Now Available: Final Rule for FDAAA 801 and NIH Policy on Clinical Trial Reporting

National Lung Screening Trial (NLST) Screening (NLST)

This study has been completed.
American College of Radiology Imaging Network
Information provided by (Responsible Party):
National Cancer Institute (NCI) Identifier:
First received: October 3, 2002
Last updated: May 2, 2014
Last verified: October 2012

RATIONALE: Effective screening tests should help doctors detect lung cancer early and plan curative treatment. It is not yet known whether low-dose helical computed tomography (LDCT) screening is more effective than chest radiography (CXR) screening in reducing death from lung cancer.

PURPOSE: Randomized clinical trial to compare the effectiveness of LDCT scan with that of CXR in screening individuals who are at high risk for developing lung cancer.

Condition Intervention Phase
Lung Cancer
Device: low-dose helical computed tomography
Device: chest radiography
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Screening
Official Title: National Lung Screening Trial A Randomized Trial Comparing Low-dose Helical CT With Chest Xray for Lung Cancer

Resource links provided by NLM:

Further study details as provided by National Cancer Institute (NCI):

Primary Outcome Measures:
  • Lung Cancer Deaths [ Time Frame: All events through December 31, 2009; median follow-up 6.5 years. ] [ Designated as safety issue: No ]
    Lung cancer deaths confirmed in participants by Endpoint Verification if available, otherwise by death certificate.

Secondary Outcome Measures:
  • Deaths From All Causes in All Randomized Participants. [ Time Frame: All events through December 31, 2009; median follow-up 6.5 years. ] [ Designated as safety issue: No ]
    Deaths from all causes were compared between the low-dose CT group and the chest radiography group among all randomized participants.

  • Lung Cancer Diagnoses [ Time Frame: All events through December 31, 2009; median follow-up 6.5 years ] [ Designated as safety issue: No ]
    Lung cancer diagnoses confirmed by medical record abstraction.

  • Complications of Diagnostic Evaluation Following a Positive Screening Test. [ Time Frame: One year from screening examination ] [ Designated as safety issue: Yes ]
    Number of participants who experienced complications during diagnostic work-up of a screening CT or CXR that was suspicious for lung cancer.

  • T0 (Baseline) Screening Results [ Time Frame: T0 (at study entry) ] [ Designated as safety issue: No ]
    Results of radiologist's interpretation of images from LDCT or CXR screening exam at T0.

  • T1 Screening Results [ Time Frame: T1 (one year after entry) ] [ Designated as safety issue: No ]
    Results of radiologist's interpretation of images from LDCT or CXR screening exam at T1. Includes a comparison with images from T0 screen.

  • T2 Screening Results [ Time Frame: T2 (two years after entry) ] [ Designated as safety issue: No ]
    Results of radiologist's interpretation of images from LDCT or CXR screening exam at T2. Includes a comparison with images from T0 and T1 screens.

Enrollment: 53454
Study Start Date: August 2002
Study Completion Date: October 2010
Primary Completion Date: October 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Low-Dose CT Device: low-dose helical computed tomography
A LDCT is a computerized tomography image with low-dose technique without contrast. The scan is done from the neck to the diaphragm in one breath-hold.
Other Name: LDCT
Experimental: Chest X-ray Device: chest radiography
The chest x-ray in this study was a single posterior-anterior film done with the participant upright.
Other Name: CXR

Detailed Description:


  • Compare whether screening with low-dose helical CT scan vs chest x-ray reduces lung cancer-specific mortality in participants who are at high risk for developing lung cancer.


NLST participants were randomized to either low-dose helical CT or chest x-ray in equal proportions. A total of 53,454 participants were enrolled (26,722 in low-dose CT and 26,732 in chest radiography) at 33 screening centers across the United States. Screening was offered three times (at baseline and two annual follow-up examinations). The primary endpoint of the study was lung cancer mortality. The study arms were compared with regard to overall mortality, lung cancer incidence, and screening-related complications.

All low-dose scanners and chest x-ray machines were certified for use and met NLST protocol requirements and American College of Radiology guidelines. Low-dose CT acquisitions and chest radiographs were interpreted by trained radiologists. Participants and their health care provider were informed of study examination results. Participants with abnormalities suspicious for lung cancer were contacted for information regarding diagnostic evaluation. Medical records were collected on diagnostic evaluation, medical complications, and initial treatment.

Participants were then contacted at least annually by mail or telephone.

The National Lung Screening Trial (NLST) represents the union of two NCI-sponsored efforts, the NCI Lung Screening Study and the American College of Radiology Imaging Network (ACRIN).


Ages Eligible for Study:   55 Years to 74 Years   (Adult, Senior)
Genders Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 55-74 years (pack-years = packs per day * years smoked)
  • 30 or more pack-years of cigarette smoking history
  • Former smokers: quit smoking within the previous 15 years
  • Ability to lie on the back with arms raised over the head
  • Signed informed consent form

Exclusion Criteria:

  • Metallic implants or devices in the chest or back, such as pacemakers or Harrington fixation rods
  • Treatment for, or evidence of, any cancer other than nonmelanoma skin cancer or carcinoma in situ (with the exception of transitional cell carcinoma in situ or bladder carcinoma in situ) in the 5 years prior to eligibility assessment
  • History of lung cancer
  • History of removal of any portion of the lung, excluding needle biopsy
  • Requirement for home oxygen supplementation
  • Participation in another cancer screening trial
  • Participation in a cancer prevention study, other than a smoking cessation study
  • Unexplained weight loss of more than 15 pounds in the 12 months prior to eligibility assessment
  • Recent hemoptysis
  • Pneumonia or acute respiratory infection treated with antibiotics in the 12 weeks prior to eligibility assessment
  • Chest CT examination in the 18 months prior to eligibility assessment
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00047385

  Show 33 Study Locations
Sponsors and Collaborators
National Cancer Institute (NCI)
American College of Radiology Imaging Network
Study Director: Christine D. Berg, MD NCI - Early Detection Research Group
Principal Investigator: Denise R. Aberle, MD Jonsson Comprehensive Cancer Center
  More Information

Additional Information:

Publications automatically indexed to this study by Identifier (NCT Number):

Responsible Party: National Cancer Institute (NCI) Identifier: NCT00047385     History of Changes
Obsolete Identifiers: NCT00028808
Other Study ID Numbers: NCI-2012-02002  U01CA079778  U01CA080098  N1CN25476A-85-0-1  NIH/NCI  CDR0000257938 
Study First Received: October 3, 2002
Results First Received: May 30, 2012
Last Updated: May 2, 2014
Health Authority: United States: Federal Government

Keywords provided by National Cancer Institute (NCI):
small cell lung cancer
non-small cell lung cancer

Additional relevant MeSH terms:
Lung Neoplasms
Respiratory Tract Neoplasms
Thoracic Neoplasms
Neoplasms by Site
Lung Diseases
Respiratory Tract Diseases processed this record on January 17, 2017