SEQUENCE-THERAPY AND INTERVAL THERAPY IN METASTATIC BREAST-CANCER WITH TAMOXIFEN AND MPA

In a prospective randomized study at the Department of Obstetrics and Gynaecology, University of Erlangen-Nuremberg, 86 patients with metastatic breast cancer and positive or unknown steroid hormone receptor status were refered to different hormone therapy schemes. One group of patients (N = 44) received a sequence therapy with 30 mg of Tamoxifen daily. In case fo relaps after original response the therapy was changed to MPA. The second group of patients (N = 42) received 30 mg/die Tamoxifen for 4 weeks. After a wash out period of 4 weeks, during which the patients had no medication, a therapy with 1000 mg/die MPA followed. After a therapeutic pause of one week the scheme was started again. Both therapy schemes showed no significant difference concerning the response rate (86 % in the sequence therapy - and 79 % in the interval therapy group). With regard to the response rate the interval therapy compared with the sequence therapy showed an advantage with respect to the lower absolute dosage used in these patients. Concerning the response duration the sequence therapy was significantly superior to the interval therapy (32 versus 21 months response duration). Particularly remarkable is the difference in patients with complete remission, which had a median response duration of 47 months in the sequence therapy group compared with only 24 months in the interval therapy group. It should be noticed, that sequence therapy patients suffered further recurrence before the therapeutic change from Tamoxifen to MPA. In contrast to this the response duration of the interval therapy refers to a single hormone therapy with Tamoxifen and MPA alternately, without a change of therapy due to a recurrence. Side-effects were minimal in both therapeutic schemes. Inspite of similar response rates the sequence therapy with its longer response duration seems to be superior ot the interval therapy, also with respect to the easier intake mode.