10-Year Follow-up on Adjuvant Tamoxifen and Exemestane in Postmenopausal Early Breast Cancer

Key Points

  • In postmenopausal women with hormone receptor–positive early breast cancer, no difference in disease-free survival was observed with exemestane vs sequential tamoxifen/exemestane.
  • No difference in overall survival was observed.

The 10-year follow-up of the phase III TEAM trial has shown that exemestane alone and sequential tamoxifen/exemestane provide similar outcomes as adjuvant endocrine therapy in postmenopausal women with hormone receptor–positive early breast cancer. The findings were reported in The Lancet Oncology by Derks et al. A prior report at a median follow-up of 5 years showed no difference between exemestane vs sequential tamoxifen and exemestane in disease-free survival.

Study Details

In the open-label trial, patients were randomized to 5 years of exemestane at 25 mg once daily or tamoxifen at 20 mg once a day for 2.5 to 3.0 years followed by exemestane for a total of 5 years. Of the original 9,776 patients, 6,120 (3,075 in exemestane group, 3,045 in the sequential group) were included in the current intention-to-treat analysis of disease-free survival. All patients from Japan (n = 184), France (n = 1,230), and the United States (n = 2,232) were excluded from the current analysis due to absence of long-term data. Patients included in the analysis were from the Netherlands, Germany, UK, Ireland, Belgium, and Luxembourg.

Disease-Free Survival

Median follow-up was 9.8 years. Disease-free survival at 10 years was 67% (95% confidence interval = 65%–69%) in the exemestane group vs 67% (95% CI = 65%–69%) in the sequential group (hazard ratio [HR] = 0.96, P = .39). Ten-year overall survival was 74% vs 73% (HR = 0.98, P = .74). The cumulative incidence of breast cancer recurrence was 20% vs 22% (subdistribution HR = 0.88, P = .03). The cumulative incidence of distant recurrence was 16% vs 18% (subdistribution HR = 0.91, P = .15).

The investigators concluded: “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 hormone receptor-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.”

The study was funded by the Dutch Cancer Foundation and Pfizer.

Cornelis J.H. van de Velde, MD, of Leiden University Medical Center, is the corresponding author of The Lancet Oncology article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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