[The antiestrogen tamoxifen in advanced breast cancer (author's transl)]

Abstract

The antiestrogenic agent tamoxifen was evaluated in 17 pre- and 103 postmenopausal women with recurrent or metastatic breast cancer at two dose levels (2 and 3 x 10 mg daily). Dose-related differences in the results were not observed. Altogether 49.2% of these patients responded to therapy (10% complete remissions, 9.2% partial remissions, 30% no change). While a response rate of 52.5% was found in the postmenopausal group, the rate was markedly worse in premenopausal women (29.4%). In postmenopausal patients there was a poorer remission rate in older women. Regarding the dominant site of lesions, the best results were achieved in patients with lung and pleural metastases, followed by soft tissue metastases. Patients with a disease-free interval of more than 100 months responded better to therapy than those with a shorter interval. Long-term results were much more favorable in patients who primarily responded to tamoxifen than in nonresponders. As the most valuable prognostic criterion, the hormone receptors were assayed. 75% of the estrogen receptor (ER) and progesterone receptor (PgR) positive and 55,6% of the ER-positive and PgR-negative patients derived benefit from this treatment in contrast to only 19% of the ER- and PgR-negative women. Plasma levels of estradiol, progesterone, testosterone, and FSH were not changed by tamoxifen, but average cortisol and prolactin concentrations were altered significantly. A short-time increase of the prolactin level 2 weeks after onset of tamoxifen treatment and a decrease thereafter also seem to be good prognostic signs. Side effects were few and did not occur more severely or frequently in the higher dose group.