title: Pre-operative oestradiol levels - relation to survival in breast cancer.
abstract: OBJECTIVE
  There are clinical observations that operation during the luteal phase of the menstrual cycle (with high oestradiol levels) may positively influence prognosis in breast cancer. However, few studies have information on plasma levels of hormones pre-operatively.
  
  
  METHODS
  We studied 774 women treated for breast cancer where plasma levels of oestradiol had been measured 1-2 days pre-operatively. Date and cause of death were ascertained from the files of the Swedish Cancer Register and 5434 person-years were observed. The endpoint was death with breast cancer as the underlying cause (n=41 and n=158 in the pre- and post-menopausal group, respectively).
  
  
  RESULTS
  In life-table analyses, only pre-menopausal patients with oestradiol 500 pmol/l and above had a tendency (not statistically significant) for better survival. Multivariate Cox models with oestradiol modelled in continuous form yielded relative hazards (RH) close to unity in all women and in strata according to menopausal status.
  
  
  CONCLUSIONS
  When oestradiol was analysed in categorized form, only women with the highest levels had a tendency for improved prognosis (RH around 0.7; not statistically significant). Moreover, this pattern was not apparent for pre-menopausal women. Our findings contradict the notion that the pre-operative oestradiol level is independently associated with breast cancer prognosis.
authors: Department of Surgery, University Hospital, Uppsala, MA, S-751 85, Sweden. lars.holmberg@roc.lul.se
authors: L
authors: L
authors: Holmberg
authors: T
authors: T
authors: Nordén
authors: A
authors: A
authors: Lindgren
authors: L
authors: L
authors: Wide
authors: M
authors: M
authors: Degerman
authors: H O
authors: HO
authors: Adami
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000097:blood* / Q000401:mortality*; D015331:Cohort Studies; D004958:Estradiol / Q000097:blood*; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D011300:Preoperative Care; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis
chemical_list: D004958:Estradiol