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Clinical Trial
. 2018 Apr;168(2):413-420.
doi: 10.1007/s10549-017-4601-1. Epub 2017 Dec 12.

Relevant factors for the optimal duration of extended endocrine therapy in early breast cancer

Erik J Blok  1   2 , Judith R Kroep  2 , Elma Meershoek-Klein Kranenbarg  1 , Marjolijn Duijm-de Carpentier  1 , Hein Putter  3 , Gerrit-Jan Liefers  1 , Johan W R Nortier  2 , Emiel J Th Rutgers  4 , Caroline M Seynaeve  5 , Cornelis J H van de Velde  6 ; IDEAL Study Group
Affiliations
Clinical Trial

Relevant factors for the optimal duration of extended endocrine therapy in early breast cancer

Erik J Blok et al. Breast Cancer Res Treat. 2018 Apr.

Abstract

Purpose: For postmenopausal patients with hormone receptor-positive early breast cancer, the optimal subgroup and duration of extended endocrine therapy is not clear yet. The aim of this study using the IDEAL patient cohort was to identify a subgroup for which longer (5 years) extended therapy is beneficial over shorter (2.5 years) extended endocrine therapy.

Methods: In the IDEAL trial, 1824 patients who completed 5 years of adjuvant endocrine therapy (either 5 years of tamoxifen (12%), 5 years of an AI (29%), or a sequential strategy of both (59%)) were randomized between either 2.5 or 5 years of extended letrozole. For each prior therapy subgroup, the value of longer therapy was assessed for both node-negative and node-positive patients using Kaplan Meier and Cox regression survival analyses.

Results: In node-positive patients, there was a significant benefit of 5 years (over 2.5 years) of extended therapy (disease-free survival (DFS) HR 0.67, p = 0.03, 95% CI 0.47-0.96). This effect was only observed in patients who were treated initially with a sequential scheme (DFS HR 0.60, p = 0.03, 95% CI 0.38-0.95). In all other subgroups, there was no significant benefit of longer extended therapy. Similar results were found in patients who were randomized for their initial adjuvant therapy in the TEAM trial (DFS HR 0.37, p = 0.07, 95% CI 0.13-1.06), although this additional analysis was underpowered for definite conclusions.

Conclusions: This study suggests that node-positive patients could benefit from longer extended endocrine therapy, although this effect appears isolated to patients treated with sequential endocrine therapy during the first 5 years and needs validation and long-term follow-up.

Keywords: Adjuvant; Extended; IDEAL; Letrozole; Postmenopausal; Subgroup.

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Figures

Fig. 1
Fig. 1
Kaplan–Meier analysis for disease-free survival of all patients that were disease free and on therapy after 2.5 years, stratified for nodal status. Log-rank tests were used to assess the differences between treatment arms for each subgroup (reported as p values)
Fig. 2
Fig. 2
Kaplan–Meier analysis of the main analysis in all patients that were disease free and on therapy after 2.5 years. Results are shown for disease-free survival, for the subgroups stratified on prior endocrine therapy and nodal status. Log-rank tests were used to assess the differences between treatment arms for each subgroup (reported as p values)
See this image and copyright information in PMC

References

    1. Derks MGM, Blok EJ, Seynaeve C, Nortier JWR, Kranenbarg EM-K, Liefers GJ, Putter H, Kroep JR, Rea D, Hasenburg A, Markopoulos C, Paridaens R, Smeets JBE, 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 - PubMed
    1. van de Velde CJ, Rea D, Seynaeve C, Putter H, Hasenburg A, Vannetzel JM, Paridaens R, Markopoulos C, Hozumi Y, Hille ET, Kieback DG, Asmar L, Smeets J, et al. Adjuvant tamoxifen and exemestane in early breast cancer (TEAM): a randomised phase 3 trial. Lancet. 2011;377:321–331. doi: 10.1016/S0140-6736(10)62312-4. - DOI - PubMed
    1. EBCTCG Aromatase inhibitors versus tamoxifen in early breast cancer: patient-level meta-analysis of the randomised trials. Lancet. 2015;386:1341–1352. doi: 10.1016/S0140-6736(15)61074-1. - DOI - PubMed
    1. Gray R, Rea D, Handley K. aTTom: long-term effects of continuing adjuvant tamoxifen to 10 years versus stopping at 5 years in 6,953 women with early breast cancer. J Clin Oncol. 2013
    1. Goss PE, Ingle JN, Martino S, Robert NJ, Muss HB, Piccart MJ, Castiglione M, Tu D, Shepherd LE, Pritchard KI, Livingston RB, Davidson NE, Norton L, et al. A randomized trial of letrozole in postmenopausal women after 5 years of tamoxifen therapy for early-stage breast cancer. N Engl J Med. 2003;349:1793–1802. doi: 10.1056/NEJMoa032312. - DOI - PubMed

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