Summary
The Minnesota Colon Cancer Control Study (MINN) was a three arm randomized screening study designed to test if colorectal cancer mortality rates could be reduced through the use of periodic screenings. The two screening arms were screened either annually or biennially (every two years). Participants in the two screening arms were asked to submit six hemoccult slides, two smears from three consecutive stools. After 13 years of follow-up, the study concluded that there was a substantial reduction in mortality and that annual screens saw the largest improvement.
Study Years: 1975-1992
Randomized trial with three arms:
- Arm I: Annual Screening
- Arm II: Biennial Screening
- Arm III: Control arm
Study Eligibility:
- Ages Eligible for Study: 50 to 80
- Sexes Eligible for Study: Male or Female
- Recruited from volunteers for the American Cancer Society and fraternal, veterans, and employee groups in Minnesota
- No prior history of colorectal cancer, familial polyposis, or chronic ulcerative colitis
- Not bedridden or otherwise disabled
Enrollment
Enrollment: 46,551
- 15,570 in Annual Screening Arm
- 15,587 in Biennial Screening Arm
- 15,394 in Control Arm
Total Study Population Demographics (46,551 Randomized and Eligible People):
- Age (years):
- Mean: 62.3
- Range: 24-93
- Median: 61.9
Schema
The Schema is a timeline of the study. It indicates start/end points, visits expected, major testing to be done, and any other information that is crucial to understanding how the study was completed.
Schema Description
Healthy volunteers are randomized into one of three arms with screening lasting up to 12 years. The first arm, called the annual arm gets yearly blood hemoccult cultures. The second arm, the biennial arm, gets hemoccult cultures taken every 2 years. The last arm is the control arm in which patients receive their usual medical care. After the main portion of the trial ended, there was annual questionnaire follow-up as well as periodic checking of death certificates and other relevant medical records.
The study had roughly 46,500 participants split between the control and two intervention arms. The intervention arms were asked to submit hemoccult slides either annually or biennially depending on arm. The participants were not to eat red meat, fish, poultry, certain fruits and vegetables, vitamin C tables, and aspirin for 24 hours before sample collection. Slides were mailed to and then tested by the laboratories at the University of Minnesota Hospital. Participants were notified of screening results and those with positive slides were asked to return to the hospital for an examination. The examination consisted of a history and physical examination, rigid proctosigmoidoscopy, single-column barium enema radiography, complete blood count, urinalysis, routine tests of blood chemistry, upper gastrointestinal series, chest radiography, electrocardiography, and a colonoscopy. The single-column barium-enema radiography was switched to a double-contrast barium enema and the proctosigmoidoscopy and upper gastrointestinal series were stopped in 1982. Along with annual questionnaires to all three arms, death certificates were also obtained and reviewed.
