Relation between immunity and survival in carcinoma of the colon and rectum.

Twenty-two patients with cancer of the colon and rectum were evaluated before and after surgical treatment by leukocyte migration inhibition assays using autologous and allogeneic tumor extracts. All patients were resected for cure. Patients with cancer of the colon demonstrated significant migration inhibition against autologous extracts before surgery and in the immediate postoperative period. Patients with rectal cancer did not demonstrate significant migration inhibition at any time. The possibility that immunity plays a role in the poorer prognosis of patients with rectal cancer is discussed.