title: Measurement of sex steroid hormones in breast adipocytes: methods and implications.
abstract: BACKGROUND
  The lack of validated methods for measuring sex steroid hormones in breast tissue has limited our knowledge of their role in the development of breast cancer. We explored the feasibility of measuring hormones in breast adipocytes for epidemiologic and clinical studies by refining an existing assay procedure and assessing the reliability of hormone measurements using the modified assay. This report presents the reproducibility of measurements of androstenedione (A), testosterone (T), estrone (E(1)), and estradiol (E(2)), using breast adipose tissue samples obtained from women undergoing surgical resection for a variety of pathologic conditions.
  
  
  METHODS
  Breast adipose tissues were obtained from 20 women. Measurements of the steroid hormones were carried out by harvesting oil from adipocytes following enzymatic digestion of the adipose tissue, extracting and chromatographing the steroids, and quantifying them by RIA. The study was conducted in three phases: first, samples from five women were used to assess the assay procedure; following this, tissues from an additional five women were assayed repeatedly to determine reproducibility of the hormone measurements. Finally, using samples from 10 women undergoing surgical resection of a breast tumor, we evaluated hormone concentrations in samples distal and proximal to the tumor. The assay coefficient of variation and intraclass correlation coefficient were used to assess hormone reproducibility.
  
  
  RESULTS
  The within-batch coefficients of variation ranged from 5% to 17%, and between-batch estimates were between 2% and 10%, suggesting that E(1), E(2), A, and T can be reliably measured in breast adipocytes. Among samples obtained from women undergoing surgical resection of a breast tumor, hormone levels did not differ between adipose tissue fragments that were distal or proximal to the tumor, with the possible exception of E(1) in which levels were 10% higher in distal fragments.
  
  
  CONCLUSIONS
  These data support the feasibility of measuring steroid hormone concentrations in breast adipocytes in epidemiologic studies. Future investigations that include the measurement of hormones in the breast microenvironment may have value in understanding breast carcinogenesis, developing prevention strategies, and assessing hormonal treatments.
authors: Division of Cancer Epidemiology and Genetics, Epidemiology and Biostatistics Program, Hormonal and Reproductive Epidemiology Branch, National Cancer Institute, 6120 Executive Boulevard S, Bethesda, MD 20892, USA. falkr@mail.nih.gov
authors: Roni T
authors: RT
authors: Falk
authors: Elisabet
authors: E
authors: Gentzschein
authors: Frank Z
authors: FZ
authors: Stanczyk
authors: Louise A
authors: LA
authors: Brinton
authors: Montserrat
authors: M
authors: Garcia-Closas
authors: Olga B
authors: OB
authors: Ioffe
authors: Mark E
authors: ME
authors: Sherman
mesh_terms: D017667:Adipocytes / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001940:Breast / Q000166:cytology / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism*; D005240:Feasibility Studies; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D011863:Radioimmunoassay; D015203:Reproducibility of Results
chemical_list: D012739:Gonadal Steroid Hormones