1. Department of General Surgery, Breast Cancer Unit, Complexo Hospitalario de Ourense, Ourense, Spain
2. Department of General Surgery, Hospital Público de Verín, Ourense, Spain
3. Department of Preventive Medicine and Public Health, University of Granada, Granada, Spain
4. Department of General Surgery, Hospital Santa Ana de Motril, Granada, Spain
5. Departmento de Cirugía General, Unidad de Mastología de Grupo Oroño, Rosario, Argentina
6. Department of General Surgery, University of Santiago de Compostela, Santiago, Spain
7. CIBER of Epidemiology and Public Health (CIBERESP), Madrid, Spain
8. Instituto de Investigación Biosanitaria IBS, Granada, Spain