This page provides study documentation for AS206. For description of the specimen results, see Specimen Results Description (open to public). Data sets of the specimen results are included in the existing WHI datasets located on the WHI Data on this site (sign in and a completed Data Distribution Agreement are required; see details on the Data site).
Investigator Names and Contact Information
Ulrike Peters, PhD, FHCRC
Colorectal cancer (CRC) is the third leading cause of cancer in US women with mortality of 50%. Identifying modifiable risk factors will be important for the prevention of this common and severe disease. Both epidemiological studies and animal studies support the beneficial effect of selenium on CRC prevention. Because selenium intake must be assessed in blood samples, most epidemiological studies are small and are therefore difficult to interpret. The effect of selenium is mediated though antioxidative properties of selenium-dependent enzymes. These selenoenzymes are abundantly expressed in the colon suggesting an important role as antioxidative defense in the colon, which is exposed to food-borne oxidants. We propose to investigate the association of a) prediagnostic selenium blood levels and b) genetic variations in selenoenzymes with CRC risk in a case-control study nested within the Women’s Health Initiative (WHI) observational study, including about 925 CRC cases and 1338 matched controls. The WHI cohort offers an excellent opportunity to study the effect of selenium and the genetic profile of selenoenzymes due to the sizable number of cases with prediagnostic blood and DNA samples and wide range of selenium intake. We will only use a small sample (0.08ml serum or plasma and 0.8μg DNA).