Acta Med. Nagasaki 35:274-288 Changes in Natural Killer Cell Activity (NK Activity) by Surgical Stress

ABSTRACT: NK activity in relation to proliferation of cancer cells was clinically evaluated in the postoperative course in patients with carcinomas of the stomach and colon as compared with that in patients with benign diseases. 1) Preoperative NK activities in patients with advanced cancers were inhibited as compared with those in patients with benign diseases and those of normal individual. In particular, it was significant in patients with poor PS of grade 2. 2) NK activities enhanced until two hours after surgery and gradually fell down to the minimum at 12 hours, thereafter resumed the activities. 3) Intraoperative decrease in NK activity was minimal in patients with favorable PS. In contrast, in patients with poor PS and advanced cancers, a decrease and recovery of NK activity was aggravated. 4) NK activity also related to the operation time and the amount of blood transfusion. 5) Main causes of depressed NK activity in the postoperative course were prolonged operation time, with or without blood transfusion, and malnutrition