Medroxyprogesterone acetate and prednisone in advanced breast cancer. A randomized trial

In a randomised trial patients with progressive metastatic breast cancer were allocated to one of three different treatments. A: Prednisone 10 mg X 3 daily. B: Medroxyprogesterone acetate (MPA) orally 500 mg daily. C: MPA i.m. 1000 mg daily for 3 weeks followed by 500 mg i.m. weekly. The study included 150 patients and was well-balanced with respect to different prognostic parameters. Most patients (83%) were postmenopausal, and 95% had previously received chemo- or hormonal therapy. In the MPA treated patients, analysis of serum MPA levels was performed once a month. The response rates were 4.6, 7.9 and 12.5% in treatments A, B and C, respectively. This difference was not statistically significant (P greater than 0.05). Furthermore, the follow-up of serum MPA levels revealed no significant difference between responders and non-responders. Analysis of time to progression did not indicate any advantage of MPA over prednisone, irrespective of MPA schedule. In accordance with these data, there was no difference as regards survival in the three groups. In conclusion, the study indicated that MPA is not superior to prednisone in this group of heavily pretreated patients with advanced breast cancer.