Although 91% of people screened for lung cancer meet the U.S. Preventive Services Task Force (USPSTF) criteria, adherence to follow-up screening is “suboptimal,” according to findings published in the Annals of Internal Medicine. Eligible men, younger people and those who had quit smoking were less likely to be screened.
“We are encouraged that people being screened largely meet the eligibility requirements,” but good adherence is essential, the study authors wrote. “Providers should emphasize that [low-dose CT screening] is not a ‘one and done’ test.”
In 2013, USPSTF recommended annual lung cancer screening using low-dose computed tomography scans for people between the ages of 55 and 80 who had a 30 pack-year history of smoking, meaning they smoked the equivalent of at least pack of cigarettes a day for 30 years. Based on these recommendations, some eight million people made the cut for screening. In 2021, USPSTF updated the previous guidelines, lowering the age to 50 years and the smoking history to 20 pack-years. This expanded the eligible population to 15 million—and opened up screening to more Black people.
Gerard Silvestri, MD, of the Medical University of South Carolina, and colleagues conducted a cohort study to define social and demographics characteristics and adherence among people screened for lung cancer.
The researchers looked at data from the first 1 million people who received an initial baseline screening at one of 3,625 centers in the United States and were recorded in the American College of Radiology’s Lung Cancer Screening Registry between 2015 and 2019. They analyzed the age, sex and smoking history of people who were screened and a group of 1,257 adults who were eligible for screening according to the 2015 National Health Interview Survey. Participants were considered to be adherent to annual screening if they received a follow-up test 11 to 15 months after the initial screening.
Of the 1,159,092 people who were screened for lung cancer, 91% met the USPSTF criteria for eligibility. In comparison with the adults who were eligible for screening according to the National Health Interview Survey, those who actually underwent screening were older (35% versus 45% between the ages of 65 and 74), more likely to be women (42% versus 48%) and more likely to currently smoke (52% versus 61%).
Only 22% of eligible individuals returned for a follow-up CT scan within 11 to 15 months of the initial screening. When this interval was extended to 24 months, the proportion increased to 34%, and it reached 40% with an interval longer than two years. Low adherence to follow-up screening may worsen mortality rates and lower the cost-effectiveness of regular screening for the eligible population, the researchers noted.
“In addition to continuing to target all eligible adults, men, those who formerly smoked and younger eligible patients may be less likely to be screened,” the study authors concluded. “Adherence to annual follow-up screening was poor, potentially limiting screening effectiveness.”
“Successful screening programs take time to mature,” they wrote. “Colorectal and breast cancer screening have had decades of experience in increasing uptake. The primary care community should leverage this experience to ensure that [lung cancer screening] is delivered to the persons most likely to benefit.”
In an accompanying editorial, Karina Davidson, PhD, of the Feinstein Institutes for Medical Research in New York City, recommended that physicians take patients’ complete smoking histories, refrain from referring patients for screening who are not likely to benefit and help patients who currently smoke to quit.