gms | German Medical Science

27th German Cancer Congress Berlin 2006

German Cancer Society (Frankfurt/M.)

22. - 26.03.2006, Berlin

Significant survival benefit of switching postmenopausal women with hormone-sensitive early breast cancer to anastrozole after 2 years adjuvant tamoxifen: results from 979 women enrolled in the ARNO 95 trial

Meeting Abstract

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  • corresponding author presenting/speaker Manfred Kaufmann - GABG, University of Fankfurt, Frankfurt am Main, Frankfurt / Main, Deutschland
  • Walter Jonat - on behalf of the GABG, University of Fankfurt, Frankfurt am Main

27. Deutscher Krebskongress. Berlin, 22.-26.03.2006. Düsseldorf, Köln: German Medical Science; 2006. DocOP024

The electronic version of this article is the complete one and can be found online at:

Published: March 20, 2006

© 2006 Kaufmann et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Background: The standard adjuvant endocrine therapy for postmenopausal women with receptor-positive, early breast cancer is changing. Due to consistent better trial results the standard 5 years tamoxifen (TAM) treatment has been replaced by a 5 years upfront treatment with an aromatase inhibitor (AI) or switching to an AI after initial 2-3 years of TAM. The combined analysis of the ARNO-95/ABCSG-8 (n=3.123 pts.) trials reported for the switch after 2-years oftamoxifen followed by 3 years of anastrozole (ANA) a significant better efficacy (EFS HR=0,60) and tolerability versus the continuous 5 years treatment with TAM. A separate publishing has been planned for both trials after reaching the requested number of primary events, but for the ARNO-95 alone the requested number has not been reached so far. This abstract presents the valid results of the secondary endpoint overall survival (OAS) for the ARNO-95 study.

Methods: The ARNO-95 trial are being conducted to assess whether switching to ANA after two years of TAM treatment is more effective than continuing TAM for the remaining three years of adjuvant therapy. The primary endpoint was recurrence-free survival (RFS), secondary endpoints was OAS.

Results: Of the 979 pts (ITT population) included in the trial 489 were randomized to switch to ANA, with 490 continuing to receive TAM. Mean age was 60,9 and 60,5 years, 74,0 and 73,1% of patients were node-negative, 97,1 and 96,3% were confirmed receptor-positive and no pat. received chemotherapy in ANA and TAM arm respectively. After a median follow-up of 30,1 months, 43 deaths have been reported: 15 in ANA and 28 in TAM group. The hazard ratio for OAS with ANA versus TAM was 0.53 (95% CI= 0.28-0,99; p<0.045).

Conclusions: In the ARNO-95 trial the switching to anastrozole treatment after two years of initial tamoxifen therapy improved significantly the secondary endpoint overall survival compared with continuing on 5 years tamoxifen. These results confirm furthermore the actual guidelines, which recommend for postmenopausal pts with receptor positive early breast cancer receiving adjuvant tamoxifen to switch treatment to anastrozole.