>>Produced by: Fetal Yolk Sac; Embryonic carcinoma elements of germ cell tumors.
>>Overall, AFP is NOT elevated in pure seminomas.
>>Half-life: 5 days
>>Produced by: Trophoblastic tissues; Syncytiotrophoblastic components of of germ cell tumors.
>>Overall, B-HCG is NOT elevated in seminomas. However, about 10% of cases may have low-level elevation of B-HCG.
>>beta-hCG is a marker for Gestational Trophoblastic Disease (GTD). However, it is not a reliable marker for Placental Site Trophoblastic Tumors (PST).
>>Half-life: 18-24 hours
>>There is some cross-reactivity in the radio-immunoassay with luteinizing hormone. Also, hCG can be falsely elevated in patients who use marijuana.