The prognostic value of tumor markers in newly diagnosed patients with primary central nervous system germ cell tumors

Abstract

To determine the impact of diagnostic serum and/or cerebrospinal fluid (CSF) alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (b-HCG) elevations on survival in newly diagnosed patients with central nervous system germ cell tumors (CNS GCT) treated with chemotherapy with the intent to avoid irradiation. Seventy-five patients with newly diagnosed CNS GCT enrolled in two sequential internationally conducted clinical trials with serum and CSF AFP and b-HCG levels available from initial diagnosis were retrospectively analyzed. Subjects received platinum based chemotherapy and were followed with serial imaging and tumor marker evaluations. The 5-year overall survival (OS) and event free survival (EFS) for patients with normal tumor markers compared with those with elevated markers at diagnosis was 78% (95% CI 51-91%) versus 60% (95% CI 46-72%) (P = 0.08) and 22% (95% CI 7-43%) versus 28% (95% CI 16-40%) (P = 0.68). The hazard ratio of death for patients with elevated markers was 1.9 times as high as that for those with normal markers (95% CI 0.58-6.5) after adjusting for other baseline characteristics. There was no observed difference in survival among patients with histologically confirmed germinomas, irrespective of level of b-HCG. Patients with elevated tumor markers appear to have poorer OS independent of tumor histology, although these differences do not reach statistical significance (P < or = 0.05). No differences were observed in EFS between groups likely due to the poor response of chemotherapy only approach to patients with normal markers. b-HCG elevations in biopsy proven germinomas do not seem to alter a patient's prognosis.