Skip to Main Content

Prostate

Approximately 38,000 males were randomized into the intervention arm. Each was expected to comply with up to four (T0-T3) digital rectal exams (DREs) and, depending on when he was randomized, between four (T0-T3) and six (T0-T5) annual blood draws. Each draw was sent to a central lab to assess the level of prostate specific antigen (PSA). Overall, about 177,000 PSA exams and 128,000 DREs (almost always concurrent with the PSA exam) were conducted among 36,000 men who complied with at least one screen.

PSA results are contained in the data in both numeric/quantitative form (e.g., 2.6 ng/ml) and summarized/qualitative result (i.e., negative, positive, inadequate), where levels above 4.0 ng/ml are considered positive. DRE cancer screening results are contained in the data as a summarized/qualitative result (i.e., negative, abnormal suspicious, abnormal non-suspicious, inadequate). Additional findings (e.g., prostate size, number of indurations) are also captured.

In the data, a DRE result in a study year is almost always given as the result of one DRE done during one visit to the screening center. However, there are some exceptions. For one, about 4700 DREs had an accompanying quality assurance (QA) DRE. 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 DRE result for that year is that of the QA screen. This occurred in about 550 of the 4700 DREs with QA. A much more infrequent exception regards a handful of inadequate DREs that were reattempted at a later visit. If the second attempt yielded an adequate result, then the DRE result for that year is that adequate result.

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

Summary Available Data
  • Intervention arm males only
  • Data summarized for each study year
  • DRE data for T0-T3
  • PSA data for T0-T5 (T4-T5 exams introduced June 1999)
  • DRE data collected on DRE (Digital Rectal Screening Examination of the Prostate) forms:
  • Screening protocol group
  • Days from randomization to screens
  • PSA results by study year
  • DRE results by study year
  • Available in screening and abnormality datasets:
    • QA / Protocol screens as separate data
    • Multiple visits to screening center as separate data
    • DRE findings (e.g., indurations)
    • Prostate symmetry and size
    • Examiner ID
    • Reason for inadequate DRE
    • Other PSA and DRE details

Lung

Approximately 77,000 participants were randomized into the intervention arm. Each was expected to comply with up to four (T0-T3) chest x-rays except for never smokers randomized after 12/7/95 who did not receive a T3 screen. Overall, about 236,000 chest x-rays were conducted among approximately 71,000 participants who complied with at least one screen.

Chest x-ray results are contained in the data as a summarized/qualitative result (i.e., negative, abnormal suspicious, abnormal non-suspicious, inadequate). The description and location of abnormalities were also captured.

In the data, a XRY result in a study year is almost always given as the result of one reading from the radiologist. However, there are some exceptions. For one, about 8,300 XRYs had an accompanying quality assurance (QA) reading by another radiologist. 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 XRY result for that year is that of the QA reading. This occurred in about 1,000 of the 8,300 XRYs with QA. A much more infrequent exception regards a handful of inadequate XRYs that were reattempted at a later visit. If the second attempt yielded an adequate result, then the XRY result for that year is that adequate result.

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

Summary Available Data
  • Intervention arm only
  • Data summarized for each study year
  • For years T0-T3
  • No T3 for never smokers after 12/7/95
  • XRY data collected on XRY (Chest X-Ray Screening Examination) forms:
  • Screening protocol group
  • Days from randomization to screens
  • Chest x-ray results by study year
  • Available through screening and abnormality data sets:
    • QA / Protocol screens as separate data
    • Multiple visits to screening center as separate data
    • Chest x-ray abnormalities & locations
    • Examiner ID
    • Reason for inadequate chest x-ray
    • Other chest x-ray details

Beginning in 2006 an effort was undertaken to create a digital copy of all PLCO screening chest x-ray films. Of the approximately 237,000 chest x-rays screened in the trial, about 189,000 (80%) are digitized. Nearly 71,000 participants (81%) who completed at least one screen have a digitized film. Images are stored in Tagged Image File Format (.tiff) with a low-contrast technique. Digitized X-rays can be obtained through a request.

Colorectal

Approximately 77,000 participants were randomized into the intervention arm. Each was expected to comply with two flexible sigmoidoscopies (FSGs): one at baseline (T0 FSG) and another 3 or 5 years later (T3/5 FSG). The T3 FSG was expected for participants randomized prior to October 1994. The T5 FSG was expected for those randomized on/after December 7th, 1995. For randomization between these dates, T3 FSG was scheduled, but if that screen was missed, T5 FSG was offered. Overall, about 107,000 screening FSGs (65,000 at baseline and 42,000 at T3 or T5) were conducted among 67,000 participants who complied with at least one screen. 39,000 participants had FSGs both at baseline and at the return visit.

FSG cancer screening results are contained in the data as a summarized/qualitative result (i.e., negative, abnormal suspicious, abnormal non-suspicious, inadequate). Additional findings (e.g., lesion size, number of lesions) are also captured.

In the data, an FSG result in a study year is almost always given as the result of one FSG done during one visit to the screening center. However, there are some exceptions. For one, about 3700 FSGs had an accompanying quality assurance (QA) FSG. 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 FSG result for that year is that of the QA screen. This occurred in about 230 of the 3700 FSGs with QA. Another exception includes 660 inadequate FSGs reattempted at a later visit that same year. In about 550 participants (83%), a reattempted FSG yielded an adequate result, and so the FSG result for that year is that adequate result.

For most purposes, screening data can be obtained within the Colorectal dataset. Additional details are contained within the Colorectal Screening dataset (one record per screening study year per person) or the Colorectal Screening Abnormalities dataset (one record per lesion per screen per person).

Summary Available Data
  • Intervention arm only
  • Data summarized for each study year
  • FSG data for T0 and T3/5 (T5 exams introduced in 1995)
  • FSG data collected on FSG (Flexible Sigmoidoscopy Screening Examination) forms:
  • Screening protocol group
  • Days from randomization to screens
  • FSG results by study year
  • Count of lesions seen
  • Lesion location and size
  • Available in screening and abnormality datasets:
    • QA / Protocol screens as separate data
    • Multiple visits to screening center as separate data
    • Examiner ID
    • Reason for inadequate FSG
    • Other FSG findings

Ovarian

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