Ian E. Smith1,2,3,4, Mitch Dowsett1,2,3,4, S R Ebbs1,2,3,4, Justin Stebbing1,2,3,4, Anthony Skene1,2,3,4, Jens‐Uwe Blohmer1,2,3,4, S. Ashley1,2,3,4, Stephen Francis1,2,3,4, Irene Boeddinghaus1,2,3,4, Geraldine Walsh1,2,3,4
1Breast Unit, Edinburgh; Royal Bournemouth Hospital, Bournemouth, United Kingdom;
2Department of Medicine, Royal Marsden Hospital, Fulham Road, London SW3 6JJ;
3From the Breast Unit, Royal Marsden Hospital, London and Sutton; Mayday University Hospital, Croydon; Edinburgh Breast Unit, Edinburgh; Royal Bournemouth Hospital, Bournemouth, United Kingdom; Universitaets Klinikum Charite, Berlin, Berlin, Germany; and Macclesfield, United Kingdom.
4Universitaets Klinikum Charite, Berlin, Berlin, Germany; and Macclesfield, United Kingdom.
Tóm tắt
Purpose The Immediate Preoperative Anastrozole, Tamoxifen, or Combined With Tamoxifen (IMPACT) trial was designed to test the hypothesis that the clinical and/or biologic effects of neoadjuvant tamoxifen compared with anastrozole and with the combination of tamoxifen and anastrozole before surgery in postmenopausal women with estrogen receptor (ER) –positive, invasive, nonmetastatic breast cancer might predict for outcome in the Arimidex, Tamoxifen Alone or in Combination (ATAC) adjuvant therapy trial. Patients and Methods Postmenopausal women with ER-positive, invasive, nonmetastatic, and operable or locally advanced potentially operable breast cancer were randomly assigned to neoadjuvant tamoxifen (20 mg daily), anastrozole (1 mg daily), or a combination of tamoxifen and anastrozole for 3 months. The tumor objective response (OR) was assessed by both caliper and ultrasound. Comparisons were also made of clinical response with ultrasound response, actual and feasible surgery with feasible surgery at baseline, OR in human epidermal growth factor receptor 2 (HER2) –positive cancers, and tolerability. Results There were no significant differences in OR in the intent-to-treat population between patients receiving tamoxifen, anastrozole, or the combination. In patients who were assessed as requiring mastectomy at baseline (n = 124), 44% of patients received breast-conserving surgery (BCS) after anastrozole compared with 31% of patients after tamoxifen (P = .23); this difference became significant for patients who were deemed feasible for BCS by their surgeon (46% v 22%, respectively; P = .03). The OR for patients with HER2-positive cancer (n = 34) was 58% for anastrozole compared with 22% for tamoxifen (P = .18). All treatments were well tolerated. Conclusion Neoadjuvant anastrozole is as effective and well tolerated as tamoxifen in ER-positive operable breast cancer in postmenopausal women, but the hypothesis that clinical outcome might predict for long-term outcome in adjuvant therapy was not fulfilled.
