1. Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
2. João de Barros Barreto University Hospital, Federal University of Pará, Belém 66075-110, PA, Brazil
3. Institute of Cancer of São Paulo-ICESP, São Paulo 01246-000, SP, Brazil
4. IMIP, Instituto de Medicina Integral Professor Fernando Figueira, Recife 50070-902, PE, Brazil