[Inhibition of the adherence of leukocytes labelled with Cr-51 in colorectal cancer].

The leukocyte adherence inhibition test (LAI) is an in vitro test of immunity. Its high sensitivity in early cancer and its organ-specificity are of great interest in the study of human tumors. We developed an isotopic method (51Cr-LAI) for colorectal cancer, which has the advantage of being easier to perform than optic-counting assays. 87 patients (35 colorectal cancers, 29 benign diseases, 23 cancers of non-colorectal origin) were studied. We obtained a statistically significant difference between the mean LAI index for colorectal cancers and that for controls (p less than 0.01). LAI values greater than 13 p. 100 were considered positive. The specificity of the test was 94 p. 100 and the sensitivity for all colorectal cancers was 66 p. 100 with the highest value in the Dukes A group (LAI = 83 p. 100). Tests were negative in disseminated neoplasms. The actual fields of interest of LAI in tumor immunology and clinical research are discussed.