Breast cancer clinical trials with Faslodex — A new class of antioestrogen

Abstract

of oral GLA/day (total = 2.8 gmsj in addition to primary tamoxifen. Clinical response (by UICC criteria) was tampared with a matched control group on tamoxifen (T) alone (n = 47). Serial tumour core-cut biopsies were taken for immunohistochemical assessment of changes in oestrogen receptor (ER) expression during treatment. Results: The T + GLA cases achieved significantly faster clinical response (objective response OR vs. static disease SD) than tamoxifen alone, evident as early as 6 weeks on treatment (p = 0.010). T + GLA cases with larger fall in ER at 6 week biopsy had significantly better early response than tamoxifen cases displaying similar degree of ER fall (OR vs. SD 6 wks p = 0.026; 3 mths p = 0.016). These findings suggest that GLA may enhance the therapeutic effects of tamoxifen-induced ER down-regulation to produce a superior clinical response. Conclusion: Our results propose GLA as a useful adjunct to primary tamoxifen in endocrine sensitive breast cancer, mechanism of action which may involve modulation of ER. Continued follow-up will determine whether this faster initial response will translate into longer ultimate duration of control.