High levels during embryogenesis and fetogenesis as well as until 8 months after birth

•a-Fetoprotein: (AFP):

–High level of AFP usually indicates malignant germ cell tumor

–Half-life of AFP, 5–7 days

–High levels of AFP also possible in hepatoblastoma, pancreatic tumor, Wilms tumor, and other disorders of liver

•b-Human chorionic gonadotropin (HCG):

–Increased levels seen in germinoma/dysgerminoma, choriocarcinoma; during tumor lysis after chemotherapy of b-HCG-positive tumors

–Half-life, 24–36 h

–Normally high levels of b-HCG during pregnancy produced by cells of the placenta

–Normal serum b-HCG level in adults, less than 5 U/ml

•Serum lactate dehydrogenase (LDH) level: nonspecifically increased when rapid proliferation of cells is present

•Fetal isoenzyme of alkaline phosphatase in the serum: increased levels in 30% of patients with germ cell tumors (in 100% of adult patients with seminoma)

16.7Therapy: Overview

•The heterogeneity of germ cell tumors demands an individual therapeutic procedure depending on the location of the tumor

•Besides surgical excision/biopsy, the addition of chemotherapy markedly improves long-term survival:

–Cisplatin in combination with actinomycin D, etoposide, vinblastine, and bleomycin, as well as cyclophosphamide/ifosfamide

–In children receiving treatment for refractory or relapsing germ cell tumor, high-dose chemotherapy with autologous stem cell transplantation may be indicated

16.8Testicular Germ Cell Tumors and Subtypes

•Two percent of solid tumors in males

•In children, 0.9–1.1 in 100,000 males less than 16 years old

•Higher risk in males with undescended testes