Endocrine Abstracts

Fulvestrant (faslodex) is currently the only available new pure antioestrogen. It has a long side chain in the 7 alpha position which impedes receptor dimerisation and function and results in increased turnover and reduced numbers of receptor molecules. Faslodex is active against tamoxifen resistant human tumour cells both in vitro[1] and in the clinic[2]. Given for 2-3 weeks preoperative Faslodex causes downregulation of both oestrogen and progesterone receptors[3].Faslodex was compared with anastrozole as second line treatment for advanced breast cancer in two trials and each showed the two drugs to be equivalent [4,5]. In a first line advanced disease trial, Faslodex was equivalent to tamoxifen in receptor positive tumours [6].Faslodex is active in patients who progress on tamoxifen and aromatase inhibitors and both groups of agents are active after Faslodex failure[7].Thus, Faslodex is an active and additional treatment for advanced breast cancer.Current studies are directed towards establishing its place in endocrine sequences and are focusing on comparisons with exemestane as second line therapy and whether it is more active when combined with AIs (SOFEA trial).

References:

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2. Howell A et al,Lancet 345:29,1995

3. DeFriend D et al, Ca Res 54:408,1994

4. Howell A et al,JCO 20:3396,2002

5. Osborne K et al,JCO 20: 3386,2002

6. Howell A et al,JCO 22: 1524,2004

7. Vergote I et al,BrCaResTr 79:207,2003