Preoperative and postoperative immunological evaluation of patients with colorectal cancer.

Twenty-two patients with cancer of the colon and rectum were studied: preoperative and postoperative cell-mediated and humoral immune factors were assessed, and local concentration of immunoglobulins in tumor tissue and in normal mucosa were measured. Lymphocyte function was found to be reduced in 50% of stage A and B and 66% of stage D patients. On the other hand, when the lymphoblastogenesis was performed in the presence of normal AB plasma, a partial restoration of lymphocyte function was noted, indicating the presence of a serum blocking factor in the blood of these patients. While there was no apparent decrease of B cell subpopulation, 57% of the tested patients showed significant reduction of T lymphocytes. Marked reduction of serum immunoglobulin levels, specifically IgG and IgM, was observed preoperatively followed by a gradual return toward normal values after surgical resection of neoplastic growth. It is noteworthy that tumor tissue contained more IgG and IgA than normal mucosa. However, IgM was below detection level both in normal and tumor tissues.