The need for an hCG assay that appropriately detects trophoblastic disease and other hCG-producing cancers

This report was conceived at the 13th World Congress of Gestational Trophoblastic Disease after multiple presentations indicated widespread discrepancies in human chorionic gonadotropin (hCG) use and results. There appears to be a need for a discussion to describe the advantages and limitations of commonly used hCG tests in the management of gestational trophoblastic disease, and to monitor testicular, germ cell and other hCG-producing malignancies. In most countries hCG tests are certified only for pregnancy testing. Use in managing gestational trophoblastic diseases and other malignancies is considered an "off-label" use. Tests are not optimized or calibrated for these applications, and their use and the results therefore have to be considered experimental. Widespread variations in results occur and may lead to needless or inappropriate therapy. It therefore seems important for laboratory directors and treating physicians to familiarize themselves with which hCG test their laboratory is using and, if necessary, to contract an external laboratory for measuring hCG in the management of gestational trophoblastic disease and cancer.