Serum and Cerebrospinal Fluid Human Chorionic Gonadotropin (hCG) and alpha-fetoprotein (AFP) in Intracranial Germ Cell Tumors

Intracranial Germinomas: Diagnosis, Pathogenesis, Clinical Presentation, and Management

PURPOSE OF REVIEW

Intracranial germinomas constitute a rare brain tumor entity of unknown etiology, characterized by unique histopathology and molecular biology. In this manuscript, we review the literature focusing on the epidemiology, histopathology with molecular biology, clinical presentation with emphasis on tumor location, diagnostic workup, and current treatment strategies with related clinical outcomes of intracranial germinomas.

RECENT FINDINGS

Although the optimal treatment strategy remains a matter of debate, intracranial germinomas respond well to radiotherapy, chemotherapy, or a combination of both and are characterized by very high cure and survival rates. It is well-known that early discrimination of germinomas from other intracranial neoplasms facilitates the timely initiation of appropriate treatment, thereby contributing to the reduction of morbidity as well as mortality. Ongoing research will need to be directed towards discovering and refining reliable parameters for early diagnosis and evaluation of prognosis in patients with intracranial germinomas.

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.

Epidemiology, Management, and Long-Term Survival Outcomes of Intracranial Typical Site Germinomas: An Analysis of the Surveillance, Epidemiology, and End-Results (SEER) Database

BACKGROUND

The correlations of epidemiological characteristics and clinical outcomes with different tumor sites in patients with intracranial typical site germinomas (ICTSGs) have not yet been well established. We analyzed ICTSGs using a multicenter database, focusing on its demographic, management patterns, and long-term survival outcomes.

METHODS

Patients diagnosed with ICTSGs were selected from the Surveillance, Epidemiology, and End-Results (SEER) database. Demographic information and management patterns of ICTSGs were extracted for data analysis stratified by different tumor sites. Kaplan-Meier curves were used to evaluate the survival outcome stratified by treatment, tumor site and tumor size.

RESULTS

Among the 327 patients enrolled in the study, 16.21% had tumors located in the suprasellar region and 83.79% in the pineal region. The proportion of males was significantly higher among pineal germinomas (94.16 vs 66.04%; P < .001). Smaller tumors (<24 mm) were more common in the suprasellar region (37.74 vs 18.87%; P < .001). A higher percentage of patients with suprasellar germinomas underwent surgery. Radiotherapy (RT) and chemotherapy (CT) was, respectively, administered to 82.97 and 60.61% of patients during the treatment period, with no significant difference between suprasellar and pineal germinomas. CT plus RT was the most common treatment modality for both pituitary (30.19%) and pineal (33.94%) germinomas. Both RT and CT were associated with improved long-term survival. No survival difference was observed between suprasellar and pineal germinomas.

CONCLUSIONS

Despite significant differences in epidemiology and management, pineal and suprasellar germinomas had a similar long-term clinical outcome.

The clinical and imaging features of infratentorial germinomas compared with supratentorial ectopic germinomas

BACKGROUND

Intracranial germinoma is very sensitive to chemoradiotherapy, while the risk of infratentorial operation is high. The accurate diagnosis can provide the more reasonable treatment, avoiding the unnecessary therapeutic risks.

PURPOSE

To evaluate the clinical and imaging features of infratentorial germinomas.

MATERIAL AND METHODS

The clinical and imaging data of 13 infratentorial germinomas were collected and compared with 17 supratentorial germinomas in the same period. The clinical and imaging findings were retrospectively analyzed.

RESULTS

Infratentorial germinomas were more common in female patients than supratentorial ones (53.85% vs. 11.76%, P = 0.020). The mean age of the infratentorial group (23.0 ± 10.2 years) was significantly older than that of supratentorial group (12.4 ± 3.3 years, P = 0.003). Most infratentorial germinomas (12/13, 92.31%) underwent surgical resection, while stereotactic biopsy was more common in the supratentorial group (11/17, 64.71%, P = 0.002). Infratentorial germinomas were significantly smaller than supratentorial ones (25.85 ± 8.13 mm vs. 37.18 ± 18.11 mm, P = 0.031). Cystic lesions were more common in supratentorial germinomas (12/17, 70.59%), while most infratentorial germinomas were solid lesions (10/13, 76.92%, P = 0.025). On post-contrast T1-weighted imaging, obvious enhancement was more common in infratentorial germinomas than in supratentorial ones (100% vs. 64.71%, P = 0.024).

CONCLUSION

In addition to the common findings with supratentorial germinomas, infratentorial lesions have some specific clinical and imaging features.

The Role of Liquid Biopsies in Pediatric Brain Tumors

Early detection and serial therapeutic monitoring for pediatric brain tumors are essential for diagnosis and therapeutic intervention. Currently, neuropathological diagnosis relies on biopsy of tumor tissue and surgical intervention. There is a great clinical need for less invasive methods to molecularly characterize the tumor and allow for more reliable monitoring of patients during treatment and to identify patients that might potentially benefit from targeted therapies, particularly in the setting where diagnostic tissue cannot be safely obtained. In this literature review, we highlight recent studies that describe the use of circulating tumor DNA, circulating tumor cells, circulating RNA and microRNA, and extracellular vesicles as strategies to develop liquid biopsies in pediatric central nervous system tumors. Liquid biomarkers have been demonstrated using plasma, urine, and cerebrospinal fluid. The use of liquid biopsies to help guide diagnosis, determine treatment response, and analyze mechanisms of treatment resistance is foreseeable in the future. Continued efforts to improve signal detection and standardize liquid biopsy procedures are needed for clinical application.

Secreting Germ Cell Tumors of the Central Nervous System: A Long-Term Follow-up Experience

INTRODUCTION

Due to the rarity of nongerminomatous germ cell tumors (NGGCT) with non-standard treatment as yet, we report retrospectively our 30 year experience with chemotherapy followed by craniospinal irradiation (CSI), plus a boost of whole ventricular irradiation (WVI)/tumor bed (TB), tailored to pre-radiation chemotherapy response.

METHODS

Between 1988 and 2016, 28 patients received four cycles of PEB (cisplatin/etoposide/bleomycin), then CSI, and two further PEB cycles. Between 1988 and1994, CSI was 25.5 Gy for patients in complete remission (CR), 30 Gy if in partial remission (PR) or metastatic, with a boost to TB up to 45-54 Gy. In the period of 1995-2010, the boost included WVI and any extra-ventricular tumor sites up to 45 Gy. After 2010, CSI was reduced to 25.5 Gy for all non-metastatic patients, and a boost was given only to TB up to 40.5/45.5 Gy, depending on patients' CR/PR status. After 2003, patients with alfafetoprotein (αFP) > 1000 ng/mL received intensified treatment, also including autologous stem cell transplantation.

RESULTS

Among 28 patients (23 males; median age 12 years, 6 metastatic), 25 responded to PEB, and three progressed (PD) after one to four cycles; 26 received radiotherapy obtaining 13 CR, 7 PR and 5 stable disease (SD), 1 PD; 6 (21%) died (5 for disease, 1 for pneumonia while in CR). Five-year overall survival (OS) and progression-free survival (PFS) were both 81%; 10 year OS and PFS 81% and 76%, respectively (median follow-up 11 years).

CONCLUSIONS

Survival for children with NGGCT, independently from disease extent, was encouraging. Further studies should elucidate which patients could benefit from reduced volume and dose irradiation.

Baseline serum/cerebrospinal fluid ratio of carcinoembryonic antigen and carbohydrate antigen series biomarkers in non-neoplastic diseases: a cross-sectional study on 224 patients

BACKGROUND

The measurement of carcinoembryonic antigen, carbohydrate antigen series biomarkers in cerebrospinal fluid (CSF), is useful for the diagnosis of brain metastasis and leptomeningeal metastases to a certain extent. Their serum/CSF ratios may be of benefit to earlier diagnosis and treatment. However, the normal reference values of the ratios were not available. Accordingly, in this study we analyzed the serum/CSF ratios of tumor markers levels in non-neoplastic diseases patients for possible normal values.

MATERIAL AND METHODS

We screened our database for paired CSF and serum samples which have been collected by lumbar puncture. 224 pairs of CSF and serum samples were obtained and compared. The 97.5th percentile, maximum value, and their serum/CSF ratios were obtained.

RESULTS

The 97.5th percentile and maximum value of CSF CEA, CA125, CA19-9, CA15-3, CA724, and CYFRA21-1 concentration for overall participants were 0.572 μ/mL, 4.343 μ/mL, 2.872 μ/mL, 2.108 μ/mL, 1.62 μ/mL, and 1.997 μ/mL, respectively. Gender had no significant difference in these CSF biomarkers except CA15-3. The 97.5th percentile serum/CSF ratio of CEA, CA125, CA19-9, CA15-3, CA724, and CYFRA21-1 level were 34.554, 44.772, 51.232, 20.941, 20.737, and 5.389 respectively. The serum/CSF ratios in different age groups were also described.

CONCLUSIONS

Here, serum/CSF ratios of six tumor markers were determined in non-neoplastic diseases. The usefulness of this index for diagnosis, management, and prognostic utility of leptomeningeal metastases must be validated in larger cohort studies over the long term.

Tumor-Associated CSF MicroRNAs for the Prediction and Evaluation of CNS Malignancies

Cerebrospinal fluid (CSF) is a readily reachable body fluid that is reflective of the underlying pathological state of the central nervous system (CNS). Hence it has been targeted for biomarker discovery for a variety of neurological disorders. CSF is also the major route for seeding metastases of CNS malignancies and its analysis could be informative for diagnosis and risk stratification of brain cancers. Recently, modern high-throughput, microRNAs (miRNAs) measuring technology has enabled sensitive detection of distinct miRNAs that are bio-chemicallystable in the CSF and can distinguish between different types of CNS cancers. Owing to the fact that a CSF specimen can be obtained with relative ease, analysis of CSF miRNAs could be a promising contribution to clinical practice. In this review, we examine the current scientific knowledge on tumor associated CSF miRNAs that could guide diagnosis of different brain cancer types, or could be helpful in predicting disease progression and therapy response. Finally, we highlight their potential applications clinically as biomarkers and discuss limitations.

Nanotechnologies in glycoproteomics

Protein glycosylation, as an important post-translational modification, is implicated in a number of ailments. Applying proteomic approaches, including mass spectrometry (MS) analyses that have played a significant role in biomarker detection and early diagnosis of diseases, to the study of glycoproteins or glycopeptides will facilitate a deeper understanding of many physiological functions and biological pathways involved in cancer, inflammatory and degenerative diseases. The abundance of glycopeptides and their ionization potential are relatively lower compared to those of non-glycopeptides; therefore, sample enrichment is necessary for glycopeptides prior to MS analysis. The application of nanotechnology in the past decade has been rapidly penetrating into many diverse scientific research disciplines. Particularly in what we now refer to as the “glycoproteomics area”, nanotechnologies have enabled enhanced sensitivity and specificity of glycopeptide detection in complex biological fluids, which are critical for disease diagnosis and monitoring. In this review, we highlight some recent studies that combine the capabilities of specific nanotechnologies with the comprehensive features of glycoproteomics. In particular, we focus on the ways in which nanotechnology has facilitated the detection of glycopeptides in complex biological samples and enhanced their characterization by MS, in terms of intensity and resolution. These studies reveal an increasingly important role for nanotechnology in helping to overcome certain technical challenges in biomarker discovery, in general, and glycoproteomics research, in particular.

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.

Circulating biomarkers of CNS tumors: an update

CNS tumors comprise approximately 120 histological subtypes. Advances of surgical resection, radiation and systemic therapy have increased the survival rates of distinct types of CNS tumor patients. There is growing interest in identification of diagnostic, prognostic or predictive blood biomarkers in CNS tumor patients, and emerging studies indicate that certain brain tumors are indeed associated with distinct profiles of circulating factors such as proteins (e.g., glial fibrillary acidic protein), DNA fragments (e.g., containing mutated IDH) or miRNAs (e.g., miRNA-21). However, blood biomarker research in neurooncology is, for the most part, at an exploratory level, and adequately powered and well-designed studies are needed to translate the available interesting but preliminary findings into actual clinical use. In this review, the current knowledge on circulating biomarkers of CNS tumors is briefly summarized.

Proteomic profiling of cerebrospinal fluid identifies prostaglandin D2 synthase as a putative biomarker for pediatric medulloblastoma: A pediatric brain tumor consortium study

The aims of this study were to demonstrate the feasibility of centrally collecting and processing high-quality cerebrospinal fluid (CSF) samples for proteomic studies within a multi-center consortium and to identify putative biomarkers for medulloblastoma in CSF. We used 2-DE to investigate the CSF proteome from 33 children with medulloblastoma and compared it against the CSF proteome from 25 age-matched controls. Protein spots were subsequently identified by a combination of in-gel tryptic digestion and MALDI-TOF TOF MS analysis. On average, 160 protein spots were detected by 2-DE and 76 protein spots corresponding to 25 unique proteins were identified using MALDI-TOF. Levels of prostaglandin D2 synthase (PGD2S) were found to be six-fold decreased in the tumor samples versus control samples (p<0.00001). These data were further validated using ELISA. Close examination of PGD2S spots revealed the presence of complex sialylated carbohydrates at residues Asn(78) and Asn(87) . Total PGD2S levels are reduced six-fold in the CSF of children with medulloblastoma most likely representing a host response to the presence of the tumor. In addition, our results demonstrate the feasibility of performing proteomic studies on CSF samples collected from patients at multiple institutions within the consortium setting.

Is biopsy needed to guide management for all patients with presumed intracranial ectopic germinomas

Intracranial germinomas may arise in sites besides pineal and suprasellar regions, which we call intracranial ectopic germinomas (IEGs). In this article we evaluated the rationality of radiotherapy in IEGs when histopathological evidence could not be obtained. Criteria for initiating experimental radiotherapy in patients with clinically presumed IEGs was established according to the reports published in this field and the experience gained from our five histopathologically verified IEG patients. When patients suspected to have IEGs met the criteria, radiotherapy following standard protocol was performed. Strict criteria was also employed to evaluate the effectiveness of radiotherapy after completion of initial experimental dose of radiation and to determine whether total dose of radiation should be delivered. Seven patients clinically suspected to have IEGs met the criteria for radiotherapy. Radiotherapy was evaluated as effective in six patients immediately after completion of initial experimental dose of radiation and the remaining dose was delivered. However, effectiveness of initial experimental radiotherapy was not testified until 2 months later in the other one patient. Total dose of radiation was completed and satisfactory results achieved in all seven patients. In conclusion, the histopathological verification is not mandatory for radiotherapy in patients with IEGs when histopathological evidence can not be obtained. Strict criteria should be followed to enroll patients to undergo experimental radiotherapy.

Clinical, hormonal and imaging findings in 27 children with central diabetes insipidus

Clinical, auxological, biological and neuroradiological characteristics of 27 children with central diabetes insipidus (CDI) were retrospectively analysed. Median age at diagnosis was 8.6 years (range: 0.3-16.1 years). Final aetiologies were postsurgical infundibulo-hypophyseal impairment (n=7), cerebral tumour (n=8), Langerhans cell histiocytosis (n=3), septo-optic dysplasia (n=1), ectrodactyly ectodermal dysplasia clefting syndrome (n=1), and idiopathic (n=7). In the non-postsurgical CDI patients, major cumulative and often subtle presenting manifestations were: polyuria (n=20), polydipsia (n=19), fatigue (n=11), nycturia (n=10), growth retardation (n=9), and headache (n=9). An associated antehypophyseal insufficiency, mainly somatotropic, was documented in 11 children. All patients except one who initially had a cerebral tomography, underwent magnetic resonance imaging revealing the lack of the physiological posterior pituitary hyperintense signal. One third of the idiopathic patients initially had a thickened pituitary stalk. All patients with idiopathic CDI were intensively followed up with 3-monthly physical examination, antehypophyseal evaluation, search for tumour markers, and cerebral MRI every 6 months. In one of them the pituitary stalk had normalized after 4.3 years. In one patient Langerhans cell histiocytosis was diagnosed after 7 months of follow-up, and in another patient a malignant teratoma was found after 2.4 years of follow-up.

CONCLUSION

CDI may be the early sign of an evolving cerebral process. The association of polyuria-polydipsia should incite a complete endocrine evaluation and a meticulous MRI evaluation of the hypothalamo-hypophyseal region. A rigorous clinical and neuroradiologic follow-up is mandatory to rule out an evolving cerebral process and to detect associated antehypophyseal insufficiencies.

Intracranial germinoma: a rare but important differential diagnosis in children with growth retardation

AIM

Intracranial germinoma is a rare malignant tumour in childhood with an excellent prognosis under adequate therapy. Finding the right diagnosis at an early stage is difficult because of the slow-growing tumour and the resulting lack of clinical symptoms.

METHODS

Our patients with histologically secured germinoma were retrospectively assessed concerning growth retardation, pituitary hormone status, magnetic resonance imaging scan results and clinical symptoms to find out whether there is a leading parameter.

RESULTS

In all our patients, the leading symptom was growth retardation of at least 2 y before being diagnosed.

CONCLUSION

Growth retardation seems to be a very early sign of germinoma in the suprasellar region. Therefore, early neuroradiological imaging combined with pituitary hormone status should be considered in every paediatric patient with a history of secondary growth retardation.

Mammalian embryonic cerebrospinal fluid proteome has greater apolipoprotein and enzyme pattern complexity than the avian proteome

During early stages of embryo development, the brain cavity is filled with Embryonic Cerebro-Spinal Fluid, which has an essential role in the survival, proliferation and neurogenesis of the neuroectodermal stem cells. We identified and analyzed the proteome of Embryonic Cerebro-Spinal Fluid from rat embryos (Rattus norvegicus), which includes proteins involved in the regulation of Central Nervous System development. The comparison between mammalian and avian Embryonic Cerebro-Spinal Fluid proteomes reveals great similarity, but also greater complexity in some protein groups. The pattern of apolipoproteins and enzymes in CSF is more complex in the mammals than in birds. This difference may underlie the greater neural complexity and synaptic plasticity found in mammals. Fourteen Embryonic Cerebro-Spinal Fluid gene products were previously identified in adult human Cerebro-Spinal Fluid proteome, and interestingly they are altered in patients with neurodegenerative diseases and/or neurological disorders. Understanding these molecules and the mechanisms they control during embryonic neurogenesis may contribute to our understanding of Central Nervous System development and evolution, and these human diseases.