title: Cervical cancer after multiple negative cytologic tests in long-term members of a prepaid health plan.
abstract: OBJECTIVE
  To estimate squamous cell cervical cancer incidence within 3.5 years of 1, 2 and > or = 3 consecutive, normal cytologic tests.
  
  
  METHODS
  Data were from a case-control study of cervical cancer screening efficacy. Long-term members of a prepaid health plan diagnosed with cancer from 1983 to 1995 (the cases) were grouped by number of prior conventional cytologic tests and by time from the last negative screening test to the diagnosis date. Women from the population at risk were estimated by multiplying the timated by multiplying the proportions of women without cancer (the matched controls) in each screening category by the numbers of long-term of the numbers of long-term female members enrolled from male members enrolled from 1983 to 1995.
  
  
  RESULTS
  Of an estimated 6,802,641 woman-years of observation, 129 cases were diagnosed within 3.5 years of > or = 21 negative screening test. After > or = 3 consecutive negative tests, incidence per 100,000 woman-years grouped by time from the last negative screening test were: 1.43 (26/1,813,552) 0-18 months later, 4.24 (17/400,584) 19-30 months later and 4.73 (10/211,217) 31- 42 months later.
  
  
  CONCLUSIONS
  The first 18 months after the last negative screening Pap test in women with > or = 3 prior negative tests, cancer incidence increases to an estimated 4-5 per 100,000 woman-years in each of the subsequent 2 years.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Fracisco, 3333 California Street, Suite 335, San Francisco, California 94143-0856, USA. sawaya@itsa.ucsf.edu
authors.forename: George F
authors.initials: GF
authors.lastname: Sawaya
authors.forename: Hai-Yen
authors.initials: HY
authors.lastname: Sung
authors.forename: Walter
authors.initials: W
authors.lastname: Kinney
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Kearney
authors.forename: Marie G
authors.initials: MG
authors.lastname: Miller
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hiatt
mesh_terms: D000328:Adult; D000368:Aged; D002140:California / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D016022:Case-Control Studies; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D017061:Prepaid Health Plans; D012189:Retrospective Studies; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D014626:Vaginal Smears