Human chorionic gonadotropin assays for testicular tumors : closing the gap between clinical and laboratory practice

BACKGROUND: Clinical practice guidelines recommend the measurement of human chorionic gonadotropin (hCG) and/or hCG in serum for management of testicular germ cell tumors (GCTs). These guidelines, however, disregard relevant biochemical information on hCG variants to be detected for oncological application. We set out to provide a critical review of the clinical evidence together with a characterization of the selectivity of currently marketed hCG immunoassays, identifying assays suitable for management of GCTs. CONTENT: Evidence sources in the available literature were critically appraised. Most instances of misdiagnosis and mismanagement of testicular GCTs have been associated with hCG results. According to the clinical evidence, 36% of patients with seminoma show an exclusive hCG increase, and 71% of patients with nonseminomatous GCTs (NSGCTs) show an increase of intact hCG and/or hCG hCG, whereas the hCG increase in NSGCTs is variable according to the tumor stage and histology. SUMMARY: hCG hCG assays that display an equimolar recognition of hCG and hCG, or at least do not overtly underestimate hCG, may be employed for management of testicular GCTs. Assays that underestimate hCG are not recommended for oncological application. In addition to the hCG hCG assay in service, an additional assay with broader selectivity for other hCG variants should be considered when false-negative or false-positive results are suspected on the basis of clinical data.