Leukocyte adherence inhibition assay in the diagnosis and follow-up of colorectal cancer patients.

Antitumor immune response to colorectal cancer extract was tested by the tube leukocyte adherence inhibition (LAI) assay. Of 70 colorectal cancer patients, 38 (54%) were LAI-positive. In contrast, 15 of 159 (9%) healthy individuals and 2 of 28 (7%) patients with nonmalignant diseases were positive. The LAI activity disappeared a few months after surgery and remained negative in patients with no evidence of disease as well as in patients with disseminated progressed disease. A change of LAI from negative to positive during the follow up period correlated in some cases with the recurrence of the disease, but was observed also in cases with no clinical evidence of disease.