Nitric Oxide-Releasing Acetylsalicyclic Acid in Preventing Colorectal Cancer in Patients at High Risk of Colorectal Cancer

OBJECTIVES:

Primary

• Evaluate the effects of nitric oxide-releasing acetylsalicyclic acid on aberrant cryptic foci (ACF) in patients at high risk for colon cancer.

Secondary

• Determine the pharmacokinetic profile of this drug in these patients.
• Determine the presence or absence of ACF in these patients.
• Determine the expression of PGE2, COX-1, COX-2, NF-kB, and β-catenin in colon tissue.
• Determine the safety and tolerability of long-term nitric oxide-releasing acetylsalicyclic acid in these patients.

OUTLINE: This is a multicenter, double-blind, randomized, placebo-controlled, parallel group study. Patients are stratified according to gender and race (black vs non-Hispanic white vs Hispanic white vs Asian). Patients are randomized to 1 of 3 treatment arms.

• Arm I: Patients receive oral nitric oxide-releasing acetylsalicyclic acid twice daily for 6 months.
• Arm II: Patients receive nitric oxide-releasing acetylsalicyclic acid twice daily for 6 months at a higher dose than in arm I.
• Arm III: Patients receive oral placebo twice daily for 6 months. Patients undergo sigmoidoscopies at baseline and at the completion of study treatment. Biopsies of aberrant cryptic foci (ACF) and non-ACF sites are collected at both sigmoidoscopies. Tissue is examined for biomarkers (PGE_2, COX, NF-kB, β-catenin).

After completion of study treatment, patients are followed periodically.

PROJECTED ACCRUAL: A total of 240 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• At risk for colorectal cancer

• History of histologically proven sporadic colon adenomas or colon cancer
• At least 5 aberrant cryptic foci on sigmoidoscopy
• Less than 20 prior cumulative adenomas and no heredity nonpolyposis colorectal cancer
• No significant asymptomatic lesions on sigmoidoscopy, including any of the following:

• Inflammation
• Strictures
• Anorectal lesions
• Fistulae
• Vascular lesions
• No adenomas or colon carcinomas on flexible sigmoidoscopy
• No history of gastrointestinal (GI) cancer other than colorectal cancer
• No inherited colorectal cancer syndromes

PATIENT CHARACTERISTICS:

• No other GI mucosal epithelial diseases (e.g., Barrett's esophagus, chronic or recurrent peptic ulcer disease, celiac sprue, or other disorders of nutrient absorption)

• No active peptic ulcer disease
• No history of inflammatory bowel disease (ulcerative colitis or Crohn's disease)
• No known or suspected alcohol ( > 5 glasses of wine or beer per day), drug, or medication abuse
• No quantitative or qualitative platelet or coagulation abnormalities
• No personal or family history of a bleeding disorder
• No uncontrolled diabetes
• No uncontrolled hypertension, or chronic congestive heart failure (New York Heart Association class II-IV heart disease)
• No myocardial infarction, transient ischemic attack, or stroke within the past 6 months
• No equilibrium disorders affecting gait or ability to stand that would preclude study participation
• No involuntary change in weight (up or down) of ≥ 15% of usual body weight within the past year
• Creatinine ≤ 2.0 mg/dL
• No chronic liver disease or pancreatitis
• No allergies to aspirin
• No prior severe adverse reactions to NSAIDs such as asthma, GI bleeding, or renal insufficiency
• No institutionalized, mentally disabled patients
• No prisoners
• Not pregnant or nursing
• Fertile patients must use effective contraception
• Negative pregnancy test

PRIOR CONCURRENT THERAPY:

• No concurrent antibiotic prophylaxis
• More than 7 days since prior nonsteroidal anti-inflammatory drug (NSAID) treatment, including aspirin
• No concurrent frequent use (> 7 days in previous month) of NSAIDs, cyclooxygenase (COX)-2 inhibitors, nitrovasodilators, or oral corticosteroids
• No concurrent macronutrient consumption below the 1st or above the 99th percentile of U.S. consumption
• No concurrent anticoagulants, ticlopidine, and clopidogrel
• More than 3 months since prior general anesthesia
• More than 3 months since prior investigational agents
• No concurrent NSAIDs, including aspirin or COX-2 inhibitors

• Acetaminophen allowed
• No concurrent nitrovasodilating drugs
• More than 3 months since prior participation in other investigational trials