Expansion of USPSTF lung screening criteria warranted
medwireNews: Results from two studies suggest that the current US Preventive Services Task Force (USPSTF) lung cancer screening criteria may exclude certain individuals who could benefit from screening.
One study assessed the suitability of the guidelines for African–American smokers, while the other focused on individuals who were long-term quitters or younger than the guidelines’ cutoff of 55 years, and both studies concluded that the USPSTF guidelines need to be revised.
Melinda Aldrich (Vanderbilt University Medical Center, Nashville, Tennessee, USA) and colleagues explain that the USPSTF screening guidelines are “based on age (55-80 years) and smoking history, targeting smokers with a 30-pack-year history who either currently smoke or quit within the previous 15 years.”
They note, however, that African–American smokers “have a higher risk of lung cancer with fewer reported smoking pack-years,” which suggests that the guidelines “are not optimal” for these individuals.
The team drew on the Southern Community Cohort Study to identify 48,364 ever smokers (67% African American, 33% White) from 12 southern US states who were followed up between March 2002 and December 2014, during which time 1269 cases of incident lung cancer were diagnosed.
Applying the current USPSTF criteria to the overall cohort showed that a significantly lower proportion of African–American than White participants were eligible for screening, at 17.4% versus 31.4%, respectively.
This was also the case when the criteria were applied to the 791 African–American and 478 White participants who developed lung cancer, at 32.2% and 56.5%, respectively, with the ineligibility primarily due to significantly fewer smoking pack–years in the African–American than White group, at a median of 25.8 versus 48.0 pack–years.
The researchers estimate that if the guidelines were revised by lowering the pack–year requirement from 30 to 20 pack–years for African–American smokers, the proportion of eligible individuals would rise to 28.5% in the overall cohort and to 48.9% among those with lung cancer, similar to the percentages among White smokers.
Additionally, if the minimum age criterion was reduced to 50 years for African Americans, 57.8% of individuals would be eligible for screening, they write in JAMA Oncology.
Aldrich et al conclude that their results and those from other studies “emphasize the need for reevaluation of screening guidelines to ensure equity in screening.”
The authors of the second study used data from a hospital cohort and a community cohort in Minnesota, USA, to evaluate overall survival (OS) among 8739 patients (90% White) aged 50–80 years with lung cancer, including those who did and did not meet the USPSTF screening criteria on the basis of age and quitting history.
At the 5-year mark, the OS rate was 27% for individuals who had quit smoking at least 15 years ago, 22% for those who were aged 50–54 years, and 23% for those who met the USPSTF criteria.
Multivariable analysis adjusting for confounders showed no significant difference in 5-year OS between long-term quitters and the USPSTF group in either the hospital or community cohort, and the findings were similar for the younger group, even after stratification by age group.
Researcher Ping Yang (Mayo Clinic, Scottsdale, Arizona, USA) and co-workers therefore write in The Lancet Oncology that “[i]ndividuals in both subgroups could benefit from screening, as expansion of USPSTF screening criteria to include these subgroups could enable earlier detection of lung cancer and improved survival outcomes.”
And they conclude: “In future, more sophisticated screening programmes combining low-dose [computed tomography] and biomarkers could be developed to identify high-risk individuals who would benefit most from screening.”
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