Contribution of prednisolone to the primary endocrine treatment of advanced breast cancer.

Two hundred and four patients with progressive locally advanced or metastatic breast cancer not controllable by local therapy alone, and who had had no prior systemic therapy for advanced disease, were treated by primary endocrine therapy according to menopausal status. Premenopausal patients received ovarian irradiation (O) whilst postmenopausal patients received tamoxifen 10 mg b.d. (T). Patients were randomised to receive either no additional treatment or prednisolone 5 mg b.d. (P). In 180 evaluable patients, T + P induced significantly more responses than T alone (26/73 vs 9/72, P less than 0.01) and the addition of P to O in premenopausal patients also induced more responses than O alone (7/16 vs 4/19), but this difference was not significant and accrual of premenopausal patients continues. There was a trend for patients receiving T + P to have a longer survival than those receiving T alone (median 25 vs 16 months). These trends occurred in patients with tumours positive for oestrogen receptors and when receptor status was unknown; patients with receptor-negative tumours had a negligible response to endocrine treatment. P mitigated the occurrence of hypercalcaemia and tumour flare sometimes seen with T alone.