title: Screening and cervical cancer cure: population based cohort study.
abstract: OBJECTIVE
  To determine whether detection of invasive cervical cancer by screening results in better prognosis or merely increases the lead time until death.
  
  
  METHODS
  Nationwide population based cohort study.
  
  
  METHODS
  Sweden.
  
  
  METHODS
  All 1230 women with cervical cancer diagnosed during 1999-2001 in Sweden prospectively followed up for an average of 8.5 years.
  
  
  METHODS
  Cure proportions and five year relative survival ratios, stratified by screening history, mode of detection, age, histopathological type, and FIGO (International Federation of Gynecology and Obstetrics) stage.
  
  
  RESULTS
  In the screening ages, the cure proportion for women with screen detected invasive cancer was 92% (95% confidence interval 75% to 98%) and for symptomatic women was 66% (62% to 70%), a statistically significant difference in cure of 26% (16% to 36%). Among symptomatic women, the cure proportion was significantly higher for those who had been screened according to recommendations (interval cancers) than among those overdue for screening: difference in cure 14% (95% confidence interval 6% to 23%). Cure proportions were similar for all histopathological types except small cell carcinomas and were closely related to FIGO stage. A significantly higher cure proportion for screen detected cancers remained after adjustment for stage at diagnosis (difference 15%, 7% to 22%).
  
  
  CONCLUSIONS
  Screening is associated with improved cure of cervical cancer. Confounding cannot be ruled out, but the effect was not attributable to lead time bias and was larger than what is reflected by down-staging. Evaluations of screening programmes should consider the assessment of cure proportions.
authors.affiliation: Centre for Research and Development, Uppsala University/County Council of Gävleborg, S-80188 Gävle, Sweden. bengt.andrae@ki.se
authors.forename: Bengt
authors.initials: B
authors.lastname: Andrae
authors.forename: Therese M-L
authors.initials: TM
authors.lastname: Andersson
authors.forename: Paul C
authors.initials: PC
authors.lastname: Lambert
authors.forename: Levent
authors.initials: L
authors.lastname: Kemetli
authors.forename: Lena
authors.initials: L
authors.lastname: Silfverdal
authors.forename: Björn
authors.initials: B
authors.lastname: Strander
authors.forename: Walter
authors.initials: W
authors.lastname: Ryd
authors.forename: Joakim
authors.initials: J
authors.lastname: Dillner
authors.forename: Sven
authors.initials: S
authors.lastname: Törnberg
authors.forename: Pär
authors.initials: P
authors.lastname: Sparén
mesh_terms: D000328:Adult; D015982:Bias; D002277:Carcinoma / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology / Q000517:prevention & control; D015331:Cohort Studies; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008403:Mass Screening; D008875:Middle Aged; D008962:Models, Theoretical; D009367:Neoplasm Staging; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D011379:Prognosis; D015996:Survival Rate; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology / Q000517:prevention & control; D014626:Vaginal Smears; D055815:Young Adult