title: Improved breast cancer survival among hormone replacement therapy users is durable after 5 years of additional follow-up.
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.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Portland, OR, USA.
authors.forename: Dara
authors.initials: D
authors.lastname: Christante
authors.forename: SuEllen
authors.initials: S
authors.lastname: Pommier
authors.forename: Jennifer
authors.initials: J
authors.lastname: Garreau
authors.forename: Patrick
authors.initials: P
authors.lastname: Muller
authors.forename: Brett
authors.initials: B
authors.lastname: LaFleur
authors.forename: Rodney
authors.initials: R
authors.lastname: Pommier
mesh_terms: D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D004305:Dose-Response Relationship, Drug; D015914:Estrogen Replacement Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D017698:Postmenopause; D011379:Prognosis; D016016:Proportional Hazards Models; D018709:Statistics, Nonparametric; D015996:Survival Rate