Abstract P1-12-03: The STAGE Study: A Phase III Comparison of Anastrozole Plus Goserelin with Tamoxifen Plus Goserelin as Pre-Operative Treatments in Premenopausal Breast Cancer Patients

Abstract

Background: Although superior antitumor activity of anastrozole over tamoxifen has been well established in postmenopausal breast cancer patients, it still remains to be examined whether or not anastrozole is superior to tamoxifen in premenopausal breast cancer patients whose ovarian function is suppressed by goserelin to postmenopausal levels. The aim of this study was to compare anastrozole plus goserelin versus tamoxifen plus goserelin as pre-operative treatment for premenopausal Japanese women with breast cancer. Methods: Phase III, randomized, double-blind, parallel-group, multi-center study (D539BC00001). Premenopausal patients (pts) with ER-positive and HER2-negative breast cancer and with operable and measurable lesions (T [2-5 cm], N0, M0) were randomized 1:1 to receive a goserelin 3.6 mg depot injection once monthly plus either anastrozole 1 mg (A+G) or tamoxifen 20 mg (T+G) p.o. once daily. Treatment continued for 24 weeks prior to surgery or until any other criterion for discontinuation was met. Concomitant chemotherapy was not permitted during the pre-operative period. The primary objective was to assess the best overall tumor response (either a complete response [CR] or a partial response [PR]), according to modified RECIST criteria. Tumor size was measured by caliper and ultrasound every 4 weeks and by magnetic resonance imaging/computed tomography (MRI/CT) every 12 weeks. Tolerability (adverse events [AEs], laboratory tests, vital signs, WHO performance status) was assessed as a secondary objective. AEs were evaluated according to CTCAE v3.0. Results: In total, 197 pts were randomized (A+G: 98, T+G: 99) and 185 pts completed the 24-week pre-operative treatment period and went on to receive breast surgery. The remaining 12 pts discontinued study treatment due to disease progression (A+G: 1; T+G: 5), voluntary discontinuation (A+G: 2; T+G: 3) and AE (T+G: 1). Pt demographics were generally well balanced. Median duration of exposure was similar for A+G (171 days) and T+G (170 days); treatment compliance was 99% for both. A+G led to a statistically significantly higher overall response rate compared with T+G, by caliper as well as by ultrasound and MRI/CT. The safety profiles were consistent with the known safety profile of anastrozole, tamoxifen and goserelin. The incidence of AEs was similar for A+G (88.8%) vs T+G (85.7%); most AEs were mild or moderate (CTC grade 1 or 2). The most common AEs were hot flash (A+G: 52.0%; T+G: 53.1%) and arthralgia (A+G: 35.7%; T+G: 20.4%). Conclusion: This study has demonstrated that the A+G combination has a superior benefit-risk profile compared with T+G as pre-operative treatment in Japanese premenopausal women with ER-positive breast cancer. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-12-03.

Neoadjuvant endocrine treatment of women with breast cancer

“…Recently, two studies have evaluated the efficacy of NHT in this subset of pts with promising results [58,59]. However, this strategy should not be used outside of clinical trials.…”

“…197 pts with operable and measurable lesions (2-5 cm) were included in the study. The best overall response which included clinical response and pathological response was significantly higher with the anastrozole arm [59].…”