# NELSON: volume-based CT screening reduces lung cancer deaths with fewer false alarms

Source: https://onco.cc/key-papers/paper-nelson-nejm-2020/  
OnCo record `paper-nelson-nejm-2020` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

In a Dutch-Belgian trial, CT screening using nodule volume rather than diameter cut lung cancer deaths in men by about a quarter at 10 years, with a far lower false-positive rate than NLST.

## Summary

NELSON randomised 15,789 current or former smokers (13,195 men and 2,594 women) aged 50-74 to CT screening at baseline, 1, 3 and 5.5 years or to no screening. Nodules were managed by volume and volume-doubling time, with an indeterminate category that triggered a repeat scan rather than a biopsy.

The primary analysis in men showed a lung cancer mortality rate ratio of 0.76 at 10 years. Screen-detected cancers were much more often stage I. The positive-screen rate was around 2%, far below NLST's, because the indeterminate category absorbed most small nodules.

NELSON confirmed NLST against a no-screening control and gave European programmes a workable protocol.

## Fields

- Kind: Key paper
- Last checked: 2026-09-08
- Journal: New England Journal of Medicine
- Year: 2020
- DOI: 10.1056/NEJMoa1911793
- Authors: de Koning HJ, van der Aalst CM, de Jong PA, et al.
- Findings: Lung cancer mortality rate ratio in men 0.76 (95% CI 0.61-0.94) at 10 years; In the smaller female cohort the rate ratio was 0.67 (95% CI 0.38-1.14), not statistically significant but consistent with benefit; Overall positive-screen rate about 2%, with the majority of screen-detected cancers at stage IA-IB; Comparator was no screening, removing the concern that chest X-ray in NLST masked part of the effect
- What it means: Lung screening works when it uses volumetric nodule management, and it works against a no-screening control. The protocol underpins the UK Targeted Lung Health Check programme and European recommendations. Benefit in women remains less precisely estimated.
- Caveats: Women were under-represented, so the female estimate is imprecise; Screening intervals lengthened to 2.5 years in the final round; the optimal interval is still debated; Some overdiagnosis is likely; the authors estimated a modest excess of cancers in the screened arm at 10 years; Participants were volunteers responding to a population mailing, which may not reflect routine uptake

## Sources

- DOI: https://doi.org/10.1056/NEJMoa1911793
- NEJM full text: https://www.nejm.org/doi/full/10.1056/NEJMoa1911793

## Connected records

- key papers: [NLST: yearly low-dose CT scans cut lung cancer deaths in heavy smokers](https://onco.cc/key-papers/paper-nlst-nejm-2011/), [Screening by chest radiograph and lung cancer mortality: the Prostate, Lung, Colorectal, and Ovarian (PLCO) randomized trial](https://onco.cc/key-papers/paper-plco-chest-radiograph-lung-cancer-mortality-jama-2011/), [Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement](https://onco.cc/key-papers/paper-uspstf-lung-cancer-screening-jama-2021/)
- ideas: [Decide who is screened for lung cancer by individual risk, not by pack-years](https://onco.cc/ideas/idea-lung-screening-eligibility-by-risk-not-pack-years/), [Lung screening eligibility by risk score, not pack-years, including high-risk never-smokers](https://onco.cc/ideas/idea-prev-lung-screening-risk-model-eligibility/)
- roadmaps: [Lung cancer roadmap: from Doll and Hill and the naming of tobacco, through the cytotoxic plateau, computed tomography screening, EGFR and ALK, immunotherapy by PD-L1, the perioperative trials and PACIFIC, to DLL3 in small-cell disease and a 2032 registry watch](https://onco.cc/roadmaps/lung-cancer-evidence-roadmap/)
- cancers: [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/)
- fronts: [Early Detection & Screening](https://onco.cc/fronts/early-detection/)
- technologies: [AI in radiology](https://onco.cc/technologies/radiology-ai-screening/), [CT (computed tomography)](https://onco.cc/technologies/ct/), [Low-dose CT lung screening](https://onco.cc/technologies/low-dose-ct-screening/)
- terms: [Positive predictive value (PPV)](https://onco.cc/terms/ppv/), [Stage shift](https://onco.cc/terms/stage-shift/)
- trials: [NLST & NELSON (low-dose CT screening)](https://onco.cc/trials/nlst-nelson/)
- bottlenecks: [Overdiagnosis and false alarms](https://onco.cc/bottlenecks/b-overdiagnosis/), [The hardest cancers are found late](https://onco.cc/bottlenecks/b-early-detection/)
- journals: [New England Journal of Medicine](https://onco.cc/journals/nejm/)
- people: [Harry J. de Koning](https://onco.cc/people/harry-de-koning/)

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