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.

An international study evaluating the epidemiology of intracranial germ cell tumors in the native versus immigrant Japanese populations: the need for an international registry.

BACKGROUND: Pediatric intra-cranial germ cell tumors (iGCTs) occur at an incidence of 0.6-1.2 cases/million/year in Western countries. The incidence is reported up to 5 times higher in Japan. It is unknown whether this increased incidence is due to genetic predisposition or environment. METHODS: The incidence of iGCTs in children ages 0-19 years was evaluated from December 1st, 1996-December 1st, 2016 in stable Japanese immigrant populations living abroad and compared to current native Japanese registry data. The incidence of medullobblastoma was used as a control to account for assumptions in the data. Sites were identified based on historical and population data of known large scale emigration from Japan during a period of industrialization from 1868-1912 which resulted in large, stable Japanese immigrant populations abroad. These three representative sites included Lima, Peru, San Paolo, Brazil, and Vancouver, Canada. Data was collected from registry and hospital-based resources within each region. RESULTS: A review of the Brain Tumor Registry of Japan from 1984-2004 revealed an incidence of 2.5 cases/million/year, lower than previously reported, and a lower incidence of medulloblastoma at 1.2 cases/million/year. Data from Vancouver, Canada, Lima, Peru, and San Paolo, Brazil included a total population of 731,174 Japanese persons. The ratio of all medulloblastoma to iGCT cases in Japan was identified as 1:2 while the ratio was 2:1, 6.5:1, and 5:1, respectively, in the other three locations. The data suggests increased incidence in native Japan may not translate to higher incidence in immigrant Japanese populations abroad and a clear genetic component was not found in our data set. CONCLUSIONS: A more precise and comprehensive study is needed to determine the cause of this difference in incidence. This study also emphasizes the importance of national and state registries and is a call to collaborate on state and country level epidemiology studies.

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.

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.

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.

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

BACKGROUND: We integrated clinical, histopathological, and molecular data of central nervous system germ cell tumors to provide insights into their management. METHODS: Data from the Intracranial Germ Cell Tumor Genome Analysis (iGCT) Consortium were reviewed. A total of 190 cases were classified as primary germ cell tumors (GCTs) based on central pathological reviews. RESULTS: All but one of the cases that were bifocal (neurohypophysis and pineal glands) and cases with multiple lesions including neurohypophysis or pineal gland were germinomas (34 of 35). Age was significantly higher in patients with germinoma than other histologies. Comparison between tumor marker and histopathological diagnoses showed that 18.2% of histopathologically diagnosed germinomas were marker positive and 6.1% of non-germinomatous GCTs were marker negative, suggesting a limitation in the utility of markers or histopathology alone using small specimens for diagnosis. Comparison between local and central histopathological diagnoses revealed a discordance of 12.7%. Discordance was significantly less frequent in biopsy cases, implying difficulty in detecting all histopathological components of heterogeneous GCTs. Germinomas at the typical sites (neurohypophysis or pineal gland) showed a better progression-free survival than those at atypical sites (P = 0.03). A molecular clinical association study revealed frequent mitogen-activated protein kinase (MAPK) pathway mutations in males (51.4% vs 14.3%, P = 0.007), and phosphatidylinositol-3 kinase/mammalian target of rapamycin (PI3K/mTOR) pathway mutations in basal ganglia cases (P = 0.004). Basal ganglia cases also had frequent chromosomal losses. Some chromosomal aberrations (2q, 8q gain, 5q, 9p/q, 13q, 15q loss) showed potential prognostic significance. CONCLUSIONS: The in-depth findings of this study regarding clinical and molecular heterogeneity will increase our understanding of the pathogenesis of this enigmatic tumor.

Employment status and termination among survivors of pediatric brain tumors: a cross-sectional survey.

BACKGROUND: Some childhood cancer survivors experience employment difficulties. This study aimed to describe pediatric brain-tumor survivors' employment status. METHODS: A cross-sectional, observational study was conducted, with questionnaires distributed to 101 pediatric brain-tumor survivors (aged 15 years or older) and their attending physicians from nine institutions in Japan. We compared category and time-series histories for participants' first-time employment using national census information. Factors related to delayed employment or early employment termination were examined using survival-time analyses. RESULTS: Excluding students and homemakers, 38 brain-tumor survivors (median age 27 years, with 15 years since diagnosis) were of working age. Of these, 12 (32%) were unemployed and 9 (24%) had never been employed. First-time employment occurred later for brain-tumor survivors than the general population, particularly in those with lower educational levels. The number of brain-tumor survivors whose first job was terminated within the first year was higher than that for the general population, particularly in male survivors and germ cell-tumor survivors. Brain-tumor survivors described their working patterns (irregular), job types (specialist or professional), reasons for early termination (unsuitable job), and thoughts about working (they wished to serve their communities but lacked confidence). CONCLUSION: Brain-tumor survivors are associated with high unemployment rates and multiple unemployment-related factors. Education and welfare systems should identify individual methods of social participation for this group.

Genome-wide methylation profiles in primary intracranial germ cell tumors indicate a primordial germ cell origin for germinomas.

Intracranial germ cell tumors (iGCTs) are the second most common brain tumors among children under 14 in Japan. The World Health Organization classification recognizes several subtypes of iGCTs, which are conventionally subclassified into pure germinoma or non-germinomatous GCTs. Recent exhaustive genomic studies showed that mutations of the genes involved in the MAPK and/or PI3K pathways are common in iGCTs; however, the mechanisms of how different subtypes develop, often as a mixed-GCT, are unknown. To elucidate the pathogenesis of iGCTs, we investigated 61 GCTs of various subtypes by genome-wide DNA methylation profiling. We showed that pure germinomas are characterized by global low DNA methylation, a unique epigenetic feature making them distinct from all other iGCTs subtypes. The patterns of methylation strongly resemble that of primordial germ cells (PGC) at the migration phase, possibly indicating the cell of origin for these tumors. Unlike PGC, however, hypomethylation extends to long interspersed nuclear element retrotransposons. Histologically and epigenetically distinct microdissected components of mixed-GCTs shared identical somatic mutations in the MAPK or PI3K pathways, indicating that they developed from a common ancestral cell.

Phase I/II trial of combination of temozolomide chemotherapy and immunotherapy with fusions of dendritic and glioma cells in patients with glioblastoma.

BACKGROUND: This trial was designed to evaluate the safety and clinical responses to a combination of temozolomide (TMZ) chemotherapy and immunotherapy with fusions of DCs and glioma cells in patients with glioblastoma (GBM). METHOD: GBM patients were assigned to two groups: a group of recurrent GBMs after failing TMZ-chemotherapy against the initially diagnosed glioma (Group-R) or a group of newly diagnosed GBMs (Group-N). Autologous cultured glioma cells obtained from surgical specimens were fused with autologous DCs using polyethylene glycol. The fusion cells (FC) were inoculated intradermally in the cervical region. Toxicity, progression-free survival (PFS), and overall survival (OS) of this trial were evaluated. Expressions of WT-1, gp-100, and MAGE-A3, recognized as chemoresistance-associated peptides (CAP), were confirmed by immunohistochemistry of paraffin-embedded tumor samples. Patient's PBMCs of pre- and post-vaccination were evaluated by tetramer and ELISPOT assays. RESULTS: FC-immunotherapy was well tolerated in all patients. Medians of PFS and OS of Group-R (n = 10) were 10.3 and 18.0 months, and those of Group-N (n = 22) were 18.3 and 30.5 months, respectively. Up-regulation and/or cytoplasmic accumulation of CAPs was observed in the recurrent tumors of Group-R patients compared with their initially excised tumors. Specific immune responses against CAPs were observed in the tetramer and ELISPOT assays. CONCLUSIONS: The combination of TMZ-treatment leading to up-regulation and/or cytoplasmic accumulation of CAPs, with FC-immunotherapy as a means of producing specific immunity against CAPs, may safely induce anti-tumor effects in patients with GBM.

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

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

Atypical clinical features of children with central nervous system tumor: Delayed diagnosis and switch in handedness.

Herein is described the cases of three children with central nervous system (CNS) tumor, who had switch in handedness occurring before diagnostic confirmation. Although the onset, age, tumor location, and histology were heterogeneous, the diagnosis of CNS tumor was delayed in all three patients. The present experience indicates that switch in handedness should be recognized as a sign of CNS tumor in pediatric patients, and which might prevent delay in diagnosis. Pediatricians should carefully examine such patients who present with some suggestive symptoms of CNS tumor, even when they are unusual, in order to make a timely and appropriate diagnosis.

Recurrent neomorphic mutations of MTOR in central nervous system and testicular germ cell tumors may be targeted for therapy.

Germ cell tumors constitute a heterogeneous group that displays a broad spectrum of morphology. They often arise in testes; however, extragonadal occurrence, in particular brain, is not uncommon, and whether they share a common pathogenesis is unknown. We performed whole exome sequencing in 41 pairs of central nervous system germ cell tumors (CNS GCTs) of various histology and their matched normal tissues. We then performed targeted sequencing of 41 selected genes in a total of 124 CNS GCTs, 65 testicular germ cell tumors (tGCTs) and 8 metastatic GCTs to the CNS. The results showed that mutually exclusive mutations of genes involved in the MAPK pathway were most common (48.4 %), typically in KIT (27.4 %), followed by those in the PI3K pathway (12.9 %), particularly in MTOR (6.5 %), among the 124 CNS GCTs. Pure germinomas and non-germinomatous germ cell tumors (NGGCTs), as well as CNS and testicular GCTs, showed similar mutational profiles, suggesting that GCTs share a common molecular pathogenesis. Mutated MTOR identified in CNS GCTs upregulated phosphorylation of the AKT pathway proteins including AKT and 4EBP1 in nutrient-deprived conditions and enhanced soft-agar colony formation; both events were suppressed in a dose-dependent manner by addition of the MTOR inhibitor pp242. Our findings indicate that the dominant genetic drivers of GCTs regardless of the site of origin are activation of the MAPK and/or PI3K pathways by somatic point mutations. Mutated MTOR represents a potential target for novel targeted therapies for refractory GCTs.

Clinical interpretation of residual uptake in 11C-methionine positron emission tomography after treatment of basal ganglia germ cell tumors: report of 3 cases.

Although (11)C-methionine (MET)-PET has been used to diagnose intracranial germ cell tumors (GCTs) arising in the basal ganglia, whether this imaging technique is useful in assessing treatment response and residual tumor is still unclear. The authors report 3 cases of basal ganglia GCTs in which the residual MET uptake at the end of treatment did not develop into a relapse, even without additional treatment. Case 1 is a 22-year-old man who had a second relapse of a left basal ganglia germinoma with diffuse dissemination on the walls of both of his lateral ventricles. MET-PET revealed high MET accumulation around tumors and their surroundings (maximum standardized uptake value [SUVmax] 3.3). After all treatments, MET-PET demonstrated mild tracer accumulation in both basal ganglia (SUVmax 2.2). Progression-free survival was 56 months from the second relapse without any further treatment. Case 2 is a 17-year-old boy with a left basal ganglia germinoma that showed increased MET uptake (SUVmax 4.2). After treatment, MET-PET revealed residual MET uptake (SUVmax 2.4) along the left posterior limb of the internal capsule. Progression-free survival was 52 months from the start of treatment. Case 3 is a 7-year-old boy with a left basal ganglia choriocarcinoma with increased tumor MET uptake (SUVmax 2.5). A minor enhanced mass remained on MRI after treatment with residual MET accumulation (SUVmax 1.4). Progression-free survival was 44 months. Treatment strategies based on MET uptake on PET should be carefully designed in patients with basal ganglia GCTs to avoid overtreatment and complications.

Human chorionic gonadotropin is expressed virtually in all intracranial germ cell tumors.

Human chorionic gonadotropin (hCG) production has been utilized as a diagnostic marker for germinoma with syncytiotrophoblastic giant cells (STGC) and choriocarcinoma. Elevated hCG in germinoma is considered to predict less favorable prognosis, and an intensive treatment strategy may accordingly be applied. However, there is some evidence that any germinoma may produce hCG to varying extent. We investigated mRNA expression of the hCG ß subunit (hCGß) using real time quantitative polymerase chain reaction in 94 germ cell tumors (GCTs). Most (93.3 %) GCTs showed higher expression levels compared with that of normal brain tissue (1.09 × 10(0)-1.40 × 10(5) fold). The expression was the highest in GCTs which harbor choriocarcinoma or STGC components. The expression level of hCGß in germinoma was highly variable (1.09 × 10(0)-5.88 × 10(4) fold) in linear but not bimodal distribution. hCG concentrations in serum and CSF correlated with gene expression, especially when GCTs with single histological component were analyzed separately. The expression was not significantly associated with recurrence in pure germinoma. These results suggest that the serum/CSF hCG levels may need to be interpreted with caution as most GCTs appear to have the capacity of producing hCG irrespective of their histology. The clinical significance of ubiquitous hCG expression in GCTs needs further investigation.

Malignant transformation of germinoma 14 years after onset: Favorable efficacy of oral etoposide.

We report the case of a 19-year-old woman with a highly malignant intracranial germ cell tumor (GCT) that developed 14 years after treatment for neurohypophyseal germinoma. Magnetic resonance imaging (MRI) showed a large neurohypophyseal mass and a synchronous lesion in the pineal region. Plasma α-fetoprotein was elevated to 3038 ng/mL. Although the tumor shrank and tumor marker levels normalized after chemotherapy and craniospinal irradiation, treatment was switched to oral etoposide for the residual tumor because of adverse events. MRI after oral etoposide introduction showed additional tumor shrinkage for 27 months after the onset of the second tumor. To the best of our knowledge, this is the longest interval between germinoma onset and the development of highly malignant recurrent GCT to be reported in the English-language literature. Oral etoposide prevented regrowth of the GCT, which has a poor prognosis, and decreased the size of the residual tumor.

Brainstem oligodendroglial tumors in children: two case reports and review of literatures.

PURPOSE: There is little information on pediatric oligodendroglial tumor located in the brainstem because of its rarity. METHODS: Here, we present two pediatric cases of pontine oligodendroglial tumors with radiological findings atypical for diffuse intrinsic pontine glioma. RESULTS: The first patient was an 8-year-old boy. Brain magnetic resonance imaging (MRI) demonstrated diffuse high-intensity changes in the pons, left middle cerebellar peduncle, and part of the left cerebellar hemisphere on T2-weighted and fluid-attenuated inversion recovery images, with an enhanced spot lesion in the left cerebellar hemisphere. The pathological diagnosis was anaplastic oligodendroglioma, and we identified a mutation in histone H3.3 in the tumor specimen. He succumbed to massive disseminated relapse 7 months from diagnosis despite local radiation therapy. The second patient, a 2-year-old girl, was diagnosed with oligoastrocytoma. Brain MRI revealed a large mass in her rostral pons extended to the fourth ventricle with obstructive hydrocephalus. The tumor recurred with intracranial dissemination 56 months post-surgery. CONCLUSIONS: Pediatric brainstem oligodendroglial tumors can include histone H3.3-mutated tumors and have a tendency to disseminate throughout the neuroaxis at the time of relapse.

Duration between onset and diagnosis in central nervous system tumors: impact on prognosis and functional outcome.

BACKGROUND: The initial presentation of central nervous system (CNS) tumors in children frequently mimics other more common and less serious conditions, resulting in diagnostic difficulty and a prolonged time to diagnosis. Yet whether early diagnosis contributes to better life prognosis and functional outcome has not been elucidated. Only a few such reports have originated from Japan, where neuroimaging techniques are the best in the world. We examined the time to diagnosis, the so-called prediagnostic symptomatic interval (PSI), and its impact on prognosis and functional outcome in children with CNS tumors. METHODS: We reviewed the records of 127 patients aged <15 years with CNS tumors, who were treated at our two institutions between November 1993 and October 2011. RESULTS: The median age at diagnosis was 7.2 years (range, 3 weeks-14.9 years). The male-to-female ratio was 63:64. Median PSI was 1.5 months (0-36 months). Overall survival and progression-free survival did not differ significantly between the groups, regardless of whether the PSI was longer than the median PSI. The PSI was significantly longer in patients with long-lasting clinical signs after the initial treatment than in patients with temporary symptoms only at onset. Both univariate and multivariate analysis showed that high histological grading was statistically correlated with short PSI. CONCLUSIONS: A short PSI was significantly associated with high-grade tumors. Earlier diagnosis did not lead to better life prognosis, but possibly to better functional outcome in children with CNS tumors.

Impact of late effects on health-related quality of life in survivors of pediatric brain tumors: motility disturbance of limb(s), seizure, ocular/visual impairment, endocrine abnormality, and higher brain dysfunction.

BACKGROUND: Survivors of pediatric brain tumors are often affected by late effects, such as motility disturbance of limb(s), seizure, ocular/visual impairment, endocrine abnormality, and higher brain dysfunction, resulting from the disease and its treatment. Appropriate provision of supportive care will require understanding the effects of these experiences on survivors' health-related quality of life (HRQOL). OBJECTIVE: The aim of this study was to identify the relationships between late effects and specific aspects of the HRQOL of pediatric brain tumor survivors. METHODS: We distributed questionnaires for measuring HRQOL to 138 survivors and their parents at 8 hospitals and 1 clinic in Japan and simultaneously surveyed late effects using information provided by the survivors' attending physicians. We compared the HRQOL of survivors with and survivors without specific late effects. RESULTS: A total of 106 survivors and their parents returned the questionnaires to the researchers. The HRQOL of survivors 18 years or older was negatively affected by all 5 late effects, indicating that their higher impairment was associated with diminished HRQOL. The HRQOL of survivors aged 12 to 17 years was negatively affected by 2 late effects (ocular/visual impairment and motility disturbance of the limbs). A part of the HRQOL subdomain (motor and cognitive functioning) of survivors aged 12 to 17 years was positively related to ocular/visual impairment. CONCLUSIONS: Five late effects influenced the HRQOL of pediatric brain tumor survivors. IMPLICATIONS FOR PRACTICE: Nurses and other health professionals should provide specific care designed to support aspects of HRQOL affected by late effects. For example, survivors with ocular/visual impairment may be expected to require additional emotional support, and those with seizures or endocrine abnormalities may be expected to require additional support for sleep disorders.

Mutually exclusive mutations of KIT and RAS are associated with KIT mRNA expression and chromosomal instability in primary intracranial pure germinomas.

Intracranial germ cell tumors (iGCTs) are the second most common brain tumors among children under 15 in Japan. The pathogenesis of iGCTs is largely unexplored. Although a subset of iGCTs is known to have KIT mutation, its impact on the biology and patients' survival has not been established. In this study, we investigated genes involved in the KIT signaling pathway. 65 iGCTs (30 pure germinomas, 14 teratomas, 18 mixed GCTs, 2 yolk sac tumors, 1 choriocarcinoma) were screened for mutation of KIT, KRAS, NRAS, HRAS, BRAF, PDGFRA, and IDH1 by direct sequencing. KIT expression was examined by immunohistochemistry and quantitative PCR. Chromosomal status was analyzed by array-comparative genomic hybridization (aCGH). Somatic mutations were detected only in KIT and RAS, which were frequently observed in pure germinomas (60.0 %), but rare in non-germinomatous GCTs (NGGCTs) (8.6 %). All KIT/RAS mutations were mutually exclusive. Regardless of the mutation status or mRNA expression, the KIT protein was expressed in all germinomas, while only in 54.3 % of NGGCTs. Amplification of KIT was found in one pure germinoma by aCGH. In pure germinomas, high expression of KIT mRNA was associated with the presence of KIT/RAS alterations and severe chromosomal instability. Our results indicate that alterations of the KIT signaling pathway play an important role in the development of germinomas. Pure germinomas may develop through two distinct pathogeneses: one with KIT/RAS alterations, elevated KIT mRNA expression and severe chromosomal instability, and the other through yet an unidentified mechanism without any of the above abnormalities.