A Prospective Pilot Study of Lung Cancer Screening in Patients at High Risk for Lung Cancer Who do not Meet Current Screening Guidelines

Abstract

Purpose: To describe the results of a lung cancer screening (LCS) study of high-risk individuals ineligible for screening by Medicare (CMS) guidelines and prospectively selected by 6-year risk score. Methods: Study inclusion criteria included individuals 40–82 years old, with a 6-yr risk score of ≥1.5% for <77 years or age or >4% for 78–82 years of age, calculated by the PLCOm2012 model, no symptoms of lung cancer, and willingness to sign a consent form. Enrollment was offered to eligible individuals referred for screening through the University of Colorado Hospital LCS program that did not meet CMS screening guidelines (55–77 years old, ≥30 pack year smoking history, current smoker or quit within the past 15 years). Enrolled participants completed a shared design making visit with a LCS clinic provider, underwent a LDCT read in Lung-RADs (LR) by thoracic radiologists, and received follow-up and additional referrals, if indicated, from the LCS clinic. Individuals could undergo up to 3 LDCTs as part of the study. Results: The study completed 66 LDCTs on 48 participants. Screened individuals were 52% male, 85% white, 52% former smokers, had a mean baseline age of 69(±9) years, and a mean 6-year risk score of 5.6%(±5.9%). LR results of the index LDCTs included 46% LRs 1, 44% LRs 2, 4% LRs 3, and 6% LRs 4. 35% of screened participants had a significant incidental finding; 59% were coronary calcifications. Reasons screened individuals were ineligible by CMS guidelines included: 12% <55 years, 21% >77 years, 27% <30 pack year smoking history, and 40% quit smoking >15 years prior. The study diagnosed two lung cancers, a stage 1A adenocarcinoma diagnosed in 74 yr old white female with a 3.3% 6-yr risk score and a carcinoid diagnosed in a 77 yr old white male with a risk score of 7.5%. Both individuals had quit smoking >15 years prior. Conclusions: Early stage lung cancers can be detected in asymptomatic individuals who are prospectively selected by risk calculators and fall outside current CMS guidelines. However, the two cancers were diagnosed in people that would not qualify for the proposed expanded US Preventive Service Task Force guidelines, lowering eligibility to 50 years of age and tobacco exposure to 20 pack years.