title: Tamoxifen and megestrol acetate for postmenopausal breast cancer: diverging effects on liver proteins, androgens, and glucocorticoids.
abstract: OBJECTIVE
  To compare the effects of tamoxifen and megestrol acetate on liver proteins, androgens, and glucocorticoids during adjuvant treatment for postmenopausal breast cancer.
  
  
  METHODS
  A subgroup of women within a large prospective multicenter trial were followed with blood sampling every 3 mo during 2 yr. Women were randomized to receive either continuous tamoxifen 40 mg/d or repeated sequential treatment with tamoxifen and megestrol acetate (MA) 160 mg/d.
  
  
  RESULTS
  We found profound and distinct differences between the two regimens. Tamoxifen increased steroid-binding proteins (SHBG and CBG) and suppressed circulating androgens and IGF-I. In contrast, the metabolic effects of tamoxifen were clearly antagonized by MA. There was a rise in IGF-I and marked suppression of steroid-binding proteins. Levels of free testosterone were reduced by 70%. MA also caused apparent adrenal suppression.
  
  
  CONCLUSIONS
  The different effects on anabolic/catabolic balance and adrenal function may relate to certain clinical effects during treatment.
authors.affiliation: Department of Surgery, St Görans Hospital, SE-112 81 Stockholm, Sweden. lars.lofgren@stgoran.se
authors.forename: L
authors.initials: L
authors.lastname: Löfgren
authors.forename: B
authors.initials: B
authors.lastname: Wallberg
authors.forename: N
authors.initials: N
authors.lastname: Wilking
authors.forename: T
authors.initials: T
authors.lastname: Fornander
authors.forename: L E
authors.initials: LE
authors.lastname: Rutqvist
authors.forename: K
authors.initials: K
authors.lastname: Carlström
authors.forename: B
authors.initials: B
authors.lastname: von Schoultz
authors.forename: E
authors.initials: E
authors.lastname: von Schoultz
mesh_terms: D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D019290:Megestrol Acetate / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D017698:Postmenopause; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013629:Tamoxifen / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D013739:Testosterone / Q000097:blood
chemical_list: D018931:Antineoplastic Agents, Hormonal; D012738:Sex Hormone-Binding Globulin; D013629:Tamoxifen; D013739:Testosterone; D007334:Insulin-Like Growth Factor I; D019290:Megestrol Acetate