title: Colorectal Adenomas in Participants of the SELECT Randomized Trial of Selenium and Vitamin E for Prostate Cancer Prevention.
abstract: Selenium and vitamin E micronutrients have been advocated for the prevention of colorectal cancer. Colorectal adenoma occurrence was used as a surrogate for colorectal cancer in an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT) for prostate cancer prevention. The primary objective was to measure the effect of selenium (as selenomethionine) on colorectal adenomas occurrence, with the effect of vitamin E (as α-tocopherol) supplementation on colorectal adenoma occurrence considered as a secondary objective. Participants who underwent lower endoscopy while in SELECT were identified from a subgroup of the 35,533 men randomized in the trial. Adenoma occurrence was ascertained from the endoscopy and pathology reports for these procedures. Relative Risk (RR) estimates and 95% confidence intervals (CI) of adenoma occurrence were generated comparing those randomized to selenium versus placebo and to vitamin E versus placebo based on the full factorial design. Evaluable endoscopy information was obtained for 6,546 participants, of whom 2,286 had 1+ adenomas. Apart from 21 flexible sigmoidoscopies, all the procedures yielding adenomas were colonoscopies. Adenomas occurred in 34.2% and 35.7%, respectively, of participants whose intervention included or did not include selenium. Compared with placebo, the RR for adenoma occurrence in participants randomized to selenium was 0.96 (95% CI, 0.90-1.02; P = 0.194). Vitamin E did not affect adenoma occurrence compared with placebo (RR = 1.03; 95% CI, 0.96-1.10; P = 0.38). Neither selenium nor vitamin E supplementation can be recommended for colorectal adenoma prevention. Cancer Prev Res; 10(1); 45-54. ©2016 AACR.
authors: University of Arizona Cancer Center, Tucson, Arizona. plance@uacc.arizona.edu.
authors: Peter
authors: P
authors: Lance
authors: University of Arizona Cancer Center, Tucson, Arizona.
authors: David S
authors: DS
authors: Alberts
authors: University of Arizona Cancer Center, Tucson, Arizona.
authors: Patricia A
authors: PA
authors: Thompson
authors: University of Arizona Cancer Center, Tucson, Arizona.
authors: Liane
authors: L
authors: Fales
authors: University of Arizona Cancer Center, Tucson, Arizona.
authors: Fang
authors: F
authors: Wang
authors: University of Arizona Cancer Center, Tucson, Arizona.
authors: Jerilyn
authors: J
authors: San Jose
authors: University of Arizona Cancer Center, Tucson, Arizona.
authors: Elizabeth T
authors: ET
authors: Jacobs
authors: SWOG Statistical Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors: Phyllis J
authors: PJ
authors: Goodman
authors: SWOG Statistical Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors: Amy K
authors: AK
authors: Darke
authors: SWOG Statistical Center, Cancer Research and Biostatistics, Seattle, Washington.
authors: Monica
authors: M
authors: Yee
authors: Division of Cancer Prevention, NCI, Bethesda, Maryland.
authors: Lori
authors: L
authors: Minasian
authors: University of Texas Health Sciences Center, San Antonio, Texas.
authors: Ian M
authors: IM
authors: Thompson
authors: University of Arizona Cancer Center, Tucson, Arizona.
authors: Denise J
authors: DJ
authors: Roe
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D019587:Dietary Supplements; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D012307:Risk Factors; D012645:Selenomethionine / Q000008:administration & dosage*; D012812:Sigmoidoscopy; D024502:alpha-Tocopherol / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D012645:Selenomethionine; D024502:alpha-Tocopherol