Blood to cerebrospinal fluid human chorionic gonadotropin-beta ratios in intracranial germ cell tumors

Abstract

<jats:p>Levels of human chorionic gonadotropin-beta (HCG-beta) are elevated in up to 43% of patients with intracranial germ cell tumors (GCTs) and are useful in the diagnosis of these tumors and the follow up of such patients. The ratio of blood HCG-beta to lumbar cerebrospinal fluid (CSF) HCG-beta in these patients at presentation has not been defined. Twenty-two patients with intracranial GCTs have been treated at St. Bartholomew's Hospital over the past 15 years. Two (17%) of 12 germinomas and seven (70%) of 10 nongerminomatous GCTs had elevated blood HCG-beta at presentation. Four cases of pineal region GCTs (one of 12 germinomas and three of 10 nongerminomatous GCTs) had paired, elevated, blood and lumbar CSF HCG-beta levels. The mean blood to CSF ratio was 1:10 (range 1.7-18.4), which is substantially lower than the ratio of 286:1 reported in systemic GCTs. The authors confirm the finding of a previous single report showing that ventricular CSF HCG-beta sampling via an accessible ventriculoperitoneal shunt reservoir may give a spuriously negative result, and they discuss the pathophysiology of the blood-brain barrier in the pineal region and the implications of the intrathecal administration of chemotherapy.</jats:p>

Diagnostic utility and correlation of tumor markers in the serum and cerebrospinal fluid of children with intracranial germ cell tumors

“…This trend has been noted previously in intracranial GCTs [13, 19]. Rogers et al offered a potential hypothesis involving the blood brain barrier to explain the increased levels of bHCG in the CSF [19]. …”

“…Although these tumors are thought to be similar to their intracranial counterpart in regard to histology, genetics, and response to therapy [6], some are significantly different [3]. It is important to validate the findings for extracranial GCT markers compared to those for intracranial GCT markers [8,10,12,13,19]. The location of intracranial GCTs allows the detection of AFP and bHCG in the cerebrospinal fluid (CSF) as well, thereby providing another relevant source to potentially diagnose and manage patients with intracranial GCTs.…”

“…On the other hand, serum samples cost less and are less invasive to obtain. Although studies have begun to look at tumor markers specifically in intracranial GCTs [8,10,12,13,19], it remains to be determined whether it is necessary to assess the concentrations of tumor markers in both the CSF and serum for intracranial GCTs. In this study, we analyze how both these sources correlate at baseline, and during follow-up, and we described their diagnostic utility.…”

Diagnostic sensitivity of serum and lumbar CSF bHCG in newly diagnosed CNS germinoma

“…Lumbar CSF is more sensitive as has been previously documented. 6 Approximately 34.5% (20/58) of patients had elevated lumbar CSF bHCG values with normal serum values. The median value of lumbar CSF bHCG was low [7.7 (2.5–16) mIU/ml] in the 22 patients with abnormal CSF values (Table III).…”

?CNS-friendly? chemoradiotherapy in pediatric neuro-oncology

“…One problem with this approach is that the neuraxis blood-brain barrier may be more intact than in the region of the primary tumor, whatever its type. This issue has recently been reviewed by us [13].We also recently reported some integrity of the blood-brain barrier in CNS germ cell tumor patients, certainly in so far as HCG is concerned (although, interestingly, less than predicted from the systemic germ cell data) [20].Unfortunately, we ran into trouble with too great a reliance on primary chemotherapy in infant medulloblastoma [21], although the experience of others is more positive.…”