Current lung cancer screening guidelines may miss significant number of African Americans at risk
Presenter: Carol Velez Martinez, MD
Current lung cancer screening recommendations from the US Preventive Services Task Force (USPSTF) miss a significant portion of African Americans at risk of lung cancer, according to a single-institution chart review of new lung cancer diagnoses.1 As a result, newer individual risk-based prediction models for the use of low-dose computed tomography (CT) screening may be needed, especially at institutions that serve a large number of African Americans, who are at greater risk of lung cancer.
Of patients ages 18 and older diagnosed with lung cancer between 2011 and 2015 at the Louisiana State University (LSU) Health Sciences Center, Shreveport, one-third did not meet current USPSTF screening guidelines, said lead study investigator Carol Velez Martinez, MD.
African Americans are 37% more likely to develop lung cancer than Whites, and African American men are 22% more likely to die from lung cancer than Whites, despite having a near comparable smoking rate.
In 2011, the National Lung Screening Trial showed a 20% relative risk reduction in mortality when applying low-dose CT. However, the generalizability of this study to communities with young African Americans was questioned because the age range of the study cohort was 55 to 59, and only 4% were African American.
In the retrospective observational cohort study presented by Dr. Martinez, approximately 1,500 charts were reviewed to identify 980 patients with newly diagnosed stage 1 to stage 4 lung cancer at LSU from 2011 to 2015.
“We found that 33% of our population did not meet screening guidelines,” said Dr. Velez Martinez.
Patients were then stratified into high risk (groups 1 and 2), moderate risk, and low risk, according to 2018 National Comprehensive Cancer Network (NCCN) Lung Cancer Screening Guidelines Version 1.2020.
- High-risk group 1 consists of individuals ages 55 to 74 with a 30 pack-year smoking history and either a current smoker or one who quit smoking within the past 15 years. High-risk group 2 comprises individuals age 50 and older with a smoking history of at least 20 pack-years and additional risk factors that increase the risk of lung cancer to 1.3% or greater. According to NCCN, high-risk group 1 and 2 are eligible for annual low-dose CT.
- Lung cancer screening is not recommended for those age 50 and older with a smoking history of at least 20 pack-years and no additional risk factors, labeled the moderate-risk group, or a low-risk group consisting of individuals age 50 or younger with or without a smoking history of less than 20 pack-years.
To differentiate between high-risk group 2 and moderate risk, the Tammemägi lung cancer risk calculator was applied, after which patients with a 6-year lung cancer probability ≥1.3% were considered as high-risk group 2 and those with a 6-year risk of lung cancer <1.3% were considered moderate risk. Characteristics included in the Tammemägi lung cancer risk calculator include body mass index, history of lung disease (ie, chronic obstructive pulmonary disease), race or ethnicity, family history of lung cancer, personal history of cancer, education, and smoking history.
One-third of the study cohort was under age 55, 49.0% were African American, and 95% were smokers. “After risk stratification, we found that 12.5% were categorized as group 2 according to revised NCCN guidelines, of whom 65.38% were African Americans,” she said. Therefore, 12.5% of screening-ineligible patients would have qualified for low-dose CT screening, and a significant portion of African Americans would have been missed by the NCCN guidelines.
“We are focusing on pack-years over age as a possibility down the line and implementing our own risk-assessment tool,” she said. In July 2020, the USPSTF eligibility criteria for low-dose CT were expanded to include individuals ages 50 and older with a smoking history of 20 pack-years or greater, she noted, which means that many more African Americans and women smokers will be eligible for potentially life-saving screening.
Reference
- 1. Velez Martinez C, Thurlapati A, Hirani S, et al. Do our current USPSTF guidelines for lung cancer screening fail young, high-risk African American smokers? CHEST 2020; 158(4 Suppl):A1454–A1455. doi:https://doi.org/10.1016/j.chest.2020.08.1313