Study Finds Adherence to Annual Lung Cancer Screening Linked to Higher Detection Rates

Lung cancer screening offers a powerful opportunity to detect the disease early, when treatment can be most effective. The U.S. Preventive Services Task Force has recommended lung cancer screening for people with an elevated risk of developing lung cancer since 2013. However, a new study, published today in JAMA Network Open, shows that sticking with annual screenings is linked to higher overall and early-stage lung cancer detection rates. It also reveals that although many at-risk individuals attend an initial screening, fewer continue with annual follow-up screenings.

The study was led by Roger Y. Kim, M.D., assistant professor of medicine (pulmonary, allergy, and critical care) at the Hospital of the University of Pennsylvania. The objective was to determine how well people adhere to annual lung cancer screenings (LCS) and whether this affects their chances of being diagnosed with lung cancer.

“For the first time, we have demonstrated that adherence to annual screening among patients undergoing routine lung cancer screening detects more lung cancers,” Kim told MHE in an email interview. Moreover, he said that the cancers “are often being diagnosed at an early stage that can be potentially cured.”

The retrospective, multicenter cohort study tracked 10,170 adults aged 55 to 75, who were current or former smokers and underwent an initial (baseline) LCS between 2015 and 2018. The researchers found that most people attended the first follow-up screening after one year (T1), but fewer came back for the second round of screening (T2).

Specifically, 61% of people returned for T1 screening, and 51% came back for T2 screening. The study also found that people who adhered to the annual screening schedule were more likely to have lung cancer detected, especially at an early stage when it is easier to treat.

“Adherence to annual lung cancer screening has been recommended as a quality metric to realize the benefit of lung cancer screening because, in large randomized clinical trials, most lung cancers were diagnosed during follow-up rounds of screening,” Kim stated. Until now, however, “there was no concrete real-world data that linked adherence across multiple rounds of screening to improved early-stage lung cancer detection rates.”

Unlike previous studies that focused on just one round of screening or immediate diagnoses after a positive result, this study examined multiple rounds and different diagnostic outcomes.

The study also has some limitations. It was observational, so there could be unmeasured factors affecting the results, though adjustments were made for known factors. There is also a risk of detection bias because the data came from only five healthcare systems (Kaiser Permanente Colorado, Kaiser Permanente Hawaii, Henry Ford Health System in Detroit, Marshfield Clinic Health System in Wisconsin, and University of Pennsylvania Health System). Some people might have received care outside of these systems. Additionally, the study excluded individuals diagnosed with lung cancer or who died during earlier screenings. Finally, incomplete smoking history data and records could have affected the results for some patients.

Ultimately, the study supports consistent participation in annual lung cancer as an important quality metric for lung cancer screening programs due to its association with higher rates of lung cancer diagnoses. The authors suggest that healthcare providers should not only encourage initial screenings but also emphasize the importance of continuous adherence.

“This study provides crucial real-world evidence and a pragmatic framework for annual lung cancer screening adherence as a quality metric for lung cancer screening programs across the country,” Kim stated.