Photo Credit: pinkomelet

This study seeks to explore a more diverse participant population while applying a risk-based model for screening criteria.

Studies have shown that the 2021 US Preventive Services Task Force (USPSTF) guidelines improved the equality of lung cancer screening protocols for African American and White patients. Questions, however, remain regarding other racial and ethnic groups. It has also been suggested that risk-model-based screening, which defines eligibility based on the patient’s individualized risk, may improve screening performance and contribute to eradicating racial and ethnic disparity.

Risk-based Screening Using PLCOm2012

To ascertain the validity of this hypothesis, Summer S. Han, PhD, and her team examined the precision of risk-based lung cancer screening and its potential to bridge the gap between racial and ethnic groups. The outcomes of this study were published in JAMA Oncology. As Dr. Han and her colleagues wrote, “In this cohort study using a prospective multiethnic population-based cohort, we scrutinize the predictive performance of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial 2012 (PLCOm2012) and assess racial and ethnic disparities and screening performance through risk-based screening using PLCOm2012 versus the revised USPSTF 2021 criteria across 5 racial and ethnic groups (ie, African American, Japanese American, Latino, Native Hawaiian/Other Pacific Islander, and White) in the US.”

The Multiethnic Cohort Study (MEC), a prospective cohort study, was the foundation for this study’s population. MEC encompassed adults aged 45 to 75 enrolled in California and Hawaii between 1993 and 1996. A total of 105,261 participants with a history of smoking were identified, and of these, 45,250 were women. The mean age was 59.8, with a standard deviation of 8.7 years. This group included 18.3% African Americans, 25.9% Japanese Americans, 20.3% Latinos, 7.9% Native Hawaiians/Other Pacific Islanders, and 27.6% White participants.

Within the identified study population, 1464 patients developed lung cancer within 6 years of enrollment. The 6-year lung cancer incidence was highest among African American patients, with a cancer rate of 2.2%. White and Native Hawaiian/Other Pacific Islanders had a lung cancer rate of 1.5%, Japanese Americans had a rate of 1.2%, and Latinos had the lowest rate of lung cancer at the 6-year mark, with 0.7%.

The predictive performance of PLCOm2012 was deemed promising, with an area under the curve (AUC) of 0.79 (95% CI, 0.78-0.80). The researchers noted, however, that PLCOm2012 underestimated risk among Japanese Americans (calibration slope: 1.66), Latinos (calibration slope: 2.45), and Native Hawaiians/Other Pacific Islanders (calibration slope: 1.39). The researchers developed a recalibrated model using MEC data and labeled the resulting model PLCOm2012-Update. This adjustment improved the equality of results across all races and ethnicities observed in the study (range of calibration slope: 0.79-1.4).

Screening Eligibility & Sensitivity

Regarding screening eligibility, USPSTF 2021 criteria was 24% among the study participants, with the highest group deemed eligible being White patients at 30.2%. As for the other racial and ethnic groups observed, 25.5% of Japanese Americans, 25.1% of Native Hawaiians/Other Pacific Islanders, 21.4% of African Americans, and 15.7% of Latinos (15.7%) were deemed eligible for screening. When risk-based screening criteria were applied using the PLCOm2012-Update model (6-year risk ≥1.3%), the difference in eligible screening designation between African Americans compared with White individuals was substantially reduced (E-I ratio: 15.9 vs 18.4; P<0.001) in comparison to the USPSTF 2021 criteria (E-I ratio: 9.5 vs 20.3; P<0.001). The risk-based screening through PLCOm2012-Update was also noted as displaying an overall higher sensitivity (67.2% vs 57.7% [USPSTF 2021]).

As concluded in their published findings, Dr. Han and colleagues shared, “Risk-based lung cancer screening using a validated risk prediction model may help reduce racial and ethnic disparities in lung cancer screening and improve screening efficiency across racial and ethnic groups in the US.”