Treatment outcomes and risk factors of patients with intracranial germ cell tumour with choriocarcinoma element or β-HCG level higher than 500 IU/L.

Background: In previous studies, patients with intracranial germ cell tumour (iGCT) with pure choriocarcinoma or mixed germ cell tumours with choriocarcinoma element showed similar dismal prognoses, with median overall survival (OS) of 22 months and 1-year survival rate of approximately 60%. However, these conclusions need to be updated because radiotherapy, which is the mainstay for this disease, was not applied in a number of patients. Additionally, prognostic factors need to be explored in this population.

Methods: Clinical data of patients with iGCTs with histologically confirmed choriocarcinoma element or beta-human chorionic gonadotropin (β-HCG) > 500 IU/L were collected from the archives of our institution and retrospectively studied.

Results: A total of 76 patients were eligible for this study. Except for two early deaths, all patients received radiotherapy (craniospinal irradiation [CSI], n = 23; non-CSI, n = 51). The median follow-up duration for the entire series was 63 months (range, 6-188 months). The 5-year event-free survival (EFS) and OS rates were 81.5% and 84.1%, respectively. Among patients who did not have early death or progressive disease after induction chemotherapy, multivariate analysis revealed that chemotherapy cycles (> 4 vs. ≤ 4) (hazard ratio [HR] for EFS 0.144, p = 0.020; HR for OS 0.111, p = 0.028) and β-HCG levels (> 3000 IU/L vs. ≤ 3000 IU/L) (HR for EFS 4.342, p = 0.059; HR for OS 6.614, p = 0.033) were independent factors for survival.

Conclusions: Patients with iGCTs with choriocarcinoma element or β-HCG > 500 IU/L showed improved survival with radiotherapy-based treatments. Additional chemotherapy cycles could result in additional survival benefits. Patients with β-HCG level > 3000 IU/L had poorer prognosis.