1. Breast Cancer Clinical Research Unit, CNIO-Spanish National Cancer Research Center, Madrid, Spain
2. Telomeres and Telomerase Group, Molecular Oncology Programme, CNIO-Spanish National Cancer Research Center, Madrid, Spain
3. Medical Oncology Department, Hospital Clinico Universitario, Valencia, Spain
4. Medical Oncology Department, Hospital 12 de Octubre, Madrid, Spain
5. Medical Oncology Department, Hospital de Montepríncipe, Madrid, Spain
6. Medical Oncology Department, Hospital Vall d´Hebron, Barcelona, Spain
7. Medical Oncology Department, Hospital Ramón y Cajal, Madrid, Spain
8. Medical Oncology Department, Hospital Clinico San Carlos, Madrid, Spain
9. Medical Oncology Department, Institut Catala d'Oncologia-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain
10. Medical Oncology Department, MD Anderson Cancer Center, Madrid, Spain
11. Medical Oncology Department, Hospital General de Albacete, Albacete, Spain
12. Medical Oncology Department, Hospital Lozano Blesa, Zaragoza, Spain
13. Medical Oncology Department, Institut Catala d'Oncologia-Hospital Dr. Josep Trueta, Girona, Spain
14. Medical Oncology Department, Hospital Arnau de Vilanova, Valencia, Spain
15. Medical Oncology Department, Hospital Clínico Universitario Virgen de la Victoria, Málaga, Spain
16. Medical Oncology Department, Hospital Universitario de Fuenlabrada, Fuenlabrada, Spain
17. GEICAM, Madrid, Spain
18. Medical Oncology Department, Hospital Universitario La Princesa, Madrid, Spain