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Background: Ganglioglioma (GG) is a low-grade mixed neuronal-glial tumor which is the most common type of long-term epilepsy-associated tumors (LEATs). However, primary anaplastic ganglioglioma (AGG) which composes of malignant changes is rare. Here, we report a case of pediatric primary AGG which is consisted of low-grade/begnin GG and high-grade glioma that was characterized by astroblastoma-like pseudorosettes. Case presentation: We describe a case of 4-year-old female who presented with medically refractory seizure for 14 months by a temporal mass. The patient underwent a gross total mass resection at the first surgery, and was only treated with antiepileptic therapy and followed by observation. After nine months, tumor recurrence was found. Followed by second operation, the patient was treated with chemotherapy (oral temozolomide and antiepileptic drugs) and local radiotherapy. At 58-month follow-up after the second operation, no epileptic seizures and tumor recurrence were found again. In the first sample, the tumor contained two different components. The major component presented the low-grade GG’s features of neoplastic glial cells and dysplastic ganglion cells. The minor component was a heterogeneous high-grade glioma characterized astroblastic-like pseudorosettes clusters with increased mitotic figure (about 4-6 per 10 high-power fields). CD34 staining was negative. BRAFV600E was positive in both components. In the recurrent sample, the heterogeneous high-grade glioma became the major component. The fuorescence in situ hybridization (FISH) of MN1 break-apart probe and MYB–QKI fusions probe were negative. BRAFV600E mutation, and deletion of CDKN2A/B, PTEN and BMPR1A were detected by targeted DNA sequencing. Conclusion: This case extends the histomorphologic spectrum and enriched genetic features of primary AGG in childhood. The high-grade glioma charactered astroblastoma-like pseudorosettes may be an important cause of tumor recurrence in a short period of time. Tumor gross total surgical resection and adjuvant chemoradiotherapy were important to achive an event-free survival.

Considering conflicting data on CDKN2A/B deletion in ALL, this study to assess its prognostic significance as an independent marker in a total of 96 pediatric B and T-ALL cases was planned. The overall frequency of CDKN2A/B deletion was 44% (n = 43) with 36% (30/83) in B-ALL and 100% (13/13) in T-ALL. CDKN2A/B deletion was significantly associated with high WBC count (p = .002) and National Cancer Institute risk (p = .01) in B-ALL. Importantly, CDKN2A/B deletion cases had poor EFS of 42% at 28 months compared to EFS of 90% in rest (p = .0004). Further, relapse free survival was only 56% for cases with CDKN2A/B deletions (n = 25), compared to 100% in control group (p = .001). Moreover, CDKN2A/B deletion was the only risk factor associated with early relapse (p = .01) compared to IKZF1 deletion (p = .73) or occurrence of BCR-ABL1 fusion transcript (p = .26). Thus our study data highlights potential prognostic role of CDKN2A/B deletions in early disease stratification in pediatric B-ALL.

Author(s): Cheaney, Barry; Bowden, Stephen; Krause, Katie; Sloan, Emily A; Perry, Arie; Solomon, David A; Han, Seunggu Jude; Wood, Matthew D

Cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) genes are frequently altered in acute lymphoblastic leukaemia (ALL) patients. The aim of this meta-analysis was to comprehensively assess the prognostic value of CDKN2A/B deletions in ALL patients.Systematic literature review was conducted in PubMed, Embase and Cochrane databases up to July 2018. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated with fixed-effects or random-effects models.A total of thirteen studies including 2857 patients were eligible for this meta-analysis. Combined HRs suggested that CDKN2A/B deletions were poor prognostic factors for both overall survival (OS) (HR = 2.15, 95% CI 1.82-2.54) and event-free survival (EFS)/disease-free survival (DFS)/relapse-free survival (RFS) (HR = 2.16, 95% CI 1.73-2.69). The adverse impact remained significant in both adult and paediatric ALL patients, and also in subgroups by ethnicity, ALL type, detection method of CDKN2A/B deletions, statistical method and endpoint.Our findings suggested that CDKN2A/B deletions were associated with poor prognosis independently in both adult and childhood ALL patients. Inclusion of CDKN2A/B status may further improve the risk stratification of ALL patients. Key Messages Although numerous studies have explored the prognostic significance of cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletions in acute lymphoblastic leukaemia (ALL) patients, the results remain conflicting. In this meta-analysis, we found that CDKN2A/B deletions were independent poor prognostic markers for both adult and paediatric ALL patients. Our findings justify the inclusion of CDKN2A/B status in the risk stratification of ALL patients.

Pediatric high-grade gliomas are rare and often hard to classify, which grow locally and show longer survival than diffuse high-grade gliomas in adults. We report a case of circumscribed high-grade astrocytoma who was initially diagnosed as glioblastoma and has 20 years survival. A 7-year-old girl suffered from epileptic seizure due to a left occipital lobe tumor. The tumor was resected in another hospital and diagnosed as glioblastoma. The tumor disappeared after extended local irradiation and chemotherapy using nimustine hydrochloride (ACNU) and cisplatin (CDDP). Eighteen years after initial onset, first recurrence was confirmed as the intra-tumoral hemorrhage. The tumor was resected and diagnosed as anaplastic oligoastrocytoma. After 6 courses of temozolomide (TMZ), the tumor disappeared. Twenty years after initial onset, the second local recurrence was confirmed. Although gamma knife and TMZ was performed, the tumor did not disappear. The tumor was surgically resected. Histopathology showed localized growth with some infiltration and mitosis but lacked pseudopallisading and microvascular proliferation. The tumor was diagnosed as circumscribed high-grade astrocytoma. Immunostaining revealed ATRX nuclear loss and CDKN2A / B homozygous deletion. After 10 courses of TMZ, the third local recurrence was confirmed. The tumor was completely removed and has not occurred recurrence more than 3 months after the last operation. Circumscribed high-grade glioma is expected to survive longer than invasive glioma. Pediatric gliomas should differ from adult gliomas in the genes of tumorigenesis. Care should be taken for its diagnosis and treatments. We also need a new classification based on histology and gene profile. HGG-30, ANALYSIS OF PEDIATRIC GLIOMAS IN OUR INSTITUTE Kaoru Tamura, Mai Fujioka, Masae Kuroha, Motoki Inaji, Yoji Tanaka, Tadashi Nariai, and Taketoshi Maehara; Tokyo Medical and Dental University, Tokyo, Japan. PURPOSE: Recent advances in genetic interrogation of pediatric glioma increase the importance of molecular diagnosis using surgical specimen. However, surgical resection may be avoided to preserve quality of life, especially in brain stem glioma cases. We retrospectively examined diagnosis and treatment of pediatric gliomas in our hospital. METHODS: This study includes 14 consecutive glioma patients under the age of 18 who underwent initial treatment at our hospital from 2000 to 2019. Histopathological diagnosis, clinical course and molecular status such as IDH, H3F3A and BRAF were analyzed. RESULTS: 5 patients (1 pilocytic astrocytoma (PA), 3 diffuse astrocytomas, 1 oligodendroglioma were treated only by surgical resection (group A). 7 patients (1 PA, 1 anaplastic oligodendroglioma, 2 diffuse midline gliomas and 3 glioblastomas (GBM)) received radiation and/or chemotherapy after surgical resection (group B). 2 diffuse intrinsic pontine gliomas (DIPG) received radiation and chemotherapy without surgical resection (Group C). No IDH mutation was observed in all pathological specimen obtained cases. BRAF alteration was observed in all PA cases. 1 case of GBM had BRAF V600Emutation and the other had H3K27M mutation. During a median of 7.7 years of follow-up, group A patients have no recurrence. Group B includes various diagnosis and prognosis. 2 group C patients diagnosed DIPG by MRI showed different clinical courses. CONCLUSION: Pediatric gliomas include diverse biological subgroups and show broad range of clinical behavior. Since pediatric glioma has a low incidence and a wide variety of genetic mutations, multicenter study is important to improve the treatment of pediatric glioma.

During the last years, genome wide association studies have discovered common germline genetic variants associated with specific glioma subtypes. We aimed to study the association between these germline risk variants and tumor phenotypes, including copy number aberrations and protein expression. A total of 91 glioma patients were included. Thirteen well known genetic risk variants in TERT, EGFR, CCDC26, CDKN2A, CDKN2B,PHLDB1, TP53, and RTEL1 were selected for investigation of possible correlations with the glioma somatic markers: EGFR amplification, 1p/19q codeletion and protein expression of p53, Ki-67, and mutated IDH1. The CDKN2A/B risk variant, rs4977756, and the CDKN2B risk variant, rs1412829 were inversely associated (p = 0.049 and p = 0.002, respectively) with absence of a mutated IDH1, i.e., the majority of patients homozygous for the risk allele showed no or low expression of mutated IDH1. The RTEL1 risk variant, rs6010620 was associated (p = 0.013) with not having 1p/19q codeletion, i.e., the majority of patients homozygous for the risk allele did not show 1p/19q codeletion. In addition, the EGFR risk variant rs17172430 and the CDKN2B risk variant rs1412829, both showed a trend for association (p = 0.055 and p = 0.051, respectively) with increased EGFR copy number, i.e., the majority of patients homozygote for the risk alleles showed chromosomal gain or amplification of EGFR. Our findings indicate that CDKN2A/B risk genotypes are associated with primary glioblastoma without IDH mutation, and that there is an inverse association between RTEL1 risk genotypes and 1p/19q codeletion, suggesting that these genetic variants have a molecular impact on the genesis of high graded brain tumors. Further experimental studies are needed to delineate the functional mechanism of the association between genotype and somatic genetic aberrations. Electronic supplementary material The online version of this article (doi:10.1007/s11060-016-2066-4) contains supplementary material, which is available to authorized users.

759 Background: PC is a lethal disease with limited treatment options. We utilized Comprehensive Genomic Profiling (CGP) to identify putative prognostic and/or predictive biomarkers. Methods: We retrospectively reviewed PC patients (pts) at our institution who underwent CGP utilizing the Foundation One assay. CGP was performed on hybrid-capture, adaptor ligation-based libraries for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. PC pts were categorized by clinical stage – localized (resectable and borderline resectable PC; LPC), locally advanced (LAPC) and metastatic (mPC). Effect of gene alterations (GAs) with at least 10% prevalence were analyzed. The marginal effect of each gene on radiographic response and survival outcomes was estimated using proportional odds and multivariate Cox regression analysis, respectively, adjusting for stage. Results: Ninety-three pts were identified - median age was 63, 55% were male, and 50% were smokers. Clinical stage at diagnosis was LPC, LAPC and mPC in 42 (45%), 23 (25%) and 28 (30%) pts, respectively. The most commonly altered genes were KRAS (94%), TP53 (75%), CDKN2A (41.2%) and SMAD4 (32.9%). All patients were microsatellite stable and the median tumor mutational burden was 1.7. 5-FU (52%) or Gemcitabine (46%) based chemotherapy combinations were utilized as the first systemic therapy. Median overall survival for patients with LPC, LAPC and mPC were 30.7, 28.8 and 9.6 months respectively. Thirty-eight (91%) pts with LPC underwent curative intent surgery compared to 15 (65%) pts with LAPC (p = 0.019). Thirty-five (95%) pts with wild type (WT) CDKN2A and 47 (94%) pts with WT CDKN2B underwent curative intent surgery compared to 13 (65%) and 1(14%) pt(s) with GAs in CDKN2A and CDKN2B respectively (p = 0.003 and p < 0.0001 respectively). The response to chemotherapy was statistically significantly higher in pts with WT CDKN2A (53%) and CDKN2B (48%) compared to pts with GAs in CDKN2A (19%) and CDKN2B (12%) (p = 0.03 and p = 0.05, respectively). Conclusions: GAs in CDKN2A/B may have a predictive and possibly a prognostic impact. The clinical validity and biological relevance of these findings need to be further explored in larger studies.

Pilocytic astrocytomas are typically grade I astrocytomas, only rarely progressing to anaplastic counterparts [1]. In the case of anaplastic pilocytic astrocytomas, some are associated with neurofibromatosis type 1 (NF1) [2], others are associated with radiation treatment [2], and the remainder appear de novo. These de novo tumours can be particularly challenging to distinguish from glioblastomas, which are grade IV and carry a worse prognosis. Here we report an unusual case of malignant transformation of a pilocytic astrocytoma in the absence of NF1 alterations or radiation treatment.

e20628 Background: Hyperprogressive disease (HPD) incidence ranges from 8% to 21% in patients treated with anti-PD-1/PD-L1 mAbs in NSCLC and is associated with poor survival. Previously published data underlined a link between HPD across different cancers types and specific genetic alterations, such as MDM2 amplification and EGFR aberrations. We present a single-center cohort of patients with NSCLC and PD-L1 > 50% treated with 1st-line pembrolizumab. We performed NGS, IHC and FISH analysis to evaluate genetic correlations with the clinical phenotype. Methods: Clinical data from 20 patients with diagnosis of advanced NSCLC treated with 1stline immunotherapy pembrolizumab were retrospectively collected. HPD was defined by Time to Treatment Failure ≤2 months and raising in Tumor Burden ≥50% compared with basal CT-scan. MDM2 amplification was investigated by FISH on FFPE tissue sections using the MDM2/CON12 break apart FISH Probe. Positive cases were defined as those with > 10% positive tumor cells. We performed IHC for MDM2 protein on FFPE tissue sections. The staining was semiquantitatively graded for the intensity as: 0, negative; 1+, weak positive; 2+, moderately positive; 3+, strongly positive, and for the extent as 0– < 1% (negative), 1–50% (focal), and > 50% (diffuse). We also performed NGS analysis (FoundationOne CDX, Foundation Medicine Inc.) on 324 preidentified genes. Results: We identified 5 cases of HPD; all five cases showed MDM2amplification by FISH analysis and a focal protein expression by IHC with the strongest nuclear staining observed in the cases showing a higher degree of MDM2 amplification (8/9 dots) and a weaker expression in those with a lower MDM2amplification (4/5 dots). NGS analysis showed MDM2amplification in 1/5 HPD patient and a loss of CDKN2A/B in 4/5 patients. None of the non-HPD patients had IHC expression of MDM2 or amplification of the gene. Among the non-HPD patients no genetic alterations regarding MDM2 and/or CDKN2A/B were found on NGS analysis. Conclusions: Our data suggest a potential role of CDKN2A/B gene loss and alteration of MDM2 on the establishment of HPD in NSCLC patients treated with immunotherapy. Because the HPD logic is not yet clear, more data is needed to better understand the link between this genomic signature and the development of HPD.

Familial melanoma-astrocytoma syndrome is a tumor predisposition syndrome caused by inactivating germline alteration of the CDKN2A tumor suppressor gene on chromosome 9p21. While some families with germline CDKN2A mutations are prone to development of just melanomas, other families develop both melanomas, astrocytomas, and occasionally other nervous system neoplasms including peripheral nerve sheath tumors and meningiomas. The histologic spectrum of the astrocytomas that arise as part of this syndrome is not well described, nor are the additional genetic alterations that drive these astrocytomas apart from the germline CDKN2A inactivation. Herein, we report the case of a young man with synchronous development of a pleomorphic xanthoastrocytoma, diffuse astrocytoma, and paraspinal mass radiographically consistent with a peripheral nerve sheath tumor. His paternal family history is significant for melanoma, glioblastoma, and oral squamous cell carcinoma. Genomic profiling revealed that he harbors a heterozygous deletion in the germline of chromosome 9p21.3 encompassing the CDKN2A and CDKN2B tumor suppressor genes. Both the pleomorphic xanthoastrocytoma and diffuse astrocytoma were found to have homozygous deletion of CDKN2A/B due to somatic loss of the other copy of chromosome 9p containing the remaining intact alleles. Additional somatic alterations included BRAF p.V600E mutation in the pleomorphic xanthoastrocytoma and PTPN11, ATRX, and NF1 mutations in the diffuse astrocytoma. The presence of germline CDKN2A/B inactivation together with the presence of multiple anatomically, histologically, and genetically distinct astrocytic neoplasms, both with accompanying somatic loss of heterozygosity for the CDKN2A/B deletion, led to a diagnosis of familial melanoma-astrocytoma syndrome. This remarkable case illustrates the histologic and genetic diversity that astrocytomas arising as part of this rare glioma predisposition syndrome can demonstrate.

Introduction: Tumors with histological features of pilocytic astrocytoma but with increased mitotic activity and additional high grade features (i.e. microvascular proliferation, necrosis) have been designated anaplastic pilocytic astrocytomas (APA). Patients with such tumors are thought to have an [for full text, please go to the a.m. URL]

Cyclin-dependent kinase inhibitor-2A/B (CDKN2A/B) has been reported as a candidate gene of type 2 diabetes (T2D) based on its chromosomal position and its important role in β-cell function and regeneration. However, studies to date have reported inconsistent findings regarding the association between T2D and CDKN2A/B. To clarify this inconsistence, we conducted a meta-analysis based on alleles and genotypes prevalence of rs10811661 and rs564398 in CDKN2A/B. The PubMed, EMBASE, and Medline databases were systematically reviewed for studies published between January, 2006, and November, 2010. A total of 35 reports were collected, among of them only 16 studies (including 24,407 cases and 33,937 controls) match the inclusion criteria and were selected for the statistical test. In the meta-analysis of published data, our results suggest that the rs10811661 T allele (OR 1.28, 95% CI 1.21–1.36, P