A randomized trial exploring the biomarker effects of neoadjuvant sequential
treatment with exemestane and anastrozole in post-menopausal women with hormone
receptor-positive breast cancer.
Author(s): Freedman OC, Amir E, Hanna W, Kahn H, O'Malley F, Dranitsaris G, Cole DE, Verma
S, Folkerd E, Dowsett M, Clemons M.
Affiliation(s): Department of Medicine, University of Toronto, Division of Medical Oncology,
Princess Margaret Hospital, Toronto, Canada. orit.freedman@utoronto.ca
Publication date & source: 2010, Breast Cancer Res Treat. , 119(1):155-61
Several adjuvant endocrine strategies exist for postmenopausal women with breast
cancer. This study compared the effect of two sequences of aromatase inhibitor
use [steroidal (exemestane) and non-steroidal (anastrozole)] on serological and
pathological biomarkers when given in the neoadjuvant setting to postmenopausal
women with breast cancer. Thirty women were assigned to receive exemestane 25 mg
or anastrozole 1 mg each given for 8 weeks in a randomized sequence. The effect
of this treatment on serum estrone sulfate and estradiol levels, as well as tumor
changes in the proliferation biomarker Ki67 were evaluated at baseline, 8 weeks
and 16 weeks. WHO clinical response criteria, patient preference, and quality of
life were also assessed. Assessable data was available from 28 patients. There
were no differences in concentration changes of serum estradiol or Ki67 between
patients in the two arms. Overall clinical response rate was 68% (19/28
assessable patients) and clinical benefit was 93% (26/28 assessable patients).
There was no significant difference in toxicity or quality of life scores. The
majority of patients expressed a personal preference for anastrozole over
exemestane. Results suggest that the order of steroidal and non-steroidal
aromatase inhibitors has little effect on outcome. The majority of patients
express clear preferences for drug treatments.
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