Lung Cancer Incidence and Mortality in Individuals With a Negative Low-Dose CT Prevalence Screen


Key Points

  • The incidence of screen-detected cancer at T1 screening was 0.34% in T0-negative participants of the National Lung Screening Trial.
  • Participants with a negative T0 screen had lower overall incidence of lung cancer and lung cancer–related mortality compared with all participants who underwent a T0 screen.

In an analysis of the National Lung Screening Trial (NLST) cohort reported in The Lancet Oncology, Patz et al found that participants who had a negative low-dose computed tomography (CT) prevalence screen had a low incidence of lung cancer detected at first annual screen and exhibited reduced overall incidence and mortality during follow-up vs all participants undergoing prevalence screening.

Study Details

The NLST compared three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk individuals (those aged 55–74 years with a ≥ 30 pack-year history of cigarette smoking, with those who were former smokers having quit within the past 15 years). Participants were followed for up to 5 years after their last annual screen. The current analysis included all 26,231 NLST participants who had received a low-dose CT prevalence (T0) screen.

Incidence and Mortality

Median follow-up was 6.4 years both among all participants with a T0 screen and among those with a negative T0 screen. The overall incidence of lung cancer was 371.88 per 100,000 person-years among 19,066 participants with a negative T0 screen compared with 661.23/100,000 person-years among all 26,231 T0-screened participants; lung cancer–related mortality was 185.82/100,000 person-years compared with 277.20/100,000 person-years.

Lung cancer was identified at T1 screening in 0.34% of T0-negative participants (62 screen-detected cancers in 18,121 screened participants), compared with 1.0% at T0 screening among all T0-screened participants (267 of 26, 231). It was estimated that if the T1 screen had not been performed in the T0-negative participants, a maximum of 28 additional participants in that group would have died of lung cancer, representing an increase in mortality from 185.82 to 212.14/100,000 person-years over the course of the study.

The investigators concluded: “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.”

Edward F. Patz, Jr, MD, of Duke University Medical Center, is the corresponding author of The Lancet Oncology article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.