Bottom Line: Low rates of physician-patient discussions about lung cancer screening have declined further since 2012 and were not associated with current smokers' intents or attempts to quit smoking.
In 2017, the prevalence of patient-physician discussions about lung cancer screening was only 4.3 percent in the general population and 8.7 percent among current smokers, down from 6.7 percent and 12.0 percent respectively in 2012.
Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
Author: Jinhai (Stephen) Huo, PhD, MD, MSPH, assistant professor in the Department of Health Services Research, Management and Policy at the University of Florida.
Background: "The low prevalence of discussions about lung cancer screening and lack of association with smokers' intents and attempts to quit are surprising," said Huo. "Our results suggest that lung cancer screening is substantially underutilized and not reaching high-risk smokers who would benefit the most."
Lung cancer is the leading cause of cancer-related death in women and men in the United States and worldwide. Since 2011, three events in support of lung cancer screening took place: In 2011, the National Lung Screening Trial (NLST), the largest trial of lung cancer screening ever conducted, demonstrated that low-dose computed tomography (CT) scan reduced lung cancer mortality by 20 percent; in 2013, the United States Preventive Services Task Force issued a recommendation for lung cancer screening; and, in 2015, the Centers for Medicare & Medicaid Services released a lung cancer screening policy.
How the Study Was Conducted: Huo and colleagues analyzed data from the National Cancer Institute's Health Information National Trends Survey (HINTS) in 2012, 2014, and 2017, right after the three events. The HINTS survey included questions on whether a respondent had talked with their doctor about having a test to check for lung cancer in the past year and their smoking status.
The researchers analyzed the prevalence of physician-patient discussions about lung cancer screening by age group, smoking status, insurance coverage, and ethnicity. Current smokers were defined as people who had smoked at least 100 cigarettes in their lifetime and were smoking cigarettes every day or some days at the time of the survey; former smokers as those who had smoked previously but did not smoke at the time of the survey; and never smokers as those who had smoked no cigarettes or less than 100 over their lifetime.
Results: Huo noted that lung cancer screening is effective in reducing lung cancer mortality in specific populations -- current or former heavy smokers ages 55 to 77 with a 30-year history of smoking, or smokers with a 20-pack-year history of smoking and other risk factors for lung cancer, such as a family history of disease or environmental exposure. (A pack-year is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years a person has smoked.)
Among 9,433 individuals surveyed, the overall prevalence of lung cancer screening discussions was very low and decreased significantly from 6.7 percent in 2012 to 4.3 percent in 2017. Further analysis by age and smoking status revealed that the highest discussion rates in 2017 were for current smokers older than 74 years (22.1 percent), current smokers aged 55 to 74 (17.9 percent), and former smokers older than 74 years (16.3 percent). Among current smokers, patients more likely to have engaged in discussions with physicians were non-Hispanic Blacks, Hispanics, patients covered by insurance, and those diagnosed with heart or lung disease.
Multivariable analysis determined that discussions about lung cancer screening were not associated with current smokers' intents to quit smoking in the next six months or attempts to quit in the past year.
Author's Comments: "More physicians need to initiate a shared decision-making process with their patients who want to have or are eligible for lung cancer screening to reduce the risk of mortality associated with lung cancer," said Huo. "For eligible high-risk smokers, a low-dose CT scan can reduce the risk of mortality. For moderate- and low-risk smokers, there is no clinical evidence demonstrating that the benefits of screening outweigh the harms. However, smoking cessation discussions should still be taking place as a high priority."
Study Limitations: The main limitation of the study is that it did not include pack-year smoking history. As a result, the researchers were not able to classify survey respondents by eligibility criteria for lung cancer screening. Other limitations include lack of detail about the content of lung cancer screening discussions, physicians' knowledge and attitudes about lung cancer screening, and the availability of screening programs where discussions occurred.
Funding & Disclosures: The study was supported by the University of Florida Health Cancer Center Research Pilot Grant through the Florida Consortium of National Cancer Institute Centers Program at the University of Florida. Huo declares no conflicts of interest.