Lung cancer incidence and mortality in National Lung Screening Trial participants who underwent low-dose CT prevalence screening: a retrospective cohort analysis of a randomised, multicentre, diagnostic screening trial

Abstract

Summary Background Annual low-dose CT screening for lung cancer has been recommended for high-risk individuals, but the necessity of yearly low-dose CT in all eligible individuals is uncertain. This study examined rates of lung cancer in National Lung Screening Trial (NLST) participants who had a negative prevalence (initial) low-dose CT screen to explore whether less frequent screening could be justified in some lower-risk subpopulations. Methods We did a retrospective cohort analysis of data from the NLST, a randomised, multicentre screening trial comparing three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals (aged 55–74 years with at least a 30 pack-year history of cigarette smoking, and, if a former smoker, had quit within the past 15 years), recruited from US medical centres between Aug 5, 2002, and April 26, 2004. Participants were followed up for up to 5 years after their last annual screen. For the purposes of this analysis, our cohort consisted of all NLST participants who had received a low-dose CT prevalence (T0) screen. We determined the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. We also estimated the effect on mortality if the first annual (T1) screen in participants with a negative T0 screen had not been done. The NLST is registered with ClinicalTrials.gov, number NCT00047385. Findings Our cohort consisted of 26 231 participants assigned to the low-dose CT screening group who had undergone their T0 screen. The 19 066 participants with a negative T0 screen had a lower incidence of lung cancer than did all 26 231 T0-screened participants (371·88 [95% CI 337·97–408·26] per 100 000 person-years vs 661·23 [622·07–702·21]) and had lower lung cancer-related mortality (185·82 [95% CI 162·17–211·93] per 100 000 person-years vs 277·20 [252·28–303·90]). The yield of lung cancer at the T1 screen among participants with a negative T0 screen was 0·34% (62 screen-detected cancers out of 18 121 screened participants), compared with a yield at the T0 screen among all T0-screened participants of 1·0% (267 of 26 231). We estimated that if the T1 screen had not been done in the T0 negative group, at most, an additional 28 participants in the T0 negative group would have died from lung cancer (a rise in mortality from 185·82 [95% CI 162·17–211·93] per 100 000 person-years to 212·14 [186·80–239·96]) over the course of the trial. Interpretation Participants with a negative low-dose CT prevalence screen had a lower incidence of lung cancer and lung cancer-specific mortality than did all participants who underwent a prevalence screen. Because overly frequent screening has associated harms, increasing the interval between screens in participants with a negative low-dose CT prevalence screen might be warranted.

Demographic, Healthcare, and Contextual Factors Associated with Smoking Status Among Sexual Minority Women

“…38 Lung cancer screening has been identified as an effective way to detect lung cancer at earlier more treatable stages, thus decreasing lung cancer mortality rates. 39 The National Lung Screening Trial (NLST), which was the first, largescale, randomly controlled trial of lung cancer early detection screening in the United States, demonstrated that low-dose helical computed tomography (LDCT) lung cancer screening (LDCT screening) in older smokers reduced lung cancer-specific mortality by 20% due to the early detection of treatable lesions. 40 Currently, private health insurance and the Centers for Medicare and Medicaid Services (CMS) provide coverage of LDCT screening to eligible high-risk older adults who meet all the eligibility criteria (age 55-80 years, no diagnosis of lung cancer, either former or current smokers, and a smoking history of at least 30 packyears).…”

Annual or biennial lung cancer CT screening?

“…Of interest is that the 2-year lung cancer probability for participants without any pulmonary nodules on screens one and two was 0.4% compared to 2.5% for those with CT-detected nodules. the benefit of an extended screening interval for individuals with a negative prevalence screen (6). These results make clear the scope for further defining a low-risk group of individuals by using data from their initial screen results (Figure 1).…”

“…A retrospective cohort analysis of data from the NLST showed that lung cancer incidence and mortality are significantly lower in participants with negative T0 screen in comparison with those with positive T0 screen. The yield of lung cancer at the first annual screen (T1) among high-risk participants with a negative T0 screen was 0.34%, a third of that reported for the T0 screen in all T0-screened participants (1.0%) (6). Less than one per 1,000 participants (0.09%) was diagnosed with lung cancer between the T0 and T1 screens among the participants with a negative T0 screen.…”

“…Lancet Oncology, it was demonstrated that annual screening may be unnecessary for individuals who have a negative low-dose CT prevalence screen (T0) (6). A negative T0 is defined as no non-calcified nodules greater than 4 mm in diameter and no other suspicious findings.…”

Screening for early stage lung cancer and its correlation with lung nodule detection

“…Despite the mortality reduction found in the NLST was based on yearly screening, whether it is necessary to conduct annual LDCT in all eligible individuals remains uncertain (80,81). Retrospective analyses of the NLST suggest that participants with negative prevalence screen or subsequent negative screens might not be in need of annual screening, on account of the relatively lower incidence of lung cancer and lung cancerspecific mortality than all screened cohorts (80).…”