The leucocyte adherence inhibtion test in cancer of the large bowel.

A recently introduced assay of cell mediated immunity and humoral inhibitory factors has been evaluated in colorectal cancer patients. Using a perchloric acid extract of adenocarcinoma of the large bowel as antigen, 16/27 patients with colorectal cancer had significant cellular reactivity when their separated peripheral leucocytes were tested in homologous AB serum. In autologous serum only 7/27 had significant reactivity; 6/20 patients with a variety of other malignancies showed sensitization to the colorectal antigen preparation. It is concluded that the leucocyte adherence inhibiton test may offer a simple method of assaying for serum blocking factors in sequential studies but will be of little value in the diagnosis of large bowel cancer.