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 University of Santiago de Compostela Santiago de Compostela Spain
5. Instituto de Investigación Biosanitaria IBS Granada Spain
6. CIBER of Epidemiology and Public Health (CIBERESP) Madrid Spain