Study: Lung Screening Alone Does Not Change Risk Perceptions for Lung Cancer

Participants in the National Lung Screening Trial (NLST) did not change their perceptions of risk for lung cancer and smoking-related disease between prescreening enrollment and a 1-year follow-up visit, regardless of the result of the screening test.

Elyse Park, PhD, MPH, of Harvard Medical School in Boston, said the screening on its own, without the addition of behavioral counseling of any kind, appears insufficient to change behavior. “Although [the screening test] was a teachable moment, because it wasn’t maximized in any way, it’s not surprising the participants didn’t change.”

The NLST previously found that lung cancer mortality was reduced among high-risk current and former smokers with a low-dose CT screen compared to a chest x-ray. In the current study, Park and colleagues used a 25-item risk perception questionnaire for 430 NLST participants, both before screening and after 1 year post-screening. Most participants were white (91.9%), and half were current smokers at baseline.

The baseline risk perception score for lung cancer was 17.91 among current smokers, and 18.09 at 1-year follow-up, a nonsignificant change. Similarly, for former smokers, the baseline and follow-up scores were both 16.28. Risk perception scores for smoking-related diseases also did not change over time in either current or former smokers, nor did determinants of smoking behavior change. The only significant change was an elevated sense of the perceived benefits of quitting smoking among former smokers.

The result of the initial screening also did not have an effect on risk perception changes. Among current smokers, a negative test was associated with a 0.17 change in lung cancer risk perception score, compared with a -0.14 change in those with a positive test result (P = .69). Former smokers with a negative test result had a -0.08 change, compared with a 0.4 change in those with a positive result (P = .62).

A total of 9.7% of current smokers at baseline reported quitting over the year of the study; 6.6% of former smokers reported resumption of smoking. Smoking status was not associated with risk perception changes in either group.

The most notable limitation of the study is the participants’ volunteer nature: Park said participants were likely already aware of lung cancer risks and were highly motivated to quit smoking or avoid a relapse.

“I do think that we might see some changes” in risk perceptions, Park said in a phone interview, pointing out that screening as “recommended now by the NCCN, is going to become more widespread in clinical practice on a more regular basis.” However, if screening does become more widespread, increasing knowledge of issues like false positives may temper some of those changes back in the other direction. In this study, Park said, 90% of positive test results ended up as false positives. An important message, she said, is that incorporating counseling into screening is more likely to change perceptions and behavior than screening alone.