B26
A randomised, phase III trial exploring the effects of neoadjuvant sequential aromatase inhibitor treatment in post-menopausal women locally advanced breast cancer (LABC)
Orit Freedman1, Eitan Amir1, George Dranitsaris1, Mitchell Dowsett2, David Cole3, Harriette Kahn4, Frances O'Malley5, Sunil Verma4, Mark Clemons1
1Princess Margaret Hospital, Toronto, Canada, 2Royal Marsden Hospital, London, UK, 3Women's College Hospital, Toronto, Canada, 4Odette Cancer Centre, Toronto, Canada, 5Mount Sinai Hospital, Toronto, Canada
Background
Despite many large randomised trials assessing adjuvant endocrine treatment for postmenopausal breast cancer patients, optimal endocrine strategy remains unknown. Neoadjuvant endocrine studies provide the opportunity to model appropriate study design in a more expeditious manner. Several large adjuvant trials are exploring sequential aromatase inhibitor (AI) strategies. This study compared the effect of two sequences of AI use [steroidal (exemestane, E) and non-steroidal (anastrozole, A)] on serological and pathological biomarkers, when given in the neoadjuvant setting to patients with LABC.
Method
30 postmenopasual women with estrogen and/or progesterone receptor positive disease were randomised to receive either E followed by A (EA group) or A followed by E (AE group). Each agent was given for 8 weeks. Serum estrone sulphate, and estradiol levels, as well as intra-tumoural Ki67 were evaluated at baseline, 8 weeks, and 16 weeks. Clinical response, patient preference, & quality of life were also assessed.
Results
Despite rapid falls in sex steroid levels with AI use, there was no difference in estradiol, estrone sulphate or Ki67 levels between groups. There was no significant difference in toxicities, or in quality of life scores. Overall clinical response rate was 68% & clinical benefit was 93%. There was a trend towards improved clinical response in the AE group. The majority of patients expressed a preference of treatment.
Conclusion
Neither sequence of steroidal or non-steroidal AI appears to offer a significant advantage over the other. A trend towards improved clinical response in patients treated with AE is hypothesis generating and needs confirmation in larger trials.
