title: Risk stratification based on screening history: the NELSON lung cancer screening study.
abstract: Debate about the optimal lung cancer screening strategy is ongoing. In this study, previous screening history of the Dutch-Belgian Lung Cancer Screening trial (NELSON) is investigated on if it predicts the screening outcome (test result and lung cancer risk) of the final screening round.
  
  
  
  15 792 participants were randomised (1:1) of which 7900 randomised into a screening group. CT screening took place at baseline, and after 1, 2 and 2.5 years. Initially, three screening outcomes were possible: negative, indeterminate or positive scan result. Probability for screening outcome in the fourth round was calculated for subgroups of participants.
  
  
  
  Based on results of the first three rounds, three subgroups were identified: (1) those with exclusively negative results (n=3856; 73.0%); (2) those with ≥1 indeterminate result, but never a positive result (n=1342; 25.5%); and (3) with ≥1 positive result (n=81; 1.5%). Group 1 had the highest probability for having a negative scan result in round 4 (97.2% vs 94.8% and 90.1%, respectively, p<0.001), and the lowest risk for detecting lung cancer in round 4 (0.6% vs 1.6%, p=0.001). 'Smoked pack-years' and 'screening history' significantly predicted the fourth round test result. The third round results implied that the risk for detecting lung cancer (after an interval of 2.5 years) was 0.6% for those with negative results compared with 3.7% of those with indeterminate results.
  
  
  
  Previous CT lung cancer screening results provides an opportunity for further risk stratifications of those who undergo lung cancer screening.
  
  
  
  Results, ISRCTN63545820.
authors.affiliation: Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Uraujh
authors.initials: U
authors.lastname: Yousaf-Khan
authors.affiliation: Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Carlijn
authors.initials: C
authors.lastname: van der Aalst
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Pim A
authors.initials: PA
authors.lastname: de Jong
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Groningen, The Netherlands.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Heuvelmans
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.|Department of Radiology, Kennemer Gasthuis, Haarlem, The Netherlands.
authors.forename: Ernst
authors.identifier: 0000-0002-1982-2763
authors.initials: E
authors.lastname: Scholten
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Groningen, The Netherlands.
authors.forename: Joan
authors.initials: J
authors.lastname: Walter
authors.affiliation: Department of Pulmonary Medicine, KU leuven, University Hospital Leuven, Leuven, Belgium.
authors.forename: Kristiaan
authors.initials: K
authors.lastname: Nackaerts
authors.affiliation: Department of Pulmonary Diseases, University of Groningen, University Medical Center Groningen,  Groningen, The Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: Groen
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Groningen, The Netherlands.
authors.forename: Rozemarijn
authors.initials: R
authors.lastname: Vliegenthart
authors.affiliation: Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Kevin
authors.initials: K
authors.lastname: Ten Haaf
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Groningen, The Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Oudkerk
authors.affiliation: Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: de Koning
mesh_terms: D000367:Age Factors; D000368:Aged; D001530:Belgium / Q000453:epidemiology; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Clinical Epidemiology; Lung Cancer; Smoking cessation; Tobacco and the lung