[Immunoreactivity in colorectal cancer. Approaches for an immunologic diagnosis?]

An attempt was made to demonstrate a specific immunoreaction against antigens of colorectal carcinoma and its precursors in vitro. Lymphocytes of patients with colorectal carcinoma or adenoma were incubated with tumor antigens from various human carcinomas. The preparation of the tumor antigens was performed with 3 m KCl extraction from cancer tissue. The cellular immunoreactivity was measured by the electrophoretic mobility test (EMT). 51 of 57 patients with colorectal cancer had specific lymphocytic reactions to extracts isolated from colorectal cancer; 8 showed cross-reactivity to antigens from adenocarcinoma of the stomach, while there was a negative lymphocytic reaction to extracts from cancer of the breast or lung. In 10 of 15 patients with colorectal adenoma, values in the tumor range were found with extracts of colorectal carcinoma. In 16 healthy controls using identical tumor extracts, 158 measurements revealed 139 negative responses (90%).