title: Screening for lung cancer: a systematic review and meta-analysis of controlled trials.
abstract: BACKGROUND
  Lung cancer is a substantial public health problem in western countries. Previous studies have examined different screening strategies for lung cancer but there have been no published systematic reviews.
  
  
  METHODS
  A systematic review of controlled trials was conducted to determine whether screening for lung cancer using regular sputum examinations or chest radiography or computed tomography (CT) reduces lung cancer mortality. The primary outcome was lung cancer mortality; secondary outcomes were lung cancer survival and all cause mortality.
  
  
  RESULTS
  One non-randomised controlled trial and six randomised controlled trials with a total of 245 610 subjects were included in the review. In all studies the control group received some type of screening. More frequent screening with chest radiography was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, 95% CI 1.00 to 1.23). A non-statistically significant trend to reduced mortality from lung cancer was observed when screening with chest radiography and sputum cytological examination was compared with chest radiography alone (RR 0.88, 95% CI 0.74 to 1.03). Several of the included studies had potential methodological weaknesses. Controlled studies of spiral CT scanning have not been reported.
  
  
  CONCLUSIONS
  The current evidence does not support screening for lung cancer with chest radiography or sputum cytological examination. Frequent chest radiography might be harmful. Further methodologically rigorous trials are required before any new screening methods are introduced into clinical practice.
authors.affiliation: Clinical Epidemiology and Health Service Evaluation Unit, Ground Floor, Charles Connibere Building, Royal Melbourne Hospital, Grattan Street, Parkville 3050, Victoria, Australia. ManserRL@mh.org.au
authors.forename: R L
authors.initials: RL
authors.lastname: Manser
authors.forename: L B
authors.initials: LB
authors.lastname: Irving
authors.forename: G
authors.initials: G
authors.lastname: Byrnes
authors.forename: M J
authors.initials: MJ
authors.lastname: Abramson
authors.forename: C A
authors.initials: CA
authors.lastname: Stone
authors.forename: D A
authors.initials: DA
authors.lastname: Campbell
mesh_terms: D018849:Controlled Clinical Trials as Topic; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000401:mortality; D008403:Mass Screening / Q000379:methods*; D010349:Patient Compliance; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013183:Sputum; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods