Final outcomes of the SOFT and TEXT phase III trials in premenopausal hormone receptor-positive early breast cancer
- Author(s)
- Francis, PA; Pagani, O; Fleming, GF; Walley, BA; Colleoni, M; Rubovszky, G; Tondini, C; Ciruelos, EM; Gomez, HL; Bonnefoi, HR; Burstein, HJ; Chini, C; Puglisi, F; Spazzapan, S; Bernardo, A; Climent, MA; Bellet, M; Ruhstaller, T; Bermejo, B; Chia, SKL; Martino, S; Geyer, CE, Jr; Goetz, MP; Ingle, JN; Stearns, V; Davidson, NE; Le Du, F; Müller, B; Coleman, RE; Loibl, S; Winer, EP; Ruepp, B; Loi, S; Láng, I; Coates, AS; Gelber, RD; Goldhirsch, A; Regan, MM; International Breast Cancer Study Group; SOFT and TEXT Investigators;
- Journal Title
- Annals of Oncology
- Publication Type
- Online publication before print
- Abstract
- BACKGROUND: The SOFT trial found adding ovarian function suppression (OFS) to tamoxifen (T) reduced breast cancer recurrence, and exemestane (E)+OFS further reduced recurrence. SOFT and TEXT combined analysis showed a significant reduction in distant recurrence with E+OFS versus T+OFS. We now report final 15-year outcomes. PATIENTS AND METHODS: Premenopausal women with hormone receptor-positive early breast cancer were enrolled, with 3047 in SOFT and 2660 in TEXT intention-to-treat populations. SOFT randomized to 5 years of T versus T+OFS versus E+OFS. TEXT randomized to 5 years of T+OFS versus E+OFS. Chemotherapy was optional, prior to SOFT entry with subsequent premenopausal oestradiol, or concurrent with OFS in TEXT. Endpoints included disease-free survival, breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI) and overall survival. 15-year Kaplan-Meier estimates, hazard ratios (HR) and 95% confidence intervals (CI) are reported. RESULTS: In SOFT, escalating endocrine therapy (ET) continued to reduce recurrence with 15-year BCFI 78.6% for E+OFS, 75.7% for T+OFS and 72.1% for T; T+OFS versus T, HR 0.82 (CI 0.69-0.98) P=0.03. In the SOFT no-chemotherapy cohort, OFS reduced breast cancer events at 15 years, while DRFI and overall survival remained high regardless of ET assignment. After prior chemotherapy for HER2-negative tumours (n=1257), SOFT 15-year overall survival was 81.0% with E+OFS versus 77.1% with T+OFS versus 76.8% with T. In women under age 35 with HER2-negative tumours (n=241), 15-year overall survival was 82.5% with E+OFS, 77.9% with T+OFS and 68.1% with T. In combined SOFT and TEXT analysis, among those with HER2-negative tumours (n=4035), E+OFS versus T+OFS reduced distant recurrence HR 0.75 (CI 0.63-0.90), with a smaller reduction in deaths HR 0.89 (CI 0.74-1.06), with absolute survival benefits largest with high-risk features, particularly young age or high-grade tumours. CONCLUSION: Meaningful overall survival benefit in hormone receptor-positive, HER2-negative breast cancer from adjuvant exemestane and/or OFS compared with tamoxifen alone is limited to high-risk premenopausal subgroups. Tamoxifen-based ET may not result in optimal outcomes in premenopausal high-grade HER2-negative tumours.
- Keywords
- endocrine therapy; ovarian function suppression; premenopausal breast cancer
- Department(s)
- Medical Oncology
- Publisher's Version
- https://doi.org/10.1016/j.annonc.2026.05.704
- Open Access at Publisher's Site
https://doi.org/10.1016/j.annonc.2026.05.704- Terms of Use/Rights Notice
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Creation Date: 2026-06-23 03:42:05
Last Modified: 2026-06-23 03:42:14