S0000D: Effect of Vitamin E and/or Selenium on Colorectal Polyps in Men Enrolled on SELECT Trial SWOG-S0000 (ACP)

• Effect of Selenium on Colorectal Adenoma (CRA) Occurrence, Analyzed by Active Selenium vs. Selenium Placebo [ Time Frame: From 1 year post randomization through study completion ]
• Effect of Selenium on Advanced Neoplasia, Analyzed by Active Selenium vs. Selenium Placebo [ Time Frame: From 1 year post randomization through study completion ]
  Adenomas with diameter >=1cm or any adenoma with villous features or high-grade dysplasia
• Effect of Selenium and/or Vitamin E on Colorectal Cancer (CRC) Incidence [ Time Frame: From 1 year post randomization through study completion ]
• Effect of Selenium on Occurrences of Multiple (>2) Adenomas [ Time Frame: From 1 year post randomization through study completion ]

• Effect of selenium on colorectal adenoma (CRA) occurrence and colorectal cancer (CRC) incidence
• Effect of selenium on number, location, size, histologic type, and degree of dysplasia of CRA

• Effect of vitamin E on CRA occurrence and CRC incidence
• Effect modification of selenium and vitamin E by aspirin on CRA occurrence
• Effect modification of selenium and vitamin E by body mass index

• Effect Modification of Selenium by Body Mass Index on CRA Occurrence, Analyzed by Active Selenium vs. Selenium Placebo [ Time Frame: From 1 year post randomization through study completion ]
• Effect Modification of Selenium by Aspirin on CRA Occurrence, Analyzed by Active Selenium vs. Selenium Placebo [ Time Frame: From 1 year post randomization through study completion ]
• Effect Modification of Vitamin E by Body Mass Index on CRA Occurence, Analyzed by Active Vitamin e vs. Vitamin e Placebo [ Time Frame: From 1 year post randomization through study completion ]
• Effect Modification of Vitamin E by Aspirin on CRA Occurrence, Analyzed by Active Vitamin e vs. Vitamin e Placebo [ Time Frame: From 1 year post randomization through study completion ]

RATIONALE: Studying tissue samples in the laboratory from participants receiving treatment on the Selenium and Vitamin E Cancer Prevention Trial (SELECT) SWOG-S0000 may help doctors predict a participant's response to treatment and help plan the best treatment.

PURPOSE: This phase III trial is studying the effect of vitamin E and/or selenium on colorectal polyps in men enrolled on SELECT Trial SWOG-S0000.

OBJECTIVES:

Primary

• To assess the effect of selenium on colorectal adenoma (CRA) occurrence.
• To assess the effect of selenium on number, location, size, histologic type, and degree of dysplasia of CRA.
• To assess the effect of selenium on colorectal cancer (CRC) incidence.

Secondary

• To assess the effect of vitamin E on CRA occurrence.
• To assess the effect of vitamin E on CRC incidence.

Tertiary

• To explore the effect modification of selenium and vitamin E by aspirin on CRA occurrence.
• To explore the effect modification of selenium and vitamin E by body mass index.

OUTLINE: This is a multicenter study.

Endoscopically obtained tissue samples are reviewed by study pathologists to confirm the presence (or absence) of a colorectal adenoma (CRA). If a CRA is present, the number, location, size, histology, and degree of dysplasia are documented. The CRA is also reviewed to exclude a diagnosis of colorectal cancer.

Additional data, including aspirin use, height and weight, date of birth, and other demographic and baseline characteristics, is also obtained. Participants' medical records are reviewed periodically.

Participants are followed annually.

• Colorectal Cancer
• Precancerous Condition

• Drug: Vitamin E
  400 IU daily by mouth for 7 - 12 years
  Other Name: alpha tocopherol
• Drug: Selenium
  200 mcg daily for 7 - 12 years
  Other Name: L-selenomethionine
• Drug: Vitamin E placebo
  1 pill by mouth daily for 7 - 12 years
  Other Name: placebo
• Drug: selenium placebo
  1 pill by mouth daily for 7 - 12 years
  Other Name: placebo

• Experimental: Vitamin E + selenium placebo
  Vitamin E and selenium placebo daily for 7 - 12 years
  Interventions:

  • Drug: Vitamin E
  • Drug: selenium placebo
• Experimental: Selenium + vitamin E placebo
  Selenium and vitamin E placebo daily for 7 - 12 years
  Interventions:

  • Drug: Selenium
  • Drug: Vitamin E placebo
• Experimental: Vitamin E + selenium
  Vitamin E and selenium daily for 7 - 12 years
  Interventions:

  • Drug: Vitamin E
  • Drug: Selenium
• Placebo Comparator: Vitamin E placebo + selenium placebo
  Vitamin E placebo and selenium placebo daily for 7 - 12 years
  Interventions:

  • Drug: Vitamin E placebo
  • Drug: selenium placebo

DISEASE CHARACTERISTICS:

• Enrolled on the Selenium and Vitamin E Cancer Prevention Trial (SELECT) SWOG-S0000
• Screened by lower endoscopy (i.e., sigmoidoscopy and/or colonoscopy) after randomization on SELECT trial

PATIENT CHARACTERISTICS:

• Willing to sign an applicable medical records release form
• Willing to allow the release of tissue for central pathology review of resected polyps and endoscopic biopsies

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics