There are a few key factors that predict which individuals who have smoked seek out CT lung cancer screening, such as having quit smoking and having a higher Lung-RADS category on low-dose CT (LDCT) according to a study published July 16 in the American Journal of Roentgenology.
Understanding why some people comply with CT lung cancer screening protocols could help researchers better develop ways to reach out to those who don't, wrote a team led by Dr. Eduardo Mortani Barbosa Jr. of the University of Pennsylvania in Philadelphia.
"Low-dose CT lung cancer screening has been shown to decrease mortality in persons with a significant smoking history," the group noted. "However, adherence in real-world [lung cancer screening] programs is significantly lower than in randomized controlled trials. [We sought] to assess real-world LDCT lung cancer screening performance and factors predictive of adherence to [lung cancer screening] recommendations."
Barbosa and colleagues conducted a study that included 260 individuals who had undergone at least two lung cancer screening exams between 2014 and 2019. Of these, 55% were current smokers at baseline assessment, while 46.5% were current smokers at the previous round of screening. The investigators assessed factors such as patient demographics, smoking history, Lung-RADS category, and compliance with screening recommendations.
Of the study cohort, 16.5% had positive LDCT scans; of these 10.8% were Lung-RADS category 3 (probably benign), while a total of 6.2% were in one of the category 4 groups (4A, 4B, and 4X). Four of the 260 study subjects were diagnosed with cancer.
The group found that overall adherence to lung cancer screening protocols was 43%, although this percentage increased the higher the Lung-RADS category. Compliance with screening was also higher in former smokers than in current smokers. In fact, the most prominent independent predictors of adherence were a previous history of smoking and a Lung-RADS category equal to or higher than 3.
| Factors predicting adherence to CT lung cancer screening | |
| Adherence category | Percentage |
| Overall | 43% |
| Former smoker | 50% |
| Current smoker | 36.2% |
| By Lung-RADS category | |
| 1 | 33.2% |
| 2 | 46.3% |
| 3 | 53.9% |
| 4A | 77.8% |
| 4B | 83.3% |
| 4X | 100% |
So how can CT lung cancer screening adherence be improved? Recognizing why some people don't comply is a good place to start, as is communication that ranges from face-to-face conversations with radiologists and letters from referring providers to reminders generated by the electronic health system, according to Barbosa and colleagues.
"Such communications should emphasize that a negative [lung cancer screening] exam does not confer immunity to future lung cancer development, and that continued participation in LCS, combined with smoking cessation, is essential to accrue the maximum benefits of mortality reduction amongst persons with substantial smoking history," they said in a statement released by the AJR.
