Logarithmic decrease of serum alpha-fetoprotein or human chorionic gonadotropin in response to chemotherapy can distinguish a subgroup with better prognosis among highly malignant intracranial non-germinomatous germ cell tumors

Abstract

Intracranial non-germinomatous germ cell tumors (NGGCTs) are a heterogeneous group of tumors. Although alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) are considered reliable markers for making diagnosis, the relationship between serum concentration of them and prognosis remains unclear. The present study investigated the decrease of serum tumor markers AFP and HCG as prognostic factors for patients with highly malignant NGGCTs. Eight consecutive patients with AFP>1000ng/ml or HCG>2000mIU/ml at initial treatments after January 2004 were retrospectively reviewed. Serum AFP or HCG concentration and tumor volume were sequentially measured during the therapeutic period. Six patients were treated by neoadjuvant chemotherapy consisting of ifosfamide, cisplatin, and etoposide, followed by salvage surgery and/or radiation therapy. A 14-year-old boy with choriocarcinoma and a 2-year-old boy with yolk sac tumor underwent radical resection because of acute hydrocephalus and mass effect on the brain stem, followed by chemotherapy and radiation therapy. Five patients showed complete response and survived at follow-up periods of 9, 26, 41, 63, and 75months, and the other three showed partial response but subsequent recurrence, finally died. Patients with complete response showed logarithmic decrease of serum AFP to the normal range in response to chemotherapy, but the others did not. Logarithmic decrease and normalization of serum AFP and HCG levels during neoadjuvant chemotherapy can distinguish a subgroup with better prognosis within highly malignant NGGCTs. To determine it, sequential measurement of serum tumor marker level was efficient. Outcomes were still dismal for slow responding patients, but this simple method may indicate more aggressive therapy.