Research shows lung cancer remains the leading cause of cancer deaths globally, with Black men in the United States experiencing the highest incidence and mortality rates. Lung-cancer screening using low-dose computed tomography (LDCT) has been shown to reduce lung cancer mortality by detecting the disease at earlier stages, particularly benefiting Black participants.
A new editorial by UW-CTRI Director Dr. Hasmeena Kathuria and Dr. Renda Soylemez Wiener (Boston University) highlights a significant limitation of the current lung-cancer screening eligibility criteria: The exclusion of many people at high-risk for lung cancer who smoke for a long duration but at a lower intensity, thus not meeting the pack-year requirement. The editorial, in the Journal of Clinical Oncology, discusses the potential benefit of adopting simpler lung-cancer screening criteria to address this limitation.
Evolving Guidelines
Federal guidelines for lung-cancer screening have evolved in recent years. For example, in 2013, the US Preventive Services Task Force (USPSTF) recommended annual LDCT for individuals aged 55-80 years with a 30-pack year smoking history, including those who had quit within the past 15 years. Despite these guidelines, Black individuals were less likely to qualify for lung-cancer screening due to lower pack-years smoked and younger age at diagnosis.
In 2021, the USPSTF revised the guidelines, lowering the smoking requirement to 20-pack years and the eligibility age to 50 years.
“The 2021 revisions to the USPSTF guidelines aimed to reduce racial disparities by lowering the pack-year requirement and eligibility age. However, studies indicate that these changes have not fully eliminated the disparity,” Kathuria explained.
New Proposals
Now, researchers are proposing ways to fine-tune those guidelines.
In a publication that accompanied Kathuria’s editorial, Potter and colleagues proposed new eligibility criteria that would replace the 20-pack year requirement with a greater-than 20-year smoking duration. This change simplifies the calculation, making it easier to identify eligible individuals and includes those with lower smoking intensity. The proposed criteria were tested using data from the Southern Community Cohort Study and the Black Women’s Health Study.
The findings showed that the proposed criteria eliminated the disparity in screening eligibility between Black and White individuals. For instance, under the 2021 guidelines, 57.6% of Black individuals with lung cancer would qualify for screening, compared to 85.3% with the proposed criteria. However, this increased sensitivity came at the cost of decreased specificity.
“Additional research is needed to develop and test simplified criteria for lung-cancer screening that are feasible to implement and reduce disparities in screening eligibility without exposing more low-risk individuals to the harms of screening,” Kathuria said. Those harms include false positives, finding cancer that may never cause symptoms, and exposure to low-level radiation.
Kathuria highlighted a study just published by Kearney and colleagues that showed simple alternative criteria (people who smoked any amount each year for at least 40 years, or people aged 60 to 80 years with at least 40 pack-years of smoking) can identify high-risk, high-benefit groups excluded by the USPSTF criteria. Importantly, many were members of racial and ethnic minorities.
Kathuria H and Wiener RW. (2024) Towards Racial Equity in Lung Cancer Screening. Journal of Clinical Oncology. 2024 Mar 27:JCO2400351. Online March 27, 2024.