NATURAL INTERFERON-BETA AND TAMOXIFEN IN HORMONE-RESISTANT PATIENTS WITH ADVANCED BREAST-CANCER

Tamoxifen (T) is the mainstay of hormonal treatment and is able to giv e high response rates in selected post-menopausal women with advanced breast cancer (ABC). nevertheless, even in responders, invariably resi stance to hormones is developed. In a previous paper we reported that in a subset of patients (pts) with metastatic breast cancer the resist ance to the antiestrogen could be overcome by pretreatment with natura l interferon-beta(nIFN-beta) followed by the association of nIFN-beta and T. In the present study we adopted a treatment schedule employing nIFN-beta (3x10(6) IU/ day im three times a week) and T (60 mg/day) co ncurrently in 30 pts with ABC progressive to previous treatment with T (30 mg/day). We obtained a 13% response rate with a median duration o f response of 8 months (range 4-16 m). All the responses occurred in p ts whose disease progressed after an initial response to T. Stabilisat ion of disease was observed in 37%. Toxicity was mild. In our opinion the use of the combination T plus nIFN-beta in the treatment of breast cancer remains investigational and the optimal scheduling still undet ermined.