Our genes and the way in which our genetic code is read makes us who we are. Unfortunately, our genetic code can be altered or misinterpreted in cancer. The 3’ untranslated region is one such example of an important part of our genetic code that is read differently in cancer. This thesis focused on defining what changes to the 3’ untranslated region occur in breast cancer, then explored which of these changes were most associated with breast cancer outcome. Extension and validation of the work in this thesis may one day lead to a better test for breast cancer outcome.