title: Antitumor immune response to colorectal cancer antigen detected by the leukocyte adherence inhibition test (LAI) in groups at high risk for colorectal cancer.
abstract: Colorectal cancer is the second leading cause of cancer death in western populations. As treatment outcome is highly correlated with stage at diagnosis, early detection is a very important task. Three high-risk groups for colorectal cancer (first-degree relatives of colorectal cancer patients; individuals with past history of colorectal neoplasms, polyps, or carcinoma; and patients with ulcerative colitis) were screened for colonic neoplasms. The study program included the leukocyte adherence inhibition test (LAI), a specific immune response test for colorectal cancer antigen; fiberoptic sigmoidoscopy or colonoscopy; and guaiac impregnated slide test. The main finding was the detection of 92 positive LAI tests out of 451 high-risk individuals tested (20%), compared to eight positive tests out of 194 (4.1%) in a control group. Fifty-six colonic neoplasms were found out of 344 (16%) colonoscopies performed, most of them adenomatous polyps and a few carcinomas. Our findings, compared with the expected 2-3% neoplasms in low-risk groups, would prove that the screenees were indeed at high risk. However, only 11/56 (19%) of the polyps identified were LAI positive. The number of polyps found among LAI positive individuals were, so far, 11/92 (11%). The guaiac impregnated slide test for occult blood in the stool was performed in 221 screenees. Of these only 10 were positive (4.5%) compared with the average of 1% positive tests in low-risk groups.
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis; D002277:Carcinoma / Q000175:diagnosis; D003093:Colitis, Ulcerative / Q000276:immunology; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000276:immunology*; D003113:Colonoscopy; D005243:Feces / Q000032:analysis; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000175:diagnosis; D007957:Leukocyte Adherence Inhibition Test; D008297:Male; D008875:Middle Aged; D012306:Risk
chemical_list: D000951:Antigens, Neoplasm; C050269:organ-specific neoantigen