WCLC 2018: NELSON Study: CT Screening for Early Lung Cancer Reduces Lung Cancer Mortality

Key Points

  • The NELSON study enrolled 15,792 individuals at high risk for lung cancer.
  • At a minimum of 10 years follow-up, reduced lung cancer mortality was reported in the study arm.
  • Of screen-detected lung cancers, 69% were detected at stage IA or IB.
  • CT screenings are effective in assessing lung nodules in people at high risk for lung cancer.

Findings from the NELSON study demonstrate that the use of computed tomography (CT) screening among asymptomatic men at high risk for lung cancer led to a 26% (95% confidence interval [CI] = 9%–41%) reduction in lung cancer deaths at 10 years of study follow-up (at 86% compliance). In the smaller subset of women, the rate-ratio of dying from lung cancer varied between 0.39 and 0.61 in different years of follow-up, indicating a significant and even larger reduction in lung cancer mortality than in men. Harry J. De Koning, MD, PhD, of Erasmus MC, Rotterdam, Netherlands, presented these findings at the International Association for the Study of Lung Cancer 19th World Conference on Lung Cancer (Abstract PL02.05).

The NELSON Study

The NELSON study was a population-based, controlled trial that enrolled 15,792 individuals who were randomized 1:1 to either the study arm or control arm. Study arm participants were offered CT screenings at baseline, 1, 3, and 5.5 years after randomization. No screenings were offered to control arm participants. Participants’ records were linked to national registries with 100% coverage regarding cancer diagnosis (Netherlands Cancer Registry), date of death (Centre for Genealogy), and cause of death (Statistics Netherlands). An expert panel reviewed 65% of cases. The follow-up period comprised a minimum of 10 years, unless deceased, for 93.7% of enrolled participants.


The results of the study showed an 86% average CT screening compliance rate, encompassing 29,736 scans. In 9.3% of participants, additional CT scans were performed within 2 months to estimate nodule volume doubling time, leading to an overall referral rate of 2.3% for suspicious nodules. Detection rates across the rounds varied between 0.8% and 1.1%, and 69% of screen-detected lung cancers were detected at stage IA or IB. A total of 261 lung cancers (52 interval cancers) were detected before the fourth round of follow-ups. In a subset of analyzed patients, surgical treatment was three times significantly more prevalent in study patients than in control arm patients (67.7% vs 24.5%, P < .001).

“These findings show that CT screenings are an effective way to assess lung nodules in people at high risk for lung cancer, often leading to detection of suspicious nodules and subsequent surgical intervention at relatively low rates and with few false-positives, and can positively increase the chances of cure in this devastating disease,” said Dr. De Koning. “It is the second largest trial in the world, with an even more favorable outcome than the first trial, the [National Lung Screening Trial], showed. These results should be used to inform and direct future CT screening in the world.”

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®.




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