title: Pathologic and biological prognostic factors of breast cancers in short- and long-term hormone replacement therapy users.
abstract: BACKGROUND
  Breast cancer tumors occurring in hormone replacement therapy (HRT) users are less aggressive, but no studies have compared tumor aggressiveness among HRT users by length and mode of therapy.
  
  
  METHODS
  A total of 1105 consecutive postmenopausal patients treated for operable breast cancer at the European Institute of Oncology were identified. Women exposed to HRT were compared with HRT nonusers by clinical stage at presentation and pathologic and biological tumor characteristics. HRT duration and administration modality were analyzed in relation to tumor characteristics in the HRT group.
  
  
  RESULTS
  Better stage distribution, including smaller pathologic tumor diameter and fewer involved axillary lymph nodes, was seen in the HRT group. Estrogen receptor-positive tumors were more frequent in the control group, but this tendency was reversed with longer exposure to HRT. Histological grade III tumors were less frequent in the HRT group. More favorable prognostic factors were associated with HRT >5 years. The proliferative fraction was higher in patients with exposure <1 vs. >5 years and in oral versus transdermal users.
  
  
  CONCLUSIONS
  Breast cancers developing during HRT have better prognostic characteristics than those seen in HRT nonusers. A trend toward better prognostic characteristics with increasing duration of HRT was seen.
authors.affiliation: Breast Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA. sacchinv@mskcc.org
authors.forename: Virgilio
authors.initials: V
authors.lastname: Sacchini
authors.forename: Stefano
authors.initials: S
authors.lastname: Zurrida
authors.forename: Gisella
authors.initials: G
authors.lastname: Andreoni
authors.forename: Alberto
authors.initials: A
authors.lastname: Luini
authors.forename: Viviana
authors.initials: V
authors.lastname: Galimberti
authors.forename: Paolo
authors.initials: P
authors.lastname: Veronesi
authors.forename: Mattia
authors.initials: M
authors.lastname: Intra
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Viale
authors.forename: Umberto
authors.initials: U
authors.lastname: Veronesi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000378:metabolism / Q000473:pathology*; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D016015:Logistic Models; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D011960:Receptors, Estrogen / Q000378:metabolism; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen