Integrated clinical, histopathological, and molecular data analysis of 190 central nervous system germ cell tumors from the iGCT Consortium

Whole-exome sequencing has revealed novel genetic characteristics in intracranial germ cell tumours in the Chinese

AIMS

Intracranial germ cell tumour (IGCT) is a type of rare central nervous system tumour that mainly occurs in children and adolescents, with great variation in its incidence rate and molecular characteristics in patients from different populations. The genetic alterations of IGCT in the Chinese population are still unknown.

METHODS AND RESULTS

In this study, 47 patients were enrolled and their tumour specimens were analysed by whole-exome sequencing (WES). We found that KIT was the most significantly mutated gene (15/47, 32%), which mainly occurred in the germinoma group (13/20, 65%), and less frequently in NGGCT (2/27, 7%). Copy number variations (CNVs) of FGF6 and TFE3 only appeared in NGGCT patients (P = 0.003 and 0.032, respectively), while CNVs of CXCR4, RAC2, PDGFA, and FEV only appeared in germinoma patients (P = 0.004 of CXCR4 and P = 0.027 for the last three genes). Compared with a previous Japanese cohort, the somatic mutation rates of RELN and SYNE1 were higher in the Chinese. Prognostic analysis showed that the NF1 mutation was associated with shorter overall survival and progression-free survival in IGCT patients. Clonal evolution analysis revealed an early branched evolutionary pattern in two IGCT patients who underwent changes in the histological subtype or degree of differentiation during disease surveillance.

CONCLUSION

This study indicated that Chinese IGCT patients may have distinct genetic characteristics and identified several possible genetic alterations that have the potential to become prognostic biomarkers of NGGCT patients.

Non-invasive differential diagnosis of teratomas from other intracranial germ cell tumours using MRI-based fractal and radiomic analyses

OBJECTIVES

The histologic subtype of intracranial germ cell tumours (IGCTs) is an important factor in deciding the treatment strategy, especially for teratomas. In this study, we aimed to non-invasively diagnose teratomas based on fractal and radiomic features.

MATERIALS AND METHODS

This retrospective study included 330 IGCT patients, including a discovery set (n = 296) and an independent validation set (n = 34). Fractal and radiomic features were extracted from T1-weighted, T2-weighted, and post-contrast T1-weighted images. Five classifiers, including logistic regression, random forests, support vector machines, K-nearest neighbours, and XGBoost, were compared for our task. Based on the optimal classifier, we compared the performance of clinical, fractal, and radiomic models and the model combining these features in predicting teratomas.

RESULTS

Among the diagnostic models, the fractal and radiomic models performed better than the clinical model. The final model that combined all the features showed the best performance, with an area under the curve, precision, sensitivity, and specificity of 0.946 [95% confidence interval (CI): 0.882-0.994], 95.65% (95% CI: 88.64-100%), 88.00% (95% CI: 77.78-96.36%), and 91.67% (95% CI: 78.26-100%), respectively, in the test set of the discovery set, and 0.944 (95% CI: 0.855-1.000), 85.71% (95% CI: 68.18-100%), 94.74% (95% CI: 83.33-100%), and 80.00% (95% CI: 58.33-100%), respectively, in the independent validation set. SHapley Additive exPlanations indicated that two fractal features, two radiomic features, and age were the top five features highly associated with the presence of teratomas.

CONCLUSION

The predictive model including image and clinical features could help guide treatment strategies for IGCTs.

CLINICAL RELEVANCE STATEMENT

Our machine learning model including image and clinical features can non-invasively predict teratoma components, which could help guide treatment strategies for intracranial germ cell tumours (IGCT).

KEY POINTS

• Fractals and radiomics can quantitatively evaluate imaging characteristics of intracranial germ cell tumours. • Model combing imaging and clinical features had the best predictive performance. • The diagnostic model could guide treatment strategies for intracranial germ cell tumours.

Histopathological, Demographic, and Clinical Signatures of Medulla Oblongata Germ Cell Tumors: A Case Report With the Review of Literature

The medulla oblongata is one of the rarest sites of occurrence for germ cell tumors (GCTs) of the central nervous system. As there is scant data regarding epidemiology, clinical presentations, optimal intervention, and long-term prognosis, we aimed to delineate the features of this rare entity by presenting our representative case and performing a quantitative review of the literature. A 24-year-old woman presented to our department with vertigo and swallowing difficulties. Magnetic resonance imaging revealed a homogenously enhanced exophytic lesion arising from the medulla oblongata and extending to the fourth ventricle. Surgical resection was performed and a histological diagnosis of pure germinoma was made. The patient underwent chemotherapy and whole-ventricular irradiation. No recurrence has been experienced for 4 months after the surgery. According to the literature, the prognosis of GCTs at the medulla oblongata seems no worse than those at typical sites. Striking features including occurrence at an older age, female preponderance, and a predominance of germinoma were noteworthy. The pattern of local recurrence suggests extensive radiation coverage is not a prerequisite. Special attention is needed for cardiac and respiratory functions as the main factors eliciting mortality.

Pediatric Neuro-oncology

OBJECTIVE

This article reviews the most common pediatric brain tumors, neurocutaneous syndromes, treatment-related neurotoxicities, and the long-term outcomes of survivors.

LATEST DEVELOPMENTS

In the era of molecular diagnostics, the classification, management, and prognostication of pediatric brain tumors and neurocutaneous syndromes has been refined, resulting in advancements in patient management. Molecular diagnostics have been incorporated into the most recent World Health Organization 2021 classification. This knowledge has allowed for novel therapeutic approaches targeting the biology of these tumors with the intent to improve overall survival, decrease treatment-related morbidity, and improve quality of life. Advances in management have led to better survival, but mortality remains high and significant morbidity persists. Current clinical trials focus on tumor biology targeted therapy, deescalation of therapy, and multimodal intensified approaches with targeted therapy in more high-risk tumors.

ESSENTIAL POINTS

Molecular diagnostics for pediatric brain tumors and neurocutaneous syndromes have led to novel therapeutic approaches targeting the biology of these tumors with the goals of improving overall survival and decreasing treatment-related morbidity. Further understanding will lead to continued refinement and improvement of tumor classification, management, and prognostication.

Advances in genetic abnormalities, epigenetic reprogramming, and immune landscape of intracranial germ cell tumors

Intracranial germ cell tumors (IGCTs) are a rare subtype of central nervous system neoplasms that predominantly affect young individuals and exhibit a higher incidence in East Asia. IGCTs can be pathologically divided into two main categories: germinomas and non-germinomatous germ cell tumors (NGGCTs). Despite the scarcity of this disease, recent advancements in molecular biology techniques have facilitated the discovery of the inherent genetic and molecular characteristics of IGCTs. Somatic mutations that result in the activation of the KIT/RAS/MAPK and PI3K/AKT/mTOR pathways, chromosomal instability leading to characteristic changes in chromosomal fragments (notably 12p gain), and potentially diagnostic miRNAs (such as miR-371a-3p) may provide valuable insights for the efficient diagnosis, targeted therapy, and prognosis evaluation of IGCTs. Additionally, transcriptomic and methylomic analyses have provided new perspectives on the intrinsic development of IGCTs, further elucidating their equivalence with GCTs at other sites. The evaluation of the tumor immune landscape may guide prognosis prediction and immunotherapy for IGCT patients. Nevertheless, current research still faces challenges such as the absence of basic laboratory research systems, a single source of large sample research data, and a limited overall volume of research. The incorporation of larger sample sizes, the implementation of more innovative evaluation systems, and the employment of novel experimental methods are urgently required to become the focus of future research.

Unraveling the impact of upfront chemotherapy and proton beam therapy on treatment outcome and follow-up in central nervous system germ cell tumors: a single center experience

Background

Germ cell tumors (GCT) account for a minority of central nervous system (CNS) malignancies, highly prevalent in adolescents and young adults. Despite their aggressive biological behavior, prognosis is excellent in most cases with risk stratified treatment, consisting in a combination of chemotherapy and radiotherapy. Whole ventricular irradiation (WVI) and craniospinal irradiation, the treatment of choice for localized and metastatic disease, pose significant risk of collateral effects, therefore proton beam radiation (PBT) has been recently proposed for its steep dose fallout.

Materials and methods

We report our experience in a consecutive series of 17 patients treated for CNS GCT at our Institution from 2015 to 2021.

Results

Most frequent lesion location were sellar/suprasellar (35%) and bifocal germinoma (35%), followed by pineal (18%) and thalamic (12%). Two patients (12%), had evidence of disseminated disease at the time of diagnosis. At the latest follow-up all but one patient showed complete response to treatment. The only relapse was successfully rescued by additional chemotherapy and PBT. PBT was well tolerated in all cases. No visual, neurological or endocrinological worsening was documented during and after treatment. Neuropsychological evaluation demonstrated preservation of cognitive performance after PBT treatment.

Conclusions

Our data, albeit preliminary, strongly support the favourable therapeutic profile of PBT for the treatment of CNS germ cell tumors.

Pineal/germ cell tumors and pineal parenchymal tumors

INTRODUCTION

Pineal region tumors (PRTs) are tumors arising from the pineal gland and the paraspinal structures. These tumors are rare and heterogeneous that account for 2.8-10.1% and 0.6-3.2% of tumors in children and in all ages, respectively. Almost all types and subtypes of CNS tumors may be diagnosed in this region. These tumors come from cells of the pineal gland (pinealocytes and neuroglial cells), ectopic primordial germ cells (PGC), and cells from adjacent structures. Hence, PRTs are consisted of pineal parenchyma tumors (PPTs), germ cell tumors (GCTs), neuroepithelial tumors (NETs), other miscellaneous types of tumors, cystic tumors (epidermoid, dermoid), and pineal cyst in addition. The symptoms of PRTs correlate to the increased intracranial cranial pressure due to obstructive hydrocephalus and dorsal midbrain compression. The diagnostic imaging studies are mainly MRI of brain (with and without gadolinium) along with a sagittal view of whole spine. Serum and/or CSF AFP/β-HCG helps to identify GCTs. The treatment of PRTs is consisted of the selection of surgical biopsy/resection, handling of hydrocephalus, neoadjuvant and/or adjuvant therapy according to age, tumor location, histopathological/molecular classification, grading of tumors, staging, and threshold value of markers (for GCTs) in addition.

METHODS

In this article, we review the following focus points: 1. Background of pineal region tumors. 2. Pineal GCTs and evolution of management. 3. Molecular study for GCTs and pineal parenchymal tumors. 4. Review of surgical approaches to the pineal region. 5. Contribution of endoscopy. 6. Adjuvant therapy (chemotherapy, radiotherapy, and combination). 7.

FUTURE DIRECTION

RESULTS

In all ages, the leading three types of PRTs in western countries were PPTs (22.7-34.8%), GCTs (27.3-34.4%), and NETs (17.2-28%). In children and young adults, the leading PRTs were invariably in the order of GCTs (40-80.5%), PPTs (7.6-21.6%), NETs (2.4-37.5%). Surgical biopsy/resection of PRTs is important for precision diagnosis and therapy. Safe resection with acceptable low mortality and morbidity was achieved after 1970s because of the advancement of surgical approaches, CSF shunt and valve system, microscopic and endoscopic surgery. Following histopathological diagnosis and classification of types and subtypes of PRTs, in PPTs, through molecular profiling, four molecular groups of pineoblastoma (PB) and their oncogenic driver were identified. Hence, molecular stratified precision therapy can be achieved.

CONCLUSION

Modern endoscopic and microsurgical approaches help to achieve precise histopathological diagnosis and molecular classification of different types and subtypes of pineal region tumors for risk-stratified optimal, effective, and protective therapy. In the future, molecular analysis of biospecimen (CSF and blood) along with AI radiomics on tumor imaging integrating clinical and bioinformation may help for personalized and risk-stratified management of patients with pineal region tumors.

Distinct patterns of copy number alterations may predict poor outcome in central nervous system germ cell tumors

We have previously reported that 12p gain may predict the presence of malignant components and poor prognosis for CNS germ cell tumor (GCT). Recently, 3p25.3 gain was identified as an independent predictor of poor prognosis for testicular GCT. Eighty-one CNS GCTs were analyzed. Copy number was calculated using methylation arrays. Five cases (6.2%) showed 3p25.3 gain, but only among the 40 non-germinomatous GCTs (NGGCTs) (5/40, 12.5%; p = 0.03). Among NGGCTs, those with a yolk sac tumor component showed a significantly higher frequency of 3p25.3 gain (18.2%) than those without (1.5%; p = 0.048). NGGCTs with gain showed significantly shorter progression-free survival (PFS) than those without (p = 0.047). The 3p25.3 gain and 12p gain were independent from each other. The combination of 3p25.3 gain and/or 12p gain was more frequent among NGGCTs with malignant components (69%) than among those without (29%; p = 0.02). Germinomas containing a higher number of copy number alterations showed shorter PFS than those with fewer (p = 0.03). Taken together, a finding of 3p25.3 gain may be a copy number alteration specific to NGGCTs and in combination with 12p gain could serve as a marker of negative prognosis or treatment resistance. Germinoma with frequent chromosomal instability may constitute an unfavorable subgroup.

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.

Neuroimaging of pediatric tumors of the sellar region-A review in light of the 2021 WHO classification of tumors of the central nervous system

Sellar/suprasellar tumors comprise about 10% of all pediatric Central Nervous System (CNS) tumors and include a wide variety of entities, with different cellular origins and distinctive histological and radiological findings, demanding customized neuroimaging protocols for appropriate diagnosis and management. The 5th edition of the World Health Organization (WHO) classification of CNS tumors unprecedently incorporated both histologic and molecular alterations into a common diagnostic framework, with a great impact in tumor classification and grading. Based on the current understanding of the clinical, molecular, and morphological features of CNS neoplasms, there have been additions of new tumor types and modifications of existing ones in the latest WHO tumor classification. In the specific case of sellar/suprasellar tumors, changes include for example separation of adamantinomatous and papillary craniopharyngiomas, now classified as distinct tumor types. Nevertheless, although the current molecular landscape is the fundamental driving force to the new WHO CNS tumor classification, the imaging profile of sellar/suprasellar tumors remains largely unexplored, particularly in the pediatric population. In this review, we aim to provide an essential pathological update to better understand the way sellar/suprasellar tumors are currently classified, with a focus on the pediatric population. Furthermore, we intend to present the neuroimaging features that may assist in the differential diagnosis, surgical planning, adjuvant/neoadjuvant therapy, and follow-up of this group of tumors in children.

Cancer Stem Cells in Tumours of the Central Nervous System in Children: A Comprehensive Review

Cancer stem cells (CSCs) are a subgroup of cells found in various kinds of tumours with stem cell characteristics, such as self-renewal, induced differentiation, and tumourigenicity. The existence of CSCs is regarded as a major source of tumour recurrence, metastasis, and resistance to conventional chemotherapy and radiation treatment. Tumours of the central nervous system (CNS) are the most common solid tumours in children, which have many different types including highly malignant embryonal tumours and midline gliomas, and low-grade gliomas with favourable prognoses. Stem cells from the CNS tumours have been largely found and reported by researchers in the last decade and their roles in tumour biology have been deeply studied. However, the cross-talk of CSCs among different CNS tumour types and their clinical impacts have been rarely discussed. This article comprehensively reviews the achievements in research on CSCs in paediatric CNS tumours. Biological functions, diagnostic values, and therapeutic perspectives are reviewed in detail. Further investigations into CSCs are warranted to improve the clinical practice in treating children with CNS tumours.

Imaging of pituitary tumors: an update with the 5th WHO Classifications-part 2. Neoplasms other than PitNET and tumor-mimicking lesions

Many types of tumors can develop in the pituitary gland. In the recently revised 5th editions of the World Health Organization (WHO) classifications (2021 WHO Classification of Central Nervous System Tumors and the 2022 WHO Classification of Endocrine and Neuroendocrine Tumors), various changes have been made to the tumors other than pituitary neuroendocrine tumor (PitNET)/pituitary adenoma, as well as PitNET. Adamantinomatous craniopharyngioma and papillary craniopharyngioma are now considered separate tumors in the 5th edition of the WHO classification. Tumors positive for thyroid transcription factor 1, a marker of posterior pituitary cells, are now grouped together in the pituicyte tumor family in the 5th edition of the WHO classification of Endocrine and Neuroendocrine Tumors. Poorly differentiated chordoma is newly listed in the 5th edition of the WHO Classification of Endocrine and Neuroendocrine Tumors. In this paper, we present the latest WHO classification of pituitary tumors (adamantinomatous craniopharyngioma, papillary craniopharyngioma, pituitary blastoma, pituicyte tumor family, tumors of pituitary origin other than those of the pituicyte tumor family, germinoma, meningioma, chordoma, metastatic tumors, lymphoma, and pituitary incidentaloma), review diseases requiring differentiation from tumors (pituitary abscess, hypophysitis, pituitary hyperplasia, Rathke's cleft cyst, arachnoid cyst, and aneurysm), and discuss diagnoses based on imaging findings.

Genetic profiling of hormone-sensitive and castration-resistant prostate cancers and identification of genetic mutations prone to castration-resistant prostate cancer

BACKGROUND

Genetic profiling of patients with prostate cancer could potentially identify mutations prone to castration-resistant prostate cancer (CRPC). Here, we aimed to identify the differences in genetic profiles of patients with hormone-sensitive prostate cancer (HSPC) and CRPC and stratify HSPC patients to identify mutations associated with CRPC progression.

METHODS

A total of 103 samples were collected, including 62 DNA samples from the tumor tissues of 59 HSPC patients and 41 cell-free DNA (cfDNA) samples from prostate cancer patients at different cancer stages. Targeted sequence was conducted on both the tissue DNA and cfDNA. The associations between mutations and clinical outcomes (CRPC-free time) were analyzed using χ2 test, logistic regression analysis, Kaplan-Meier analysis, and Cox regression analysis.

RESULTS

By comparing to that of cfDNA sequencing, the results from DNA sequencing of 1-needle (80%) and mixed 12-needle (77.8%) biopsies are highly comparable. FOXA1 (30.5%), CDK12 (23.7%), and TP53 (22.0%) were the top 3 most frequently mutated genes in HSPC patients; 50.8% (30/59) and 44.1% (26/59) HSPC patients had mutations in DDR and HRR pathway, respectively. Mutations in AR and APC as well as the members involved in the regulation of stem cell pluripotency and EMT pathway were often observed in CRPC samples. We established a panel of four genetic mutations (MSH2, CDK12, TP53, and RB1) to predict the risk of CRPC early progression with concordance index = 0.609 and the area under curve of the ROC curve as 0.838.

CONCLUSIONS

In this study, we demonstrated that the cfDNA can be used in genetic profiling in prostate cancer and our newly established panel is capable of predicting which mHSPC patient has a high risk of early CRPC progression.

High endothelial venules in intracranial germinomas: Implications for lymphocytes infiltration

PURPOSE

Reactive lymphocytes are substantial components of germinoma, which are believed to be related to the favorable prognosis of this intracranial tumor and better response to immunotherapy. However, the mechanisms managing the recruitment of lymphocytes are poorly understood. High endothelial venules (HEVs) are specialized blood vessels that play key roles in lymphocyte trafficking in Lymph nodes. These vessels are associated with lymphocyte infiltration in chronic inflammatory diseases and various malignant tumors, but their distribution and implications in germinoma are unknown. This study aimed to investigate the distribution and implications of HEVs in intracranial germinomas.

METHODS

We investigated the presence and distribution of HEVs in 42 germinomas by immunohistochemical staining of peripheral node addressin (PNAd) and transmission electron microscopic examination. The correlation of the densities of HEVs with the extent of T and B lymphocyte infiltration and several clinicopathological characteristics were also analyzed to determine whether HEVs are responsible for lymphocyte recruitment and their roles in anti-tumor immunity in germinoma.

RESULTS

PNAd-positive HEVs were detected in 31% (13/42) of germinomas, and their presence correlated with abundant infiltrating CD3+ T cells, CD20 + B cells and CD8+ cytotoxic T lymphocytes (p = 0.0410, 0.0023, and 0.0061, respectively). Higher HEVs density was also correlated with several clinicopathological parameters, which are recognized indicators for favorable prognosis in germinomas, including typical tumor location (p = 0.0093), lower tumor cell content (p = 0.0428), and younger age at diagnosis (p = 0.0121). Furthermore, bioinformatics analysis showed HEVs-associated genes mainly enriched in immune-related Gene Ontology terms, including innate immune response, inflammatory response, and B cell receptor signaling pathway. The xCell analysis revealed that germinomas with higher HEVs enrichment scores had increased levels of the immune score, microenvironment score, dendritic cells, CD8+ central memory T-cells, CD4+ memory T-cells, and B-cells.

CONCLUSIONS

Our findings indicate that HEVs could contribute to lymphocyte recruitment in germinomas, thus may serve as a predictor of favorable prognosis and better response to immunotherapy in this intracranial tumor.

Implications of deferred diagnosis of paediatric intracranial germ cell tumours

AIMS

This study analysed the clinical features of a cohort of children with intracranial germ cell tumours (IC-GCTs). We retrospectively reviewed timelag between symptoms onset, clinic-radiological findings, diagnosis and outcomes.

METHODS

Symptoms at diagnosis were divided into four groups: (1) raised intracranial pressure (RICP); (2) visual impairment; (3) endocrinopathies; (4) other. Total diagnostic interval (TDI), defined as the interval between symptom onset (including retrospective recall of symptoms) and definitive diagnosis of IC-GCT, was calculated and compared to survival rates.

RESULTS

Our cohort included 55 children with median follow-up of 78.9 months (0.5-249.9). The majority (63.6%) had germinomas and 10.9% were metastatic at diagnosis. IC-GCTs were suprasellar (41.8%), pineal (36.4%), bifocal (12.7%) or in atypical sites (9.1%). The most common presenting symptoms were related to RICP (43.6%); however, by the time of tumour diagnosis, 50.9% of patients had developed endocrine dysfunctions. All pineal GCTs manifested with RICP or visual impairment. All suprasellar GCTs presented with endocrinopathies. TDI ranged between 0.25 and 58.5 months (median 4 months). Pineal GCTs had the shortest TDI (median TDI 1 month versus 24 months in suprasellar GCTs, p < .001). TDI > 6 months was observed in 47.3% of patients and was significantly associated with endocrine presenting symptoms. No statistically significant difference was found in progression-free survival and overall survival between patients with TDI > 6 months and with TDI ≤ 6 months.

CONCLUSION

Approximately half of the IC-GCT patients in this cohort had TDI > 6 months. These presented mostly with endocrine deficits. TDI > 6 months was not associated with increased relapse or mortality rates.

Targeted treatment of solid tumors in pediatric precision oncology

The treatment of childhood solid cancer has markedly evolved in recent years following a refined molecular characterization and the introduction of novel targeted drugs. On one hand, larger sequencing studies have revealed a spectrum of mutations in pediatric tumors different from adults. On the other hand, specific mutations or immune dysregulated pathways have been targeted in preclinical and clinical studies, with heterogeneous results. Of note, the development of national platforms for tumor molecular profiling and, in less measure, for targeted treatment, has been essential in the process. However, many of the available molecules have been tested only in relapsed or refractory patients, and have proven poorly effective, at least in monotherapy. Our future approaches should certainly aim at improving the access to molecular characterization, to obtain a deeper picture of the distinctive phenotype of childhood cancer. In parallel, the implementation of access to novel drugs should not only be limited to basket or umbrella studies but also to larger, multi-drug international studies. In this paper we reviewed the molecular features and the main available therapeutic options in pediatric solid cancer, focusing on available targeted drugs and ongoing investigations, aiming at providing a useful tool to navigate the heterogeneity of this promising but complex field.

Brain and Spinal Tumors Originating from the Germ Line Cells

Primary central nervous system germ cell tumors (CNS GCTs) are part of the GCTs in children and adults. This tumor entity presents with geographic variation, age, and sex predilection. There are two age peaks of incidence distribution at the first few months of life and in adolescence. CNS GCTs are heterogeneous in histopathological subtypes, locations, and tumor marker (AFP, β-hCG) secretions. In the WHO CNS tumor classification, GCTS are classified as germinoma and nongerminomatous GCT (NGGCT) with different subtypes (including teratoma). Excluding mature teratoma, the remaining NGGCTs are malignant (NGMGCT). In teratoma, growing teratoma syndrome and teratoma with somatic-type malignancy should be highlighted. The common intracranial locations are pineal region, neurohypophysis (NH), bifocal pineal-NH, basal ganglia, and cerebral ventricle. Above 50% of intracranial GCTs (IGCTs) present obstructive hydrocephalus. Spinal tumors are rare. Age, locations, hydrocephalus, and serum/CSF titer of β-hCG correlate with clinical manifestations. Delayed diagnosis is common in tumors arising in neurohypophysis, bifocal, and basal ganglia resulting in the increasing of physical dysfunction and hormonal deficits. Staging work-up includes CSF cytology for tumor cells and contrast-enhanced MRI of brain and spine for macroscopic metastasis before treatment commences. The therapeutic approach of CNS GCTs integrates locations, histopathology, staging, tumor marker level, and therapeutic classification. Treatment strategies include surgical biopsy/excision, chemotherapy, radiotherapy (single or combination). Secreting tumors with consistent imaging may not require histopathological diagnosis. Primary germinomas are highly radiosensitive and the therapeutic aim is to maintain high survival rate using optimal radiotherapy regimen with/without chemotherapy combination. Primary NGNGCTs are less radiosensitive. The therapeutic aim is to increase survival utilizing more intensive chemotherapy and radiotherapy. The negative prognostic factors are residue disease at the end of treatment and serum or CSF AFP level >1000 ng/mL at diagnosis. In refractory or recurrent NMGGCTs, besides high-dose chemotherapy, new therapy is necessary. Molecular profiling and analysis help for translational research. Survivors of pediatric brain tumors frequently experience cancer-related cognitive dysfunction, physical disability, pituitary hormone deficiency, and other CNS complications after cranial radiotherapy. Continuous surveillance and assessment may lead to improvements in treatment protocols, transdisciplinary interventions, after-treatment rehabilitation, and quality of life.

Proton therapy for pediatric diencephalic tumors

Diencephalic tumors tend to be low grade tumors located near several critical structures, including the optic nerves, optic chiasm, pituitary, hypothalamus, Circle of Willis, and hippocampi. In children, damage to these structures can impact physical and cognitive development over time. Thus, the goal of radiotherapy is to maximize long term survival while minimizing late effects, including endocrine disruption leading to precocious puberty, height loss, hypogonadotropic hypogonadism, and primary amenorrhea; visual disruption including blindness; and vascular damage resulting in cerebral vasculopathy. Compared to photon therapy, proton therapy offers the potential to decrease unnecessary dose to these critical structures while maintaining adequate dose to the tumor. In this article, we review the acute and chronic toxicities associated with radiation for pediatric diencephalic tumors, focusing on the use of proton therapy to minimize treatment-related morbidity. Emerging strategies to further reduce radiation dose to critical structures will also be considered.

A 2-step prediction model for diagnosis of germinomas in the pineal region

Background

Germinomas are sensitive to radiation and chemotherapy, and their management distinctly differs from other kinds of pineal region tumors. The aim of this study was to construct a prediction model based on clinical features and preoperative magnetic resonance (MR) manifestations to achieve noninvasive diagnosis of germinomas in pineal region.

Methods

A total of 126 patients with pineal region tumors were enrolled, including 36 germinomas, 53 nongerminomatous germ cell tumors (NGGCTs), and 37 pineal parenchymal tumors (PPTs). They were divided into a training cohort (n = 90) and a validation cohort (n = 36). Features were extracted from clinical records and conventional MR images. Multivariate analysis was performed to screen for independent predictors to differentiate germ cell tumors (GCTs) and PPTs, germinomas, and NGGCTs, respectively. From this, a 2-step nomogram model was established, with model 1 for discriminating GCTs from PPTs and model 2 for identifying germinomas in GCTs. The model was tested in a validation cohort.

Results

Both model 1 and model 2 yielded good predictive efficacy, with c-indexes of 0.967 and 0.896 for the diagnosis of GCT and germinoma, respectively. Calibration curve, decision curve, and clinical impact curve analysis further confirmed their predictive accuracy and clinical usefulness. The validation cohort achieved areas under the receiver operating curves of 0.885 and 0.926, respectively.

Conclusions

The 2-step model in this study can noninvasively differentiate GCTs from PPTs and further identify germinomas, thus holding potential to facilitate treatment decision-making for pineal region tumors.

MicroRNA-profiling of miR-371~373- and miR-302/367-clusters in serum and cerebrospinal fluid identify patients with intracranial germ cell tumors

PURPOSE

Intracranial germ cell tumors (iGCT) comprise germinoma and non-germinoma. Their diagnosis predominantly relies on biopsy as only one-fifth of patients present with elevated biomarkers (AFP/ß-HCG) in serum or cerebrospinal fluid (CSF). MicroRNAs (miR/miRNA) have emerged as non-invasive biomarkers in extracranial GCT and may potentially facilitate non-invasive diagnosis in iGCT.

METHODS

We analyzed eight miRNAs in serum and CSF from the miR-371~373- and miR-302/367-clusters and four miRNAs differentially expressed in iGCT tissue (miR-142-5p/miR-146a-5p/miR-335-5p/miR-654-3p) from eight iGCT patients (age 10-33 years) and 12 control subjects by pre-amplified RT-qPCR. MiR-30b-5p (serum) and miR-204-5p (CSF) acted as reference genes. ΔC_t-values were expressed as [Formula: see text] after standardization against controls.

RESULTS

Between iGCT and control patients' serum ΔC_t-values of miR-371a-3p (p = 0.0159), miR-372-3p (p= 0.0095, miR-367 (p = 0.0190), miR-302a (p = 0.0381) and miR-302d-3p (p = 0.0159) differed significantly. Discriminatory pattern in CSF was similar to serum as miR-371a (p = 0.0286), miR-372-3p (p = 0.0028), miR-367-3p (p = 0.0167) and miR-302d-3p (p = 0.0061) distinguished between patients and controls. Abundant [Formula: see text] levels of each of these miRNAs were found across all serum and CSF samples including biomarker-negative patients.

CONCLUSION

With the largest data set so far, we underline the suitability of miR-371a, miR-372, miR-367 and miR-302d in serum and CSF for diagnosis of iGCT, particularly in biomarker-negative germinoma. Diagnosis of iGCT by miRNA analysis is a feasible and valid approach, particularly as serum can be readily obtained by a less invasive procedure. MiRNA analysis may discriminate iGCT from other tumors with similar radiological findings and may allow to monitor response to therapy as well as early relapse during follow-up.

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.

Primary midbrain germinoma relapse-free for 5 years: A case report

Background

The biology and clinical course of intracranial germinomas differ as per their location of occurrence. Germinoma of the primary midbrain is particularly rare, and its clinical features, treatment strategies, and long-term prognosis remain uncertain.

Case Description

A 39-year-old man who had been diagnosed with midbrain germinoma by open biopsy through the occipital transtentorial approach had undergone chemoradiotherapy and achieved 5 years with no recurrence.

Conclusion

Germinomas should be considered as a differential diagnosis for adolescents and young adult men with mesencephalic tumors, and reliable sampling followed by chemoradiotherapy must be performed.

Genomic characterization of intracranial teratomas using whole genome sequencing

Background

Intracranial teratoma is a rare neoplasm of the central nervous system, often classified into mature and immature types and occurs mainly in children and adolescents. To date, there has been no comprehensive genomic characterization analysis of teratoma due to its rarity of the cases.

Methods

Forty-six patients with intracranial teratomas were collected and 22 of them underwent whole-exome sequencing, including 8 mature teratomas and 14 immature teratomas. A comprehensive analysis was performed to analyze somatic mutations, copy number variants (CNVs), mutational signatures, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway in our cohort.

Results

The most common somatic mutated gene in intracranial teratomas was CARD11 (18%) and IRS1 (18%), followed by PSMD11, RELN, RRAS2, SMC1A, SYNE1 and ZFHX3, with mutation rates of 14% for the latter six genes. Copy number variation was dominated by amplification, among which ARAF (50%), ATP2B3 (41%), GATA1 (41%), ATP6AP1 (36%), CCND2 (36%) and ZMYM3 (36%) were the most frequently amplified genes. Copy number deletion of SETDB2 and IL2 only appeared in immature teratoma (43% and 36%, respectively), but not in mature teratoma (p = 0.051 and 0.115, respectively). Prognostic analysis showed that TP53 mutations might be associated with poor prognosis of intracranial teratomas patients.

Conclusions

Our study revealed the genetic characteristics of intracranial teratoma which might be valuable for guiding future targeted therapies.

Long-term consequences of residual lesions after chemoradiotherapy in patients with germinoma at onset

OBJECTIVE

In patients with intracranial germ cell tumors, residual lesions are sometimes observed after completion of primary chemoradiotherapy. Although salvage resection of these end-of-treatment residual lesions is recommended for patients with nongerminomatous germ cell tumors, the necessity of early salvage resection for those with germinoma is not clear. The aim of this study was to investigate the frequency of residual germinoma lesions after primary chemoradiotherapy, as well as their management, long-term consequences, and prognosis.

METHODS

The authors retrospectively reviewed patients who were primarily treated for germinoma between 2002 and 2021. Residual lesions were evaluated with MRI with and without contrast enhancement within 2 weeks after chemoradiotherapy. The decision to perform salvage resection of residual lesions was at the discretion of the treating physicians. The change in appearance of residual lesions was assessed with serial MRI. Overall survival (OS), progression-free survival (PFS), and recurrence pattern were also investigated.

RESULTS

Sixty-nine patients were treated with chemoradiotherapy for germinoma, with a mean follow-up period of 108 months. Residual lesions were radiologically observed in 30 patients (43.5%). Among these, 5 patients (3 with pineal lesions and 2 with basal ganglia lesions) underwent salvage resection. Pathological examination revealed teratomatous components in 3 patients, whereas no tumoral components were identified in 2 patients. One patient with a basal ganglia lesion showed worsening of hemiparesis postoperatively. The remaining 25 patients received watchful observation without surgical intervention. Chronological periodic radiological change in residual lesions was evaluated in 21 patients. One year after primary treatment, the size of the residual lesions was stable and had decreased in 10 and 11 patients, respectively. None of the lesions increased in size. The 10-year PFS and OS rates were 96.7% and 97.3% in patients without residual lesions (n = 39), and 87.1% and 100% in patients with residual lesions (n = 30), respectively. Presence of residual lesions had no significant effect on PFS or OS. All recurrences occurred at distant sites or via dissemination without progression of the primary tumor site, regardless of the presence of residual lesion.

CONCLUSIONS

End-of-treatment residual lesions are not rare in patients with germinoma, and these residual lesions seldom show progression. Because of the potential risk of surgical complications, the indication for early salvage surgery for residual lesions should be carefully determined. Watchful observation is recommended for the majority of these cases.

Multiparametric Framework Magnetic Resonance Imaging Assessment of Subtypes of Intracranial Germ Cell Tumors Using Susceptibility Weighted Imaging, Diffusion-Weighted Imaging, and Dynamic Susceptibility-Contrast Perfusion-Weighted Imaging Combined With Conventional Magnetic Resonance Imaging

BACKGROUND

Intracranial germ cell tumors (iGCTs) are classified into two pathological subtypes (germinomas [GEs] and nongerminomatous germ cell tumors [NGGCTs]), with distinct treatment strategy and prognosis. Accurate preoperative determination of iGCT subtypes is essential to guide clinical decision-making and prognosis assessment.

PURPOSE

To investigate the diagnostic value of diffusion-weighted imaging (DWI), susceptibility weighted imaging (SWI), and dynamic susceptibility-contrast perfusion-weighted imaging (DSC-PWI) combined with conventional magnetic resonance imaging (cMRI) in finding subtypes of iGCTs.

STUDY TYPE

Retrospective.

POPULATION

A total of 40 patients (45% male and 55% female) with iGCTs.

FIELD STRENGTH/SEQUENCE

A 3 T; &lt;T1WI, T2WI, T1WI + C, DWI, SWI, DSC-PWI&gt;.

ASSESSMENT

The parameters of DWI and DSC-PWI were calculated based on extracted parameters of multiparametric MRIs. The characteristics of SWI and cMRI were also compared in GEs and NGGCTs.

STATISTICAL TESTS

The diagnostic efficacy of the minimum apparent diffusion coefficient (ADCmin), time-to-peak (TTP), relative mean transit time (rMTT), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV) maps, and cMRI features in iGCT classification was evaluated by receiver operating characteristic curve (ROC) analyses. We calculated the sensitivity, specificity, AUC, and Youden index of the hybrid MR evaluation methods. A prospective cohort (five GEs and five NGGCTs) was designed as a simulation set to test the model. The significance threshold was set at P &lt; 0.01.

RESULTS

The ADCmin (1039.100 ± 453.830 vs. 1400.050 ± 394.650), rCBF values (20.650 ± 6.260 vs. 51.170 ± 6.570), and TTP values (24.450 ± 3.160 vs. 28.950 ± 5.120) were significantly lower in GEs than in NGGCTs. The combination of ADCmin, DSC-PWI, and cMRI showed the heights AUC (AUC = 0.962). The iGCT multiparametric framework showed the AUC was 0.958 in the simulation set.

DATA CONCLUSION

The iCGT multiparametric framework might be an effective diagnostic approach of iGCT subtype. The application of cMRI (T1WI, T2WI, and Gd-T1WI) with advanced imaging modalities (DWI, SWI, and PWI) had the best performance for classifying iGCT subtypes.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Factors Influencing Craniospinal Relapse of Intracranial Germinoma After Complete Remission

OBJECTIVE

To evaluate the pathomechanism of the recurrence of intracranial germinoma after complete response and to confirm the association of the initial magnetic resonance imaging and therapeutic factors with recurrence.

METHODS

This study included patients who were followed up for ≥5 years and who were treated in our hospital from 1980 to 2021. Those with germinoma and germinoma with syncytiotrophoblastic giant cells were diagnosed pathologically. Data were categorizedbased on "gender," "single region," "intraventricular dissemination at the initial diagnosis," "hydrocephalus," "types of radiation therapy (RT)," and "chemotherapy." Fisher's exact probability test was used to assess differences between the no recurrence and recurrence groups.

RESULTS

Among 43 patients, 34 had no recurrence, 5 had delayed recurrence (≥60 months), and 4 had early recurrence (<60 months). Follow-up periods were 143.5 (60-380), 198 (88-222), and 132.5 (75-291) months for the no recurrence, delayed recurrence, and early recurrence groups, respectively. Five patients with delayed recurrence showed 3 intracranial lesions and 2 spinal lesions. Four patients with early recurrence showed 3 intracranial lesions and 1 spinal lesion. Differences in delayed recurrences (focal RT vs. RT including whole-ventricle system; P = 0.0491) were significant in Fisher's exact test.

CONCLUSIONS

RT including the whole-ventricle system reduces delayed craniospinal relapses including dissemination, local, and distant recurrences even ≥5 years after complete response in patients with primary central nervous system germinoma.

A Case of Non-Germinomatous Germ Cell Tumors of the Frontal Lobe Arising From the Lateral Ventricle With a Synchronous Pineal Lesion

Non-germinomatous germ cell tumours (NGGCT) are rare intracranial tumours that account for 1% to 3% of cases. They are usually seen in the pineal and suprasellar regions. NGGCT of the frontal lobe arising from the lateral ventricle with a synchronous pineal lesion is uncommon. We present a case of NGGCT with multifocal lesions in the pineal gland, frontal lobe, and pons treated with chemotherapy followed by craniospinal irradiation (CSI).

Pathogenesis of central nervous system germ cell tumors

Intracranial germ cell tumors (IGCTs) are clinically rare. They are more common in children and adolescents and the incidence in Asia is higher than in Western countries. Histologically, IGCTs are divided into germinoma and non-germinomatous germ cell tumor (NGGCT). Germinoma is sensitive to radiotherapy and chemotherapy and therefore, patients with germinoma have a good prognosis. However, NGGCTs, especially those with malignant components, are not sensitive to radiotherapy and chemoradiotherapy, leading to a poor prognosis. The pathogenesis of IGCTs is not fully understood. By summarizing previous literature, we found that the occurrence of IGCTs may be related to the following factors: chromosomal instability, MAPK and/or PI3K pathway changes, and DNA hypomethylation in pure germ cell tumors.

Biomarkers for risk-based treatment modifications for CNS germ cell tumors: Updates on biological underpinnings, clinical trials, and future directions

CNS germ cell tumors (GCTs) preferentially occur in pediatric and adolescent patients. GCTs are located predominantly in the neurohypophysis and the pineal gland. Histopathologically, GCTs are broadly classified into germinomas and non-germinomatous GCTs (NGGCTs). In general, germinoma responds well to chemotherapy and radiation therapy, with a 10-year overall survival (OS) rate of approximately 90%. In contrast, NGGCTs have a less favorable prognosis, with a five-year OS of approximately 70%. Germinomas are typically treated with platinum-based chemotherapy and whole-ventricular radiation therapy, while mature teratomas can be surgically cured. Other NGGCTs require intensive chemotherapy with radiation therapy, including whole brain or craniospinal irradiation, depending on the dissemination status and protocols. Long-term treatment-related sequelae, including secondary neoplasms and cerebrovascular events, have been well recognized. These late effects have a tremendous impact in later life, especially since patients are mostly affected in childhood or young adults. Intending to minimize the treatment burden on patients, the identification of biomarkers for treatment stratification and evaluation of treatment response is of critical importance. Recently, tumor cell content in germinomas has been shown to be closely related to prognosis, suggesting that cases with low tumor cell content may be safely treated with a less intensive regimen. Among the copy number alterations, the 12p gain is the most prominent and has been shown to be a negative prognostic factor in NGGCTs. MicroRNA clusters (mir-371-373) were also revealed to be a hallmark of GCTs, demonstrating the potential for the application of liquid biopsy in the diagnosis and detection of recurrence. Recurrent mutations have been detected in the MAPK or PI3K pathways, most typically in KIT and MTOR and low genome-wide methylation has been demonstrated in germinoma; this most likely reflects the cell-of-origin primordial germ cells for this tumor type. These alterations can also be leveraged for liquid biopsies of cell-free DNA and may potentially be targeted for treatment in the future. Advancements in basic research will be translated into clinical practice and can directly impact patient management. Additional understanding of the biology and pathogenesis of GCTs will lead to the development of better-stratified clinical trials, ultimately resulting in improved treatment outcomes and a reduction in long-term treatment-related adverse effects.

Socio-behavioral dysfunction in disorders of hypothalamic-pituitary involvement: The potential role of disease-induced oxytocin and vasopressin signaling deficits

Disorders involving hypothalamic and pituitary (HPIT) structures-including craniopharyngioma, Langerhans cell histiocytosis, and intracranial germ cell tumors-can disrupt brain and endocrine function. An area of emerging clinical concern in patients with these disorders is the co-occurring socio-behavioral dysfunction that persists after standard hormone replacement therapy. Although the two neuropeptides most implicated in mammalian social functioning (oxytocin and arginine vasopressin) are of hypothalamic origin, little is known about how disease-induced damage to HPIT structures may disrupt neuropeptide signaling and, in turn, impact patients' socio-behavioral functioning. Here we provide a clinical primer on disorders of HPIT involvement and a review of neuropeptide signaling and socio-behavioral functioning in relevant animal models and patient populations. This collective evidence suggests that neuropeptide signaling disruptions contribute to socio-behavioral deficits experienced by patients with disorders of HPIT involvement. A better understanding of the biological underpinnings of patients' socio-behavioral symptoms is now needed to enable the development of the first targeted pharmacological strategies by which to manage patients' socio-behavioral dysfunction.

Endocrine manifestations of paediatric intracranial germ cell tumours: from diagnosis to long-term follow-up

PURPOSE

We examined endocrine manifestations in a cohort of paediatric patients with IC-GCTs at diagnosis and during follow-up, integrating clinical, radiological, histopathological and laboratory data.

METHODS

Diabetes insipidus (DI), growth hormone deficiency (GHD), hypothyroidism, adrenal insufficiency, precocious puberty (PP)/hypogonadism were diagnosed clinically and biochemically. The prevalence of endocrine manifestations was compared to survival rates.

RESULTS

Our population included 55 children (37 males, 18 females) diagnosed with IC-GCT with a median follow-up of 78.9 months from diagnosis (range 0.5-249.9). At tumour diagnosis, 50.9% patients displayed endocrinopathies: among them, 85.7% were affected by DI, 57.1% central adrenal insufficiency, 50% central hypothyroidism, 28.5% GHD, 10.7% hypogonadotrophic hypogonadism, 10.7% PP. These patients presented predominantly with suprasellar germinoma. If not diagnosed previously, endocrine disorders arose 15.15 months (1.3-404.2) after end of treatment (EOT) in 16.4% patients. At least one endocrinopathy was identified in 67.3% of subjects at last follow-up visit, especially GHD and adrenal insufficiency. DI, hypothyroidism, and adrenal insufficiency occurred earlier than other abnormalities and frequently preceded tumour diagnosis. Subjects with and without endocrine manifestations who survived beyond 12 months after EOT did not show significant difference in overall survival and progression-free survival (p = 0.28 and p = 0.88, respectively).

CONCLUSION

Endocrinopathies were common presenting symptoms in our population. If present at diagnosis, they often persisted hence after. The spectrum of endocrinopathies expanded during follow-up up to 33.7 years after EOT. Although they did not seem to affect survival rate in our cohort, close lifelong surveillance is mandatory to provide the best care for these patients.

Diagnosis and Treatment of Pineal Region Tumors in Adults: A EURACAN Overview

Simple Summary

Pineal region tumors are rare intracranial tumors. A deeper knowledge of these tumors’ molecular mechanisms has been gained in recent years, which has led to a new classification and new potential systemic treatments. Surgery remains the mainstay of treatment, while radiotherapy and systemic therapy depend on histological, molecular, and clinical characteristics. This paper highlights recent developments in the diagnosis and treatment of these tumors.

Abstract

Pineal region tumors are rare intracranial tumors, accounting for less than 1% of all adult intracranial tumor lesions. These lesions represent a histologically heterogeneous group of tumors. Among these tumors, pineal parenchymal tumors and germ cell tumors (GCT) represent the most frequent types of lesions. According to the new WHO 2021 classification, pineal parenchymal tumors include five distinct histotypes: pineocytoma (PC), pineal parenchymal tumors of intermediate differentiation (PPTID), papillary tumor of the pineal region (PTPR), pinealoblastoma (PB), and desmoplastic myxoid tumor of the pineal region, SMARCB1-mutant; GCTs include germinoma, embryonal carcinoma, yolk sac tumor, choriocarcinoma, teratoma, mixed GCTs. Neuroradiological assessment has a pivotal role in the diagnostic work-up, surgical planning, and follow-up of patients with pineal masses. Surgery can represent the mainstay of treatment, ranging from biopsy to gross total resection, yet pineal region tumors associated with obstructive hydrocephalus may be surgically managed via ventricular internal shunt or endoscopic third ventriculostomy. Radiotherapy remains an essential component of the multidisciplinary treatment approach for most pineal region tumors; however, treatment volumes depend on the histological subtypes, grading, extent of disease, and the combination with chemotherapy. For localized germinoma, the current standard of care is chemotherapy followed by reduced-dose whole ventricular irradiation plus a boost to the primary tumor. For pinealoblastoma patients, postoperative radiation has been associated with higher overall survival. For the other pineal tumors, the role of radiotherapy remains poorly studied and it is usually reserved for aggressive (grade 3) or recurrent tumors. The use of systemic treatments mainly depends on histology and prognostic factors such as residual disease and metastases. For pinealoblastoma patients, chemotherapy protocols are based on various alkylating or platinum-based agents, vincristine, etoposide, cyclophosphamide and are used in association with radiotherapy. About GCTs, their chemosensitivity is well known and is based on cisplatin or carboplatin and may include etoposide, cyclophosphamide, or ifosfamide prior to irradiation. Similar regimens containing platinum derivatives are also used for non-germinomatous GCTs with very encouraging results. However, due to a greater understanding of the biology of the disease’s various molecular subtypes, new agents based on targeted therapy are expected in the future. On behalf of the EURACAN domain 10 group, we reviewed the most important and recent developments in histopathological characteristics, neuro-radiological assessments, and treatments for pineal region tumors.

Radiological Latency in Pineal Germinoma: A Case Report and Literature Review

Suprasellar germinomas can present with non-diagnostic, or even normal results on imaging. The spectrum of reported cases ranges from normal imaging, thickened pituitary stalks, to discrete tumour growths. This similar phenomenon is less commonly seen in the pineal region, or bifocal germinomas, and the literature is sparse with only a few case series or reports mentioning a similar presentation of signs and symptoms preceding radiological evidence of diagnosis. We report a case of pineal germinoma presenting with dorsal midbrain syndrome with no evidence of tumour growth on initial imaging despite symptoms. For patients presenting with this clinical radiological latent period, follow-up imaging is useful to identify interval development of germinomas. This applies to patients with dorsal midbrain syndrome, or even other unexplained ophthalmoplegia, as the initial sign of pineal region germinoma, despite normal imaging.

Evaluation of the Perioperative and Postoperative Course of Surgery for Pineal Germinoma in the SIOP CNS GCT 96 Trial

Background: CNS germinoma, being marker-negative, are mainly diagnosed by histological examination. These tumors predominantly appear in the suprasellar and/or pineal region. In contrast to the suprasellar region, where biopsy is the standard procedure in case of a suspected germ-cell tumor to avoid mutilation to the endocrine structures, pineal tumors are more accessible to primary resection. We evaluated the perioperative course of patients with pineal germinoma who were diagnosed by primary biopsy or resection in the SIOP CNS GCT 96 trial. Methods: Overall, 235 patients had germinoma, with pineal localization in 113. The relationship between initial symptoms, tumor size, and postoperative complications was analyzed. Results: Of 111 evaluable patients, initial symptoms were headache (n = 98), hydrocephalus (n = 93), double vision (n = 62), Parinaud syndrome (n = 57), and papilledema (n = 44). There was no significant relationship between tumor size and primary symptoms. A total of 57 patients underwent primary resection and 54 underwent biopsy. Postoperative complications were reported in 43.2% of patients after resection and in 11.4% after biopsy (p < 0.008). Biopsy was significantly more commonly performed on larger tumors (p= 0.002). Conclusions: These results support the practice of biopsy over resection for histological confirmation of pineal germinoma.

A Novel Germline SDHA Gene Mutation and Co-Occurring Somatic KIT Activating Mutation in a Patient With Pediatric Central Nervous System Germ Cell Tumor: Case Report

Central nervous system germ cell tumors (CNS GCTs) are a heterogeneous group of primary CNS tumors. GCTs are more common and mostly observed in pediatric and young adult patients. CNS GCTs are divided into germinomas and non-germinomatous germ cell tumors (NGGCTs), with different therapeutic strategies depending on diagnosis. Herein, we report a patient with pediatric central nervous system germinoma harboring a somatic KIT p.Y823D and a heterozygous germline SDHA p. T396Nfs*14 mutation detected by next generation sequencing. After surgery, the patient received chemotherapy (temozolomide + nedaplatin + etoposide). This is the first report of a Chinese pediatric patient with CNS GCT harboring concurrent germline SDHA and somatic KIT mutation, which enriches molecular profiles of CNS GCTs and provides more molecular evidence of clinical diagnosis and potential targeted therapy in CNS GCTs.

Roles of Tumor Markers in Central Nervous System Germ Cell Tumors Revisited with Histopathology-Proven Cases in a Large International Cohort

The central nervous system germ cell tumor (CNS GCT) is a rare and incompletely understood disease. A major outstanding question in the 2015 consensus document for CNS GCT management was the utility and interpretation of the tumor markers human chorionic gonadotropin (HCG) and alpha fetoprotein (AFP) in the diagnosis of malignant non-germinomatous GCTs (hereafter NGGCTs) prior to treatment. In the current study, we assembled two geographically and ethnically different clinical cohorts from the Mayo Clinic (1988-2017) and the intracranial GCT Genome Analysis Consortium (iGCT Consortium) in Japan to address this question. Patients with both histopathological diagnosis and tumor markers available were eligible for inclusion (n = 162). Biopsy and surgical resection were performed in 85 and 77 cases, respectively. Among 77 resections, 35 demonstrated positivity for HCG, AFP, or both (45%). Seventeen of the marker-positive cases had no malignant non-germinomatous component identified on histopathology, but they were composed strictly of germinoma, teratoma, or both (49%). One embryonal carcinoma was the only marker-negative NGGCT in the study sample. Among 85 biopsies, 18 were marker positive (21%). Seven of these patients had no malignant non-germinomatous component on histopathology, suggesting the potential limitations of limited tissue sample volumes. Neither histopathological diagnosis nor tumor markers alone reliably diagnose NGGCTs due to the secretion of HCG and AFP by germinomas and teratomas. Treatment planning should incorporate integrated histopathological and laboratory-based diagnosis to optimize diagnostic and treatment strategies for this unusual and histologically heterogeneous tumor.

Transcriptome and methylome analysis of CNS germ cell tumor finds its cell-of-origin in embryogenesis and reveals shared similarities with testicular counterparts

BACKGROUND

CNS germ cell tumors (GCTs) predominantly develop in pediatric and young adult patients with variable responses to surgery, radiation, and chemotherapy. This study aimed to examine the complex and largely unknown pathogenesis of CNS GCTs.

METHODS

We used a combined transcriptomic and methylomic approach in 84 cases and conducted an integrative analysis of the normal cells undergoing embryogenesis and testicular GCTs.

RESULTS

Genome-wide transcriptome analysis in CNS GCTs indicated that germinoma had a transcriptomic profile representative of primitive cells during early embryogenesis with high meiosis/mitosis potentials, while nongerminomatous GCTs (NGGCTs) had differentiated phenotypes oriented toward tissue formation and organogenesis. Co-analysis with the transcriptome of human embryonic cells revealed that germinomas had expression profiles similar to those of primordial germ cells, while the expression profiles of NGGCTs were similar to those of embryonic stem cells. Some germinoma cases were characterized by extensive immune-cell infiltration and high expression of cancer-testis antigens. NGGCTs had significantly higher immune-cell infiltration, characterized by immune-suppression phenotype. CNS and testicular GCTs (TGCTs) had similar mutational profiles; TGCTs showed enhanced copy number alterations. Methylation analysis clustered germinoma/seminoma and nongerminoma/nonseminoma separately. Germinoma and seminoma were co-categorized based on the degree of the tumor microenvironment balance.

CONCLUSIONS

These results suggested that the pathophysiology of GCTs was less dependent on their site of origin and more dependent on the state of differentiation as well as on the tumor microenvironment balance. This study revealed distinct biological properties of GCTs, which will hopefully lead to future treatment development.

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.

Intracranial germ cell tumors in Adolescents and Young Adults: European and North American consensus review, current management and future development

The incidence of intracranial germ cell tumors (iGCT) is much lower in European and North American (E&NA) than in Asian population. However, E&NA cooperative groups have simultaneously developed with success treatment strategies with specific attention paid to long-term sequelae. Neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or cerebrospinal fluid (CSF) and/or serum analysis, deferring the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated as either germinoma or non-germinomatous germ cell tumors (NGGCT). Metastatic disease is defined by a positive CSF cytology and/or distant drops in craniospinal MRI. The combination of surgery and/or chemotherapy and radiation therapy is tailored according to grouping and staging. With more than 90% 5-year event-free survival (EFS), localized germinomas can be managed without aggressive surgery, and benefit from chemotherapy followed by whole ventricular irradiation with local boost. Bifocal germinomas are treated as non-metastatic entities. Metastatic germinomas may be cured with craniospinal irradiation. With a 5-year EFS over 70%, NGGCT benefit from chemotherapy followed by delayed surgery in case of residual disease, and some form of radiotherapy. Future strategies will aim at decreasing long-term side effects while preserving high cure rates.

12p gain is predominantly observed in non-germinomatous germ cell tumors and identifies an unfavorable subgroup of central nervous system germ cell tumors

BACKGROUND

Central nervous system (CNS) germ cell tumors (GCTs) are neoplasms predominantly arising in pediatric and young adult populations. While germinomas generally respond to chemotherapy and radiation, non-germinomatous GCTs (NGGCTs) require more intensive treatment. This study aimed to determine whether 12p gain could predict the prognosis of CNS GCTs.

METHODS

Eighty-two CNS GCTs were included in this study. The 12p gain was defined by an additional 12p in the background of potential polyploidy or polysomy. Cases were analyzed using an Illumina methylation 450K array for copy number investigations and validated by fluorescence in situ hybridization (FISH).

RESULTS

A 12p gain was found in 25-out-of-82 cases (30%) and was more frequent in NGGCTs (12% of germinoma cases and 50% of NGGCT cases), particularly in cases with malignant components, such as immature teratoma, yolk sac tumor, choriocarcinoma, and embryonal carcinoma. 12p gain and KIT mutation were mutually exclusive events. The presence of 12p gain correlated with shorter progression-free (PFS) and overall survival (OS) (10-year OS: 59% vs 94%, with and without 12p gain, respectively, P = 0.0002), even with histology and tumor markers incorporated in the multivariate analysis. Among NGGCTs, 12p gain still had prognostic significance for PFS and OS (10-year OS: 47% vs. 90%, respectively, P = 0.02). The 12p copy number status was shared among histological components in mixed GCTs.

CONCLUSIONS

12p gain may predict the presence of malignant components of NGGCTs, and poor prognosis of the patients. It may be associated with early tumorigenesis of CNS GCT.

The Japan Society for Neuro-Oncology Guideline on the Diagnosis and Treatment of Central Nervous System Germ Cell Tumors

Primary CNS germ cell tumors (GCTs) are rare neoplasms predominantly observed in the pediatric and young adult populations. In line with the hypothesis that the primordial germ cell is the cell-of-origin, histopathological examinations for this pathology involve a diverse range of components mirroring the embryogenic developmental dimensions. Chemotherapy and radiotherapy are the mainstays of treatment, with surgery having a limited role for diagnosis and debulking of residual tissue after treatment. While better management has been achieved over recent decades by modifying radiation coverage and selecting appropriate chemotherapy, standardization of treatment remains challenging, partly due to the low volume of cases encountered in each institution. As the incidence is higher in East Asia, including Japan, the Japan Society for Neuro-Oncology established a multidisciplinary task force to create an evidence-based guideline for CNS GCTs. This guideline provides recommendations for multiple dimensions of clinical management for CNS GCTs, with particular focus on diagnostic measures including serum markers, treatment algorithms including surgery, radiotherapy and chemotherapy, and under-investigated but important areas such as treatment for recurrent cases, long-term follow-up protocols and long-term sequelae. This guideline serves the purpose of helping healthcare professionals keep up to date with current knowledge and standards of management for patients with this rare disease in daily clinical practice, as well as driving future translational and clinical research by recognizing unmet needs concerning this tumor.

Multi-institutional analysis of treatment modalities in basal ganglia and thalamic germinoma

BACKGROUND

Central nervous system (CNS) germinomas are treatment-sensitive tumors with excellent survival outcomes. Current treatment strategies combine chemotherapy with radiotherapy (RT) in order to reduce the field and dose of RT. Germinomas originating in the basal ganglia/thalamus (BGTGs) have proven challenging to treat given their rarity and poorly defined imaging characteristics. Craniospinal (CSI), whole brain (WBI), whole ventricle (WVI), and focal RT have all been utilized; however, the best treatment strategy remains unclear.

METHODS

Retrospective multi-institutional analysis has been conducted across 18 institutions in four countries.

RESULTS

For 43 cases of nonmetastatic BGTGs, the 5- and 10-year event-free survivals (EFS) were 85.8% and 81.0%, respectively, while the 5- and 10-year overall survivals (OS) were 100% and 95.5%, respectively (one patient fatality from unrelated cause). Median RT doses were as follows: CSI: 2250 cGy/cGy(RBE) (1980-2400); WBI: 2340 cGy/cGy(RBE) (1800-3000); WVI: 2340 cGy/cGy(RBE) (1800-2550); focal: 3600 cGy (3060-5400). Thirty-eight patients (90.5%) received chemotherapy. There was no statistically significant difference in the EFS based on initial field extent (p = .84). Nevertheless, no relapses were reported in patients who received CSI or WBI. Chemotherapy alone had significantly inferior EFS compared to combined therapy (p = .0092), but patients were salvageable with RT.

CONCLUSION

Patients with BGTGs have excellent outcomes and RT proved to be an integral component of the treatment plan. This group of patients should be included in future prospective clinical trials and the best RT field should be investigated further.

Low tumor cell content predicts favorable prognosis in germinoma patients

Background

Germinoma preferentially occurs in pediatric and young adult age groups. Although they are responsive to treatment with chemotherapy and radiation, the treatment may cause long-term sequelae in their later lives. Here, we searched for clinical and histopathological features to predict the prognosis of germinoma and affect treatment response.

Methods

A total of 114 germinoma cases were included in the analysis. We investigated the association between clinical factors, tumor cell content, and progression-free survival (PFS).

Results

The tumor cell content was widely distributed from <5% to 90% in the specimens, with a median value of 50%. Female patients showed higher tumor cell content in the specimens (P = .002). Cases with lesions at atypical sites showed shorter PFS than those with lesions at other sites (P = .03). Patients with a higher tumor cell content (≥50%) showed shorter PFS than those with a lower tumor cell content (<50%) (P = .03). In multivariate analysis, tumor cell content was the only statistically significant prognostic factor (P = .04). Among the 7 cases treated with local radiation and chemotherapy, all 3 cases that recurred (2 outside of the radiation field, 1 unknown) had tumor cell content of ≥50% in the original specimen, whereas all 4 cases without recurrence had tumor cell contents of <50%.

Conclusions

We found that tumor cell content significantly affected the prognosis of germinomas. Although validation of these results using an independent and larger cohort is necessary, this potentially opens the possibility of leveraging this pathological factor in future clinical trials when stratifying the treatment intensity.

Genomic gain of RRS1 promotes hepatocellular carcinoma through reducing the RPL11-MDM2-p53 signaling

Hepatocellular carcinomas (HCCs) are characterized by frequent somatic genomic copy number alterations (CNAs), with most of them biologically unexplored. Here, we performed integrative analyses combining CNAs with the transcriptomic data to reveal the cis- and trans-effects of CNAs in HCC. We identified recurrent genomic gains of chromosome 8q, which exhibit strong trans-effects and are broadly associated with ribosome biogenesis activity. Furthermore, 8q gain-driven overexpression of ribosome biogenesis regulator (RRS1) promotes growth of HCC cells in vitro and in vivo. Mechanistically, RRS1 attenuates ribosomal stress through retaining RPL11 in the nucleolus, which, in turn, potentiates MDM2-mediated ubiquitination and degradation of p53. Clinically, higher RRS1 expression levels predict poor clinical outcomes for patients with HCC, especially in those with intact p53 Our findings established that the chromosome 8q oncogene RRS1 promotes HCC development through attenuating the RPL11-MDM2-p53 pathway and provided new potential targets for treatment of this malignancy.

Characteristics of growth disturbances in patients with intracranial germinomas of different origins

PURPOSE

To explore the characteristics of growth disturbance in patients with intracranial germinoma with different origins.

METHODS

Clinical data of 151 patients with single-origin germinomas were studied retrospectively. Z-score of height (ZSOH) at both diagnosis and the last follow-up was calculated using the WHO AnthroPlus software. Linear regression was used to analyse the correlation between the absolute change in ZSOH (|ZSOH _{last follow-up} - ZSOH _diagnosis|) and clinical factors.

RESULTS

The mean ZSOH decreased significantly in every origin subgroup at the last follow-up. In patients with sellar germinoma (n = 62), the mean ZSOH values at both diagnosis and the last follow-up were significantly lower than those in patients with pineal (n = 30) (p < 0.001) or basal ganglia germinomas (n = 59) (p < 0.001), respectively. In patients with basal ganglia germinoma, the mean absolute change in ZSOH decreased significantly compared to that in the patients with sellar (p = 0.006) or pineal germinomas (p = 0.04). Linear analysis revealed that sex (male vs female; p = 0.003) and age at diagnosis (≤10 years vs >10 years; p = 0.026) had negative correlations, while radiation dose at the hypothalamic-pituitary axis (HPA) (≤40 Gy vs >40 Gy; p = 0.085) had a marginally positive correlation, with absolute change in ZSOH.

CONCLUSIONS

Patients with germinoma experienced growth retardation after treatments. The growth disturbance was consistent and more severe in patients with germinoma of sellar origin, while the greatest aggravation was observed in patients with germinoma of basal ganglia origin. Decreasing radiation dose to the HPA may minimize the negative impact of radiotherapy on growth.

Histopathology and prognosis of germ cell tumors metastatic to brain: cohort study

INTRODUCTION

Germ cell tumors (GCTs) are uncommon neoplasms predominantly arising in midline tissues. The prognostic significance of histopathology in predicting metastatic GCT behavior is poorly understood.

METHODS

Multicenter international cohort study including 29 patients with GCTs metastatic to brain were retrospectively investigated (18 patients from Mayo Clinic and 11 patients from the intracranial germ cell tumor genome analysis consortium in Japan). Clinical characteristics were analyzed using the Chi-square test (two-tailed) for categorical variables and using the log-rank test for survival data.

RESULTS

Median age at treatment was 31 years (range 14-58). Primary disease sites were testis (71%), mediastinum (18%), and female reproductive organs (11%). Median metastatic interval was 223 days (range, 6-6124). Median follow-up was 346 days (range, 1-5356), with 16 deaths (57%) occurring after the median overall survival of 455 days. Actuarial one-year survival was 51%; 12-of-16 deaths (75%) were attributed to intracranial disease. Appearance of the same GCT subtype at the metastatic site as the primary was high for non-seminomatous GCT (NSGCT, 64-100%), but low for seminoma/dysgerminoma and mature teratoma (MT, 14, 17%, respectively). Gain of a new component was seen in 4 (20%)-3 of which included embryonal carcinoma (EC) at the primary site (75%). Incidence of cases without seminoma/dysgerminoma increased significantly after metastasis (p = 0.02). Metastatic interval was shorter in cases with histological change (199 vs 454 days, p = 0.009). Overall survival was associated with MT primary histopathology (p = 0.02).

CONCLUSION

Histological differentiation at the primary GCT site influences metastatic prognosis. Aggressive behavior is associated with NSGCT, while EC frequently demonstrates multi-directional histological differentiation after brain metastasis, and such histological dynamism is associated with shorter metastatic interval. Most metastases occurred within one year of diagnosis, emphasizing the need for close surveillance in newly diagnosed extra-cranial GCT.

Molecular Pathology and Targeted Therapies for Personalized Management of Central Nervous System Germinoma

Intracranial germinomas are rare tumours, usually affecting male paediatric patients. They frequently develop in the pineal and suprasellar regions, causing endocrinological disturbances, visual deficits, and increased intracranial pressure. The diagnosis is established on magnetic resonance imaging (MRI), serum and cerebrospinal fluid (CSF) markers, and tumour stereotactic biopsy. Imaging techniques, such as susceptibility-weighted imaging (SWI), T2* (T2-star) gradient echo (GRE) or arterial spin labelling based perfusion-weighted MRI (ASL-PWI) facilitate the diagnosis. Germinomas are highly radiosensitive tumours, with survival rates >90% in the context of chemoradiotherapy. However, patients with resistant disease have limited therapeutic options and poor survival. The aim of this review is to highlight the genetic, epigenetic, and immunologic features, which could provide the basis for targeted therapy. Intracranial germinomas present genetic and epigenetic alterations (chromosomal aberrations, KIT, MAPK and PI3K pathways mutations, DNA hypomethylation, miRNA dysregulation) that may represent targets for therapy. Tyrosine kinase and mTOR inhibitors warrant further investigation in these cases. Immune markers, PD-1 (programmed cell death protein 1) and PD-L1 (programmed death-ligand 1), are expressed in germinomas, representing potential targets for immune checkpoint inhibitors. Resistant cases should benefit from a personalized management: genetic and immunological testing and enrolment in trials evaluating targeted therapies in intracranial germinomas.