FemZone trial: a randomized phase II trial comparing neoadjuvant letrozole and zoledronic acid with letrozole in primary breast cancer patients
- Equal contributors
1 University Breast Center, Department of Gynecology and Obstetrics, Erlangen University Hospital, Friedrich Alexander University of Erlangen–Nuremberg, Erlangen Comprehensive Cancer Center Erlangen-EMN, Erlangen, Germany
2 Departement of Gynecology and Obstetrics, Spital Rheinfelden, Switzerland
3 Breast Center, Klinikum Essen-Mitte, Essen, Germany
4 Department of Gynecology and Obstetrics, Essen University Hospital, Essen, Germany
5 Department of Gynecology and Obstetrics, Cologne University Hospital, Cologne, Germany
6 Kliniken der Stadt Köln Holweide, Cologne, Germany
7 Clinic for Gynecology and Obstetrics "Nathanstift" Klinikum Fürth, Fürth, Germany
8 Department of Gynecology and Obstetrics, Klinikum Harlaching, Munich, Germany
9 Department of Gynecology and Obstetrics, Sana-Klinikum Lichtenberg, Oskar-Ziethen-Krankenhaus, Berlin, Germany
10 Department of Gynecology and Obstetrics, Freiburg University Hospital, Freiburg, Germany
11 Department of Gynecology and Obstetrics, Ulm University Hospital, Ulm, Germany
12 Frauenklinik, Klinikum Hanau, Hanau, Germany
13 Department of Gynecology and Obstetrics, Klinikum Esslingen, Esslingen, Germany
14 Medizinisches Zentrum Ulm, Ulm, Germany
15 Frauenklinik und Poliklinik der Technischen Universität München, Munich, Germany
16 Frauenklinik Grosshadern, Universitätsklinik der Ludwig-Maximilians-Universität, Munich, Germany
17 Frauenklinik, Allgemeines Krankenhaus Celle, Celle, Germany
18 Novartis Pharma GmbH, Nuremberg, Germany
19 Institute of Diagnostic Radiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen–Nuremberg, Erlangen, Germany
BMC Cancer 2014, 14:66 doi:10.1186/1471-2407-14-66Published: 5 February 2014
The objective of this prospectively randomized phase II trial (Trial registration: EUCTR2004-004007-37-DE) was to compare the clinical response of primary breast cancer patients to neoadjuvant therapy with letrozole alone (LET) or letrozole and zoledronic acid (LET + ZOL).
Patients were randomly assigned to receive either LET 2.5 mg/day (n = 79) or the combination of LET 2.5 mg/day and a total of seven infusions of ZOL 4 mg every 4 weeks (n = 89) for 6 months. Primary endpoint was clinical response rate as assessed by mammogram readings. The study was terminated prematurely due to insufficient recruitment. We report here on an exploratory analysis of this data.
Central assessment of tumor sizes during the treatment period was available for 131 patients (66 LET, 65 LET + ZOL). Clinical responses (complete or partial) were seen in 54.5% (95% CI: 41.8-66.9) of the patients in the LET arm and 69.2% (95% CI: 56.6-80.1) of those in the LET + ZOL arm (P = 0.106). A multivariate model showed an OR of 1.72 (95% CI: 0.83-3.59) for the experimental arm.
No increase in the clinical response rate was observed with the addition of ZOL to a neoadjuvant treatment regimen with LET. However a trend towards a better reponse in the LET + ZOL arm could be observed. This trend is consistent with previous studies that have investigated the addition of ZOL to chemotherapy, and it may support the evidence for a direct antitumor action of zoledronic acid.