Lung Cancer Screening Guidelines Exclude Patients

More sensitive lung cancer screening criteria may be necessary in order to detect cancers in an increasing number of at-risk patients, according to a study published in JAMA.

Researchers from the Mayo Clinic in Rochester, MN sought to examine the trends in the proportion of patients with lung cancer who meet the USPSTF screening criteria. Their concern was that there may be more high-risk patients who would not have been screened for lung cancer given the current guidelines. Currently, the criteria for screening include asymptomatic adults, aged 55 to 80, having a 30 pack-year smoking history, and currently smoking or having quit within the past 15 years.

The study involved almost 140,000 people, 20 years and older, in one county in Minnesota; 83% of the subjects were non-Hispanic white and socioeconomically similar to the general Midwestern U.S. population. The researchers looked for all pathologically confirmed incident cases of primary lung cancer recorded between 1984 and 2011. The proportion of cases meeting USPSTF screening criteria was then noted.

The researchers identified 1,351 patients who had been diagnosed with primary lung cancer in this period. “The proportion of patients with lung cancer who smoked more than 30 pack-years declined, and the proportion of former smokers, especially those who quit smoking more than 15 years ago, increased,” the authors wrote.

There was also a decline in the relative proportion of patients with lung cancer meeting the USPSTF criteria overall, from 57% in 1984-1990 to 43% in 2005 to 2011, dropping the proportion of screening eligible women from 52% to 37%, and men from 60% to 50%.

"The decline in the proportion of patients meeting USPSTF high-risk criteria indicates that an increasing number of patients with lung cancer would not have been candidates for screening,” the authors concluded. “More sensitive screening criteria may need to be identified while balancing the potential harm from computed tomography."