Some immunologic characteristics of carcinoma of the colon and rectum.

The leukocyte migration inhibition assay was used to asses in vitro cell mediated immunity in patients with surgically staged carcinoma of colon and rectum. Tumor cells and extracts were used in both the autologous and the homologous systems. The study was doubly controlled by the use of leukocytes from normal healthy volunteers and by autologous intestinal mucosa cells and extracts. The results revealed that the leukocytes of patients were significantly sensitized to autologous tumor cells but not to homologous tumor cells or extracts when compared with the leukocytes of normal healthy volunteers. Leukocytes of patients tested with autologous tumors or mucosa showed that only those of patients with Dukes C classification were significantly sensitized to their tumors. These results would suggest that patients with Dukes C classification were highly sensitized to their tumors and that carcinomas of the colon and rectum are heterogenous tumors.