Goserelin (Zoladex) in premenopausal advanced breast cancer: duration of response and survival

Abstract

In premenopausal women with advanced breast cancer the luteinising hormone-releasing hormone agonist goserelin (Zoladex, ICI plc) will produce serum levels of oestradiol equivalent to those following surgical oophorectomy or the menopause. This paper reports our further experience of using this drug in 75 premenopausal patients with advanced breast cancer. In addition to response rates, duration of response is reported. An objective response was seen in 25 patients (33%), the median duration of which was in excess of 15 months. Seven patients (9%) showed a complete response to therapy; median duration greater than 37 months. There was no significant difference in time to disease progression (Lee-Desu statistic 18.26, 1 d.f., P = 0.43) and probability of survival (Lee-Desu statistic 3.41, 1 d.f., P = 0.07) between those patients assessed as having either static disease, or those showing a partial response at six months. Response to therapy correlates significantly with the oestrogen receptor status of the primary tumour (X2 = 20.59, 6 d.f., P less than 0.005). The modest side-effects, ease of administration and reversibility make this approach to therapy very attractive. This is to be remembered in that 53% of patients had disease progression whilst receiving goserelin. These patients thus avoided the unnecessary and irreversible morbidity associated with surgical oophorectomy. With the proven efficacy and minimal morbidity associated with goserelin we believe there is no current role for surgical oophorectomy in the management of premenopausal patients with advanced breast cancer.