Psychological risks of screening
Neither the NLST nor NELSON reported relevant psychological aspects of harm from CT screening for lung cancer, two researchers reported in a letter responding to the NELSON findings.
The trial-participation request letters, which were sent to 606,409 people in the general population, “in order to identify 15,792 persons (2.6%) who were eligible to participate, may have caused fear,” wrote Jes Lindholt, MD, DMSc, and Rikke Søgaard, PhD, from Odense University Hospital in Denmark.
“That raises the question: Do people want to be screened? I can’t understand why the US and Britain consider it so definitive to start a screening program,” Dr. Lindholt said in an interview.
In addition to a psychological cost, he questioned the financial cost-benefit ratio of a screening program. “What strikes me is that they haven’t done any cost analysis on any of these randomized trials.”
“Of the 203 men who got the diagnosis of lung cancer, 160 (78.8%) died from lung cancer. Whether screening actually improved or prolonged their remaining lifetime should be considered,” Dr. Lindholt and Dr. Søgaard wrote.
Challenges of implementation
Despite the extensive trials, there are still questions about how to implement screening in the real world. “Did NLST select patients who were, on average, healthier and less likely to have complications?” Dr. Gould asked.
Everyday practice might not find the same favorable outcomes as NLST. “Can the results of the NTLST be replicated in real-world settings? Not yet,” he said. Hospitals and health systems are struggling to implement screening.
Follow-up and tracking are not where they should be. General practitioners don’t have the same resources as the NLST researchers had, he explained. They were able to remind patients to come back for another test and call them with the results, all under the umbrella of implementation, “and they’re still not on target.”
Getting people scanned is key, said Michael Barry, MD, from Massachusetts General Hospital in Boston, who is a current member of the USPSTF and is working on new lung cancer screening recommendations to be published this summer.
“We have an implementation problem,” he said. “The heavier smokers are being way underscreened.”
People need to have more information to review the pros and cons of screening, Dr. Barry said. “We’ve got large trials that show that benefits outweigh the harms, but we could benefit from implementation research. This is an issue for many screening tasks.”
Eight million Americans meet the eligibility requirements for lung cancer screening with low-dose CT, according to a 2019 report from the American College of Radiology.
Screening tests are covered by Medicare, but getting people to the clinic has not been easy. In 2018, Saved by the Scan, a big-budget national advertising campaign launched by the ALA, featured ex-smokers who survived lung cancer because of early detection with a low-dose CT scan, as reported by Medscape Medical News.
And many people being scanned are not part of the USPSTF target group. In 2017, lung cancer screening was reported “by 12.5% of smokers who met USPSTF criteria and 7.9% of smokers aged 55-80 years who did not meet USPSTF criteria,” according to a recent analysis of data from the Behavioral Risk Factor Surveillance System published by the Centers for Disease Control and Prevention.
The CDC report concludes that some people are being screened without needing screening, and that “avoidance of screening inconsistent with USPSTF criteria could reduce the potential for harms such as overdiagnosis and overtreatment.”
Dr. Gould said he agrees that this factor needs to be looked at. “There is underutilization in those who need screening, and maybe overscreening in those who aren’t at risk.”
There are also epidemiologic data that show that black Americans are at higher risk at a younger age for the same level of smoking. “So should there be a lower threshold for smoking and lower age, particularly in the African American population?” Dr. Gould asked.
The NELSON trial had significant results in a population younger than that in NLST, he pointed out. “That needs to be considered.”