Potential role of ventricular tumor markers in CNS germ cell tumors

Role of Alpha-Fetoprotein (AFP) in Diagnosing Childhood Cancers and Genetic-Related Chronic Diseases

Alpha-fetoprotein (AFP) is a protein commonly found during fetal development, but its role extends beyond birth. Throughout the first year of life, AFP levels can remain high, which can potentially mask various conditions from the neurological, metabolic, hematological, endocrine, and early childhood cancer groups. Although AFP reference values and clinical utility have been established in adults, evaluating AFP levels in children during the diagnostic process, treatment, and post-treatment surveillance is still associated with numerous diagnostic pitfalls. These challenges arise from the presence of physiologically elevated AFP levels, inconsistent data obtained from different laboratory tests, and the limited population of children with oncologic diseases that have been studied. To address these issues, it is essential to establish updated reference ranges for AFP in this specific age group. A population-based study involving a statistically representative group of patients could serve as a valuable solution for this purpose.

Clinical Outcomes and Diagnostic Consistency of Serum and CSF Tumor Markers in Pediatric Intracranial Germ Cell Tumors in Thailand: A Multicenter Study

The diagnostic and treatment outcomes of intracranial germ cell tumors (ICGCTs) among low and middle income countries are limited. A total of 63 ICGCTs patients with a median age of 11.6 years were studied. A 30 (47.6%) and 33 (52.4%) patients were classified as pure germinomas and nongerminomatous germ cell tumors (NGGCTs), respectively. The concordances between serum and cerebrospinal fluid (CSF) alpha-fetoprotein (84.3%) and beta-human chorionic gonadotropin (68.4%) were addressed. The 5-year overall survival (OS) and event-free survival (EFS) rates of pure germinomas versus NGGCTs were 83.9 versus 69.1% and 74.6 versus 57.7%, respectively. Patients undergoing radiation had higher 5-year OS and EFS than those without radiation treatment with P < .001. Chemotherapy combined with radiation is a cornerstone treatment to achieve outcomes. Adverse prognostic factors included age <8 years, surgery, and nonradiation treatment. Either serum or CSF tumor markers were adequately required as a diagnostic test among patients with ICGCTs.

Cerebrospinal Fluid biomarkers in pediatric brain tumors: A systematic review

Central nervous system (CNS) tumors are the leading cause of cancer death in pediatric patients. Though these tumors typically require invasive surgical procedures to diagnose, cerebrospinal fluid (CSF) liquid biopsy presents a potential method for rapid and noninvasive detection of markers of CNS malignancy. To characterize molecular biomarkers that can be used in the diagnosis, prognosis, and monitoring of pediatric cancer patients, a literature review was conducted in accordance with PRISMA guidelines. PubMed and EMBASE were searched for the terms biomarkers, liquid biopsy, cerebrospinal fluid, pediatric central nervous system tumor, and their synonyms. Studies including pediatric patients with CSF sampling for tumor evaluation were included. Studies were excluded if they did not have full text or if they were case studies, methodology reports, in languages other than English, or animal studies. Our search revealed 163 articles of which 42 were included. Proteomic, genomic, and small molecule markers associated with CNS tumors were identified for further analysis and development of detection tools.

A clinical approach to parasellar lesions in the transition age

Many reviews have summarised the pathology and management of the parasellar region in adult patients, although an analysis of these aspects in the transition years, from puberty onset to the age of peak bone mass, has been lacking. A comprehensive search of English-language original articles, published from 2000 to 2020, was conducted in the MEDLINE database (December 2019 to March 2020). We selected all studies regarding epidemiology, diagnosis and management of the following parasellar lesions: germinoma, craniopharyngioma, Langerhans cell histiocytosis, optic glioma, hypothalamic hamartoma, tuber cinereum hamartoma, cranial chordoma, Rathke cleft cyst, hypophysitis and hypothalamitis during the transition age from childhood to adulthood. In the present review, we provide an overview of the principal parasellar lesions occurring in the transition age. Symptoms are usually a result of the mass effect of the lesions on nearby structures, as well as anterior pituitary deficits. Diabetes insipidus occurs frequently in these patients. In this age group, pubertal developmental disorders may be more evident compared to other stages of life. Parasellar lesions in the transition age mostly include neoplastic lesions such as germinomas, hamartomas, optic gliomas, craniopharyngiomas Langerhans cell histiocytosis and chordomas, and rarely inflammatory lesions (hypophysitis, hypothalamitis). There are limited data on the management of parasellar lesions in the transition age. Endocrine evaluation is crucial for identifying conditions that require hormonal treatment so that they can be treated early to improve the quality of life of the individual patient in this complex age range. The clinical approach to parasellar lesions involves a multidisciplinary effort.

Clinical and pathological features of 124 patients with indistinguishable sellar lesions and central diabetes insipidus

BACKGROUND

Sellar lesions with central diabetes insipidus have a wide range of causes, and diagnosis is relatively difficult. The indication and clinical value of biopsy are still controversial.

OBJECTIVE

To describe the etiology, demographic characteristics, manifestations, laboratory tests and imaging findings of this disease and to explore the clinical value and safety of endoscopic transsphenoidal biopsy.

METHODS

Retrospective analysis of 124 patients with sellar lesions and central diabetes insipidus who underwent endoscopic transsphenoidal biopsy at the Neurosurgery Department, Peking Union Medical College Hospital, from 2011 to 2019.

RESULTS

The main etiology includes congenital diseases, inflammatory/infectious diseases and tumor diseases. The most common diseases were germ cell tumors, Langerhans cell histiocytosis, lymphocytic hypophysitis, and Rathke's cleft cysts. Except for the age at the time of biopsy of patients with tumor diseases, which was significantly lower than that of the other two, the other clinical manifestations of the three types of diseases were not significantly different. Among the 124 patients, biopsy was performed via an endoscopic transsphenoidal approach for 101 with intrasellarly available lesions or via an endoscopic extended transsphenoidal approach for 23 with intrasellarly unavailable lesions. 6 patients had central nervous system infections after surgery, and 3 had cerebrospinal fluid rhinorrhea, of which 2 were surgically repaired. These incidences were basically the same as those of classic surgery. 2 patients had worse visual acuity, 2 had worse visual field, and 2 had worse eye movement. Excepting one patient, all of whom have recovered after treatment.

CONCLUSIONS

Noninvasive examination is difficult for identifying the common causes of this type of disease. Endoscopic transsphenoidal biopsy is relatively safe and effective, helps doctors to select the best treatment for patients, and is worth promoting.

Human CNS barrier-forming organoids with cerebrospinal fluid production

Cerebrospinal fluid (CSF) is a vital liquid, providing nutrients and signaling molecules and clearing out toxic by-products from the brain. The CSF is produced by the choroid plexus (ChP), a protective epithelial barrier that also prevents free entry of toxic molecules or drugs from the blood. Here, we establish human ChP organoids with a selective barrier and CSF-like fluid secretion in self-contained compartments. We show that this in vitro barrier exhibits the same selectivity to small molecules as the ChP in vivo and that ChP-CSF organoids can predict central nervous system (CNS) permeability of new compounds. The transcriptomic and proteomic signatures of ChP-CSF organoids reveal a high degree of similarity to the ChP in vivo. Finally, the intersection of single-cell transcriptomics and proteomic analysis uncovers key human CSF components produced by previously unidentified specialized epithelial subtypes.

Human chorionic gonadotropin detection in cerebrospinal fluid of patients with a germinoma and its prognostic significance: assessment by using a highly sensitive enzyme immunoassay

OBJECTIVE Human chorionic gonadotropin (HCG) can be detected in a certain population of patients with a germinoma, but the frequency of germinoma HCG secretion and the prognostic value of HCG in the CSF are unknown. METHODS The authors measured HCG levels in sera and CSF in patients with a histologically confirmed germinoma by using a highly sensitive assay known as an immune complex transfer enzyme immunoassay (EIA), which is more than 100 times as sensitive as the conventional method, and they analyzed the correlation between HCG levels and the prognoses of patients with a germinoma. RESULTS HCG levels in sera and CSF of 35 patients with a germinoma were examined with the immune complex transfer EIA. The median CSF HCG levels in patients with a germinoma during the pretreatment and posttreatment evaluations were 192.5 pg/ml (range 1.2-13,116.5 pg/ml) and 18.7 pg/ml (1.2-283.9 pg/ml), respectively. Before treatment, the CSF HCG level was greater than the cutoff value in 85.7% of the patients with a germinoma. The authors compared survival rates among the patients by using a CSF HCG cutoff level of 1000 pg/ml, and the difference was statistically significant between the groups (p = 0.029, log-rank test). CONCLUSIONS Results of this study demonstrate that most germinomas secrete HCG. Patients with a germinoma that secretes higher amounts of HCG in their CSF experienced recurrence more frequently than those with lower CSF HCG levels.

Recent advances in molecular biology and treatment strategies for intracranial germ cell tumors

BACKGROUND

Intracranial germ cell tumors (IGCTs) are a group of rare pediatric brain tumors which include various subtypes. The current understanding of the etiology of the tumors and their optimal management strategies remain controversial.

DATA SOURCES

The data on IGCTs were collected from articles published in the past 20 years, and the origin and etiology of IGCTs at molecular level as well as the relative roles of varied treatment strategies in different prognosis groups according to Matsutani's classification were reviewed.

RESULTS

Recent cellular and molecular evidence suggests that IGCTs may arise from the transformation of endogenous brain cells; and findings in the molecular characterization of IGCTs suggest roles of CCND2, RB1, and PRDM14 in the pathogenesis of IGCTs and identify the KIT/RAS and AKT1/mTOR pathways as potential therapeutic targets in future. According to Matsutani's classification of IGCTs, the good prognosis group includes both germinomas and mature teratomas. For germinomas, both radiation alone and reduced-dose radiotherapy in combination with adjuvant chemotherapy are effective, while complete surgical excision is recommended for mature teratomas. In the intermediate prognosis group, immature teratoma has been successfully treated with gamma knife surgery. However, for intermediate prognosis IGCTs other than immature teratomas, gross total resection with adjuvant chemotherapy and radiotherapy or gamma knife surgery may be necessary to achieve cure. In the poor prognosis group, survival outcomes are unsatisfactory, and complete surgical resection combined with more intensive chemotherapy and radiotherapy remains the best available treatment option at this time.

CONCLUSIONS

IGCTs should be strictly classified according to their pathological categories before administering pathology-specific treatments. Although open microsurgical excision is the traditional surgical strategy for IGCTs, recent publications also support the role of endoscopic surgical options for pineal region IGCTs.

CNS germ cell tumors: a clinical review and future directions

CNS germ cell tumors (GCT) are rare tumors that arise in midline brain regions (mostly pineal or suprasellar). They are of two types, germinoma and nongerminomatous GCT (NGGCT) which include teratoma, choriocarcinoma, yolk sac, embyronal carcinoma and mixed GCT. Tissue is needed for diagnosis unless serum or cerebrospinal fluid markers, b-HCG or AFP, are elevated. Germinomas can be cured with radiation therapy (RT) alone (whole ventricle fields, if localized), but chemotherapy may permit RT dose-reduction. Best outcomes for NGGCT are with RT and chemotherapy. Craniospinal RT is needed for all disseminated tumors and best survival for localized NGGCT has included craniospinal RT. Recent genetic findings in CNS GCT may lead to therapies targeting their oncogenic pathways.

Determining an Optimal Cutoff of Serum β-Human Chorionic Gonadotropin for Assisting the Diagnosis of Intracranial Germinomas

Background

Beta (β)-human chorionic gonadotropin (β-HCG) is used to confirm the diagnosis and plan treatment of intracranial germinomas. However, the cutoff values of serum β-HCG in diagnosis of intracranial germinomas reported in the literature are inconsistent. To establish an appropriate cutoff value of serum β-HCG for diagnosis of intracranial germinomas, we retrospectively reviewed the records of intracranial tumor patients who received serum β-HCG and α-fetoprotein (AFP) tests for diagnostic purposes at our hospital from 2005 to 2014.

Methods

A total of 93 intracranial germinomas and 289 intracranial non-germ cell tumors were included in this study. Receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of 3 cutoffs (0.1, 0.4, and 0.5 mIU/mL) for diagnosing intracranial germinomas. The serum β-HCG level of intracranial germinoma patients was further analyzed to investigate the effect of metastasis status and tumor location on serum β-HCG level.

Results

The area under the ROC curve was 0.81 (P < .001), suggesting β-HCG is an effective marker. Of the 3 cutoff values, 0.1 mIU/mL possessed a highest sensitivity (66.67%) and good specificity (91%). Although there was no β-HCG level difference between metastatic and non-metastatic intracranial germinoma patients, the diagnostic rate of metastatic neurohypophyseal germinomas was significantly higher than that of its non-metastatic counterpart (P < .05), implying that the location of the germinoma might need to be considered when β-HCG is used as a marker to predict metastasis.

Conclusions

Determining an optimal cutoff of serum β-HCG is helpful for assisting the diagnosis of intracranial germinoma.

Consensus on the management of intracranial germ-cell tumours

The management of intracranial germ-cell tumours is complex because of varied clinical presentations, tumour sites, treatments and outcomes, and the need for multidisciplinary input. Participants of the 2013 Third International CNS Germ Cell Tumour Symposium (Cambridge, UK) agreed to undertake a multidisciplinary Delphi process to identify consensus in the clinical management of intracranial germ-cell tumours. 77 delegates from the symposium were selected as suitable experts in the field and were invited to participate in the Delphi survey, of which 64 (83%) responded to the invitation. Invited participants represented multiple disciplines from Asia, Australasia, Europe, and the Americas. 38 consensus statements encompassing aspects of intracranial germ-cell tumour work-up, staging, treatment, and follow-up were prepared. To achieve consensus, statements required at least 70% agreement from at least 60% of respondents. Overall, 34 (89%) of 38 statements met consensus criteria. This international Delphi approach has defined key areas of consensus that will help guide and streamline clinical management of patients with intracranial germ-cell tumours. Additionally, the Delphi approach identified areas of different understanding and clinical practice internationally in the management of these tumours, areas which should be the focus of future collaborative studies. Such efforts should translate into improved patient outcomes.

Common molecularcytogenetic alterations in tumors originating from the pineal region

Tumors of the pineal region (PR) are rare and can be subdivided into four main histomorphological groups: Pineal-parenchymal tumors (PPT), germ cell tumors (GCT), glial tumors and miscellaneous tumors. The appropriate pathological classification and grading of these malignancies is essential for determining the clinical management and prognosis. However, an early diagnosis is often delayed due to unspecific clinical symptoms, and histological support is not always decisive to identify the diversity of tumors of the PR. The present study aimed to characterize 18 tumors of the PR using comparative genomic hybridization. All the tumors were primarily surgically resected without any previous irradiation or chemotherapy. In addition to chromosomal aberrations in PPT and different GCTs of the PR, the present study described, for the first time, the chromosomal changes in a few rare entities (solitary-fibrous and neuroendocrine tumors) of the PR. The tumors in the study, regardless of histology and World Health Organization grade, were characterized by frequent gains at 7, 9q, 12q, 16p, 17 and 22q, and losses at 13q. While the detection of chromosomal aberrations in these tumors appears not to be indicative enough of histological entities and their grade of malignancy, the present data may be of use to select genes of interest for higher resolution genomic analyses.

Management of CNS germinoma

The following is a general overview of the management of CNS germinomas. Over the last 35 years, CNS germinomas have become one of the pediatric brain tumors with the best outcomes with a greater than 85% overall survival over 5 years. This is in part due to the fact that germinomas are very responsive to chemotherapy and radiation. Some of the major challenges going forward will be to find ways to minimize the adverse effects of our treatments particularly with regard to radiation and to improve the quality of life of patients who develop neurologic, neurocognitive and/or endocrine deficiencies.

Tumoral markers in tumors of the pineal region

In cases of pineal tumors, a germ cell tumor should always be suspected. As some of them are secreting tumors, tumoral markers (AFP and/or hGC) are an important part of the diagnostic process. Their positivity either in the serum and/or in the cerebrospinal fluid may lead to an accurate diagnosis, avoiding a potentially dangerous surgical biopsy. Follow-up of tumoral markers is useful during and after treatment in order to monitor response to chemotherapy or a remission status.

Proteomic analyses of CSF aimed at biomarker development for pediatric brain tumors

Primary brain tumors cumulatively represent the most common solid tumors of childhood and are the leading cause of cancer related death in this age group. Traditionally, molecular findings and histological analyses from biopsies of resected tumor tissue have been used for diagnosis and classification of these diseases. However, there is a dearth of useful biomarkers that have been validated and clinically implemented for pediatric brain tumors. Notably, diseases of the central nervous system (CNS) can be assayed through analysis of cerebrospinal fluid (CSF) and as such, CSF represents an appropriate medium to obtain liquid biopsies that can be informative for diagnosis, disease classification and risk stratification. Proteomic profiling of pediatric CNS malignancies has identified putative protein markers of disease, yet few effective biomarkers have been clinically validated or implemented. Advances in protein quantification techniques have made it possible to conduct such investigations rapidly and accurately through proteome-wide analyses. This review summarizes the current literature on proteomics in pediatric neuro-oncology and discusses the implications for clinical applications of proteomics research. We also outline strategies for translating effective CSF proteomic studies into clinical applications to optimize the care of this patient population.