The effect of endocrine therapy with medroxyprogesterone acetate, 4-hydroxyandrostenedione or tamoxifen on plasma concentrations of insulin-like growth factor (IGF)-I, IGF-II and IGFBP-1 in women with advanced breast cancer.
Tamoxifen treatment of women with advanced breast cancer has previously been reported to reduce plasma insulin-like growth factor-type I (IGF-I) concentrations. In this study we have examined the effect of treatment with Tamoxifen, medroxyprogesterone acetate (MPA) or 4-hydroxyandrostenedione (4-OHA) on plasma IGF-I and IGF-II concentrations. As IGF-binding proteins (IGFBPs) can modulate the biological effects of IGF-I, plasma IGFBP-I levels were also measured. Treatment with Tamoxifen for 2 weeks resulted in a small, but significant, decrease in IGF-I levels, but increase in the plasma concentration of IGFBP-I. In contrast, treatment with MPA increased levels of IGF-I, but significantly reduced plasma IGFBP-I concentrations. Treatment with 4-OHA had no significant overall effect on plasma IGF-I or IGFBP-I levels, although changes were detected for some subjects. Plasma IGF-II concentrations were not altered by treatment with Tamoxifen, MPA or 4-OHA. It is concluded that although treatment with Tamoxifen or MPA produced significant changes in plasma IGF-I concentrations, any physiological effects of such changes are likely to be modulated by the corresponding alterations in plasma IGFBP-I concentrations.
Reed
M J
MJ
Unit of Metabolic Medicine, St. Mary's Hospital Medical School, London, UK.
Christodoulides
A
A
Koistinen
R
R
Seppälä
M
M
Teale
J D
JD
Ghilchik
M W
MW
D000368:Aged; D000735:Androstenedione / Q000031:analogs & derivatives* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D002352:Carrier Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D008525:Medroxyprogesterone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D017258:Medroxyprogesterone Acetate; D009376:Neoplasms, Hormone-Dependent / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D013629:Tamoxifen / Q000627:therapeutic use*
D002352:Carrier Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D013629:Tamoxifen; D000735:Androstenedione; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D017258:Medroxyprogesterone Acetate; D008525:Medroxyprogesterone; C014594:formestane