Skip to Main Content

An official website of the United States government


Approximately 39,000 females were randomized into the intervention arm. Each was expected to comply with up to four (T0-T3) trans-vaginal ultrasounds (TVUs) and, depending on when she was randomized, between four (T0-T3) to six (T0-T5) annual blood draws. Each draw was sent to a central lab to assess the level of cancer antigen 125 (CA-125). Overall, about 150,000 CA-125 exams and 106,000 TVUs (almost always concurrent with the CA-125 exam) were conducted among nearly 31,000 women who complied with at least one screen.

CA-125 results are contained in the data in both numeric/quantitative form (e.g., 20 U/ml) and summarized/qualitative result (i.e., negative, positive, inadequate), where levels greater than or equal to 35 U/ml are considered positive. TVU cancer screening results are contained in the data as a summarized result (i.e., negative, abnormal suspicious, abnormal non-suspicious, inadequate). Additional findings (e.g., ovary size, cyst size, number of abnormalities) are also captured.

In the data, a TVU result in a study year is almost always given as the result of one TVU done during one visit to the screening center. However, there are some exceptions. For one, about 7500 TVUs had an accompanying quality assurance (QA) TVU. For these screens, if the QA result was more severe than that of the scheduled protocol screen (severity: abnormal suspicious > abnormal non-suspicious > negative > inadequate) then the TVU result for that year is that of the QA screen. This occurred in about 300 of the 7500 TVUs with QA. A much more infrequent exception regards a handful of inadequate TVUs that were reattempted at a later visit. If the second attempt yielded an adequate result, then the TVU result for that year assumes that adequate result.

For most purposes, screening data can be obtained within the Ovarian dataset. Additional details are contained within the Ovarian Screening dataset (one record per screening study year per person) and the Ovarian Screening Abnormalities dataset (one record per TVU abnormality per person).

Summary Available Data
  • Intervention arm females only
  • Data summarized for each study year
  • TVU data for years T0-T3
  • CA-125 data for years T0-T5
  • T4 and T5 CA-125 exams introduced in June 1999
  • TVU data collected on TVU (Transvaginal Ultrasound Screening Examination) forms:
  • Screening protocol group
  • Days from randomization to screens
  • CA-125 results by study year
  • TVU results by study year
  • Available through screening and abnormality datasets:
    • QA / Protocol screens as separate data
    • Multiple visits to screening center as separate data
    • Ovary visualization and size
    • Cyst/abnormality size, outline, etc.
    • Examiner ID
    • Reason for inadequate TVU
    • Other CA-125 and TVU details