Three-year follow-up analysis of phase 1/2 study on tirabrutinib in patients with relapsed or refractory primary central nervous system lymphoma

Background

The ONO-4059-02 phase 1/2 study showed favorable efficacy and acceptable safety profile of tirabrutinib, a second-generation Bruton's tyrosine kinase inhibitor, for relapsed/refractory primary central nervous system lymphoma (PCNSL). Here, we report the long-term efficacy and safety after a 3-year follow-up.

Methods

Eligible patients were aged ≥ 20 years with histologically diagnosed PCNSL and KPS of ≥ 70. Patients received oral tirabrutinib once daily at 320 or 480 mg, or 480 mg under fasted conditions.

Results

Between October 19, 2017, and June 13, 2019, 44 patients were enrolled: 33 and 9 had relapsed and refractory, respectively. The 320, 480, and 480 mg fasted groups included 20, 7, and 17 patients, respectively. The median follow-up was 37.1 months. The overall response rate was 63.6% (95% CI: 47.8-77.6) with complete response (CR), unconfirmed CR, and partial response in 9, 7, and 12 patients, respectively. The median duration of response (DOR) was 9.2 months, with a DOR rate of 19.8%; the median progression-free survival (PFS) and median overall survival (OS) were 2.9 months and not reached, respectively, with PFS and OS rates of 13.9% and 56.7%, respectively. Adverse events occurred in 38 patients (86.4%): grade ≥ 3 in 23 (52.3%) including 1 patient with grade 5 events. KPS and quality of life (QoL) scores were well maintained among patients receiving long-term treatment.

Conclusions

The results demonstrated the long-term clinical benefit of tirabrutinib, with deep and durable response in a subset of patients and acceptable safety profile, while KPS and QoL scores were maintained.

Differentiating primary central nervous system lymphoma from glioblastoma by time-dependent diffusion using oscillating gradient

BACKGROUND

This study aimed to elucidate the impact of effective diffusion time setting on apparent diffusion coefficient (ADC)-based differentiation between primary central nervous system lymphomas (PCNSLs) and glioblastomas (GBMs) and to investigate the usage of time-dependent diffusion magnetic resonance imaging (MRI) parameters.

METHODS

A retrospective study was conducted involving 21 patients with PCNSLs and 66 patients with GBMs using diffusion weighted imaging (DWI) sequences with oscillating gradient spin-echo (Δeff = 7.1 ms) and conventional pulsed gradient (Δeff = 44.5 ms). In addition to ADC maps at the two diffusion times (ADC7.1 ms and ADC44.5 ms), we generated maps of the ADC changes (cADC) and the relative ADC changes (rcADC) between the two diffusion times. Regions of interest were placed on enhancing regions and non-enhancing peritumoral regions. The mean and the fifth and 95th percentile values of each parameter were compared between PCNSLs and GBMs. The area under the receiver operating characteristic curve (AUC) values were used to compare the discriminating performances among the indices.

RESULTS

In enhancing regions, the mean and fifth and 95th percentile values of ADC44.5 ms and ADC7.1 ms in PCNSLs were significantly lower than those in GBMs (p = 0.02 for 95th percentile of ADC44.5 ms, p = 0.04 for ADC7.1 ms, and p < 0.01 for others). Furthermore, the mean and fifth and 95th percentile values of cADC and rcADC were significantly higher in PCNSLs than in GBMs (each p < 0.01). The AUC of the best-performing index for ADC7.1 ms was significantly lower than that for ADC44.5 ms (p < 0.001). The mean rcADC showed the highest discriminating performance (AUC = 0.920) among all indices. In peritumoral regions, no significant difference in any of the three indices of ADC44.5 ms, ADC7.1 ms, cADC, and rcADC was observed between PCNSLs and GBMs.

CONCLUSIONS

Effective diffusion time setting can have a crucial impact on the performance of ADC in differentiating between PCNSLs and GBMs. The time-dependent diffusion MRI parameters may be useful in the differentiation of these lesions.

Pilocytic Astrocytoma Presenting with Spontaneous Cerebellar Hemorrhage: A Case Report

Hemorrhagic pilocytic astrocytomas (PAs) are rare, accounting for 1.1%-8.0% of all PA cases. They are reported to occur more frequently in older populations, with a male predominance. In this study, we report a case of a 14-year-old boy who presented with a headache, vertigo, and diplopia. As per his brain computed tomography scan, a small hematoma was observed in the left inferior cerebellar peduncle. Follow-up magnetic resonance imaging (MRI) revealed repeated minor bleeding from the lesion and mild expansion, with no neurological deficits. Four years later, the patient developed nausea, vomiting, and left abducens palsy. MRI revealed a mulberry-shaped mass surrounded by a hypointense rim, suggesting a cavernous angioma. The lesion was surgically resected via midline occipital craniotomy with the opening of the cerebellomedullary fissure. Histopathological examination of the lesion revealed PA. Next-generation sequencing analyses revealed that PAs harbored mutations in the ARID1A, ATM, and POLE genes but not in the BRAF gene. To the best of our knowledge, there are yet no reported studies on these mutations in PAs to date. Thus, PA should be considered in the differential diagnosis of cerebellar hemorrhage, especially in young adults and children．.

A case of glioblastoma harboring non-amplified epidermal growth factor receptor variant III: Critical molecular detection using RNA-based panel analysis

Amplification of the epidermal growth factor receptor gene (EGFR) and its variants are the most commonly detected pathogenic gene alterations in glioblastoma. Herein, we report a case of molecularly defined glioblastoma harboring an EGFR variant III (EGFRvIII) without EGFR amplification. The initial histological diagnosis was isocitrate dehydrogenase (IDH)-wildtype low-grade glioma, due to an absence of anaplasia, necrosis, and microvascular proliferation, and a low Ki-67 labeling index. DNA-based next-generation sequencing (NGS) panel analysis revealed a TERTp promoter mutation but no EGFR mutation or amplification, supporting the diagnosis of "molecular glioblastoma." However, RNA-based NGS panel analysis revealed mRNA expression of EGFRvIII. Therefore, the final integrative diagnosis was glioblastoma with non-amplified EGFRvIII. Our report suggests that non-amplified EGFRvIII might be an early molecular event in glioblastoma tumorigenesis. In addition to the usual DNA-based analysis, RNA-based analysis is required to identify exon-skipping EGFR variants without EGFR amplification.

Difficult differential diagnosis of ectopic germinoma from multiple sclerosis: A case report and literature review

INTRODUCTION AND IMPORTANCE

Intracranial germinomas are germ cell tumors that commonly develop in the pineal or neurohypophysis regions. As ectopic germinomas are rarely observed within the cerebrum and are associated with atypical image findings, diagnosis is challenging.

CASE PRESENTATION

A 14-year-old boy was admitted to our hospital with complaints of vomiting and headache. Gadolinium-enhanced magnetic resonance imaging revealed ring-enhancing lesions in his left frontal lobe and basal ganglia. Susceptibility-weighted imaging indicated that the subependymal veins passing through the lesion centers were engorged, while electrophoretic analysis of cerebrospinal fluid identified oligoclonal bands (OCBs); both were typical of multiple sclerosis (MS). Tumor biopsy revealed many cells with atypical mitotic figures and nuclear enlargements, suggesting malignant disease. As the tumor rapidly proliferated, we opted for surgical excision of the lesions. Histopathological analyses revealed "two-cell patterns" characteristic of germinoma. Immunohistochemistry was positive for placental alkaline phosphatase and c-KIT. The definitive diagnosis was germinoma. After chemoradiotherapy, the patient was discharged without neurological deficits.

CLINICAL DISCUSSION

OCBs and several magnetic resonance imaging features (including open ring enhancement, T2 hypointense rims, mild mass effects, mild perilesional edema, peripheral restriction around the lesion, and vessel-like structures running through the lesion center) are useful diagnostic signs for the radiological discrimination of MS from germinoma. However, owing to these factors, some cases are difficult to diagnose.

CONCLUSION

Our case report of an unusual ectopic cerebral germinoma illustrates the difficulty of distinguishing it from MS. Therefore, we recommend proper tissue sampling in such cases, especially in adolescent patients, to make definitive germinoma diagnoses.

Favorable prognostic impact of phosphatase and tensin homolog alterations in wild-type isocitrate dehydrogenase and telomerase reverse transcriptase promoter glioblastoma

Background

Telomerase reverse transcriptase promoter (TERTp) mutations are a biological marker of glioblastoma; however, the prognostic significance of TERTp mutational status is controversial. We evaluated this impact by retrospectively analyzing the outcomes of patients with isocitrate dehydrogenase (IDH)- and TERTp-wild-type glioblastomas.

Methods

Using custom next-generation sequencing, we analyzed 208 glioblastoma samples harboring wild-type IDH.

Results

TERTp mutations were detected in 143 samples (68.8%). The remaining 65 (31.2%) were TERTp-wild-type. Among the TERTp-wild-type glioblastoma samples, we observed a significant difference in median progression-free survival (18.6 and 11.4 months, respectively) and overall survival (not reached and 15.7 months, respectively) in patients with and without phosphatase and tensin homolog (PTEN) loss and/or mutation. Patients with TERTp-wild-type glioblastomas with PTEN loss and/or mutation were younger and had higher Karnofsky Performance Status scores than those without PTEN loss and/or mutation. We divided the patients with TERTp-wild-type into 3 clusters using unsupervised hierarchical clustering: Good (PTEN and TP53 alterations; lack of CDKN2A/B homozygous deletion and platelet-derived growth factor receptor alpha (PDGFRA) alterations), intermediate (PTEN alterations, CDKN2A/B homozygous deletion, lack of PDGFRA, and TP53 alterations), and poor (PDGFRA and TP53 alterations, CDKN2A/B homozygous deletion, and lack of PTEN alterations) outcomes. Kaplan-Meier survival analysis indicated that these clusters significantly correlated with the overall survival of TERTp-wild-type glioblastoma patients.

Conclusions

Here, we report that PTEN loss and/or mutation is the most useful marker for predicting favorable outcomes in patients with IDH- and TERTp-wild-type glioblastomas. The combination of 4 genes, PTEN, TP53, CDKN2A/B, and PDGFRA, is important for the molecular classification and individual prognosis of patients with IDH- and TERTp-wild-type glioblastomas.

Alterations in EGFR and PDGFRA are associated with the localization of contrast-enhancing lesions in glioblastoma

Background

Glioblastoma (GBM) is a malignant brain tumor, with radiological and genetic heterogeneity. We examined the association between radiological characteristics and driver gene alterations.

Methods

We analyzed the driver genes of 124 patients with IDH wild-type GBM with contrast enhancement using magnetic resonance imaging. We used a next-generation sequencing panel to identify mutations in driver genes and matched them with radiological information. Contrast-enhancing lesion localization of GBMs was classified into 4 groups based on their relationship with the subventricular zone (SVZ) and cortex (Ctx).

Results

The cohort included 69 men (55.6%) and 55 women (44.4%) with a mean age of 66.4 ± 13.3 years. EGFR and PDGFRA alterations were detected in 28.2% and 22.6% of the patients, respectively. Contrast-enhancing lesion touching both the SVZ and Ctx was excluded because it was difficult to determine whether it originated from the SVZ or Ctx. Contrast-enhancing lesions touching the SVZ but not the Ctx had significantly worse overall survival than non-SVZ lesions (441 days vs. 897 days, P = .002). GBM touching only the Ctx had a better prognosis (901 days vs. 473 days, P < .001) than non-Ctx lesions and was associated with EGFR alteration (39.4% vs. 13.2%, P = .015). Multiple contrast lesions were predominant in PDGFRA alteration and RB1-wild type (P = .036 and P = .031, respectively).

Conclusions

EGFR alteration was associated with cortical lesions. And PDGFRA alteration correlated with multiple lesions. Our results suggest that clarifying the association between driver genes and tumor localization may be useful in clinical practice, including prognosis prediction.

Karnofsky Performance Status and quality of life in patients with relapsed or refractory primary CNS lymphoma from a phase I/II study of tirabrutinib

Background

Tirabrutinib, a second-generation inhibitor of Bruton's tyrosine kinase, was approved in March 2020 for the treatment of relapsed or refractory primary central nervous system lymphoma (r/r PCNSL) based on phase I/II studies in Japan. We previously reported the overall response rate and safety profile. We describe Karnofsky Performance Status (KPS) and the quality of life (QoL) in patients with r/r PCNSL receiving tirabrutinib based on more than 1-year follow-up data.

Methods

Patients with r/r PCNSL, age ≥20 years, and KPS ≥70 were treated with tirabrutinib once daily at a dose of 320, 480, or 480 mg under fasted conditions. QoL was assessed using questionnaires issued by the European Organization for Research and Treatment of Cancer (EORTC), namely EORTC QLQ-C30, EORTC QLQ-BN20, and EuroQol 5 dimensions 3-level (EQ-5D-3L) along with KPS.

Results

Forty-four patients (mean age, 60 years [range 29-86]) were enrolled. The median follow-up period was 14.9 months (range, 1.4-27.7). The median KPS of the patients at baseline was 80.0 (range, 70-100), and this remained constant during the treatment. The global health status/QoL in the QLQ-C30 showed significant improvements from baseline through cycles 3-17 and remained relatively constant thereafter until cycle 23. Improvements were also seen in emotional functioning and constipation in the QLQ-C30 segments. Other items of QLQ-C30 and QLQ-BN20, EQ-5D visual analog scales, and EQ-5D index were maintained during the treatment.

Conclusions

Tirabrutinib generally maintains KPS and QoL scores with some improvements in specific QoL items in patients with r/r PCNSL.

Combination of asleep and awake craniotomy as a novel strategy for resection in patients with butterfly glioblastoma: Two case reports

Background:

Several studies have reported that gross total resection contributes to improved prognosis in patients with butterfly glioblastoma (bGBM). However, it sometimes damages the corpus callosum and cingulate gyrus, leading to severe neurological complications.

Case Description:

We report two cases of bGBM that was safely and maximally resected using brief and exact awake mapping after general anesthesia. Two patients had butterfly tumors in both the frontal lobes and the genu of the corpus callosum. Tumor resection was first performed on the nondominant side under general anesthesia to shorten the resection time and maintain patient concentration during awake surgery. After that, awake surgery was performed for the lesions in the dominant frontal lobe and genu of the corpus callosum. Tumor resection was performed through minimal cortical incisions in both frontal lobes. Postoperative magnetic resonance imaging showed gross total resection, and the patients had no chronic neurological sequelae, such as akinetic mutism and abulia.

Conclusion:

bGBM could be safely and maximally resected by a combination of asleep and brief awake resection, which enabled patients to maintain their attention to the task without fatigue, somnolence, or decreased attention. The bilateral approach from a small corticotomy can avoid extensive damage to the cingulate gyrus.

Molecular Genetic Profile of 300 Japanese Patients with Diffuse Gliomas Using a Glioma-tailored Gene Panel

Rapid technological advances in molecular biology, including next-generation sequencing, have identified key genetic alterations in central nervous system (CNS) tumors. Accordingly, the fifth edition of the World Health Organization (WHO) CNS tumor classification was published in 2021. We analyzed 303 patients with diffuse glioma using an amplicon-based glioma-tailored gene panel for detecting 1p/19q codeletion and driver gene mutations such as IDH1/2, TERTp, EGFR, and CDKN2A/B on a single platform. Within glioblastomas (GBMs), the most commonly mutated genes were TERTp, TP53, PTEN, NF1, and PDGFRA, which was the most frequently mutated tyrosine kinase receptor in GBM, followed by EGFR. The genes that most commonly showed evidence of loss were PTEN, CDKN2A/B, and RB1, whereas the genes that most commonly showed evidence of gain/amplification were EGFR, PDGFRA, and CDK4. In 22 grade III oligodendroglial tumors, 3 (14%) patients had CDKN2A/B homozygous deletion, and 4 (18%) patients had ARID1A mutation. In grade III oligodendroglial tumors, an ARID1A mutation was associated with worse progression-free survival. Reclassification based on the WHO 2021 classification resulted in 62.5% of grade II/III isocitrate dehydrogenase (IDH)-wildtype astrocytomas being classified as IDH-wildtype GBM and 37.5% as not elsewhere classified. In summary, our glioma-tailored gene panel was applicable for molecular diagnosis in the WHO 2021 classification. In addition, we successfully reclassified the 303 diffuse glioma cases based on the WHO 2021 classification and clarified the genetic profile of diffuse gliomas in the Japanese population.

Distribution and favorable prognostic implication of genomic EGFR alterations in IDH-wildtype glioblastoma

BACKGROUND

We aimed to evaluate the mutation profile, transcriptional variants, and prognostic impact of the epidermal growth factor receptor (EGFR) gene in isocitrate dehydrogenase (IDH)-wildtype glioblastomas (GBMs).

METHODS

We sequenced EGFR, evaluated the EGFR splicing profile using a next-generation sequencing oncopanel, and analyzed the outcomes in 138 grade IV IDH-wildtype GBM cases.

RESULTS

EGFR mutations were observed in 10% of GBMs. A total of 23.9% of the GBMs showed EGFR amplification. Moreover, 25% of the EGFR mutations occurred in the kinase domain. Notably, EGFR alterations were a predictor of good prognosis (p = 0.035). GBM with EGFR alterations was associated with higher Karnofsky Performance Scale scores (p = 0.014) and lower Ki-67 scores (p = 0.005) than GBM without EGFR alterations. EGFRvIII positivity was detected in 21% of EGFR-amplified GBMs. We identified two other EGFR variants in GBM cases with deletions of exons 6-7 (Δe 6-7) and exons 2-14 (Δe 2-14). In one case, the initial EGFRvIII mutation transformed into an EGFR Δe 2-14 mutation during recurrence.

CONCLUSIONS

We found that the EGFR gene profiles of GBM differ among cohorts and that EGFR alterations are good prognostic markers of overall survival in patients with IDH-wildtype GBM. Additionally, we identified rare EGFR variants with longitudinal and temporal transformations of EGFRvIII.

Factors Influencing the Improvement of Activities of Daily Living during Inpatient Rehabilitation in Newly Diagnosed Patients with Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor. To identify the factors influencing the improvement of the activities of daily living (ADL) in newly diagnosed patients with GBM, we investigated the characteristics and variable factors and overall survival. A total of 105 patients with GBM were retrospectively analyzed and categorized into the following three groups according to the quartile of change of their Barthel index score from admission to discharge: deterioration (n = 25), no remarkable change (n = 55), and good recovery (n = 25). A statistical difference was observed in the pre-operative, intra-operative, post-operative, and rehabilitation-related factors between the deterioration and good recovery groups. Multiple regression analysis identified the following significant factors that may influence the improvement of ADL after surgery: the improvement of motor paralysis after surgery, mild fatigue during radio and chemotherapy, and length up to early walking training onset. The median overall survival was significantly different between the deterioration (10.6 months) and good recovery groups (18.9 months, p = 0.025). Our findings identified several factors that may be associated with post-operative functional improvement in patients with GBM. The inpatient rehabilitation during radio and chemotherapy may be encouraged without severe adverse events and can promote functional outcomes, which may contribute to the overall survival of newly diagnosed patients with GBM.

Prognostic impact of PDGFRA gain/amplification and MGMT promoter methylation status in patients with IDH wild-type glioblastoma

Background

Platelet-derived growth factor receptor alpha (PDGFRA) is the second most frequently mutated tyrosine kinase receptor in glioblastoma (GBM). However, the prognostic impact of PDGFRA amplification on GBM patients remains unclear. Herein, we evaluated this impact by retrospectively analyzing outcomes of patients with IDH wild-type GBM.

Methods

Using a custom-made oncopanel, we evaluated PDGFRA gain/amplification in 107 GBM samples harboring wild-type IDH, along with MGMT promoter (MGMTp) methylation status.

Results

We detected PDGFRA gain/amplification in 31 samples (29.0%). PDGFRA gain/amplification predicted poor prognosis (P = .003). Compared to unamplified PDGFRA, PDGFRA gain/amplification in GBM was associated with higher patient age (P = .031), higher Ki-67 score (P = .019), and lower extent of surgical resection (P = .033). Unmethylated MGMTp also predicted poor prognosis (P = .005). As PDGFRA gain/amplification and unmethylated MGMTp were independent factors for poor prognosis in multivariate analyses, we grouped GBM cases based on PDGFRA and MGMTp status: poor (PDGFRA gain/amplification and unmethylated MGMTp), intermediate (PDGFRA gain/amplification or unmethylated MGMTp), and good (PDGFRA intact and methylated MGMTp) prognosis. The Kaplan-Meier survival analysis indicated that these groups significantly correlated with the OS of GBM patients (P < .001).

Conclusions

Here we report that PDGFRA gain/amplification is a predictor of poor prognosis in IDH wild-type GBM. Combining PDGFRA gain/amplification with MGMTp methylation status improves individual prognosis prediction in patients with IDH wild-type GBM.

ET-7 Roles for hENT1 and dCK in gemcitabine sensitivity and malignancy of meningioma

Background: High-grade meningiomas are aggressive tumors with high morbidity and mortality rates that frequently recur even after surgery and adjuvant radiotherapy. However, limited information is currently available on the biology of these tumors, and no alternative adjuvant treatment options exist. Although we previously demonstrated that high-grade meningioma cells were highly sensitive to gemcitabine in vitro and in vivo, the underlying molecular mechanisms remain unknown. Methods: We examined the roles of hENT1 (human equilibrative nucleoside transporter 1) and dCK (deoxycytidine kinase) in the gemcitabine sensitivity and growth of meningioma cells in vitro. Tissue samples from meningiomas (26 WHO grade I and 21 WHO grade II/III meningiomas) were immunohistochemically analyzed for hENT1 and dCK as well as for Ki-67 as a marker of proliferative activity. Results: hENT1 and dCK, which play critical roles in the intracellular transport and activation of gemcitabine, respectively, were responsible for the high gemcitabine sensitivity of high-grade meningioma cells and were strongly expressed in high-grade meningiomas. hENT1 expression was required for the proliferation and survival of high-grade meningioma cells and dCK expression. Furthermore, high hENT1 and dCK expression levels correlated with stronger tumor cell proliferative activity and shorter survival in meningioma patients. Conclusions: The present results suggest that hENT1 is a key molecular factor influencing the growth capacity and gemcitabine sensitivity of meningioma cells and also that hENT1, together with dCK, may be a viable prognostic marker for meningioma patients as well as a predictive marker of their responses to gemcitabine.

Outcomes of salvage fractionated re-irradiation combined with bevacizumab for recurrent high-grade gliomas that progressed after bevacizumab treatment*

BACKGROUND

There is no standard treatment for patients with recurrent high-grade gliomas who progress after bevacizumab treatment. We evaluated the outcomes of re-irradiation combined with bevacizumab for patients refractory to bevacizumab.

METHODS

Between January 2015 and September 2019, patients with progression after bevacizumab treatment were treated with re-irradiation combined with bevacizumab (25 Gy in five fractions).

RESULTS

Fourteen patients [glioblastoma, isocitrate dehydrogenase (IDH) wild type (N = 6), glioblastoma, IDH mutant (N = 4), anaplastic astrocytoma, IDH wild type (N = 1), anaplastic astrocytoma, IDH mutant (N = 1), glioblastoma, not otherwise specified (N = 1) and radiologically diagnosed brainstem glioma (N = 1)] were included in this study. The median survival and progression-free survival times after re-irradiation combined with bevacizumab were 6.1 and 3.8 months, respectively. The 6-month survival and progression-free survival rates were 54.5 and 15.7%, respectively. Patients with a Karnofsky performance status of ≥70 tended to have longer median survival time (9.3 vs. 5.4 months, respectively; P = 0.058) and had a significantly longer median progression-free survival time (4.2 vs. 3.7 months, respectively; P = 0.046) than those with a Karnofsky performance status of <70. Four patients (28.6%) achieved a complete or partial radiological response, and three patients (21.4%) had an improved Karnofsky performance status after re-irradiation combined with bevacizumab. Grade 3/4 toxicities included leukopenia in four patients (28.6%), hypertension in three (21.4%), proteinuria in one (7.1%) and gastrointestinal hemorrhage in one (7.1%).

CONCLUSIONS

Re-irradiation combined with bevacizumab for patients with recurrent high-grade gliomas who progress after bevacizumab treatment was feasible. Re-irradiation combined with bevacizumab is a potential treatment option, especially for patients with a Karnofsky performance status of ≥70.

Roles for hENT1 and dCK in gemcitabine sensitivity and malignancy of meningioma

Background

High-grade meningiomas are aggressive tumors with high morbidity and mortality rates that frequently recur even after surgery and adjuvant radiotherapy. However, limited information is currently available on the biology of these tumors, and no alternative adjuvant treatment options exist. Although we previously demonstrated that high-grade meningioma cells were highly sensitive to gemcitabine in vitro and in vivo, the underlying molecular mechanisms remain unknown.

Methods

We examined the roles of hENT1 (human equilibrative nucleoside transporter 1) and dCK (deoxycytidine kinase) in the gemcitabine sensitivity and growth of meningioma cells in vitro. Tissue samples from meningiomas (26 WHO grade I and 21 WHO grade II/III meningiomas) were immunohistochemically analyzed for hENT1 and dCK as well as for Ki-67 as a marker of proliferative activity.

Results

hENT1 and dCK, which play critical roles in the intracellular transport and activation of gemcitabine, respectively, were responsible for the high gemcitabine sensitivity of high-grade meningioma cells and were strongly expressed in high-grade meningiomas. hENT1 expression was required for the proliferation and survival of high-grade meningioma cells and dCK expression. Furthermore, high hENT1 and dCK expression levels correlated with stronger tumor cell proliferative activity and shorter survival in meningioma patients.

Conclusions

The present results suggest that hENT1 is a key molecular factor influencing the growth capacity and gemcitabine sensitivity of meningioma cells and also that hENT1, together with dCK, may be a viable prognostic marker for meningioma patients as well as a predictive marker of their responses to gemcitabine.

Phase I/II study of tirabrutinib, a second-generation Bruton's tyrosine kinase inhibitor, in relapsed/refractory primary central nervous system lymphoma

Background

The safety, tolerability, efficacy, and pharmacokinetics of tirabrutinib, a second-generation, highly selective oral Bruton’s tyrosine kinase inhibitor, were evaluated for relapsed/refractory primary central nervous system lymphoma (PCNSL).

Methods

Patients with relapsed/refractory PCNSL, Karnofsky performance status ≥70, and normal end-organ function received tirabrutinib 320 and 480 mg once daily (q.d.) in phase I to evaluate dose-limiting toxicity (DLT) within 28 days using a 3 + 3 dose escalation design and with 480 mg q.d. under fasted conditions in phase II.

Results

Forty-four patients were enrolled; 20, 7, and 17 received tirabrutinib at 320, 480, and 480 mg under fasted conditions, respectively. No DLTs were observed, and the maximum tolerated dose was not reached at 480 mg. Common grade ≥3 adverse events (AEs) were neutropenia (9.1%), lymphopenia, leukopenia, and erythema multiforme (6.8% each). One patient with 480 mg q.d. had grade 5 AEs (pneumocystis jirovecii pneumonia and interstitial lung disease). Independent review committee assessed overall response rate (ORR) at 64%: 60% with 5 complete responses (CR)/unconfirmed complete responses (CRu) at 320 mg, 100% with 4 CR/CRu at 480 mg, and 53% with 6 CR/CRu at 480 mg under fasted conditions. Median progression-free survival was 2.9 months: 2.1, 11.1, and 5.8 months at 320, 480, and 480 mg under fasted conditions, respectively. Median overall survival was not reached. ORR was similar among patients harboring CARD11, MYD88, and CD79B mutations, and corresponding wild types.

Conclusion

These data indicate favorable efficacy of tirabrutinib in patients with relapsed/refractory PCNSL.

Trial registration

JapicCTI-173646.

Associations of PD-L1, PD-L2, and HLA class I expression with responses to immunotherapy in patients with advanced sarcoma: post hoc analysis of a phase 1/2 trial

BACKGROUND

Although immunotherapy is thought to be a promising cancer treatment, most patients do not respond to immunotherapy. In this post hoc analysis of a phase 1/2 study, associations of programmed death ligand 1 (PD-L1), PD-L2, and HLA class I expressions with responses to dendritic cells (DCs)-based immunotherapy were investigated in patients with advanced sarcoma.

METHODS

This study enrolled 35 patients with metastatic and/or recurrent sarcomas who underwent DC-based immunotherapy. The associations of PD-L1, PD-L2, and HLA class I expressions in tumor specimens, which were resected before immunotherapy, with immune responses (increases of IFN-γ and IL-12) and oncological outcomes were evaluated.

RESULTS

Patients who were PD-L2 (+) showed lower increases of IFN-γ and IL-12 after DC-based immunotherapy than patients who were PD-L2 (-). The disease control (partial response or stable disease) rates of patients who were PD-L1 (+) and PD-L1 (-) were 0% and 22%, respectively. Disease control rates of patients who were PD-L2 (+) and PD-L2 (-) were 13% and 22%, respectively. Patients who were PD-L1 (+) tumors had significantly poorer overall survival compared with patients who were PD-L1 (-). No associations of HLA class I expression with the immune response or oncological outcomes were observed.

CONCLUSIONS

This study suggests that PD-L1 and PD-L2 are promising biomarkers of DC-based immunotherapy, and that addition of immune checkpoint inhibitors to DC-based immunotherapy may improve the outcomes of DC-based immunotherapy.

LGG-20. CLINICAL FEATURES AND TREATMENT RESULTS FOR PEDIATRIC OPTICO-HYPOTHALAMIC ASTROCYTOMA

Current consensus for the treatment of optico-hypothalamic astrocytoma (OHA) is a chemotherapy-first policy, limiting the role of surgery for histopathological diagnosis and partial decompression. However, a subgroup of OHA patients show resistance to chemotherapy and have a worse prognosis. In this study, we retrospectively analyzed our clinical experiences of the treatment of patients with OHA in two university hospitals. We have extracted and analyzed the medical charts of 15 pediatric OHA patients treated in two university hospitals since 1990. NF-1-associated OHA patients were excluded. Patient ages ranged from 10 months to 21 years (median 7 years). Out of 15 cases, 12 patients had a tumor larger than 3 cm and classified as Dodge 3. The final histopathological diagnosis was pilocytic astrocytoma in 13 cases. Three patients with tumors classified as Dodge 1 or 2 show good prognosis only by biopsy or partial resection. However, regarding Dodge 3 tumor, patient prognosis is worse regardless of chemotherapy and radiotherapy. After the initial surgery, chemotherapy was administered in 11 cases and radiotherapy in 5 cases. Multiple surgeries are needed for tumor control in 7 patients. Four patients died of tumor progression or treatment-associated complications. When the initial tumor is large enough to cause neurological deterioration, a chemotherapeutic tumor suppressive effect might be limited in a subset of large OHA cases. Therefore, it is important to consider the proper timing of safe surgical decompression in the early phase when a large tumor does not respond to chemotherapy.

LGG-32. CLINICAL OUTCOME OF PEDIATRIC GLIOMAS IN SINGLE INSTITUTION

Gliomas in children are rarer than in adult, then treatment strategies might vary from facility to facility. We report clinical features and outcome of pediatric glioma in our institution. Twenty-nine patients diagnosed with glioma, exclude ependymoma, 14 boys and 15 girls, among 98 pediatric brain tumor patients treated at Kagoshima University Hospital since 2006 were reviewed histopathology, extent of resection, adjuvant therapy and outcome, etc. Mean age at surgery was 10.4 (S.D. 5.6) years. Median follow-up period was 19.1 months. Histopathological diagnosis comprised 8 pilocytic astrocytoma, 3 ganglioglioma, 2 subependymal giant cell astrocytoma, 5 WHO grade Ⅱ astrocytoma, 8 glioblastoma, and desmoplastic infantile astrocytoma, anaplastic astrocytoma and astroblastoma were one case each. Tumor resection was performed in 24 cases, and 5 cases underwent biopsy. Chemotherapy was performed in 15 cases and irradiation was performed in 9 cases. Out of 5 WHO grade Ⅱ astrocytoma cases, 2 cases underwent biopsy following chemotherapy, 1 case underwent biopsy only and other 1 case underwent total resection. The four cases show long survival ranged from 71 to 136 months without irradiation. All of eight glioblastoma cases show poor prognosis ranged from 8.6 to 26.7 months regardless of chemo-radiotherapy. In management for pediatric brain tumor patients, irradiation is often laid over until recurrence. In WHO grade Ⅱ astrocytoma, the treatment strategy might be reasonable using appropriate chemotherapy even though biopsy cases.

HGG-42. CLINICAL FEATURES AND TREATMENT OUTCOME OF MALIGNANT GLIOMAS IN CHILDREN AND ADOLESCENTS

INTRODUCTION

Malignant gliomas in children and adolescents are rare. They are difficult to treat and are associated with an extremely poor prognosis.

SUBJECTS AND METHODS

The treatment and outcomes of WHO grade IV -gliomas and diffuse intrinsic pontine gliomas (DIPG) in children and adolescents (Age 4–39, median 28) treated at our institute since 2001 were retrospectively reviewed. Thirty-five cases were included in this study. Nine cases were located in their brain stem and 2 of them were diagnosed as DIPG clinically without biopsy. Three (brain stem -2, thalamus- 1) cases were diffuse midline glioma H3 K27 M mutant. Remaining 30 cases were diagnosed histologically as glioblastoma. Expect for 2 cases, all were irradiated. Twenty-four cases were treated with temozolomide (TMZ). Bevacizumab (BEV) was administrated as an initial therapy in 10 cases (concomitant with TMZ in 9 cases) and was administrated at the time of relapse in 9 cases. In summary, 19 cases were treated with BEV.

RESULTS

Median survival time (MST) of all cases was 16.8 (4.4 -152.3) months. In total, BEV did not prolonged overall survival (OS), MST 16.02 vs 14.44, (p=0.498). Among adolescents (age 15–39), patients treated with BEV had a trend of longer OS but did not reached statistical significance, MST 19.64 vs 10.76 (p=0.167). An extent of resection and KPS =>70 at discharge from hospital were beneficial factors associated with prolonged OS.

CONCLUSION

As well as in elderly cases, multidisciplinary treatment including resection, radiation and chemotherapy including BEV improves outcomes.

RARE-04. INTELLECTUAL DEVELOPMENT IN CHILDREN WITH PEDIATRIC CRANIOPHARYNGIOMA AFTER TUMOR REMOVAL

INTRODUCTION

Intellectual assessment in children with craniopharyngioma after tumor removal is still unknown. We assessed intellectual development in children who underwent microsurgical resection in our institute over the last twelve years.

MATERIALS AND METHODS

Ten children among 41 patients with craniopharyngioma treated and followed at Kagoshima University Hospital between 2007 and 2019 were reviewed. We also assessed intellectual development in 10 years or younger children with craniopharyngioma one year after tumor removal. Intelligence was assessed using the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-Ⅳ).

RESULTS

Ten children underwent microsurgical tumor removal. The mean age at surgery was 5.8 (range 1–10) years. Transcranial approach was performed in 8 children, transsphenoidal approach in two children. The mean follow up period was 110 months. Gamma knife surgery (GKS) was performed in 6 children less than 6 months after first surgery. Regional recurrences occurred in 5 children, and additional GKS was performed in four children, second microsurgical removal in one child. Severe obesity with a transient electrolyte imbalance occurred in one child. Eight children with GH deficiency underwent GH replacement therapy. Eight children were assessed working memory index (WMI), processing speed index (PSI), Perceptual reasoning index (PRI), and verbal comprehension index (VCI) using WISC 4. Each mean value of WMI, PSI, and PRI was lower than VCI, except for 2 children with normal full scale intelligence quotient.

CONCLUSION

WMI, PSI and PRI in children with intellectual disabilities were lower tendency than VCI after surgical removal of craniopharyngiomas in the present study.

ML-05 One-year follow-up data of phase I/II study of tirabrutinib in patients with relapsed or refractory primary central nervous system lymphoma

In March 2020, Tirabrutinib (TIR), a second-generation oral Bruton’s tyrosine kinase inhibitor, was approved for the indication of relapsed or refractory PCNSL (r/rPCNSL) based on the results of a phase I/II study in Japan. In this study, 44 Japanese patients with r/rPCNSL were treated with TIR QD at 320 mg, 480 mg, or 480 mg in the fasted condition (480 mg fasted QD). The primary endpoint was overall response rate (ORR) assessed by an independent review committee according to International PCNSL Collaborative Group criteria. We previously reported the results of this study with data cutoff in June 2019 (Narita et al. Neuro Oncol. 2020). In the report, 17 of 44 patients were treated with TIR at 480 mg fasted QD which is an approved dose, and had ORR of 52.9%, median progression-free survival of 5.8 months, and median overall survival of not reached (median follow-up: 3.8 months). In 44 patients, ORR was similar among patients harboring either of the oncogenic mutants CARD11, MYD88, CD79B, or wild type. Throughout the whole patients, most common adverse events (AEs) at any grade were rash (31.8%), neutropenia (22.7%), leukopenia (18.2%), and lymphopenia (15.9%), and grade ≥3 AEs were neutropenia (9.1%), lymphopenia, leukopenia, and erythema multiforme (6.8% each). One patient with 480 mg QD had grade 5 AEs (pneumocystis jirovecii pneumonia and interstitial lung disease). We will present one-year follow-up data of this study at the meeting. As of data cutoff (February 2020), 11 of 44 patients continued to receive TIR, including 6 patients with 480 mg fasted QD. Updated data for overall survival, duration of response, and time to onset of AEs will also be presented. TIR is a promising new treatment for r/rPCNSL.

A tailored next-generation sequencing panel identified distinct subtypes of wildtype IDH and TERT promoter glioblastomas

Central nervous system tumors are classified based on an integrated diagnosis combining histology and molecular characteristics, including IDH1/2 and H3-K27M mutations, as well as 1p/19q codeletion. Here, we aimed to develop and assess the feasibility of a glioma-tailored 48-gene next-generation sequencing (NGS) panel for integrated glioma diagnosis. We designed a glioma-tailored 48-gene NGS panel for detecting 1p/19q codeletion and mutations in IDH1/2, TP53, PTEN, PDGFRA, NF1, RB1, CDKN2A/B, CDK4, and the TERT promoter (TERTp). We analyzed 106 glioma patients (grade II: 19 cases, grade III: 23 cases, grade IV: 64 cases) using this system. The 1p/19q codeletion was detected precisely in oligodendroglial tumors using our NGS panel. In a cohort of 64 grade Ⅳ gliomas, we identified 56 IDH-wildtype glioblastomas. Within these IDH-wildtype glioblastomas, 33 samples (58.9%) showed a mutation in TERTp. Notably, PDGFRA mutations and their amplification were more commonly seen in TERTp-wildtype glioblastomas (43%) than in TERTp-mutant glioblastomas (6%) (P = .001). Hierarchical molecular classification of IDH-wildtype glioblastomas revealed 3 distinct groups of IDH-wildtype glioblastomas. One major cluster was characterized by mutations in PDGFRA, amplification of CDK4 and PDGFRA, homozygous deletion of CDKN2A/B, and absence of TERTp mutations. This cluster was significantly associated with older age (P = .021), higher Ki-67 score (P = .007), poor prognosis (P = .012), and a periventricular tumor location. We report the development of a glioma-tailored NGS panel for detecting 1p/19q codeletion and driver gene mutations on a single platform. Our panel identified distinct subtypes of IDH- and TERTp-wildtype glioblastomas with frequent PDGFRA alterations.

Diffuse Large B-Cell Lymphoma of the Central Nervous System Manifesting with Intratumoral Hemorrhage: A Case Report and Literature Review

BACKGROUND

Cases of primary central nervous system lymphoma manifesting with hemorrhage are very rare, with only a few previous studies available.

CASE DESCRIPTION

A 49-year-old man presented with occipital headache and visual disturbance for the past 4 months. Computed tomography showed a high-density area involving the left basal ganglia, with surrounding vasogenic edema. Head T2∗-weighted imaging showed a hypointense signaling area. Edematous changes and a midline shift were observed on fluid attenuated inversion recovery magnetic resonance imaging. Radiologic features were highly suggestive of intracerebral hemorrhage. Methylprednisolone pulse therapy improved his symptoms transiently and reduced the size of the lesion. Nonetheless, there was recurrence 1 month later. The patient was referred to our institution; a biopsy was performed, and a diffuse large B-cell lymphoma was diagnosed. After 3 cycles of high-dose methotrexate and whole-brain radiation therapy, his symptoms improved, and there were no signs of recurrence.

CONCLUSIONS

We report a very rare case of diffuse large B-cell lymphoma manifested with intratumoral hemorrhage. This case indicates the importance of regular clinical and radiologic follow-up, histopathologic examination, and combined treatment with high-dose methotrexate and whole-brain radiation therapy.

A sellar neuroblastoma showing rapid growth and causing syndrome of inappropriate secretion of antidiuretic hormone: A case report

Background:

Sellar neuroblastoma is a very rare entity. We report a rare case of arginine vasopressin (AVP)- producing sellar neuroblastoma presumed to have originated from the lower part of sellar turcica, which grew very rapidly.

Case Description:

A 33-year-old woman was found to have a sellar lesion with a diameter of 18 mm invading into the bilateral cavernous sinus on magnetic resonance imaging (MRI) performed for dizziness. Six years later, when she visited the clinic due to bilateral visual disturbance, MRI showed a rapid growth of the tumor, with a maximal diameter of 56 mm at the current state, strongly compressing the optic nerve and chiasm. Transsphenoidal decompression of the optic chiasm revealed an intact pituitary gland on the top of the tumor. The tumor was composed of neoplastic cells that were immunohistochemically positive for neuronal markers and arginine vasopressin (AVP), but negative for all anterior pituitary hormones, glial fibrillary acidic protein, or thyroid transcription factor-1; these findings were suggestive of sellar neuroblastoma. She underwent 50-Gy radiation therapy, which has controlled the growth for the past 3 years.

Conclusion:

Awareness of rare sellar neuroblastomas will allow the accumulation of clinicopathologic information that may facilitate the understanding of their origin, clinical features, neuroimaging characteristics, and pertinent adjuvant treatment.

Formin-like 1 (FMNL1) Is Associated with Glioblastoma Multiforme Mesenchymal Subtype and Independently Predicts Poor Prognosis

Glioblastoma multiforme (GBM), the most common primary malignant brain tumor in adults, is characterized by rapid proliferation, aggressive migration, and invasion into normal brain tissue. Formin proteins have been implicated in these processes. However, the role of formin-like 1 (FMNL1) in cancer remains unclear. We studied FMNL1 expression in glioblastoma samples using immunohistochemistry. We sought to analyze the correlation between FMNL1 expression, clinicopathologic variables, and patient survival. Migration and invasion assays were used to verify the effect of FMNL1 on glioblastoma cell lines. Microarray data were downloaded from The Cancer Genome Atlas and analyzed using gene set enrichment analysis (GSEA). FMNL1 was an independent predictor of poor prognosis in a cohort of 217 glioblastoma multiforme cases (p < 0.001). FMNL1 expression was significantly higher in the mesenchymal subtype. FMNL1 upregulation and downregulation were associated with mesenchymal and proneural markers in the GSEA, respectively. These data highlight the important role of FMNL1 in the neural-to-mesenchymal transition. Conversely, FMNL1 downregulation suppressed glioblastoma multiforme cell migration and invasion via DIAPH1 and GOLGA2, respectively. FMNL1 downregulation also suppressed actin fiber assembly, induced morphological changes, and diminished filamentous actin. FMNL1 is a promising therapeutic target and a useful biomarker for GBM progression.

MPC-15 FEASIBILITY OF GLIOMA SPECIFIC ONCOPANEL IN THE DIAGNOSIS OF GLIOMA

AIM

Molecular classification of glioma is a mandatory in the diagnosis of glioma according to the WHO 2016 classification of tumors of the central nervous system. However, WHO does not indicate the molecular methodology to be integrated, and the versatility and cost-effectiveness of molecular diagnosis is a concern. In this study, we evaluate the feasibility of a glioma specific tailored NGS panel where driver gene mutation and 1p/19q codeletion can be analyzed in a single platform.

MATERIALS AND METHODS

We developed a glioma specific tailored NGS panel consisting of 48 key driver genes including IDH1/2, TP53, PTEN, EGFR, PDGFR, NF1, RB1, CDKN2A, and the TERT promoter. DNA was extracted from FFPE tumor tissues histologically identified by a pathologist, and from patient derived blood to serve as a control. In this system, gene mutations and copy number alterations can be precisely characterized, thus 1p/19q co-deletion can also be evaluated. We have analyzed 106 glioma patients (Grade II: 19 cases, Grade III: 23 cases, Grade IV: 64 cases) using this system.

RESULTS

From these 106 cases, IDH1 and TERT promoter mutations were detected in 33 cases (28%) and 55 cases (52%), respectively. 1p/19q co-deletion was detected in 19 cases (18%), with IDH1 mutations in all cases. In 57 Grade IV cases, TP53, PTEN, RB1, NF1, PDGFRA mutations were detected in 25 cases (43%), 24 cases (41%), 10 cases (17%), 8 cases (14%) and 6 cases (10%). Although EGFR mutation frequency was low (3%), amplification was detected in 14 cases (24%). As for deletion, PTEN and CDKN2A loci were deleted in 36 cases (62%) and 30 cases (52%), respectively. To note, MET alterations were detected in 2 cases. The cases in which histopathological diagnosis is difficult to make have a tendency to show atypical genetic alterations.

CONCLUSION

Diagnosis of glioma patients with this glioma-specific tailored NGS panel is feasible.

COT-14 CLINICAL FEATURES OF PEDIATRIC CENTRAL NERVOUS SYSTEM TUMORS

INTRODUCTION

Here,we discuss the presentation,histology,therapy,and outcome of central nervous system tumors in children.

METHODS

Treatment outcome and management was assessed for children diagnosed with central nervous tumors from 2007 to 2017 at Kagoshima University.

RESULTS

Eight-eight patients (56 boys,32 girls) with a mean age of 10.3 years were included in this study. Patient tumor types included: germ cell tumor (n = 26); medulloblastoma (n = 16); pilocytic astrocytoma (n = 8); glioblastoma (n = 8); ependymoma (n = 6,1 with grade 2,5 with grade 3); hemangioblastoma,schwannoma,and ganglioglioma (n = 3 each); SEGA,pilomyxoid astrocytoma,and diffuse astrocytoma (n = 2 each),and anaplastic astrocytoma,PPTID,PNET,PXA,DIA,central neurocytoma,astroblastoma,meningioma,and choroid plexus papilloma (n = 1 each). The most common patient clinical features were headache and vomiting associated with hydrocephalus. The median follow-up period was 61 months. All patients with germ cell tumors underwent adjuvant chemotherapy and radiation therapy (RT); patients with germinoma or immature teratoma were still alive,while patients with embryonal carcinoma,yolk sac tumor,or choriocarcinoma had poor prognosis with a median survival of 16 months. For cases of ependymoma,three patients received ICE chemotherapy and RT,and two patients received RT alone; median survival time was 31 months. For high grade glioma,seven patients received temozolomide and RT,and two patients received temozolomide alone; median survival time was 13 months.

CONCLUSIONS

Patients with germ cell tumors had a relatively good prognosis,while patients with ependymoma or high grade glioma had a poor prognosis. As treatment strategies for ependymoma and high grade glioma are currently limited,it is necessary to evaluate treatment options in consideration of clinical course and quality of life,in addition to histologic and genetic findings.

MPC-18 CATEGORIZATION OF LOWER GRADE GLIOMA USING ONCOPANEL

PURPOSE

We are developing a 48-gene OncoPanel (Kagoshima Brain Tumor 48 OncoPanel) specializing in glioma diagnosis. Clinical application of genetic diagnosis derived from genetic alterations detected by OncoPanel, including IDH mutation, 1p/19q-codeletion, and other gene mutations in lower-grade glioma was verified.

METHODS

The 48 genes consist of 24 genes related to glioma and 24 genes on chromosomes 1 and 19. DNA was extracted from tumor FFPE samples and blood samples, and then single nucleotide variants and copy number variants were detected using next-generation sequencer.

RESULTS

Among the 99 diffuse glioma cases that had undergone OncoPanel analysis by July 2019, 40 cases diagnosed histologically as WHO grade 2 or 3 diffuse glioma were included. The integrated diagnosis by conventional gene analysis were Diffuse astrocytoma 10 cases, anaplastic astrocytoma 11 cases, oligodendroglioma 10 cases, anaplastic oligodendroglioma 9 cases. IDH1 mutation was detected in 30 cases, of which in 19 cases 1p/19q-codeletion was detected, all with TERT mutation. Among 11 cases with 1p/19q-non-codeletion, ATRX mutation was detected in 10 cases and was almost mutually exclusive with TERT mutation. In 10 cases without IDH mutation, EGFR amplification or mutation was detected in 6 cases, of which 4 cases were accompanied by TERT mutation.

DISCUSSION

KBT48 can detect TERT and ATRX mutations in a mutually exclusive manner and can improve the classification accuracy of oligodendroglioma and astrocytoma. Groups with gene profiles similar to glioblastoma with EGFR amplification/mutation and TERT mutation can also be classified.

CONCLUSIONS

In the diagnostic classification of lower-grade glioma, KBT48 can well classify into oligodendroglioma group, astrocytoma group and glioblastoma-like group, and is considered to be applicable in clinical practice.

PATH-50. ROUTINE MOLECULAR DIAGNOSIS OF GLIOMA PATIENTS USING A GLIOMA-SPECIFIC NGS PANEL

AIM

The 2016 WHO classification requires molecular diagnosis in routine glioma diagnostics. However, analysis of key driver gene mutations and chromosome 1p/19q co-deletions cannot be performed in a single platform. In this study, we evaluated the feasibility of a glioma-specific NGS panel for molecular diagnosis of glioma patients.

MATERIALS AND METHODS

We developed a glioma-specific NGS panel consisting of 48 genes, including glioma-relevant key driver genes and 21 genes mapped to chromosome 1 and 19. DNA was extracted from formaldehyde fixed-paraffin embedded (FFPE) tumor tissues histologically identified by a pathologist, and from patient-derived blood as a control. In this system, we implemented a molecular barcodes method to enhance confidence in clinical samples and analyzed 80 glioma patients (Grade II: 17 cases, Grade III: 16 cases, Grade IV: 47 cases).

RESULTS

From these 80 cases, IDH1 and H3F3A mutations were detected in 23 cases (29%) and 2 cases (5%), respectively. The 1p/19q co-deletion was detected in 15 cases (19%), with all cases also containing IDH1 mutations. In Grade IV cases, EGFR, PDGFR, and FGFR mutations were detected in 6% (amp 19%), 9%, and 4% (amp 17%) of cases, respectively. PTEN, TP53, NF1, RB1, and CDKN2A mutations were detected in 37% (del 72%), 45% (del 13%), 21% (del 23%), 15% (del 60%), and 2% (del 53%) of cases, respectively.

CONCLUSION

Diagnosis of glioma patients with this glioma-specific NGS panel is feasible.

ANGI-06. FUNCTION OF FORMIN-LIKE 1 (FMNL1) IN GLIOBLASTOMA MULTIFORME

INTRODUCTION

Glioblastoma multiforme is the most common primary malignant brain tumour in adults. It is characterised by rapid proliferation, aggressive migration, and invasion into normal brain tissue. Formin proteins have been implicated in cancer progression, invasion, and migration. However, the role of FMNL1 in cancer remains unclear. We are the first to investigate FMNL1 in GBM.

METHODS

Clinical specimens were obtained from tumours surgically removed and pathologically confirmed as GBM from 217 GBM patients treated from 2000 to 2015 at the Department of Neurosurgery, Kagoshima University Hospital. We studied the expression of FMNL1 in glioblastoma samples by immunohistochemistry to analyse the correlation between FMNL1 expression, clinicopathologic variables, and patient survival. Migration and invasion assays were used to verify the effect of FMNL1 on glioblastoma cell lines. Microarray data were downloaded from TCGA and analysed using Gene Set Enrichment Analysis (GSEA).

RESULTS

FMNL1 was found to be a predictor of poor prognosis in a cohort of 217 cases (P < 0.001). GSEA showed that upregulation and downregulation of FMNL1 were associated with mesenchymal and proneural markers, respectively. Contrarily, downregulation of FMNL1 suppressed migration and invasion of glioblastoma multiforme cells via DIAPH1 and GOLGA2, respectively. Downregulation of FMNL1 also suppressed assembly of actin fibres, induced morphological changes, and diminished filamentous actin.

CONCLUSION

Our studies show that abundant FMNL1 expression in GBM patients is correlated with an unfavourable prognosis. FMNL1 is a promising therapeutic target and a useful biomarker for GBM progression.

Ganglioglioma in the Third Ventricle: A Case Report and Literature Review

Gangliogliomas typically arise in the cerebral hemispheres, but may occur rarely in the ventricles. Herein, we report a 38-year-old woman who was treated for hydrocephalus caused by a ganglioglioma of the third ventricle. Magnetic resonance imaging (MRI) revealed a heterogeneously enhanced tumor occupying the anterior part of the third ventricle. A left trans-lateral ventricular trans-foramen of Monroi approach was effective in achieving subtotal resection of the tumor, which had arisen from the medial part of left thalamus to the hypothalamus. Follow-up MRI showed no recurrence of the tumor 5-years after surgery. On pathological examination, the tumor was composed of a glial component that presented features mimicking pilocytic astrocytoma with proliferations of large gangliocytic cells that stained positive for neuronal markers. A review of six similar cases in the literature, including our own, revealed hydrocephalus to be the main symptom of gangliogliomas, with pituitary insufficiencies and visual disturbances having also been reported. In conclusion, we highlight the importance of gangliogliomas in the differential diagnosis of third ventricular tumors presenting with hydrocephalus.

Anaplastic astrocytoma cells not detectable on autopsy following long-term temozolomide treatment: A case report

We herein present an autopsy case of a glioma patient who received long-term treatment with temozolomide (TMZ). The patient, a 35-year-old man with a hypointense tumor of the left frontal lobe, without contrast enhancement following gadolinium (Gd) administration on T1-weighted images, underwent tumor removal surgery, after which the tumor was diagnosed as anaplastic astrocytoma. By the third round of surgery, the tumor had progressed to anaplastic astrocytoma with contrast enhancement following Gd administration, and the patient received 60 Gy of external beam radiotherapy and nimustine hydrochloride (ACNU)-based chemotherapy. After the fifth tumor removal surgery, TMZ was substituted with ACNU chemotherapy, which suppressed tumor progression. Following the 41st TMZ treatment, hemorrhage was observed in the residual tumor, and the hematoma had been replaced by a hemangioma. The hemangioma and surrounding brain tissue was removed during the sixth surgery. The patient survived for 14 years and 9 months after the initial surgery, but succumbed to hydrocephalus due to bleeding from hemangiomas. The histopathological specimens of the first to the sixth surgeries revealed mutant isocitrate dehydrogenase 1 (IDH1; R132H point mutation) and p53-positive tumor cells, but cells positive for the R132H mutation or p53 could not be detected by immunohistochemistry in the autopsy specimens of the brain after 108 courses of TMZ treatment. Mutant IDH1 (R132H) cells were also not detected in the autopsy specimens of the brain by polymerase chain reaction analysis.

Radiologic and histologic features of the T2 hyperintensity rim of meningiomas on magnetic resonance images

A hyperintensity rim is often seen at the brain-tumor interface of meningiomas upon T2-weighted (T2WI) magnetic resonance imaging (MRI), and it is referred to as the cerebrospinal fluid (CSF) space; however, the true nature of the rim remains unclear. We surveyed the MRI findings and the histopathologic characteristics of such rims. Our study population consisted of 53 consecutive patients who underwent meningioma removal at our hospital. The intensity of the rim on MRI scans obtained with different imaging sequences was assessed in all patients. We used 22 tumors for histopathologic investigation: tissue samples were acquired from both the tumor surface and from a deep intratumoral site. Of the 53 meningiomas, 37 (69.8%) manifested a hyperintensity rim on T2WI (T2-rim). The other 16 showed neither a hyperintense nor a hypointense rim on their T2WI. An enhancement effect corresponding to the rim was observed in 28 of the 37 (75.7%) T2-rim positive tumors. While 9 among the 37 tumors with a T2-rim (24.3%) did not show rim enhancement, they showed low intensity on fluid-attenuated inversion recovery (FLAIR) images. The microvascular density in the tumor capsule was significantly greater in the 12 T2-rim and rim enhancement positive tumors than in 10 tumors that were T2-rim negative or T2-rim positive, but rim enhancement-negative ( p < 0.001, Mann-Whitney U test). We found that 75.7% of T2 hyperintense rims that were detected at the brain-meningioma interface reflected a microvascular-rich capsule layer, rather than the CSF space.

Efficacy of bevacizumab therapy for unresectable malignant glioma: A retrospective analysis

Bevacizumab (BEV), an inhibitor of vascular endothelial growth factor A, has been used for primary and recurrent malignant gliomas in Japan since June, 2013. Previous randomized controlled studies demonstrated that BEV prolonged the progression-free survival, but not the overall survival (OS) of patients with newly diagnosed glioblastoma. The aim of the present study was to elucidate the effect of BEV on the OS of patients with unresectable malignant gliomas. Of the 440 cases of malignant glioma initially treated in our institute between 2000 and 2015, 88 were not suitable for maximal resection due to patient age, physical condition, tumor location and extent, or the patient's wishes. Based on the biopsy results, the pathological diagnosis was glioblastoma, anaplastic astrocytoma and anaplastic oligodendroglioma in 60, 19 and 9 patients, respectively. Kaplan-Meier and log-rank analyses were performed to investigate the effect of BEV on OS. OS was longer in the BEV group (n=24) compared with that in the non-BEV group [n=64; median survival time (MST), 566 vs. 243 days, respectively; hazard ratio (HR)=0.413; 95% confidence interval (CI): 0.216-0.787; P=0.003]. In the 41 patients who received temozolomide (TMZ) and radiotherapy and the 31 patients with glioblastoma who received TMZ and radiotherapy, OS was longer in the BEV group compared with that in the non-BEV group (MST, 568 vs. 334 days, HR=0.404, 95% CI: 0.175-0.933, P=0.016; and MST, 566 vs. 160 days, HR=0.253, 95% CI: 0.099-0.646, P=0.001, respectively). In the Cox hazard model analysis of 41 patients who underwent TMZ-based chemoradiotherapy after biopsy, the use of BEV was the strongest independent beneficial factor associated with prolonged OS (HR=0.101; P=0.0002). Our retrospective survey suggested that BEV prolongs the OS of patients with unresectable malignant gliomas. However, these results must be verified by a well-designed prospective randomized controlled trial.

Solitary Cranial Langerhans Cell Histiocytosis: Two case reports

Langerhans cell histiocytosis (LCH) is a proliferation of Langerhans cells intermixed with inflammatory cells, in particular eosinophils, that may manifest as a unisystem (unifocal or multifocal) or multisystem disease. We describe the clinical and histologic spectrum of LCH of the orbit and skull in our two cases. Both cases had unifocal erosive skull lesions with a history of trauma. Typical histologic features included numerous histiocytes with varying degrees of giant cell formation and scattered eosinophilic granulocytes. The presence of Langerhans cells was confirmed by CD1a and S100 immunohistochemistry. LCH has an excellent prognosis when treated with surgical resection, steroids and radiotherapy or chemotherapy. One of our patients is disease free at 7 year follow-up and one patient had regression of lesion on follow-up.

Choroid Plexus Tumors: Experience of 10 Cases with Special References to Adult Cases

Choroid plexus tumors (CPTs) are rare intraventricular neoplasms accounting for about 0.3–0.6% of all intracranial tumors. This retrospective study on CPTs presents clinico-pathological features and management strategies based on a 20-year single-institutional experience. This series included 10 consecutive patients with pathologically proven CPTs; 5 choroid plexus papillomas (CPPs), 3 atypical CPPs (ACPPs), and 2 choroid plexus carcinomas (CPCs). Their clinical, radiological, and histopathological features as well as management including follow-up studies were reviewed. The patients included five males and five females, aging from 0 years to 61 years with median of 28 years. The affected site was lateral ventricle in two adults and fourth ventricle in eight patients; four children and four adults. The most common symptoms were gait disturbance and memory disturbance. All the patients underwent craniotomy with total, subtotal, and partial removals achieved in 50%, 40%, and 10% of the patients, respectively. The occurrence of the high grade subtypes was 50% in both the adult and pediatric groups. The Ki-67/MIB-1 index increased across the three histological subtypes, from CPP to ACPP and then to CPC. Adjuvant therapy was administered in three patients. The two patients (one adult and one child) with CPC died of whole central nervous system dissemination. At a median of 62-month follow-up, the other eight patients were alive, with only one patient having recurrence and reoperation. The results demonstrate that gross total resection is usually curative for CPP and ACPP, and adjuvant chemoradiotherapy would be required for CPC and incompletely resected ACPP.

Revision of the Massarineae (Pleosporales, Dothideomycetes)

We here taxonomically revise the suborder Massarineae (Pleosporales, Dothideomycetes, Ascomycota). Sequences of SSU and LSU nrDNA and the translation elongation factor 1-alpha gene (tef1) are newly obtained from 106 Massarineae taxa that are phylogenetically analysed along with published sequences of 131 taxa in this suborder retrieved from GenBank. We recognise 12 families and five unknown lineages in the Massarineae. Among the nine families previously known, the monophyletic status of the Dictyosporiaceae, Didymosphaeriaceae, Latoruaceae, Macrodiplodiopsidaceae, Massarinaceae, Morosphaeriaceae, and Trematosphaeriaceae was strongly supported with bootstrap support values above 96 %, while the clades of the Bambusicolaceae and the Lentitheciaceae are moderately supported. Two new families, Parabambusicolaceae and Sulcatisporaceae, are proposed. The Parabambusicolaceae is erected to accommodate Aquastroma and Parabambusicola genera nova, as well as two unnamed Monodictys species. The Parabambusicolaceae is characterised by depressed globose to hemispherical ascomata with or without surrounding stromatic tissue, and multi-septate, clavate to fusiform, hyaline ascospores. The Sulcatisporaceae is established for Magnicamarosporium and Sulcatispora genera nova and Neobambusicola. The Sulcatisporaceae is characterised by subglobose ascomata with a short ostiolar neck, trabeculate pseudoparaphyses, clavate asci, broadly fusiform ascospores, and ellipsoid to subglobose conidia with or without striate ornamentation. The genus Periconia and its relatives are segregated from the Massarinaceae and placed in a resurrected family, the Periconiaceae. We have summarised the morphological and ecological features, and clarified the accepted members of each family. Ten new genera, 22 new species, and seven new combinations are described and illustrated. The complete ITS sequences of nrDNA are also provided for all new taxa for use as barcode markers.

Reduction of MLH1 and PMS2 confers temozolomide resistance and is associated with recurrence of glioblastoma

Although there is a relationship between DNA repair deficiency and temozolomide (TMZ) resistance in glioblastoma (GBM), it remains unclear which molecule is associated with GBM recurrence. We isolated three TMZ-resistant human GBM cell lines and examined the expression of O⁶-methylguanine-DNA methyltransferase (MGMT) and mismatch repair (MMR) components. We used immunohistochemical analysis to compare MutL homolog 1 (MLH1), postmeiotic segregation increased 2 (PMS2) and MGMT expression in primary and recurrent GBM specimens obtained from GBM patients during TMZ treatment. We found a reduction in MLH1 expression and a subsequent reduction in PMS2 protein levels in TMZ-resistant cells. Furthermore, MLH1 or PMS2 knockdown confered TMZ resistance. In recurrent GBM tumours, the expression of MLH1 and PMS2 was reduced when compared to primary tumours.

Improvement in treatment results of glioblastoma over the last three decades and beneficial factors

BACKGROUND

The purpose of this study is to elucidate the trend of glioblastoma outcome and scrutinize the factors contributing to better outcome over three decades.

METHODS

Survival time and the influencing factors were retrospectively analyzed in 223 newly diagnosed primary glioblastoma patients during 1980-2010. Appraised factors included age, sex, tumor site, year of surgery, extent of resections, use of surgery supporting system, Karnofsky Performance Status (KPS), chemotherapy, conventional external beam radiotherapy (EBRT), and CyberKnife stereotactic radiotherapy (CK-SRT) use.

RESULTS

The median survival time (MST) in all patients was 13.6 months. The MSTs for 4 periods were 9.8 (1980-1990), 13.7 (1991-2000), 12.9 (2001-2005), and 15.8 months (2006-2010), respectively (p=0.0047). Total resection, subtotal resection, partial resection, and biopsy had MSTs of 31.8, 13.9, 11.4, and 7.0 months, respectively (p<0.0001). Regarding chemotherapy, MSTs of the temozolomide base group and nimustine hydrochloride (ACNU) base group were 16.9 and 14.6 months, respectively, whereas the MST of patients without chemotherapy was only 9.8 months (p<0.0001). The MSTs for 40-Gy EBRT plus CK-SRT and 60-Gy EBRT were 19.1 and 10.7 months, respectively (p<0.0001). But in sub-selected patients, treated during 2001-2010, whose resection rate was total resection or subtotal resection, EBRT was completed and postoperative KPS was greater than or equal to 70, the MST with and without CK-SRT was 26.6 and 18.3 months, respectively (p=0.1529). According to the Cox proportional hazards model, degree of resection, KPS, ACNU use, temozolomide use, bevacizumab use, EBRT dose, and CK-SRT use were good prognostic factors. Use of neuronavigation and use of intraoperative magnetic resonance imaging were related to higher resection rate, but not determined as prognostic factors.

CONCLUSIONS

We observed a gradual improvement in glioblastoma outcome, presumably because of improvements in therapeutic modalities for surgery, anticancer agents, and radiation, but the efficacy of CK-SRT remains unclear.

Third ventricular atypical meningioma which recurred with further malignant progression

Meningiomas in the third ventricle are rare, with only very few cases reported in the literature. We report a case of primary third ventricular anaplastic meningioma in a 49-year-old man who presented with progressive weakness of the left limbs and headache. Magnetic resonance imaging revealed a tumor which seemed to arise from the right thalamus and extending into third ventricle. The tumor was heterogeneously enhanced with gadolinium. It was totally removed by right transventricular-subchoroidal approach. The lesion was intraoperatively found to be whitish hard and embedded in right thalamus, but had attachment to choroid plexus near foramen Monroi with narrow interface. The histological diagnosis was atypical meningioma, WHO Grade II. Lesion recurred 20 months later and was resected via the same approach, which turned out to be papillary meningioma, WHO Grade III. The patient had second recurrence 23 months after second surgery which was operated and the final diagnosis was anaplastic meningioma (WHO Grade III). Literature review showed meningioma of the third ventricle is quite exceptional and more than half of the cases were aggressive subtypes (Grade II or III).

Primary malignant melanoma in the pineal region treated without chemotherapy

Background:

Primary pineal malignant melanomas are uncommon intracranial tumor. Here we discuss and review a case of primary pineal malignant melanoma over its feature of imaging studies, pathological findings, and management.

Case Description:

A 49-year-old woman receiving renal dialysis underwent computed tomography due to a 4-month history of tinnitus and hearing disturbance. A high-density 35-mm diameter tumor was detected in the pineal region; there was obstructive hydrocephalus. The tumor was heterogeneously hyperintense on T1-weighted magnetic resonance images, iso- and low-mixed intense on T2-weighted images with hemorrhagic components, and very low-intense on T2^* images. A tumor was subtotally removed via the occipital transtentorial approach. Histologically, it consisted of densely proliferated spindle-shaped or polygonal cells with rich cytoplasmic melanin. The neoplastic cells manifested cellular pleomorphism, nuclear atypia, and mitosis (3/10 high-power fields) and were immunopositive for HMB45, Melan-A, and S100 protein. The MIB-1 index was 17.4%. Whole-body 18-fluoro-deoxyglucose positron emission tomography did not demonstrate any sites with hyper uptake. Examination of the skin and mucosa identified no lesions suggestive of melanoma. She underwent treatment with the whole brain and extended local boost irradiation. Chemotherapy was not delivered due to renal failure. Follow-up imaging studies showed no recurrence or distant lesions 56 weeks after surgery.

Conclusion:

We report a rare case of primary pineal malignant melanoma with prolonged survival of more than 56 weeks after subtotal tumor resection followed by whole-brain and extended local irradiation without chemotherapy. Radiotherapy without chemotherapy might be sufficient for the treatment of this tumor.

Posterior fossa immature teratoma in an infant with trisomy 21: A case report and review of the literature

BACKGROUND

Intracranial teratoma associated with Down syndrome is rare. With only three previously reported cases, our case is the first one presenting an immature component.

CASE DESCRIPTION

A 2-month-old boy with trisomy 21 presented with lethargy and head enlargement. A magnetic resonance imaging (MRI) study showed an obstructive hydrocephalus with 0.5 cm posterior fossa tumor compressing the cerebellum. The tumor revealed a mixed intensity on T1- and T2-weighted MRI images and was surrounded by peritumoral cysts. It was heterogeneously enhancing and showed multinodular mass. The tumor was gross totally removed via suboccipital craniotomy and histologically diagnosed as immature teratoma. Four cycles of chemotherapy consisting of cisplatin and etoposide followed the surgery. The radiotherapy was withheld due to infancy. Recurrent lesions in the tumor bed were noted 10 months later. They were removed in the second surgery and histologically identified as mature teratoma.

CONCLUSION

Maturation of immature teratoma may be a result of natural conversion of multipotent embryonal cells into mature tissues and following chemotherapy.