Screening for lung cancer leads to early detection and treatment, but can it also make people stop smoking before they get cancer? The answer is that it depends on the seriousness of the results, according to a study published in the JNCI: Journal of the National Cancer Institute.

To determine if there is an association between type of screening result and smoking cessation, Martin C. Tammemagi of the Department of Health Sciences, Brock University in St. Catharines, Ontario, Canada, and colleagues used data from the Lung Screening Study component of the US National Lung Screening Trial on 14,621 current smokers, 55-70 years old, with a 30 or more pack-year smoking history and who had smoked during the last 15 years. The researchers excluded participants who developed lung cancer in follow-up.

For smoking information, the authors used the results of annual study updates starting at one, two, and up to 7 years later. Results for baseline, year one and year two screenings were classified in five levels, ranging from "normal, no abnormalities" to "positive (suspicious) for lung cancer." In analyses adjusted for sociodemographic factors including age, race, marital status and education, and for exposures such as cigarette smoking intensity and duration, past or current pipe or cigar smoking, and exposure to secondhand smoke at home, Tammemagi et al. found that the more serious the screening result the greater the likelihood of stopping smoking. In addition, the effect appeared to be durable, lasting 5 years after the last screening.

The researchers point out that "...abnormal screening results may present a 'teachable moment'," and suggest that "Future lung cancer screening programs should take advantage of this opportunity to apply effective smoking cessation programs."

In an accompanying editorial, Stephen A. Deppen and colleagues of the Department of Thoracic Surgery, Division of Epidemiology and Division of Medicine, Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, praise the rigor of Dr. Tammemagi's study but write that more information is needed on whether those with negative scans stop smoking as well. They also write that screening programs offer the opportunity to conduct research on "...the prevalence of the health-certificate effect and the intervention intensity required to achieve the maximum smoking cessation."