The role of the radioimmunoassay of serum alpha-fetoprotein and human chorionic gonadotropin in the intensive chemotherapy and surgery of metastatic testicular tumors.

Quantitative measurement of serum alpha-fetoprotein and human chorionic gonadotropin by double antibody radioimmunoassays reflects the efficacy of surgical, radiation and/or chemotherapeutic regimens in patients with bulky disseminated testicular tumors. When these therapies are effective they produce an immediate decrease in serum levels of these markers that reflects the decrease in tumor size and could be as rapid as the catabolic decay rate for alpha-fetoprotein or human chorionic gonadotropin. The alpha subunit of human chorionic gonadotropin has a short half-life (20 minutes) and has been used for the first time to localize a recurrent metastatic testicular tumor. Cellular localization of these markers by immunochemical techniques has helped us to understand the natural history of this cancer and the cell types responsible for production of the markers.