title: Baseline cytology, human papillomavirus testing, and risk for cervical neoplasia: a 10-year cohort analysis.
abstract: BACKGROUND
  Annual Pap smear screening has been favored over less frequent screening in the United States to minimize the risk of cervical cancer. We evaluated whether simultaneous screening with a Pap test and human papillomavirus (HPV) testing is useful for assessing the risk for cervical intraepithelial neoplasia (CIN) 3 or cervical cancer.
  
  
  METHODS
  We enrolled 23 702 subjects in a study of HPV infection at Kaiser Permanente, Northwest Division, Portland, OR. Data were analyzed for 20 810 volunteers who were at least 16 years old (mean = 35.9 years) with satisfactory baseline Pap tests and suitable samples for HPV testing. Women were followed for up to 122 months (from April 1, 1989, to June 30, 1999) to determine the risk for histopathologically confirmed CIN3 or cancer.
  
  
  RESULTS
  Among 171 women with CIN3 or cancer diagnosed over 122 months, 123 (71.9%, 95% confidence interval [CI] = 65.2% to 78.7%) had baseline Pap results of atypical squamous cells or worse and/or a positive HPV test, including 102 (86.4%, 95% CI = 80.3% to 92.6%) of the 118 cases diagnosed within the first 45 months of follow-up. During this 45-month period, the cumulative incidence of CIN3 or cancer was 4.54% (95% CI = 3.61% to 5.46%) among women with a Pap test result of atypical squamous cells or worse, positive HPV tests, or both compared with 0.16% (95% CI = 0.08% to 0.24%) among women with negative Pap and HPV tests. Age, screening behavior, a history of cervical cancer precursors, and a history of treatment for CIN minimally affected results.
  
  
  CONCLUSIONS
  Negative baseline Pap and HPV tests were associated with a low risk for CIN3 or cancer in the subsequent 45 months, largely because a negative HPV test was associated with a decreased risk of cervical neoplasia. Negative combined test results should provide added reassurance for lengthening the screening interval among low-risk women, whereas positive results identify a relatively small subgroup that requires more frequent surveillance.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. shermanm@mail.nih.gov
authors.forename: Mark E
authors.initials: ME
authors.lastname: Sherman
authors.forename: Attila T
authors.initials: AT
authors.lastname: Lorincz
authors.forename: David R
authors.initials: DR
authors.lastname: Scott
authors.forename: Sholom
authors.initials: S
authors.lastname: Wacholder
authors.forename: Philip E
authors.initials: PE
authors.lastname: Castle
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Glass
authors.forename: Iwona
authors.initials: I
authors.lastname: Mielzynska-Lohnas
authors.forename: Brenda B
authors.initials: BB
authors.lastname: Rush
authors.forename: Mark
authors.initials: M
authors.lastname: Schiffman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002584:Cervix Uteri / Q000473:pathology* / Q000821:virology*; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D065006:Papanicolaou Test; D027383:Papillomaviridae / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000150:complications / Q000175:diagnosis*; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014412:Tumor Virus Infections / Q000150:complications / Q000175:diagnosis*; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000517:prevention & control* / Q000821:virology; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000473:pathology / Q000517:prevention & control* / Q000821:virology