National Lung Screening Trial Explained

National Lung Screening Trial
Headerstyle:background:#ccf;
Labelstyle:background:#ddf;
Label3:other names
Data3:NLST, NCT00047385
Label4:sponsor
Data4:National Cancer Institute
Label5:number of participants
Data5:53,454
Label6:start
Data6:August 2002
Label7:end
Data7:October 2010
Label8:primary completion
Data8:October 2010

The National Lung Screening Trial was a United States-based clinical trial which recruited research participants between 2002 and 2004.[1] It was sponsored by the National Cancer Institute and conducted by the American College of Radiology Imaging Network and the Lung Screening Study Group.[1] The major objective of the trial was to compare the efficacy of low-dose helical computed tomography (CT screening) and standard chest X-ray as methods of lung cancer screening.[2] The primary study ended in 2010, and the initial findings were published in November 2010, with the main results published in 2011 in the New England Journal of Medicine.

The trial led to a recommendation in the United States in 2013 that CT screening be used on people at high risk for developing lung cancer in an effort to detect the cancer earlier and reduce mortality.[3] Current United States Preventive Services Task Force recommendations are "annual screening for lung cancer with low-dose computed tomography (LDCT) in adults aged 50 to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years" (Grade B).[4]

Study design

The study looked at 53,454 current or former heavy smokers from 33 medical centers in the US. The ages of the patients in the trial varied from 55 to 74. When their initial findings were published in the New England Journal of Medicine, the researchers reported that low-dose CT scanning was associated with a 20% decrease in deaths from lung cancer,[5] [6] and that this effect was visible in both current smokers and former smokers.[7] More recent research based on this trial, published in JAMA Internal Medicine,[8] has found that low-dose computed tomography detects many false positives—in the study, 18% of total detections were considered to be an overdiagnosis, i.e. the cancer would never have threatened the life of the patient.[9]

The National Cancer Institute funded a $300m study, the National Lung Screening Trial (NLST), which began in 2002, to compare the effectiveness of CT scan screening versus X-ray screening.[10] This study, too, raised concern in the media over potential conflicts of interest related to the tobacco company, although this time on the contra-CT scan side: on October 8, 2007, the Wall Street Journal reported that at least two lead investigators of the study had conflicts of interest arising from their serving as paid, expert defense witnesses for the tobacco industry – one of them had given testimony asserting that promoting CT screening was "reckless or irresponsible", and another had provided an expert report warning that CT screening "may do more harm than good."[11]

Results

Deaths in either group were then logged for up to five years. As of October 2010, 354 people in the CT scan group had died from lung cancer, versus 442 people in the X-ray group; in other words, deaths in the CT scan group of patients were 20.3% lower than in the X-ray group.[12] The study's review board concluded that this difference was statistically significant and recommended terminating the study. The director of the National Cancer Institute's director, Harold Varmus, said that early analysis results appeared to indicate that CT scans detected more lung cancers, at an earlier and more treatable stage, and that CT scans could therefore reduce the number of deaths in patients at high risk of lung cancer.

Further reading

The trial's main result is here:

External links

Notes and References

  1. Web site: National Lung Screening Trial (NLST) Screening - Full Text View - ClinicalTrials.gov . National Cancer Institute . National Cancer Institute . clinicaltrials.gov . 2014 . 23 July 2014.
  2. http://www.cancer.gov/clinicaltrials/noteworthy-trials/nlst National Lung Screening Trial
  3. Denise Aberle. Abtin. F.. Brown. K.. Computed Tomography Screening for Lung Cancer: Has It Finally Arrived? Implications of the National Lung Screening Trial. Journal of Clinical Oncology. 31. 8. 2013. 1002–1008. 0732-183X. 10.1200/JCO.2012.43.3110. 23401434. 3589698.
  4. Web site: 2021 . Lung Cancer: Screening . 2024-05-03 . U.S. Preventative Services Task Force.
  5. National Lung Screening Trial Research Team . Aberle . D. R. . Adams . A. M. . Berg . C. D. . Black . W. C. . Clapp . J. D. . Fagerstrom . R. M. . Gareen . I. F. . Gatsonis . C. . Marcus . P. M. . Sicks . Reduced Lung-Cancer Mortality with Low-Dose Computed Tomographic Screening . 10.1056/NEJMoa1102873 . New England Journal of Medicine . 365 . 5 . 395–409 . 2011 . 21714641. 4356534.
  6. http://www.cancer.gov/newscenter/newsfromnci/2011/NLSTprimaryNEJM NIH-funded study shows 20 percent reduction in lung cancer mortality with low-dose CT compared to chest X-ray
  7. Panel Advises Annual Lung Cancer Screening for Current and Former Smokers . . 30 July 2013 . 20 December 2013 . Sifferlin, Alexandra.
  8. Patz Jr . E. F. . Pinsky . P. . Gatsonis . C. . Sicks . J. D. . Kramer . B. S. . Tammemägi . M. C. . Chiles . C. . Black . W. C. . Aberle . D. R. . for the NLST Overdiagnosis Manuscript Writing Team . Overdiagnosis in Low-Dose Computed Tomography Screening for Lung Cancer . JAMA Internal Medicine . 2013 . 10.1001/jamainternmed.2013.12738 . 24322569 . 4040004. 174 . 2 . 269–74.
  9. https://www.sciencedaily.com/releases/2013/12/131209160708.htm Study Suggests Overdiagnosis in Screening for Lung Cancer With Low-Dose CT
  10. https://www.nytimes.com/2006/10/31/health/31prof.html?pagewanted=2&ref=research When It Comes to Lung Cancer, She Doesn’t Believe in Waiting
  11. https://www.wsj.com/articles/SB119179920110451468?pagewanted=1&_r=1&hp Critics Question Objectivity Of Government Lung-Scan Study
  12. https://online.wsj.com/article/BT-CO-20101104-717833.html UPDATE: US Lung Cancer Screening Study Shows Benefit With CT Vs. X-Ray