RATIONALE: Screening tests, such as colonoscopy and fecal occult blood test, may help doctors find tumor cells early and plan better treatment for colorectal cancer.

PURPOSE: This randomized phase III trial is studying colonoscopy to see how well it works compared to fecal occult blood test in screening healthy participants for colorectal cancer.

OBJECTIVES:

• Compare the neoplastic outcome of participants at average risk for colorectal cancer who undergo colonoscopy vs annual fecal occult blood tests.
• Compare the endoscopic and clinical resources required for these screening methods in these participants.
• Compare the benefit-to-harm ratio in participants undergoing these screening methods.
• Determine the level of participation of participants undergoing these screening methods.

OUTLINE: This is a randomized, two-part, multicenter study.

Participants are asked whether they are interested in participating in a randomized controlled trial of colorectal cancer screening.

• Screening colonoscopy feasibility study I (accrual completed as of 12/14/2004): Participants who are interested in participating in a screening trial are randomized to 1 of 2 screening arms.

  • Arm I: Participants undergo baseline screening colonoscopy.
  • Arm II: Participants receive standard care.

• Screening colonoscopy feasibility study II: Participants who are interested in participating in a screening trial are randomized to 1 of 2 screening arms.

  • Arm I: Participants undergo baseline screening colonoscopy. Participants are given individualized recommendations for further surveillance based on the results of the colonoscopy.
  • Arm II: Participants undergo a baseline fecal occult blood test (FOBT). Participants are given individualized recommendations for further surveillance based on the results of the FOBT. Participants with negative baseline FOBT undergo FOBT annually for up to 4 years in the absence of a positive FOBT.

All participants are followed annually for up to 4 years.

PROJECTED ACCRUAL: A total of 1,402 participants (701 per screening arm) have been accrued for feasibility study I within 3 years (accrual completed as of 12/14/2004). An additional 3,550 participants (1,775 per screening arm) will be accrued for feasibility study II within 5 years.

DISEASE CHARACTERISTICS:

• Healthy participants at average risk for developing colorectal cancer
• No history of colorectal cancer
• No history of familial adenomatous polyposis
• More than 5 years since prior flexible sigmoidoscopy
• No prior colonoscopy

PATIENT CHARACTERISTICS:

Age

• 50 to 69 (40 to 69 at the Louisiana State University participating site)

Performance status

• Not specified

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Not specified

Cardiovascular

• No myocardial infarction within the past year
• No congestive heart failure

Pulmonary

• No chronic obstructive pulmonary disease

Gastrointestinal

• No history of ulcerative colitis
• No history of Crohn's disease
• No history of inflammatory bowel disease

Other

• No serious comorbid condition
• No consumption of red meat within 3 days prior to and during FOBT (feasibility study II, arm II only)

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• No concurrent chemotherapy other than for nonmelanoma skin cancer

Endocrine therapy

• Not specified

Radiotherapy

• Not specified

Surgery

• Not specified

Other

• No vitamin C consumption > 250 mg within 3 days prior to and during fecal occult blood testing (FOBT) (feasibility study II arm II only)
• No nonsteroidal anti-inflammatory drugs within 7 days prior to and during FOBT (feasibility study II, arm II only)
• No concurrent anticoagulants
• No concurrent anticancer therapy except for treatment of nonmelanoma skin cancer