Primary Central Nervous System Germ Research Articles

A novel lactate dehydrogenase-based risk score model to predict the prognosis of primary central nervous system germ cell tumor treated with chemoradiotherapy

BackgroundThe prognostic role of lactate dehydrogenase (LDH) has been confirmed in many malignant tumors, but the role of serum LDH in primary central nervous system germ cell tumor (GCT) remains unknown. This study aimed to assess the prognostic value of LDH in GCT patients and develop a nomogram to predict prognosis in patients undergoing chemoradiotherapy. MethodsA total of 161 patients with GCT were included in this study. Using a restricted cubic spline (RCS) model, the optimal cutoff point for LDH was determined to be 217 U/L. The survival of GCT patients was evaluated using the Kaplan-Meier method and log-rank test to analyze the effects of LDH levels. Univariate Cox regression, multivariate Cox regression, and LASSO Cox regression were conducted to identify prognostic factors, which were incorporated into a nomogram for predicting overall survival (OS). The predictive accuracy of the nomogram was assessed using the C-index, calibration curve, area under the time-dependent receiver operating characteristic curve (time-dependent AUC), and risk group stratification. The net benefits of the nomogram at different threshold probabilities were quantified using decision curve analysis (DCA). ResultsThe high-LDH group had significantly shorter OS compared to the low-LDH group (P = 0.016). Based on the SYSUCC cohort, three variables were shown to be significant factors for OS and were incorporated in the nomogram: LDH, histopathology, and dissemination. It showed good discrimination ability, with C-index of 0.789 (95% CI, 0.671–0.907). Additionally, the clinical usefulness of the nomogram was confirmed by calibration curves and time-dependent AUC. DCA further highlighted the potential of the nomogram to guide clinical treatment strategies for patients. Moreover, there was a significant difference in OS among patients categorized into different risk groups (P < 0.001). ConclusionLDH levels may serve as a reliable predictor for assessing the therapeutic effect of chemoradiotherapy in GCT. The developed nomogram exhibits high accuracy in predicting survival outcomes, aiding in the classification of prognostic groups, and supporting informed clinical decision-making.

Primary central nervous system germ cell tumors in children and young adults: A review of controversies in diagnostic and treatment approach

Primary central nervous system (CNS) germ cell tumors (GCT) are a rare heterogenous group of cancers, arising most commonly in the second decade of life. Through several clinical trials conducted around the world by various groups, the treatment approach for CNS GCT has advanced substantially with generally improved overall outcomes. In recent years, the goal of clinical trials has been focused on reduction of the radiotherapy burden and minimization of long-term toxicity. This review summarizes the current diagnostic and treatment regimens for CNS GCT, examines the controversies associated with these approaches, gaps in contemporary knowledge, and underscores the challenges we face. We also explore future directions in the management of CNS GCT with the ultimate overall aim of preserving curative outcomes, identifying novel biomarkers, and mitigating neurocognitive, endocrine, and psychological toxicity through prospective clinical studies.

LINC-10. The Adequate Treatment of Children and Adolescents with Primary Central Nervous System Germ Cell Tumors (CNS GCT) in a Developing Country

INTRODUCTION: Primary central nervous system germ cell tumors (CNS GCT) are a heterogeneous group of malignancies that can be divided into germinomas and non-germinomatous GCT (NGGCT), accounting for 2-3% of brain tumors in children/adolescents in the Western hemisphere. The study aim is to report the ability to adequately treat Brazilian patients with CNSGCT through a consortium protocol, reporting their treatment, response and survival. Methods: Since 2013, 58 patients with histologic and/or tumor marker (TM) diagnosis of germinoma with/without HCGβ levels ≤200mIU/ml (n=43), five of them between 100-200mIU/ml, received carboplatin/ etoposide (4 cycles) and NGGCT (n=15), received carboplatin/etoposide/cyclophosphamide (6 cycles), all followed by 18Gy ventricular field irradiation and primary site(s) boost. Autologous hematopoietic cell transplant (AuHCT) was undertaken for NGGCT slow responders. Results: Mean age 13.2 years, 42 males. Diagnosis was made by TM (n=19), surgery (n=25) and both (n=12). Two bifocal cases with negative TM and inconclusive biopsy were treated as germinoma. Primary tumor location was pineal (n=30), suprasellar (n=16), bifocal (n=11) and basal ganglia/thalamus (n=1). Eighteen had ventricular/spinal spread. Second-look surgery occurred in seven patients. For the germinoma group, 36 achieved complete responses (CR) after chemotherapy, seven showed residual teratoma/scar. For the NGGCT after 4/6 cycles, six patients showed CR, two failure/progression and seven partial responses (five with negative TM). Two with positive TM underwent AuHCT. Radiotherapy was utilized as described, except in three patients. Four NGGCT patients died (two disease progression, two other causes with no disease). Toxicity was mostly grade 3/4 neutropenia/thrombocytopenia during chemotherapy. At a median follow-up of 40 months, event-free and overall survival was 100% for germinoma and 64.5% NGGCT. Conclusion: The proposed treatment was feasible to be performed in a developing country, with suitable survival even with VFI dose reduction to 18Gy.

GCT-18. Endoscopic third ventriculostomy (ETV) and tumor biopsy are not associated with relapse rate or patterns in primary central nervous system (CNS) germ cell tumor (GCT)

Abstract BACKGROUND: ETV and tumor biopsy are central to the surgical management of children with primary CNS GCT. An ETV creates a communication between the intraventricular compartment and the subarachnoid spaces and decompartmentalizes the ventricular system. “Tumor spill” or shedding may result from surgical interventions, such as biopsy. ETV with simultaneous biopsy may impart a greater tendency for dissemination and possible distant relapse. This is a concern in CNS GCT given the attempts of irradiation field and dose reduction following chemotherapy. METHODS: We performed a retrospective review of the prospective database for the Children’s Oncology Group (COG) ACNS1123 study. Possible associations were explored among ETV, endoscopic biopsy, and combined ETV+biopsy with relapse, distant relapse, progression free survival (PFS), and time to distant relapse. RESULTS: Among 244 eligible patients, 97 ETV+/-biopsies were performed, and 30 relapses occurred. There were no associations among ETV and/or biopsy with relapse (Cochran-Mantel-Haenszel [CMH] test, with histology (germinoma vs. nongerminomatous germ cell tumor (NGGCT)) as stratification variable: ETV: p=0.3167, biopsy: p=0.3375, combined: p=0.3066), distant relapse (CMH test, ETV: p=0.4631, ETV+biopsy: p=0.6795), PFS (log-rank test, ETV: NGGCT p=0.1632, germinoma p=0.9288; biopsy: NGGCT p=0.1682, germinoma p=0.9701; ETV+Biopsy: NGGCT p=0.1306, germinoma p=0.7758), or time to distant relapse with death/local relapse as competing risk (Gray’s test, ETV: NGGCT p=0.5694, germinoma p=0.2327; biopsy: NGGCT p=0.3505, germinoma p=0.5747; ETV+Biopsy: NGGCT p=0.3988, germinoma p=0.6839). CONCLUSIONS: Based on a secondary analysis of prospective data from the ACNS1123 trial, ETV and biopsy did not impart a greater likelihood of relapse in children with primary CNS GCT treated with combined chemotherapy and irradiation. However, three tract recurrences did occur (all germinoma), suggesting that they may affect pattern of relapse. Current and future prospective trials should continue to explore associations among these variables and relapse, including patterns of relapse.

GCT-15. Multi-institutional analysis and literature review of central nervous system germ cell tumors in patients with Down syndrome

Abstract BACKGROUND: A standard-of-care has not been established for the management of patients with Down syndrome (DS) who develop primary central nervous system (CNS) germ cell tumors (GCTs) – the most common CNS neoplasm in DS – despite being more susceptible to treatment-related adverse events. METHODS: Data from large academic institutions were collected and a comprehensive review of the medical literature was conducted. RESULTS: Ten patients from six institutions (five USA, one Brazil) were reviewed. Additionally, thirty-one patients were identified in the literature from 1975-2021. Of the 41 total patients, mean age was ten years (range, birth to 35 years); males were predominant (61%). Basal ganglia were the most common tumor location (n=12; 29%), followed by posterior fossa (n=7; 17%). Sixteen patients had non-germinomatous germ cell tumors (NGGCTs) (39%), 14 had pure germinomas (34%), and eight had teratomas (20%); histology was unreported for two (5%). Nine patients (22%) experienced disease relapse, of which four died from tumor progression (one germinoma versus three teratoma). Fifteen patients (37%) experienced treatment-related complications - seven died (four germinoma versus three NGGCT). Of the germinoma patients, two died from chemotherapy-related sepsis, one from post-surgery cardiopulmonary failure, and one from Moyamoya following radiation-therapy (RT) only. Of the NGGCT patients, one died from chemotherapy-related sepsis, one from post-surgical infection, and one from pneumonia following surgery/chemotherapy/RT. Three-year overall survival (OS) was 66% for all histological types - 62% germinoma, 79% for NGGCT, and 53% for teratoma. Three-year OS for patients who received RT or chemotherapy was 71% and 75% respectively. Twenty-seven patients remain alive at latest follow-up (mean follow-up from diagnosis: 46.8 months). CONCLUSIONS: Patients with DS treated for CNS GCTs are at an increased risk of treatment-related adverse events. A different therapeutic approach may need to be considered for this patient population to mitigate treatment-related complications and long-term neurocognitive sequelae.

SURG-12. Endoscopic evaluation of ventricular dissemination in primary central nervous system (CNS) germ cell tumors (GCTs)

Abstract INTRODUCTION: Endoscopic third ventriculostomy and endoscopic tumor biopsy have become integral to the surgical management of children with primary CNS GCTs. Observing ependymal tumor dissemination at the time of endoscopic surgery has been anecdotally reported. The incidence and impact of this finding in CNS GCT has not been reported. METHODS: Baseline neurosurgery data capture forms and operative reports from the Children’s Oncology Group (COG) ACNS1123 study were reviewed for ventriculoscopic findings of suspected tumor dissemination. The association between these findings and relapse was determined using Fisher’s exact test for each stratum and the Cochran-Mantel-Haenszel test for the entire cohort. Progression-free survival (PFS) was defined as time from enrollment to relapse, progression, death, or last follow-up; and survival probabilities were estimated using the Kaplan-Meier method with log-rank tests for outcome comparisons. RESULTS: 110/244 patients (45.1%) underwent endoscopic neurosurgery. Twelve patients (10.9%) had a documented observation suggestive of metastatic disease within the ventricular compartment. Ten were in the third ventricle and two were in the lateral ventricle. Nine of 12 were nongerminomatous germ cell tumors (NGGCTs) and three were germinoma. Ventriculoscopic findings of metastatic tumor were not significantly associated with relapse in NGGCT (p=0.4091), germinoma (p=0.1832), or overall (p=0.1540); odds ratio 2.57 (95%CI:0.66–10.11). PFS was not influenced in NGGCT (Log-rank test, p=0.1953) but was negatively impacted in germinoma (p=0.0250) when tumor dissemination was found during ventriculoscopy. CONCLUSIONS: Ventriculoscopic observation of tumor dissemination was reported in 10.9% of cases. This may negatively influence outcomes in children with germinoma, though due to the small number of relapses, more data is needed to verify these findings. Ventriculoscopic observation of tumor dissemination may contribute toward more accurate staging and influence future therapy, but a larger sample size is needed. Prospective studies should routinely integrate documentation of endoscopic observation in the study protocol.

LINC-22. Primary central nervous system (CNS) germ cell tumors (GCT) in Central America and the Caribbean region: an AHOPCA 20-year experience

BACKGROUND: Primary CNS GCT are rare neoplasms in pediatrics. Treatment depends on histological subtype and extent of disease. Overall survival (OS) is above 85% in high-income countries (HIC). OBJECTIVE: To describe the experience in treating CNS GCT in 4 of 8 countries, members of AHOPCA (Asociación de Hemato-Oncología Pediátrica de Centro América) and 5-year OS. DESIGN/METHODS: We conducted a retrospective chart review of patients treated for CNS GCT. Epidemiological, clinical characteristics, histology, treatment modalities and outcome were analyzed. RESULTS: From 2001 to 2021, 45 patients were included. Guatemala: 22, Nicaragua: 15, Dominican Republic: 3 and El Salvador: 5. Thirty (66.6%) were male, mean age at diagnosis was 8.6 years (range 12 months to 17 years). Presenting symptoms were headaches/vomiting (n=26, 57.7 %), visual disturbances (n=15, 33.3%), diabetes insipidus (n=7, 15.5%). Two patients (NGGCT) presented with precocious puberty. Upfront surgery was done in 33 cases (73.33%); 21 (63.6%) germinomas, 9 (27.2%) NGGCT and 3 (9%) CNS GCT. Eight patients were diagnosed and treated based on CSF tumor marker elevation; four germinomas (BHCG 11.32-29.41mUI/mL) and four NGGCT (BHCG 84.43-201.97mUI/mL or positive AFP>10 ng/mL). Tumor locations included suprasellar (n=15, 33.3%), pineal (n=14, 31.1%), thalamus/basal ganglia (n=5, 11%), other (n=6, 13.3%); and one bifocal. Four (8.8%) had metastatic disease, 6 with positive CSF, staging data was incomplete in 25 patients (55.5%). Patients were treated with varied chemotherapy and radiotherapy modalities. Nine patients had incomplete data regarding treatment. Five-year OS was 65% (61.5% for germinoma and 56% for NGGCT). Two patients with histologically confirmed germinoma relapsed. CONCLUSIONS: Germinoma was the most common histology and there was a male predominance. More than half patients had incomplete staging data and treatment was variable. OS is lower compared to HIC. Standardized treatment protocols will aid in adequate staging, treatment planning, prevent complications and improve survival.

Long-term outcome of and prognostic factors for the primary central nervous system germ cell tumors

Long-term outcome of and prognostic factors for the primary central nervous system germ cell tumors

Primary Central Nervous System Germ Cell Tumors: A Review and Update.

Primary central nervous system (CNS) germ cell tumors (GCT) are a heterogeneous group of tumors that are still poorly understood. In North America, GCTs comprise approximately 1% of primary brain tumors in pediatric and young adult patients. GCTs can occur as pure or mixed subtypes; they are divided into germinomas, which are the most common subtype, and non-germinomatous germ cell tumors (NGGCTs), which consist of approximately one-third of GCTs and include teratomas, embryonal carcinomas, choriocarcinomas, and yolk sac tumors. While the etiology of primary CNS GCT is not entirely clear, the various subtypes are lineage-related and may involve progenitor germ cells that fail to migrate and become trapped in midline locations. Primary CNS GCT most commonly arises in the pineal region but also occur in other areas. Presenting symptoms can include headache, Parinaud syndrome, diabetes insipidus, precosious puberty, ataxia, or hemiparesis. Diagnosis of primary CNS GCTs can be difficult and is often delayed. Various imaging studies and tumor markers can assist in specific diagnosis. Treatment plans differ depending on the subtype of GCT and may vary among physicians and institutions. Germinomas have a favorable prognosis with a greater than 90% overall survival, while NGGCTs only have survival rates ranging from 40-70%. Germinomas seem to be most effectively treated with chemotherapy and radiation, while NGGCT usually require surgical resection, chemotherapy, and radiation with the exception of mature teratomas frequently curable with surgery alone. Gamma knife radiosurgery is a promising treatment that may be an effective additional treatment option. Cytogenic and molecular analyses are attempting to further specify the different GCT subtypes and are helping to direct the development of distinct therapeutic targets to improve treatment and prognosis.

360P - Primary central nervous system germ cell tumours: A single institution retrospective study

360P - Primary central nervous system germ cell tumours: A single institution retrospective study

Treatment Outcome in Patients with Primary Central Nervous System Germ Cell Tumour: Clinical Experience from a Regional Cancer Centre in North India

Background: Primary intracranial germ cell tumour is a rare entity and constitutes 2-3% of all paediatric brain tumours in Western countries. We herein intend to report the clinical features and treatment outcome of patients with primary central nervous system germ cell tumour treated at our institute. Methods: Clinical data were collected by retrospective chart review from 2006 to 2012. Histopathology slides were reviewed and relevant immunohistochemistry stains were done. Overall survival (OS) and progression-free survival (PFS) were analysed by the Kaplan-Meier product-limit method. Results: Twenty patients met the study criterion (male:female = 7:3). Median age at presentation was 13 years. Tumour location was pineal in 10 patients, suprasellar in 6, thalamic in 2, basal ganglion in 1, and spinal in 1. Leptomeningeal spread was noted in 1 patient at presentation. Surgical resection was gross-total in 7 patients (35%), near-total in 2 (10%), subtotal in 4 (20%), and limited to biopsy in 6 (30%). The tumours were germinomatous, non-germinomatous, and of mixed germ cell subtype in 17 patients (85%), 2 patients (10%), and 1 patient (5%), respectively. Systemic chemotherapy (median of 4 cycles) was given to 19 patients (95%). The common regimens used were a combination of bleomycin, etoposide and cisplatin (BEP) in 14 patients (70%) and etoposide and cisplatin (EP) in 5 patients (25%). Radiation therapy (40-50 Gy in conventional fractionation; median of 42 Gy) was delivered to 17 patients (85%): local radiation in 6 and whole ventricular, whole brain, and craniospinal irradiation followed by a boost in 5, 3, and 3 patients, respectively. After a median follow-up of 44.52 months, 17 patients (85%) were in complete response and 3 (15%) had progressive disease. Death and disease recurrence were noted in 6 patients (30%) and 1 patient, respectively. Median OS and PFS were not reached. The actuarial rates of OS at 3 and 5 years were 75.8 and 68.9%, respectively. The actuarial rates of PFS at both 3 and 5 years were 81.6%. Conclusion: Multimodality treatment consisting of limited resection followed by platinum-based systemic chemotherapy and radiotherapy (40-50 Gy) is a reasonable treatment strategy in patients of primary central nervous system germ cell tumour in a developing nation.

Cystic Trophoblastic Tumor Arising in a Post Chemotherapy Pediatric Primary Central Nervous System Germ Cell Tumor

Cystic Trophoblastic Tumor Arising in a Post Chemotherapy Pediatric Primary Central Nervous System Germ Cell Tumor

Expression and mutation of c-Kit in intracranial germ cell tumors: A single-centre retrospective study of 30 cases in China.

Although primary central nervous system (CNS) germ cell tumors (GCTs) are one of the most treatable types of malignant brain tumor, a subset of patients remain resistant to standard chemotherapy. Gain-of-function mutations of the c-Kit gene, and KIT protein expression, have been observed in a number of GCTs, including testicular seminoma, ovarian dysgerminoma and mediastinal seminoma in various ethnic groups. Although a small number of studies have reported the role of c-Kit in CNS GCTs, few have focused on Chinese patients exhibiting CNS GCTs. In the present study, the frequency and location of c-Kit mutations and KIT protein expression levels in CNS GCTs were investigated in 30 patients, between January 1994 and October 2014. Immunohistochemical assays suggested that KIT protein expression was present in 59.1% patients (66.7% in males and 42.9% in females); however, no statistically significant correlation was identified between KIT protein expression and patient clinicopathological features. By performing PCR amplification and direct sequencing, 4 mutational hot spots of the c-Kit gene (exons 9, 11, 13 and 17) were examined, and c-Kit gene mutation was identified in 1/17 (5.9%) CNS germinoma cases. This mutation was located in exon 11 at codon 557–558 WK (Tryptophan-Lysine). No c-Kit gene mutations were detected in non-germinomatous GCTs. Imatinib, a tyrosine kinase inhibitor, may be an effective treatment against standard chemotherapy-resistant CNS germinoma patients exhibiting c-Kit mutations.

Prediction of radiosensitivity in primary central nervous system germ cell tumors using dynamic contrast-enhanced magnetic resonance imaging.

To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for predicting tumor response to radiotherapy in patients with suspected primary central nervous system (CNS) germ cell tumors (GCTs). DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic (ROC) curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve. A significant elevation in transfer constant (K(trans)) and extravascular extracellular space (Ve) (P=0.000), as well as a significant reduction in rate constant (Kep) (P=0.000) was observed in tumors. K(trans), relative K(trans), and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K(trans) showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value (PPV) of 95.8%, and negative predictive value (NPV) of 100%. Relative K(trans) appeared promising in predicting tumor response to radiation therapy (RT). It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.

The clinical characteristics and treatment outcome of 57 children and adolescents with primary central nervous system germ cell tumors.

Primary central nervous system germ cell tumors (CNS-GCTs) in children and adolescents have unique clinical features and methods of treatment compared with those in adults. There is little information about Chinese children and adolescents with CNS-GCTs. Therefore, in this study we retrospectively analyzed the clinical features and treatment outcome of Chinese children and adolescents with primary CNS-GCTs. Between January 2002 and December 2012, 57 untreated patients from a single institution were enrolled. They were diagnosed with CNS-GCTs after pathologic or clinical assessment. Of the 57 patients, 41 were males and 16 were females, with a median age of 12.8 years (range, 2.7 to 18.0 years) at diagnosis; 43 (75.4%) had non-germinomatous germ cell tumors (NGGCTs) and 14 (24.6%) had germinomas; 44 (77.2%) had localized disease and 13 (22.8%) had extensive lesions. Fifty-three patients completed the prescribed treatment, of which 18 underwent monotherapy of surgery, radiotherapy, or chemotherapy, and 35 underwent multimodality therapies that included radiotherapy combined with chemotherapy or surgery combined with chemotherapy and/or radiotherapy. PEB (cisplatin, etoposide, and bleomycin) protocol was the major chemotherapy regimen. The median follow-up time was 32.3 months (range, 1.2 to 139 months). Fourteen patients died of relapse or disease progression. The 3-year event-free survival (EFS) and overall survival rates for all patients were 72.2% and 73.8%, respectively. The 3-year EFS was 92.9% for germinomas and 64.8% for NGGCTs (P = 0.064). The 3-year EFS rates for patients with NGGCTs who underwent monotherapy and multimodality therapies were 50.6% and 73.5%, respectively (P = 0.042). Our results indicate that multimodality therapies including chemotherapy plus radiotherapy were better treatment option for children and adolescents with CNS-GCTs.

Incidence of Primary Central Nervous System Germ Cell Tumors in Childhood: A Regional Survey in Kumamoto Prefecture in Southern Japan

Background/Aims: Central nervous system germ cell tumors (CNS-GCTs) are relatively rare. While their incidence was thought to be higher in East Asia than the USA, recent evidence suggests the difference between Japan and the USA is not statistically significant. The aim of this study was to determine the rate of pediatric primary CNS-GCTs in Kumamoto prefecture, Japan. Methods: We surveyed 6,615 new cases of primary intracranial tumors diagnosed in Kumamoto prefecture between 1989 and 2011. Among these, 251 (3.8%) occurred in patients younger than 15 years. The age-adjusted incidence rates were calculated by the direct method using 5-year age groupings; the incidence in the total Japanese population in the year 2000 was the standard. Results: During the 23-year period, 70 cases of primary GCT were diagnosed. Of these tumors, 31 (44.3%) arose in patients aged between 0 and 14 years (22 boys, 9 girls). Their tumor location was pineal in 45.2%; the other sites were nonpineal. There were more germinomas (64.5%) than nongerminomas (35.5%) in this group. The age-adjusted annual incidence rate was 0.45 cases (boys: 0.64, girls: 0.28) per 10⁵ children. At 2.29, the ratio of CNS-GCTs was higher in these boys than girls. Our data showed higher rates than data from CBTRUS 2012 (0.18/10⁵), SEER 2008 (0.15/10⁵) and Germany (0.10/10⁵). Conclusions: Our survey showed that the incidence of primary CNS-GCTs in children was higher in Kumamoto prefecture than in the USA and other Western countries, suggesting that racial backgrounds play a role.

Primary CNS germ cell tumors: current epidemiology and update on treatment

Primary central nervous system (CNS) germ cell tumors (GCTs) are a heterogeneous group of lesions that account for 0.5 % of all primary brain and CNS tumors, occurring at an incidence rate of 0.10 per 100,000 person-years in the United States with approximately 90 % of the cases before the age of 20 years. Primary CNS GCTs demonstrate a remarkable difference in incidence based on gender and location within the brain with males having a 15:1 incidence in the pineal region while the gender incidence is nearly 1:1 in the rest of the brain. Also, historically the incidence was noted to be significantly higher in Japan and East Asia, but recent studies in Japan demonstrate similar incidence as in the United States. They are broadly classified as germinomas and non-germinomatous germ cell tumors (NGGCTs) based on clinicopathologic features. Germinomas are sensitive to treatment with radiotherapy and chemotherapy with high cure rates and carry an excellent prognosis, while NGGCTs display various forms of differentiation, have a poorer prognosis and are refractory to therapy. Standard management of CNS GTCs remains unsettled and ongoing research aims to achieve best possible survival rates and post-treatment quality of life by reduction in treatment intensity.

Surgical management of primary central nervous system germ cell tumors

The successful treatment of children with a primary CNS germ cell tumor can be greatly influenced by the neurosurgeon involved in the diagnostic and therapeutic care of these children. Variability in surgical philosophies no doubt exists due to the relatively infrequent incidence of these tumors, a lack of consensus regarding diagnostic and therapeutic approaches, and the advent of recent surgical innovations. Many of these issues were discussed at the Second International Symposium on Central Nervous System Germ Cell Tumors through presented abstracts and invited presentations. The neurosurgical aspects of these proceedings are summarized here in an effort to present the agreed-upon and debated issues that may confront the pediatric neurosurgeon.

Pediatric primary central nervous system germ cell tumors of different prognosis groups show characteristic miRNome traits and chromosome copy number variations

BackgroundIntracranial pediatric germ cell tumors (GCTs) are rare and heterogeneous neoplasms and vary in histological differentiation, prognosis and clinical behavior. Germinoma and mature teratoma are GCTs that have a good prognosis, while other types of GCTs, termed nongerminomatous malignant germ cell tumors (NGMGCTs), are tumors with an intermediate or poor prognosis. The second group of tumors requires more extensive drug and irradiation treatment regimens. The mechanisms underlying the differences in incidence and prognosis of the various GCT subgroups are unclear.ResultsWe identified a distinct mRNA profile correlating with GCT histological differentiation and prognosis, and also present in this study the first miRNA profile of pediatric primary intracranial GCTs. Most of the differentially expressed miRNAs were downregulated in germinomas, but miR-142-5p and miR-146a were upregulated. Genes responsible for self-renewal (such as POU5F1 (OCT4), NANOG and KLF4) and the immune response were abundant in germinomas, while genes associated with neuron differentiation, Wnt/β-catenin pathway, invasiveness and epithelial-mesenchymal transition (including SNAI2 (SLUG) and TWIST2) were abundant in NGMGCTs. Clear transcriptome segregation based on patient survival was observed, with malignant NGMGCTs being closest to embryonic stem cells. Chromosome copy number variations (CNVs) at cytobands 4q13.3-4q28.3 and 9p11.2-9q13 correlated with GCT malignancy and clinical risk. Six genes (BANK1, CXCL9, CXCL11, DDIT4L, ELOVL6 and HERC5) within 4q13.3-4q28.3 were more abundant in germinomas.ConclusionsOur results integrate molecular profiles with clinical observations and provide insights into the underlying mechanisms causing GCT malignancy. The genes, pathways and microRNAs identified have the potential to be novel therapeutic targets.

Isochromosome 12p and polysomy 12 in primary central nervous system germ cell tumors: frequency and association with clinicopathologic features

Germ cell tumors arising within the central nervous system are rare neoplasms that typically occur along midline structures in children and young adults. Although isochromosome 12p is established as a frequent chromosomal abnormality in testicular germ cell tumors, studies examining isochromosome 12p in primary central nervous system germ cell tumors are limited. Herein, we studied 24 primary central nervous system germ cell tumors from 23 patients using fluorescence in situ hybridization to determine the frequency of isochromosome 12p in these neoplasms. Of the 24 primary central nervous system germ cell tumors, fluorescence in situ hybridization detected isochromosome 12p in 6 (25%) tumors, whereas 11 (46%) tumors showed polysomy (multiple copies) of chromosome 12. One case with isochromosome 12p also showed increased 12p independent of isochromosome 12p formation. The remaining 7 tumors yielded a normal result by fluorescence in situ hybridization. Clinical follow-up of this patient cohort indicated 8 patients (32%) developed a recurrence, although no association was demonstrated between the presence or absence of chromosomal 12 abnormalities and tumor relapse. We confirm that isochromosome 12p is less frequent in primary central nervous system germ cell tumors relative to testicular germ cell tumors, and although our numbers are limited, the presence or absence of isochromosome 12p does not appear to impact tumor recurrence. Similarly, although polysomy 12 was identified in nearly half of our central nervous system germ cell tumors, no prognostic significance was attributed to this abnormality. These results suggest that fluorescence in situ hybridization studies for isochromosome 12p or polysomy 12 may have limited use in the evaluation of these rare neoplasms.