This page provides study documentation for BA21. 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
This application proposes a prospective nested case-control study of endogenous sex hormones and their associations with risk of incident colorectal cancer. Specifically, we will measure circulating levels of estradiol, estrone, progesterone and sex hormone binding globulin (SHBG) in 400 incident colorectal cancer cases and 800 controls (matched by time in the WHI-CT, age, race, and study arm), randomly selected from the non-treatment arms of the WHI-CT; i.e., those randomized to placebo in the E and E+P trials, or who opted to participate only in the dietary and calcium intervention trials. Each group of women met the eligibility criteria for the WHI-CT and were recruited in the same manner as those who received E+P. Multivariate conditional logistic regression will be used to assess the independent associations between each sex hormone and colorectal cancer, controlling for insulin, free IGF-I, CRP and other colorectal cancer risk factors. We note that this study was specifically designed to have adequate statistical power to assess the independent associations of each of the several somewhat correlated factors that will be measured.
See Publications: 1173. WHI publications by study lists published WHI papers that have been generated by ancillary studies. A complete list of WHI papers is available in the Bibliography section of this website.