1. Department of Surgery and Pathology, Hospital de Câncer de Barretos, Rua Antenor Duarte Villela, 1331-Bairro Paulo Prata, 14784-400 Barretos, SP, Brazil
2. Division of Surgery, Basingstoke and North Hampshire NHS Foundation Trust, ldermaston Road Basingstoke, Hampshire RG24 9NA, UK
3. Department of Clinical Oncology, Hospital Amaral Carvalho, R Dona Silveria, 150 17203-570 Jaú SP, Brazil