Improved breast cancer survival among hormone replacement therapy users is durable after 5 years of additional follow-up
Received 22 April 2008; received in revised form 3 June 2008
Abstract
Background
We previously reported that breast cancer patients who used hormone replacement therapy (HRT) had significantly lower stage tumors and higher survival than never-users. We present an update with longer follow-up, HRT use data, and in vitro research.
Methods
Our database of 292 postmenopausal breast cancer patients was updated to include HRT type, duration, and disease status. In vitro effects of estrogen (E) and/or medroxyprogesterone (MPA) on breast cancer cell growth were measured.
Results
Tumor prognostic factors were better and survival rates higher for both E and combination HRT users of any duration. Use greater than 10 years correlated with node-negative disease, mammographically detected tumors, and 100% survival. E supported minimal proliferation; MPA induced cell death; E+MPA results were similar to E alone.
Conclusions
HRT users, regardless of type or duration of HRT use, continued to have higher survival rates. In vitro results supported the clinical finding that outcomes for users of E and E+MPA were similar.
ABSTRACT