2015 and 2018 across 5 US health care systems, adherence to annual LCS decreased with each round of screening, and adherence during round T1 was associated with subsequent round T2 adherence. Annual LCS adherence was significantly associated with increased lung cancer detection during each round of screening and a greater ratio of early- to late-stage disease by round T2,” lead study author Roger Y. Kim, MD, MSCE, from the Division of Pulmonary, Allergy and Critical Care in the Department of Medicine at Perelman School of Medicine of University of Pennsylvania, Philadelphia, wrote with coauthors.1 “The finding that annual LCS adherence rates decreased across subsequent rounds of screening supports the use of annual adherence as a quality metric for LCS programs seeking to maximize the benefits of LCS for early lung cancer detection and, ultimately, reduced lung cancer-related deaths.”

Regarding the rationale for the study, the authors noted the importance of continued screening engagement to reduce lung cancer mortality based on findings from a microsimulation modeling study showing that the number of averted lung cancer deaths went from 501 to 175 per 100,000 persons as annual LCS adherence decreased from 100% to 29%.2 Investigators aimed to apply a pragmatic definition of longitudinal annual LCS adherence to estimate annual LCS rates while exploring how LCS adherence, incident lung cancer detection rates, and cancer stage distribution related to one another across 3 rounds of LCS.

The study included a total of 10,170 individuals 55 to 75 years old who underwent baseline LCS with low-dose CT imaging from January 1, 2015 to December 31, 2018. Those with a diagnosis of lung cancer within a year of baseline LCS (T0) were not included in the T1 sample, which consisted of those with a diagnosis between 12 and 24 months from baseline. Additionally, those in the T1 set were excluded from the T2 adherence sample, which included those with a diagnosis from 24 to 36 months following baseline.

Investigators analyzed data collected from the Population-Based Research to Optimize the Screening Process-Lung Consortium. For negative baseline results, T1 screening adherence was defined as CT imaging conducted between 10 and 18 months following baseline screening; T2 screening was defined as between 22 and 30 months after baseline. For patients with positive baseline results, T1 adherence was defined as 11 to 21 months after baseline, and T2 was defined as 28 to 36 months afterwards.

One of the study’s main outcomes was annual T1 and T2 LCS adherence rates and how they were associated with annual lung cancer diagnosis incidence in rounds T0, T1, and T2. Investigators also evaluated cancer stage distribution.

The median patient age was 65 years (IQR, 60-69), and most patients were male (53.2%). Patients mostly identified as White (73.1%) followed by Black (14.2%), Hispanic (3.8%), and Asian (3.2%). Most patients had current smoking status (58.7%) and a Charlson Comorbidity Index of 0 or 1 (66.5%).

References

1. Kim RY, Rendle KA, Mitra N, et al. Adherence to annual lung cancer screening and rates of cancer diagnosis. JAMA Netw Open. 2025;8(3):e250942. doi:10.1001/jamanetworkopen.2025.0942.
2. Han SS, Erdogan SA, Toumazis I, Leung A, Plevritis SK. Evaluating the impact of varied compliance to lung cancer screening recommendations using a microsimulation model. Cancer Causes Control. 2017;28(9):947-958. doi:10.1007/s10552-017-0907-x