Long-Term Data from the TEAM Trial Support Individualized Adjuvant Endocrine Therapy Strategy for Postmenopausal Women with HR-Positive Early Breast Cancer

The Tamoxifen Exemestane Adjuvant Multinational (TEAM) clinical trial was a multicenter, open-label, randomized, controlled phase 3 trial that enrolled postmenopausal women with early-stage HR-positive breast cancer from 9 countries.^1,2 Patients in this trial were randomized in a 1:1 ratio to either 5 years of exemestane at 25 mg once daily (N = 4904) or tamoxifen at 20 mg once daily for 2.5 to 3.0 years followed by exemestane 25 mg once daily (N = 4875) for a total of 5 years. Patients had completed local treatment with curative intent, and endocrine therapy was started within 10 weeks after surgery and the end of chemotherapy, if indicated. After a median follow-up of 5 years, there were no significant differences in disease-free survival (DFS), overall survival (OS), or relapse-free survival between the 2 groups of patients.^1,2

The extension trial included results from 10 years of follow-up on 3045 patients in the intent-to-treat (ITT) analysis for sequential therapy (tamoxifen/exemestane) and 3075 patients in the ITT analysis for exemestane alone.¹ The 10-year DFS was not significantly different between the 2 groups (67% in each arm; P = .39). In addition, the 10-year OS was not significantly different between the groups: 74% with exemestane and 73% with sequential therapy (P = .74). The researchers also reported no difference in the cumulative incidence of distant recurrent disease between the groups (16% with exemestane vs 18% with sequential therapy; P = .15). A small benefit was reported for exemestane monotherapy with regard to cumulative incidence of any breast cancer recurrence—20% recurrence with exemestane versus 22% with sequential therapy.¹

The researchers concluded that, “The long-term findings of the TEAM trial confirm that both exemestane alone and sequential treatment with tamoxifen followed by exemestane are reasonable options as adjuvant endocrine therapy in postmenopausal patients with HR-positive early breast cancer. These results suggest that the opportunity to individualise adjuvant endocrine strategy accordingly, based on patient preferences, comorbidities, and tolerability, might be possible.”

References
1. Derks MGM, Blok EJ, Seynaeve C, et al. Adjuvant tamoxifen and exemestane in women with postmenopausal early breast cancer (TEAM): 10-year follow-up of a multicentre, open-label, randomised, phase 3 trial. Lancet Oncol. 2017;18:1211-1220.
2. van de Velde CJ, Rea D, Seynaeve C, et al. Adjuvant tamoxifen and exemestane in early breast cancer (TEAM): a randomised phase 3 trial. Lancet. 2011;377:321-331.