An evaluation of leukocyte adherence inhibition in the immunodiagnosis of colorectal cancer.

The leukocyte adherence inhibition technique was used to assess cell-mediated immunoreactivity and serum-blocking factors related to adenocarcinoma of the colon or rectum. In the group of 48 patients with confirmed tumors of this type, 36 of 38 had reactive leukocytes and 46 of 47 had serum-blocking factors. Patients whose tumors had been removed surgically, with no sign of recurrence, retained their leukocyte activity for up to 3.5 years in 6 of 6 cases, but only a small proportion (7 of 30) retained blocking factors. In 67 controls (who were patients with nonmalignant gastrointestinal disorders, patients with gastrointestinal tumors other than colorectal adenocarcinoma, patients with other cancers, or healthy volunteers), negative reactions were obtained, with diverticular disease the only prominent exception. The leukocyte adherence inhibition test appeared to be highly sensitive and specific. Application to the immunodiagnosis of colorectal cancer thus seems to be warranted.