In an interim analysis of a prospective cohort study reported in The Lancet Oncology, Tammemägi et al found that the Prostate Lung Colorectal and Ovarian Cancer Screening Trial 2012 risk prediction model (PLCOm2012) may be more efficient than U.S. Preventive Services Task Force 2013 (USPSTF2013) criteria in selecting individuals who should be considered eligible for computed tomography lung cancer screening.
Study Details
The study included 5,819 participants in the International Lung Screening Trial aged 55 to 80 years who were current or former smokers (ie, had ≥ 30 pack-year history or ≤ 15 quit-years) and who met USPSTF2013 criteria or the PLCOm2012 eligibility risk threshold of ≥ 1.51%. They were enrolled within 6 years of baseline screening from sites in Canada, Australia, Hong Kong, and the United Kingdom between June 2015 and December 2020.
For purposes of analysis, a PLCOm2012 risk threshold of ≥ 1.70% at 6 years was used to produce a population of 4,540 individuals, matching the number meeting the USPSTF2013 criteria. The main outcome measures were comparison of lung cancer detection rates and cumulative life expectancies in patients with lung cancer using USPSTF2013 criteria vs the PLCOm2012 model at a threshold of ≥ 1.70% at 6 years.
PLCOm2012 appears to be more efficient than the USPSTF2013 criteria for selecting individuals to enroll into lung cancer screening programs and should be used for identifying high-risk individuals who benefit from inclusion in these programs.— Tammemägi et al
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Key Findings
Compared with individuals meeting the USPSTF2013 criteria, those meeting the PLCOm2012 ≥ 1.70% threshold were older (mean age = 65.7 vs 63.3 years, P < .0001) and had more comorbidities (median = 2 vs 1, P < .0001).
At a mean follow-up of 2.3 years, 135 lung cancers occurred in 4,540 individuals meeting USPSTF2013 criteria and 162 occurred in 4,540 meeting the PLCOm2012 ≥ 1.70% threshold (cancer sensitivity difference = 15.8%, 95% confidence interval [CI] = 10.7%–22.1%; absolute odds ratio = 4.00, 95% CI = 1.89–9.44, P < .0001).
Among patients who were subsequently diagnosed with lung cancer, mean life expectancy at baseline was 14.8 years among those meeting USPSTF2013 criteria and 13.9 years among those meeting the PLCOm2012 risk threshold. Cumulative estimated life expectancy from baseline for individuals diagnosed with lung cancer had they not developed lung cancer was higher in those meeting the PLCOm2012 risk threshold vs those who met USPSTF2013 criteria (2,248.6 years vs 2,000.7 years; difference = 247.9 years, P = .015).
The investigators concluded, “PLCOm2012 appears to be more efficient than the USPSTF2013 criteria for selecting individuals to enroll into lung cancer screening programs and should be used for identifying high-risk individuals who benefit from inclusion in these programs.”
Martin C. Tammemägi, PhD, of the Department of Health Sciences, Brock University, St. Catharines, Ontario, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by the Terry Fox Research Institute, UBC-VGH Hospital Foundation and BC Cancer Foundation, Australian National Health and Medical Research Council, Cancer Research UK, and others. For full disclosures of the study authors, visit thelancet.com.
