Inhibition of human leukocyte migration in agar by 3-M potassium chloride extracts of stomach, colon, and lung cancers.

Inhibition of leukocyte migration in agarose-agar was used as a probe for tumor-associated antigen in 3-M KCl solubilized extracts of gastric, colon, and lung cancers from humans. Twelve of 40 (30%) leukocyte preparations from gastric cancer patients, 10 of 21 (48%) from colon cancer patients, and 7 of 14 (50%) from lung cancer patients were inhibited by their respective histologically homologus cancer extract. However, among 75 preparations from various cancer patients, leukocytes from only 2 gastric cancer patients were inhibited by paired normal gastric tissue extracts. Only 2 of 68 preparations from normal individuals and none of 67 preparations from patients with nonmalignant diseases, such as gastric peptic ulcer, gastritis, colon polyposis, colitis, pulmonary tuberculosis, chronic bronchitis, and sarcoidosis, were inhibited by cancer extracts. These findings suggest the presence in KCl extracts of gastric cancer of presumed tumor-associated antigen(s) that is antigenically distinct from that of either colon or lung cancer.