USPSTF Proposes Expanded Lung Cancer Screening

The U.S. Preventive Services Task Force (USPSTF) recently proposed guidelines that would expand the criteria for lung cancer screening by reducing the requirements for age and smoking history. If finalized, the recommendations may address existing racial disparities by increasing screening eligibility among African Americans.

In 2013, the USPSTF published guidelines recommending annual screening with low-dose CT scans in adults ages 55 to 80 who have a 30 pack-year smoking history and who currently smoke or quit within the past 15 years. (To calculate pack-years, divide the number of daily cigarettes by 20 and multiply by years of smoking.) However, recent research suggests that these recommendations do not account for differences in patterns of lung cancer risk and smoking behavior among African Americans.

“African Americans tend to be diagnosed at earlier ages, smoke about half as many cigarettes per day,” and have a higher risk of lung cancer overall than whites, explains Melinda Aldrich, PhD, MPH, of Vanderbilt University Medical Center in Nashville, TN. Last year, Aldrich and her team published a study exploring how these differences translate into screening disparities. They found that only 32% of African Americans eventually diagnosed with lung cancer were eligible for screening, compared with 56% of whites—and this disparity could be reduced by lowering the age and pack-year requirement for screening.

The updated USPSTF recommendations propose lowering the minimum age for screening to 50 and reducing the minimum pack-years to 20 based on evidence from the National Lung Cancer Screening Trial (NLST) and the NELSON study. “I think expanding these guidelines will be helpful in closing the gap in some of the health care disparities for lung cancer and picking up more African Americans” because they are likely to get lung cancer earlier with less tobacco exposure, says Eric L. Flenaugh, MD, of Morehouse School of Medicine and Grady Hospital in Atlanta, GA. Flenaugh published a separate study on screening disparities last year.

Flenaugh primarily sees African American patients with lung cancer, many of whom are younger than the current age minimum—and he often receives calls from clinicians seeking screening for individuals who don't meet the pack-year requirement. “This is going to give people a little more flexibility with being able to get their patients screened that they really feel are high risk,” he says. The proposed guidelines may also have benefits beyond earlier detection. For example, if patients are screened younger, they will have earlier access to smoking cessation resources available through many screening programs.

“I think these guidelines are a step in the right direction, but the disparities will continue to exist,” Aldrich stresses, noting that studies on lung cancer screening have historically lacked minority participants. In the NLST, for example, only 4.4% of participants were African American. “We really need to move our research into populations that are racially diverse, where we have sufficient statistical power to be able to derive the appropriate guidelines,” she says.

As screening increases, Flenaugh hopes researchers will create databases that track how lung cancer presents in different populations and how it is linked to factors such as race/ethnicity, sex, and socioeconomic status. Such information could lead to different screening criteria for different populations. “We have to keep in mind that guidelines are great, but one size doesn't fit all,” he says. “We need to really fine-tune this process and try to discover all of the pockets of patients that might be at risk.” –Catherine Caruso