Lung Cancer Screening: Do Updated Criteria Address Racial Disparities?

The 2021 lung cancer screening criteria from the U.S. Preventative Services Task Force (USPSTF) was found to reduce racial disparities in access to screening compared to the 2013 version of this guideline, according to a study published in JAMA Oncology.

Read the 2021 USPSTF Lung Cancer Screening Criteria here.

Compared with the 2013 USPSTF criteria, the 2021 criteria excluded significantly fewer African American patients from eligibility for screening and demonstrated greater sensitivity. On the other hand, the 2021 USPSTF criteria demonstrated worse sensitivity and specificity compared with a modified 2012 Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCOm2012) predictive model.

Why Are There Racial Disparities in Screening Criteria?

One factor that causes disparities in screening criteria is differences in behaviors that are considered benchmarks for screening eligibility. For example, White individuals have a greater smoking pack per year history compared with African Americans; despite this, African Americans still have the same or higher lung cancer risk, according to the authors.

Patient characteristics may also play a factor. The 2013 USPSTF criteria recommended screening for individuals starting at age 55 years. However, the authors noted, African Americans have a lower average age at lung cancer diagnosis than White individuals. Under the 2021 criteria from the USPSTF, eligibility begins at age 50 years. Additionally, the criteria were broadened to include individuals with a 20 pack-year history, compared with a 30 pack-year history in the previous version.

Even with these updates, “the dichotomous nature of fixed criteria based on smoking history and age alone may miss other important risk factors, such as chronic obstructive pulmonary disease, family history, and personal history of cancer that are better accounted for by prediction model criteria,” wrote the authors.

Related: Improving Diversity in Smoking Cessation Trials

Comparing Lung Cancer Screening Criteria

For this study, the researchers enrolled 912 patients with lung cancer and 1,457 controls without lung cancer. The primary outcome was qualification for lung cancer screening using the 2013 USPSTF, 2021 USPSTF, and PLCOm2012 criteria.

The PLCOm2012 was selected for this assessment because it “is the most studied prediction model, to our knowledge, and was recommended by the National Comprehensive Cancer Network in 2018 as an alternative guideline for the enrollment of patients into lung cancer screening if they do not fulfill the fixed criteria,” the authors wrote.

The researchers also assessed sensitivity and specificity of these criteria according to patient race. Sensitivity was defined as the percentage of patients with lung cancer who qualified for screening, specificity was percentage of controls who did not quality for lung cancer screening.

Participants were enrolled in an epidemiology study in the Detroit metropolitan area between 2012 and 2018, and were aged between 21 and 89 years. Patients with lung cancer and controls who were never smokers were excluded.

Using the 2021 USPSTF criteria, 65% of patients with lung cancer were eligible for screening, compared with 68% using PLCOm2012 and 49% using 2013 USPSTF criteria. The 2021 guidelines excluded 49% of controls, PLCOm2012 excluded 58%, and the 2013 criteria excluded 49%.

Racial Disparities in Screening Eligibility

Regarding differences in screening eligibility between African American and White patients with lung cancer, the 2021 USPSTF criteria and the PLCOm2012 both demonstrated comparable eligibility rates regardless of race (2021 USPSTF, 65% of White patients vs. 63% of African American patients; PLCOm2012, 68% vs. 67%, respectively). This rate was a significant improvement from the 2013 criteria (52% of White patients vs. 42% of African American patients).

The 2021 criteria and the PLCOm2012 also excluded controls at a similar rate among White and African American individuals (48% vs. 50% and 57% vs. 60%, respectively). The 2013 criteria excluded fewer White controls (61%) than African American controls (70%).

In summary, the authors wrote, “The 2021 USPSTF guideline improves on earlier, fixed screening criteria for lung cancer and broadens eligibility to include more African American individuals. The predictive model risk-based criteria using PLCOm2012 still has higher sensitivity and specificity in selecting those who will most benefit from lung cancer screening, although its implementation remains difficult.”

The authors acknowledged that the retrospective nature of this study was a limitation. They also noted that few lung cancers were diagnosed among the control group, but the group was not followed up with 2 additional CT scans.

“Ultimately, a large prospective trial with good racial representation is needed to provide data on the benefits of screening African American individuals to allow for the development of better guidelines,” the authors wrote.

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