CCCaST - Canadian Cervical Cancer Screening Trial


We are very proud to bring you this portal for information on cervical cancer, human papillomavirus (HPV) and the CCCaST Study. For information on HPV and Pap smears, please follow the appropriate links on your left.

About the CCCaST Study

The Canadian Cervical Screening Trial (CCCaST) is a randomized controlled trial to compare the relative efficacy of HPV and Pap testing for primary screening for cervical cancer precursors in Montreal and St. John’s.

  • CCCaST targeted women over 30 years from family medicine practices both in Montreal and St. John’s.
  • Women presenting for their routine Pap smears were enrolled to have both an HPV test and a Pap smear, but were randomized as to the order in which these tests will be done.
  • All women with an abnormal Pap smear or a positive HPV test and a random sample with both negative tests have undergone colposcopy and biopsy.
  • Women found to have disease on biopsy were managed according to prevailing clinical guideline.  Women with normal colposcopy and biopsies underwent a repeat colposcopy six month later.  Women with both negative screening tests were rescreened one year later.
  • Between 2002 and 2005 we invited 14,953 women to participate, of which 10,171 were randomized and 10,154 were confirmed eligible and evaluated: 4,400 in Montreal and 5,754 in St. John’s.
  • A total of 5,059 women were randomized to the Focus on pap arm ad 5, 095 to the Focus on HPV arm.
  • On the basis of cross-sectional results at enrolment the verification-bias adjusted sensitivity of Pap cytology was 55.4% (95%CI: 13.7-77.2) and of HPV testing was 94.7% (95%CI: 84.3-100).  The specificity estimates for these two tests were 97.2% (95%CI: 96.7-97.7) and 94.1% (95%CI: 93.4-94.8), respectively.


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