Oestrogenic effects of adjuvant tamoxifen in postmenopausal breast cancer.
Oestrogenic influence of the non-steroidal anti-oestrogen tamoxifen may have consequences for the morbidity pattern among women on long-term adjuvant treatment. Subclinical oestrogenic effects of adjuvant tamoxifen on the tissue level was studied among 16 postmenopausal women in three different organ systems: the pituitary, the liver and bone. After 3 months of adjuvant tamoxifen prolactin levels decreased 66% (P < 0.001) in comparison with pretreatment levels. There was an 80% increase in basal growth hormone after 3 months of treatment in comparison with pretreatment levels, which did not reach statistical significance (P = 0.07). Sex hormone binding globulin levels increased 39% (P < 0.01) and IGF-1 (somatomedin C) levels decreased 20% (P < 0.05). The levels of bone GLA protein (BGP; osteocalcin), a marker of bone osteoblastic activity, decreased 28% (P < 0.01). In 13 of the patients bone mineral density (BMD) was measured before treatment and after 1 year. No significant change in BMD was observed. The results thus suggest a clear oestrogenic effect of tamoxifen on the pituitary, liver and bone in postmenopausal women.
Fornander
T
T
Radiumhemmet, Karolinska Hospital, Stockholm, Sweden.
Rutqvist
L E
LE
Wilking
N
N
Carlström
K
K
von Schoultz
B
B
D000368:Aged; D015519:Bone Density; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D004967:Estrogens / Q000627:therapeutic use; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D011388:Prolactin / Q000097:blood; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013629:Tamoxifen / Q000627:therapeutic use*
D004967:Estrogens; D012738:Sex Hormone-Binding Globulin; D013629:Tamoxifen; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I; D011388:Prolactin; D013006:Growth Hormone