Ângelo do Carmo Silva Matthes1,2, Gustavo Zucca Matthes3,4,5. 1. Universidade de Ribeirão Preto-UNAERP, Ribeirão Preto, Brazil. amatthes@unaerp.br. 2. University of Ribeirão Preto, Av Costabile Romano, 2201, Ribeirão Preto, 14096-000, SP, Brazil. amatthes@unaerp.br. 3. Hospital de Câncer de Barretos, Barretos, Brazil. 4. Faculty of Medicine of Botucatu - UNESP, Botucatu, Brazil. 5. Cancer Hospital of Barretos, Barretos, Brazil.