This nested case-control study by Woolcott and colleagues extends the existing evidence of the association between sex hormones and breast cancer risk from mainly white study populations into a multiethnic cohort. The study confirms, for the first time, that high levels of sex hormones and low levels of sex hormone-binding globulin are associated with increased breast cancer risk in an ethnically diverse population. Woolcott
et al.,
Endocrine-Related Cancer.
DOI: 10.1677/ERC-09-0211