The Importance of Local Synthesis of Estrogen Within the Breast

Steroids. Oct-Dec 1987;50(4-6):537-48. doi: 10.1016/0039-128x(87)90037-7.


Tumor aromatase has been correlated with clinical response to treatment with aminoglutethimide in patients with estrogen receptor-positive advanced breast cancer. There was a significant positive relationship between aromatase status and likelihood of response to therapy, none of five patients with aromatase-negative tumors responding compared with 11 of 18 having aromatase-positive cancers. Measurement of in vitro aromatase in sequential biopsies of large primary tumors before and during treatment with aminoglutethimide-hydrocortisone showed a marked but paradoxical rise in activity following therapy. Assays of aromatase in adipose tissue from the different quadrants of mastectomy specimens from patients with breast cancer indicate that activity was always higher in quadrants associated with tumor as compared with non-involved quadrants. These results emphasize the importance of local estrogen synthesis within the breast in terms of both the natural history and behavior of breast cancers.

MeSH terms

  • Adipose Tissue / enzymology
  • Aminoglutethimide / administration & dosage
  • Aminoglutethimide / therapeutic use
  • Breast / drug effects
  • Breast / metabolism*
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / enzymology
  • Estrogens / biosynthesis*
  • Female
  • Humans
  • Hydrocortisone / administration & dosage
  • Hydrocortisone / therapeutic use
  • Menopause / metabolism


  • Estrogens
  • Aminoglutethimide
  • Hydrocortisone