Antigenic changes associated with liver carcinogenesis.

Carcinogen-induced experimental hepatomas are often characterized by new individually distinct antigens capable of inducing tumor immunity in syngeneic hosts. These antigens arise as a consequence of cell-carcinogen interaction and may result from modification or replacement of normal cell-surface components. Their role in immunosurveillance is not established, but they offer a target for tumor immunotherapy. Reexpressed fetal antigens have also been detected, either as secretory products (alpha 1-fetoprotein) or as common cell-surface components on hepatoma cells. The role of fetal antigens in therapy is doubtful, but they may be important diagnostic indicators of neoplastic change. Possibly associated with these are common antigens initiated early after carcinogen treatment, before malignant cells are detected. Together, the antigens associated with liver carcinogenesis may prove to be powerful tools in understanding the process of liver neoplasia.