Human chorionic gonadotropin as a target for cancer vaccines.

Human chorionic gonadotropin (hCG) is expressed by common cancers and may play a role in cell transformation as well as angiogenic, metastatic, and immune escape phenomena that are central to cancer progression. Clinical trials with a vaccine targeting the carboxy-terminal peptide of -hCG have indicated that tolerance to this oncofetal antigen can be broken. Humoral responses that may modulate the biologic activity of tumor-associated hCG as well as cellular responses to hCG have been generated. Studies are in progress to further define the biologic significance of hCG in cancer and to develop a vaccine approach that will best target this expression.