Abstract
Objective : The effect of splenectomy on a 1, 2-dimethylhydrazine (DMH) -induced colon cancer model in rats was studied histopathologically and immunologically. Materials and methods : The animals were divided into 3 groups as follows, Group I; splenectomy 1 week before subcutaneous DMH injection, Group II; splenectomy simultaneous with DMH injection, Group III; splenectomy 5 weeks after DMH injection. Histopathologically, CD4, CD8 and Natural Killer (NK) activity was examined. Results : The incidence of cancer was 100% in all groups. The average number of tumors per rat was not significantly different between the groups. In the histological examination, large-size, over 5mm in diameter, tumors that advanced over the muscle layer, and poorly differentiated adenocarcinoma demonstrated a significantly high incidence in Group III (p<0.05). In the immunological examination, NK activity at 1 week after splenectomy was significantly lower than before splenectomy (p<0.05), and was the lowest in Group III. Conclusions : Splenectomy before and simultaneously with DMH administration had little effect on tumor growth. However, tumor growth was enhanced by splenectomy 5 weeks after DMH injection.
