Absence of lumph nodes in the resected specimen after radical surgery for distal rectal cancer and neoadjuvant chemoradiation therapy:: what does it mean? - Habr Gama, Angelita; Perez, Rodrigo O.; Proscurshim, Igor; Rawet, Viviane; Pereira, Diego D.; Sousa, Afonso H. S.; Kiss, Desiderio; Cecconello, Ivan (Diseases of the colon & rectum, 2008)