Dramatic Response of BRAF V600E Mutant Papillary Craniopharyngioma to Targeted Therapy

Prevalence of Endocrine and Metabolic Comorbidities in a National Cohort of Patients with Craniopharyngioma

OBJECTIVE

The major part of craniopharyngioma (CP) morbidity is the tumor and/or treatment-related damage, which results in impaired function of the hypothalamic-pituitary axes and metabolic derangements. The aim of the study was to analyze the prevalence of long-term endocrine and metabolic comorbidities in a national cohort of CP patients based on the age at diagnosis and histology criteria.

DESIGN

A retrospective-prospective longitudinal cohort analysis.

METHODS

Forty-six patients with CP treated from 1979 onwards (19 with childhood-onset disease) in a single university institution were included in our study. Median follow-up from presentation was 12.8 years (interquartile range: 8.3-22.2 years) and comparable between age-at-diagnosis and histological subtype groups. Data on tumor histology were extracted from patients' records and re-evaluated if tissue samples were available (n = 32).

RESULTS

Childhood-onset patients presented more frequently with headache, and adult-onset with visual impairment. Prevalence of at least one pituitary axis affected increased from 54% at presentation to 100% at follow-up in childhood-onset and from 41 to 93% in adult-onset CP. Growth hormone deficiency, central diabetes insipidus, and panhypopituitarism were more prevalent in childhood-onset adamantinomatous CP (aCP) and least prevalent in adult-onset papillary CP (pCP). At follow-up, metabolic syndrome (MetS) was diagnosed in 80% of childhood-onset and 68% of adult-onset patients (p = 0.411). In the latter group, it tended to be more frequent in the aCP than pCP subtype (80 vs. 50%, p = 0.110).

CONCLUSIONS

Long-term endocrine and metabolic complications are very frequent in childhood- and adult-onset CP patients of both histological subtypes. The prevalence of MetS was higher compared to the largest cohort previously reported.

Endoscopic endonasal approach for craniopharyngiomas

The operative management of craniopharyngiomas has evolved over the last two decades. Traditional transcranial microsurgical approaches were the only option until the advent of the endoscopic endonasal approach. It has given surgeons the ability to tackle a challenging entity from a new perspective with comparable if not superior results. In this review we outline the advancements in endoscopic endonasal approach for craniopharyngiomas, address controversies and review the current literature.

Creative and Innovative Methods and Techniques for the Challenges in the Management of Adult Craniopharyngioma

Craniopharyngioma remains a major challenge in daily clinical practice. The pathobiology of the tumor is still elusive, and there are no consensus or treatment guidelines on the optimal management strategy for this relatively rare tumor. However, recent technical and scientific advances, including genomic and radiomic profiling, innovation in surgical approaches, more precise radiotherapy protocols, targeted therapy, and restoration of lost functions all have the potential to significantly improve the outcome of patients with craniopharyngioma in the near future. Although many of these innovative tools in the new armamentarium of the clinician are still in their infancy, they could reduce craniopharyngioma-related morbidity and mortality and improve the patients' quality of life. In this article, we discuss these creative and innovative approaches that may offer solutions to the obstacles faced in treating craniopharyngioma and future possibilities in improving the care of these patients.

Aggressive Childhood-onset Papillary Craniopharyngioma Managed With Vemurafenib, a BRAF Inhibitor

The papillary subtype of craniopharyngioma (CP) rarely occurs in children and commonly presents as a suprasellar lesion. Patients with papillary CPs frequently harbor the BRAF-V600E mutation, and treatment with a BRAF inhibitor results in tumor shrinkage in several patients. Herein, we report a patient with childhood-onset papillary CP treated with vemurafenib for 40 months after multiple surgeries. At age 10, he presented with growth failure secondary to an intrasellar cystic lesion. He had 3 transsphenoidal surgeries before age 12 and a 4^th surgery 25 years later for massive tumor recurrence. Pathology showed a papillary CP with positive BRAF-V600E mutation. Rapid tumor regrowth 4 months after surgery led to treatment with vemurafenib that resulted in tumor reduction within 6 weeks. Gradual tumor regrowth occurred after a dose reduction of vemurafenib because of elevated liver enzymes. He had further surgeries and within 7 weeks after stopping vemurafenib, there was massive tumor recurrence. He resumed treatment with vemurafenib before radiation therapy and similar tumor shrinkage occurred within 16 days. In this patient with childhood-onset papillary CP that was refractory to multiple surgeries, the use of vemurafenib resulted in significant tumor shrinkage that allowed for the completion of radiation therapy and tumor control.

Blood-Based Detection of BRAF V600E in Gliomas and Brain Tumor Metastasis

Simple Summary

The BRAF V600E mutation has been identified as a key driver in brain tumors and brain tumor metastasis. The ability to detect this mutation in a minimally invasive plasma assay offers advantages over traditional tissue-based biopsy for the disease diagnosis and monitoring. The aim of this study was to develop an assay for the detection of BRAF V600E in the plasma of patients with brain tumors and brain tumor metastasis. We demonstrate BRAF V600E detection using a novel plasma-based ddPCR assay. We detect the mutation in circulating nucleic acids in 4/5 patients with mutant gliomas and metastatic melanoma. We also show correlation between plasma BRAF V600E and clinical status. This proof of principle study is important in the context of application of liquid biopsy in plasma to the neuro-oncologic field. The assay may be useful as a diagnostic adjunct, prognostication tool, and method for monitoring of disease and treatment response.

Abstract

Liquid biopsy provides a minimally invasive platform for the detection of tumor-derived information, including hotspot mutations, such as BRAF V600E. In this study, we provide evidence of the technical development of a ddPCR assay for the detection of BRAF V600E mutations in the plasma of patients with glioma or brain metastasis. In a small patient cohort (n = 9, n = 5 BRAF V600E, n = 4 BRAF WT, n = 4 healthy control), we were able to detect the BRAF V600E mutation in the plasma of 4/5 patients with BRAF V600E-tissue confirmed mutant tumors, and none of the BRAF WT tumors. We also provide evidence in two metastatic patients with longitudinal monitoring, where the plasma-based BRAF V600E mutation correlated with clinical disease status. This proof of principle study demonstrates the potential of this assay to serve as an adjunctive tool for the detection, monitoring, and molecular characterization of BRAF mutant gliomas and brain metastasis.

Genomics and Epigenomics of Pituitary Tumors: What Do Pathologists Need to Know?

Molecular pathology has advanced our understanding of many tumors and offers opportunities to identify novel therapies. In the pituitary, the field has uncovered several genetic mutations that predispose to pituitary neuroendocrine tumor (PitNET) development, including MEN1, CDKN1B, PRKRIα, AIP, GPR101, and other more rare events; however, these genes are only rarely mutated in sporadic PitNETs. Recurrent genetic events in sporadic PitNETs include GNAS mutations in a subset of somatotroph tumors and ubiquitin-specific peptidase mutations (e.g., USP8, USP48) in some corticotroph tumors; to date, neither of these has resulted in altered management, and instead, the prognosis and management of PitNETs still rely more on cell type and subtype as well as local growth that determines surgical resectability. In contrast, craniopharyngiomas have either CTNNB1 or BRAF^V600E mutations that correlate with adamantinomatous or papillary morphology, respectively; the latter offers the opportunity for targeted therapy. DICER1 mutations are found in patients with pituitary blastoma. Epigenetic changes are implicated in the pathogenesis of the more common sporadic pituitary neoplasms including the majority of PitNETs and tumors of pituicytes.

Adamantinomatous craniopharyngioma: moving toward targeted therapies

The evolving characterization of the biological basis of adamantinomatous craniopharyngioma (ACP) has provided insights critical for novel systemically delivered therapies. While current treatment strategies for ACP are associated with low mortality rates, patients experience severely lowered quality of life due to high recurrence rates and chronic sequelae, presenting a need for novel effective treatment regimens. The identification of various dysregulated pathways that play roles in the pathogenesis of ACP has prompted the investigation of novel treatment options. Aberrations in the CTNNB1 gene lead to the dysregulation of the Wnt pathway and the accumulation of nuclear β-catenin, which may play a role in tumor invasiveness. While Wnt pathway/β-catenin inhibition may be a promising treatment for ACP, potential off-target effects have limited its use in current intervention strategies. Promising evidence of the therapeutic potential of cystic proinflammatory mediators and immunosuppressants has been translated into clinical therapies, including interleukin 6 and IDO-1 inhibition. The dysregulation of the pathways of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), epidermal growth factor receptor (EGFR), and programmed cell death protein 1 and its ligand (PD-1/PD-L1) has led to identification of various therapeutic targets that have shown promise as clinical strategies. The Sonic Hedgehog (SHH) pathway is upregulated in ACP and has been implicated in tumorigenesis and tumor growth; however, inhibition of SHH in murine models decreased survival, limiting its therapeutic application. While further preclinical and clinical data are needed, systemically delivered therapies could delay or replace the need for more aggressive definitive treatments. Ongoing preclinical investigations and clinical trials of these prospective pathways promise to advance treatment approaches aimed to increase patients' quality of life.

Guidelines in the management of CNS tumors

INTRODUCTION

Evidence-based, clinical practice guidelines in the management of central nervous system tumors (CNS) continue to be developed and updated through the work of the Joint Section on Tumors of the Congress of Neurological Surgeons (CNS) and the American Association of Neurological Surgeons (AANS).

METHODS

The guidelines are created using the most current and clinically relevant evidence using systematic methodologies, which classify available data and provide recommendations for clinical practice.

CONCLUSION

This update summarizes the Tumor Section Guidelines developed over the last five years for non-functioning pituitary adenomas, low grade gliomas, vestibular schwannomas, and metastatic brain tumors.

Modern endoscopic skull base neurosurgery

INTRODUCTION

Since the early use of the endoscopic view for treating simple intrasellar pituitary adenomas, the skull base surgery has experienced an unprecedented revolution elevating the treatment of skull base lesions to the next level in proficiency and excellence of care.

METHODS

We have reviewed the preclinical and clinical evidence supporting the use of the endoscope in the treatment of skull base lesions. In this article, we aim to discuss and provide a wide view of the current indications and future perspectives of the endoscopic endonasal approaches (EEA) and of the endoscopic transcranial approaches.

RESULTS

As in the development of any other technique, EEA have gone through a transformation process from theoretical anatomic models to a pragmatic clinical use. Along the way, EEA have required several modifications, as well as pushbacks in the application of this technique in some indications. This process has resulted in the provision of an additional tool to the current surgical armamentarium that allows the skull base surgeon to face most challenging lesions along the skull base.

CONCLUSIONS

The judicious combination of transcranial and endoscopic-transnasal approaches warrants highest chances of achieving satisfactory tumors resection with a reduced risk of complications.

Pediatric Glioma: An Update of Diagnosis, Biology, and Treatment

Simple Summary

Recent research has enhanced our understanding of the diverse biological processes that occur in pediatric gliomas; and molecular genetic analysis has become essential to diagnose and treat these conditions. Because targetable molecular aberrations can be detected in pediatric gliomas, identifying these aberrations is very important. This review provides an overview of pediatric gliomas, and describes recent developments made in strategies for their diagnosis and treatment. Additionally, it presents a current picture of pediatric gliomas in light of advances in molecular genetics, and describes the current scientific progress in gliomas’ treatment using information from recently completed and ongoing clinical trials. The era of incorporating molecular genetic analysis into clinical practice is emerging.

Abstract

Recent research has promoted elucidation of the diverse biological processes that occur in pediatric central nervous system (CNS) tumors. Molecular genetic analysis is essential not only for proper classification, but also for monitoring biological behavior and clinical management of tumors. Ever since the 2016 World Health Organization classification of CNS tumors, molecular profiling has become an indispensable step in the diagnosis, prediction of prognosis, and treatment of pediatric as well as adult CNS tumors. These molecular data are changing diagnosis, leading to new guidelines, and offering novel molecular targeted therapies. The Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) makes practical recommendations using recent advances in CNS tumor classification, particularly in molecular discernment of these neoplasms as morphology-based classification of tumors is being replaced by molecular-based classification. In this article, we summarize recent knowledge to provide an overview of pediatric gliomas, which are major pediatric CNS tumors, and describe recent developments in strategies employed for their diagnosis and treatment.

Subtype-dependent difference of glucose transporter 1 and hexokinase II expression in craniopharyngioma: an immunohistochemical study

Papillary craniopharyngiomas are characterized by the BRAF V600E mutation. Enhancement of glucose metabolism may be involved in the downstream of the BRAF V600E mutation in many types of tumors. Glucose metabolism was investigated in craniopharyngioma using immunohistochemical analysis. The study included 29 cases of craniopharyngioma (18 adamantinomatous type [ACP], 11 papillary type [PCP]). Immunohistochemical analysis was performed with anti-glucose transporter-1 (GLUT-1), anti-hexokinase-II (HK-II), anti-BRAF V600E, and anti-beta-catenin antibodies. Expressions of GLUT-1 and HK-II were evaluated using a semiquantitative 4-tiered scale as 0, 1+, 2+, 3+, and divided into negative (0 or 1+) or positive (2+ or 3+) group. GLUT-1 expression level was significantly higher in PCPs than ACPs (0, 1+, 2+, 3+ = 2, 12, 4, 0 cases in ACP, respectively, 0, 1+, 2+, 3+ = 0, 2, 5, 4 in PCP, p = 0.001), and most PCPs were classified into positive group (positive rate, 22.2% [4/18] in ACP, 81.8% [9/11] in PCP; p = 0.003). HK-II expression was also conspicuous in PCPs (0, 1+, 2+, 3+ = 7, 9, 2, 0 cases in ACP, 0, 3, 3, 5 in PCP; p = 0.001), and most of them divided into positive group (positive rate, 11.1% [2/18] in ACP, 72.7% [8/11] in PCP; p = 0.001). Expression patterns of BRAF V600E and beta-catenin reflected the clinicopathological subtypes. Both GLUT-1 and HK-II expressions were prominent in PCP. Glucose metabolism might be more enhanced in PCP than ACP. PCP may use the glucose metabolic system downstream of the BRAF V600E mutant protein.

Magnetic resonance imaging of the hypothalamo-pituitary region

The diagnosis and management of mass lesions in the sellar and parasellar areas remain challenging. When approaching patients with possible sellar or hypothalamic masses, it is important not only to focus on imaging but also detect possible pituitary hormone deficits or excess, in order to establish an appropriate diagnosis and initiate treatment. The imaging modalities used to characterize hypothalamic and pituitary lesions have significantly evolved over the course of the past several years. Computed tomography (CT) and CT angiography play a major role in detecting various sellar lesions, especially in patients who have contraindications to magnetic resonance imaging (MRI) and can also yield important information for surgical planning. However, MRI has become the gold standard for the detection and characterization of hypothalamic and pituitary tumors, infections, cystic, or vascular lesions. Indeed, the imaging characteristics of hypothalamic and sellar lesions can help narrow down the differential diagnosis preoperatively. In addition, MRI can help establish the relationship of mass lesions to surrounding structures. A pituitary MRI examination should be obtained if there is concern for mass effect (including visual loss, ophthalmoplegia, headache) or if there is clinical suspicion and laboratory evidence of either hypopituitarism or pituitary hormone excess. The information obtained from MRI images also provides us with assistance in planning surgery. Using intraoperative MRI can be very helpful in assessing the adequacy of tumor resection. In addition, MRI images yield reliable data that allow for noninvasive monitoring of patients postoperatively.

Reirradiation for recurrent craniopharyngioma

Purpose

Reirradiation is rarely administered to patients with recurrent craniopharyngioma owing to concerns regarding visual and endocrine side effects. The purpose of this case series was to evaluate our institutional experience of patients with craniopharyngioma treated with 2 courses of fractionated radiation therapy.

Methods and Materials

A retrospective study was performed of all patients with craniopharyngioma treated with 2 courses of fractionated radiation therapy at a single institution. Electronic medical records and radiation therapy records were reviewed.

Results

We identified 4 eligible patients with recurrent craniopharyngioma. With a median follow-up of 33 months after reirradiation, 3 patients attained disease control; 1 patient developed progressive disease, 27 months after reirradiation. In 3 evaluable patients, vision remained stable or improved after reirradiation; one patient had no light perception before reirradiation. None of the patients experienced additional endocrine toxicities after reirradiation, apart from one patient who had low serum thyroid stimulating hormone before reirradiation and later developed hypothyroidism after treatment.

Conclusions

Reirradiation may represent a safe and effective therapeutic option for selected patients with recurrent, refractory craniopharyngioma and without other salvage treatment options. Larger studies with longer-term follow up are warranted to better understand outcomes in these patients.

Successful Use of BRAF/MEK Inhibitors as a Neoadjuvant Approach in the Definitive Treatment of Papillary Craniopharyngioma

Craniopharyngiomas are rare tumors that arise in the suprasellar region of the brain and are known for their aggressive nature despite their WHO grade I. This is due to the complex neuroanatomy of the sellar/suprasellar region and their proximity to the optic nerve apparatus, hypothalamic-pituitary tract, and other critical neuroanatomical structures. Definitive treatment is based on a multidisciplinary approach and often involves a combination of surgical, radiation, and medical therapy. However, there is high morbidity associated with surgery and RT due to the complex neuroanatomy of this region. Recently, BRAFV600E somatic mutation has been identified in most papillary craniopharyngiomas. This discovery has led to the novel use of RAF pathway inhibitors to treat these tumors. We report the successful use of dabrafenib (BRAF inhibitor) and trametinib (mitogen-activated protein kinase kinase inhibitor) in the neoadjuvant setting followed by definitive stereotactic radiosurgery. We propose an algorithm based on available literature on the integration of targeted therapy in the management of papillary craniopharyngiomas. Our observations, together with prior case reports, advocate the incorporation of targeted therapy for unresectable craniopharyngiomas and reinforce that treatment with dual-targeted therapy is safe and effective.

Dual BRAF/MEK therapy in BRAF V600E-mutated primary brain tumors: a case series showing dramatic clinical and radiographic responses and a reduction in cutaneous toxicity

OBJECTIVE

BRAF V600E is a common oncogenic driver in a variety of primary brain tumors. Dual inhibitor therapy using dabrafenib (a selective oral inhibitor of several mutated forms of BRAF kinase) and trametinib (a reversible inhibitor of MEK1 and MEK2) has been used successfully for treatment of metastatic melanoma, anaplastic thyroid cancer, and other tumor types, but has been reported in only a few patients with primary brain tumors and none with pleomorphic xanthoastrocytoma. Here, the authors report on the substantial clinical response and reduction in cutaneous toxicity in a case series of BRAF V600E primary brain cancers treated with dual BRAF/MEK inhibitor therapy.

METHODS

The authors treated 4 BRAF V600E patients, each with a different type of primary brain tumor (pilocytic astrocytoma, papillary craniopharyngioma, ganglioglioma, and pleomorphic xanthoastrocytoma) with the combination of dabrafenib and trametinib.

RESULTS

The patients with pilocytic astrocytoma, pleomorphic xanthoastrocytoma, and papillary craniopharyngioma experienced near-complete radiographic and complete clinical responses after 8 weeks of therapy. A substantial partial response (by RANO [Response Assessment in Neuro-Oncology] criteria) was observed in the patient with ganglioglioma. The patient with craniopharyngioma developed dramatic, diffuse verrucal keratosis within 2 weeks of starting dabrafenib. This completely resolved within 2 weeks of adding trametinib.

CONCLUSIONS

Dual BRAF/MEK inhibitor therapy represents an exciting treatment option for patients with BRAF V600E primary brain tumors. In addition to greater efficacy than single-agent dabrafenib, this combination has the potential to mitigate cutaneous toxicity, one of the most common and concerning BRAF inhibitor-related adverse events.

Genome Medicine for Brain Tumors: Current Status and Future Perspectives

As a result of rapid progress in genome medicine technologies, such as the evolution of DNA sequencing and the development of molecular targeted drugs, the era of precision cancer medicine has begun. In 2019, a nationwide genome medicine system was established and cancer gene panel sequencing began being covered by national health insurance in Japan. However, patients with brain tumors have not benefited much from genome medicine, even though gliomas contain many potential molecular targets, such as alterations in EGFR, IDH1/2, BRAF, and Histone H3K27. Targeted therapies for these molecules are currently under enthusiastic development; however, such attempts have not yet achieved remarkable success. To date, only a limited number of targeted drugs for brain tumors such as immune checkpoint, neurotrophic tyrosine receptor kinase (NTRK), and Bruton tyrosine kinase (BTK) inhibitors are available, and only in limited cases. Several obstacles remain in the development of drugs to treat brain tumors, including the difficulties in conducting clinical trials because of the relatively rare incidence and in drug delivery through the blood–brain barrier (BBB). Furthermore, general problems for numerous types of cancer, such as tumor heterogeneity, also exist for brain tumors. We hope that overcoming these issues could enable precision genome medicine to be more beneficial for patients with brain tumors such as malignant gliomas. In addition, careful consideration of ethical, legal, and social issues (ELSIs) is important as it is indispensable for maintaining good relationships with patients, which is one of the keys for genome medicine promotion.

Advances in Targeted Therapies for Pediatric Brain Tumors

Purpose of Review

Over the last years, our understanding of the molecular biology of pediatric brain tumors has vastly improved. This has led to more narrowly defined subgroups of these tumors and has created new potential targets for molecularly driven therapies. This review presents an overview of the latest advances and challenges of implementing targeted therapies into the clinical management of pediatric brain tumors, with a focus on gliomas, craniopharyngiomas, and medulloblastomas.

Recent Findings

Pediatric low-grade gliomas (pLGG) show generally a low mutational burden with the mitogen-activated protein kinase (MAPK) signaling presenting a key driver for these tumors. Direct inhibition of this pathway through BRAF and/or MEK inhibitors has proven to be a clinically relevant strategy. More recently, MEK and IL-6 receptor inhibitors have started to be evaluated in the treatment for craniopharyngiomas. Aside these low-grade tumors, pediatric high-grade gliomas (pHGG) and medulloblastomas exhibit substantially greater molecular heterogeneity with various and sometimes unknown tumor driver alterations. The clinical benefit of different targeted therapy approaches to interfere with altered signaling pathways and restore epigenetic dysregulation is undergoing active clinical testing. For these multiple pathway-driven tumors, combination strategies will most likely be required to achieve clinical benefit.

Summary

The field of pediatric neuro-oncology made tremendous progress with regard to improved diagnosis setting the stage for precision medicine approaches over the last decades. The potential of targeted therapies has been clearly demonstrated for a subset of pediatric brain tumors. However, despite clear response rates, questions of sufficient blood-brain barrier penetration, optimal dosing, treatment duration as well as mechanisms of resistance and how these can be overcome with potential combination strategies need to be addressed in future investigations. Along this line, it is critical for future trials to define appropriate endpoints to assess therapy responses as well as short and long-term toxicities in the growing and developing child.

Surgical aspects in craniopharyngioma treatment

Objectives

Total surgical resection is the gold standard in the treatment of craniopharyngioma. However, there is concern that aggressive surgical resection might result in high rates of endocrinologic, metabolic, and behavioral morbidities. Subtotal resection (SR) with subsequent radiation therapy (RT) may reduce surgical complications, but it may also increase the risk of tumor recurrence and radiation-induced side effects. Therefore, the optimal surgical strategy remains debatable.

Methods

To determine the optimal surgical strategy, we assessed the clinical courses of 39 patients (19 male patients and 20 female patients) with newly diagnosed craniopharyngioma who were treated at our institute. The median age at diagnosis was 34 years (range: 0–76 years). The median follow-up period was 8.5 years (range: 3–160 months). Our treatment strategy comprised gross total resection (GTR) for craniopharyngioma in patients that were not at surgical risk. Conversely, after adequate tumor decompression, we used RT, mainly Gamma Knife radiosurgery, in patients at risk. We divided the patients into the following three groups depending on the treatment course: GTR, SR with RT, and SR with staged surgery. We compared tumor characteristics, as well as patients’ conditions at the preoperative stage and last follow-up, among the three groups.

Results

There were 8, 21, and 10 patients in the GTR, SR with RT, and SR with staged surgery groups, respectively. There were no differences in the maximum tumor diameter, tumor volume, composition, and presence of calcification among the groups. Among the 39 patients, 24 underwent transcranial microsurgery and 15 underwent trans-sphenoidal surgery as the initial treatment. No cases involving surgical mortality, cerebrospinal fluid leakage, severely deteriorated visual function, or severe hypothalamic damage were observed. No tumor recurrence was noted in the GTR group. One patient required additional RT, and one patient underwent second surgery for tumor recurrence in the SR with RT group. In the SR with staged surgery group, 8 of the 10 patients eventually underwent RT, but tumor control was achieved in all patients at the latest follow-up. In this group, the third trans-sphenoidal surgery caused a severe vascular injury in one patient. At the final follow-up, 33 (85%) patients were undergoing anterior pituitary hormone replacement, and the rate of diabetes insipidus was 51%. There was no significant difference in the pituitary dysfunction rate among the groups.

Conclusions

We observed a low rate of surgical complications and a sufficient tumor control rate in response to our treatment strategy. Despite attempting preservation of the pituitary stalk, we found it difficult to rescue anterior pituitary function.

Genetic characterization of a case of sellar metastasis from bronchial carcinoid neuroendocrine tumor

Background

Metastasis to the pituitary gland from neuroendocrine tumors is a rare occurrence that may originate from primary tumors the lung, gastrointestinal tract, thyroid, and pancreas, among others. Patients may present with signs of endocrine dysfunction secondary to pituitary involvement, as well as mass effect-related symptoms including headaches and visual deficits. Despite a small but accumulating body of literature describing the clinical and histopathological correlates for pituitary metastases from neuroendocrine tumors, the genetic basis underlying this presentation remains poorly characterized.

Case Description

We report the case of a 68-year-old with a history of lung carcinoid tumor who developed a suprasellar lesion, causing mild visual deficits but otherwise without clinical or biochemical endocrine abnormalities. She underwent endoscopic endonasal resection of her tumor with final pathology confirming metastasis from her original neuroendocrine tumor. Whole-exome sequencing was performed on the resected sellar tumor and matching blood, revealing increased genomic instability and key mutations in PTCH1 and BCOR that have been previously implicated in both systemic neuroendocrine and primary pituitary tumors with potentially actionable therapeutic targets.

Conclusion

This is the first genomic characterization of a metastatic tumor to the sella and reports potential genetic insight, implicating PTCH1 and BCOR mutations, into the pathophysiology of sellar metastasis from primary systemic tumors.

BRAF Alteration in Central and Peripheral Nervous System Tumors

BRAF (alternately referred to as v-raf murine sarcoma viral oncogene homolog B1) is a proto-oncogene involved in the mitogen-activated protein kinase (MAPK) pathway. BRAF alterations are most commonly missense mutations or aberrant fusions. These mutations are observed in numerous primary central nervous system tumors as well as metastases. This review discusses the prevalence of BRAF alteration within select notable CNS tumors, and their prognostic associations. Included are some novel entities such as diffuse leptomeningeal glioneuronal tumor (DLGNT), polymorphous low grade neuroepithelial tumor of the young (PLNTY), and multinodular and vacuolating neuronal tumor (MVNT). Knowledge of this gene’s integrity in CNS and PNS tumors can have profound diagnostic and therapeutic implications. Also reviewed are the current state of targeted therapy against aberrant BRAF as it pertains mostly to the CNS and to a lesser extent in PNS, and certain diagnostic aspects.

Endoscopic Endonasal Approach for Craniopharyngiomas with Intraventricular Extension: Case Series, Long-Term Outcomes, and Review

BACKGROUND

Traditionally, craniopharyngiomas with intraventricular extension were approached transcranially; however, endoscopic approaches are now increasingly used. We sought to study the endoscopic endonasal approach (EEA) in the setting of complex craniopharyngiomas with intraventricular extension and to compare it with existing literature.

METHODS

Patients undergoing EEA for resection of craniopharyngioma with ventricular involvement from 2002 to 2015 were retrospectively reviewed. Outcomes were compared with previously published EEA and transcranial approach (TCA) studies for all craniopharyngioma locations.

RESULTS

Sixty-two patients were included. Average tumor and intraventricular volume were 13.93 cm³ and 2.61 cm³, respectively. Patients presented with visual impairment, endocrinopathy, and, headache. Gross total resection (GTR) was achieved in 47% of all cases and increased to 77% after 2012 Approximately 98% experienced improvement or stability of vision. Postoperative cerebrospinal fluid (CSF) leak and meningitis rates were 19% and 8.1%, respectively. However, nasoseptal flap (NSF) use reduced CSF leak rate to 10%. Six (9.6%) patients required shunting before resection and 25% were shunted postoperatively. Seven of 10 patients (70%) treated before NSF use required shunting, whereas only 7 of 46 (15%) required shunting with NSF reconstruction. Review demonstrated similar outcomes between the present cohort and EEA or TCA for all craniopharyngioma locations. TCA had a greater GTR, however, with large study variation. EEA showed improved visual outcomes but also increased CSF leaks.

CONCLUSIONS

EEA for craniopharyngiomas with intraventricular extension shows similar outcomes to TCA and EEA for all craniopharyngiomas, expanding this anatomic limit. Given ventricular involvement, CSF leak rates are expectedly high. GTR increased and CSF leak rates dramatically decreased with time, suggestive of the steep learning curve to complex resection.

The potential of cerebrospinal fluid-based liquid biopsy approaches in CNS tumors

Cerebrospinal fluid (CSF) may be the best hope for minimally invasive diagnosis and treatment monitoring of central nervous system (CNS) malignancies. Discovery/validation of cell-free nucleic acid and protein biomarkers has the potential to revolutionize CNS cancer care, paving the way for presurgical evaluation, earlier detection of recurrence, and the selection of targeted therapies. While detection of mutations, changes in RNA and miRNA expression, epigenetic alterations, and elevations of protein levels have been detected in the CSF of patients with CNS tumors, most of these biomarkers remain unvalidated. In this review, we focus on the molecular changes that have been identified in a variety of CNS tumors and profile the approaches used to detect these alterations in clinical samples. We further emphasize the importance of systemic collection of CSF and the establishment of standardized collection protocols that will lead to better cross-study biomarker validation and hopefully FDA-approved clinical markers.

The medical necessity of advanced molecular testing in the diagnosis and treatment of brain tumor patients

Accurate pathologic diagnoses and molecularly informed treatment decisions for a wide variety of cancers depend on robust clinical molecular testing that uses genomic, epigenomic, and transcriptomic-based tools. Nowhere is this more essential than in the workup of brain tumors, as emphasized by the incorporation of molecular criteria into the 2016 World Health Organization classification of central nervous system tumors and the updated official guidelines of the National Comprehensive Cancer Network. Despite the medical necessity of molecular testing in brain tumors, access to and utilization of molecular diagnostics is still highly variable across institutions, and a lack of reimbursement for such testing remains a significant obstacle. The objectives of this review are (i) to identify barriers to adoption of molecular testing in brain tumors, (ii) to describe the current molecular tools recommended for the clinical evaluation of brain tumors, and (iii) to summarize how molecular data are interpreted to guide clinical care, so as to improve understanding and justification for their coverage in the routine workup of adult and pediatric brain tumor cases.

Revived Attention for Adult Craniopharyngioma

Craniopharyngioma as a rare tumor originating from cells of rathke's pouch and representing 2-5% of all intracranial tumors is a rare and generally benign neoplasm of the central nervous system with two incidence peaks one in childhood and one after 40 years of age. Data on adult patients is scarce compared to childhood onset tumors, however the burden of disease caused by the tumors and related treatment options is significant. Clinical symptoms range from headaches, visual disability, cranial nerve affection or hypothalamic symptoms (e. g. morbid obesity) to endocrine disorders. Most symptoms are related to tumor mass effect. The current standard of diagnostics is the determination of serum hormone levels and contrast enhanced magnetic resonance imaging often resulting in surgical treatment which holds a key role in all treatment concepts and should follow a hypothalamus sparing path. Radiation therapy may prove beneficial as adjuvant therapeutic option or in recurrent tumor, especially papillary tumors may be targeted using BRAF-600 inhibitors, targeted therapies for adamantinomatous craniopharyngioma have not yet reached a stage of clinical testing. Although prognosis regarding overall survival is favorable, life expectancy may be reduced due to the tumor itself as well as due to treatment effects. An important aspect especially in the adult population is the reduction in quality of life which is comparable to primary malignant brain tumors and metastases, calling for individual patient specific treatment approaches.

Adamantinomatous craniopharyngioma in the molecular age and the potential of targeted therapies: a review

Pediatric adamantinomatous craniopharyngiomas (ACPs) are histologically benign brain tumors that often follow an aggressive clinical course. Arising in the sellar/suprasellar region, they grow in close proximity to critical neurological and vascular structures and can result in significant neuroendocrine morbidity. First-line treatment often involves surgical resection with or without radiotherapy and has been associated with significant morbidity and poor quality of life outcomes. As a result, the discovery of alternative effective and safe treatments is clearly desirable. In recent years, laboratory studies have harnessed sophisticated techniques to identify the upregulation of several markers that may represent potential therapeutic targets. These targets include IL-6, PD1/PD-L1, MEK, IDO-1, and others. Agents that target these pathways exist, and there is an opportunity to investigate their potential efficacy in the treatment of ACP. Trials investigating some of these agents as monotherapy and in combination for the treatment of pediatric ACP are underway or in development. If positive, these trials may result in a paradigm shift in treatment that will hopefully result in reduced morbidity and better outcomes for patients.

Surgical management of craniopharyngiomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section

BACKGROUND AND OBJECTIVE

Craniopharyngiomas are locally aggressive neuroepithelial tumors infiltrating nearby critical neurovascular structures. The majority of published surgical series deal with childhood-onset craniopharyngiomas, while the optimal surgical management for adult-onset tumors remains unclear. The aim of this paper is to summarize the main principles defining the surgical strategy for the management of craniopharyngiomas in adult patients through an extensive systematic literature review in order to formulate a series of recommendations.

MATERIAL AND METHODS

The MEDLINE database was systematically reviewed (January 1970-February 2019) to identify pertinent articles dealing with the surgical management of adult-onset craniopharyngiomas. A summary of literature evidence was proposed after discussion within the EANS skull base section.

RESULTS

The EANS task force formulated 13 recommendations and 4 suggestions. Treatment of these patients should be performed in tertiary referral centers. The endonasal approach is presently recommended for midline craniopharyngiomas because of the improved GTR and superior endocrinological and visual outcomes. The rate of CSF leak has strongly diminished with the use of the multilayer reconstruction technique. Transcranial approaches are recommended for tumors presenting lateral extensions or purely intraventricular. Independent of the technique, a maximal but hypothalamic-sparing resection should be performed to limit the occurrence of postoperative hypothalamic syndromes and metabolic complications. Similar principles should also be applied for tumor recurrences. Radiotherapy or intracystic agents are alternative treatments when no further surgery is possible. A multidisciplinary long-term follow-up is necessary.

Adamantinomatous Craniopharyngioma in an Adult: A Case Report with NGS Analysis

PURPOSE

Several recent studies have documented CTNNB1 and BRAF mutations which are mutually exclusive for adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP) tumors. This discovery is helpful in the development of novel targeted therapies in successful clinical trials with BRAF mutations in PCP cases. However, no such targeted therapy is available yet for ACP. Here, we report novel mutations, which are not previously reported, in a case of an adult ACP using NGS analysis.

RESULTS

Patient DNA was sequenced using Ion PI v3 chip on Ion Proton. A total of 16 variants were identified in this tumor by NGS analysis, out of which four were missense mutations, seven were synonymous mutations, and five were intronic variants. In CTNNB1 gene a known missense mutation in c.101G>T; in TP53 a known missense mutation in c.215C>G; and two known missense variants in PIK3CA, viz., in c.1173A>G; in exon 7, and in c.3128T>C; in exon 21, were found, respectively. Seven synonymous mutations were detected in this tumor, viz., in IDH1 (rs11554137), in FGFR3 (rs7688609), in PDGFRA (rs1873778), in APC (COSM3760869), in EGFR (rs1050171), in MET (rs35775721), and in RET (rs1800861), respectively. Three known, intronic variants were found in genes, such as PIK3CA, KDR, and JAK3, respectively. Also, a 3'-UTR and a splice site acceptor site variant in CSF1R and FLT3 genes were found in this tumor. We have shown allele coverage, allele ratio, and p-value, for all these mutations. The p-values and Phred quality score were significantly high for these variants.

CONCLUSION

As reported in previous studies, in ACP tumors we found a CTNNB1 mutation by NGS analysis. The PIK3CA variants we detected were not known previously in ACP tumors. Finding the PIK3CA mutations in the ACP tumors may help develop targeted therapy for a subset of craniopharyngiomas with PIK3CA activating mutations. Clinical trials are in progress with specific PIK3CA inhibitors in advanced stages of many cancers.

Genomic Biomarker Assessment in Gliomas: Impacts of Molecular Testing on Clinical Practice and Trial Design

Recent discoveries elucidating the genetic underpinnings of glial neoplasms have revealed myriad recurrent alterations that have clinical value by improving accuracy of diagnosis and prognosis. Furthermore, this wealth of genomic information provides the basis for targeted therapies and the subsequent design of biomarker-based clinical trials. This review summarizes the current landscape of clinically relevant molecular alterations in gliomas and describes the role of routine molecular testing in context of treatment planning for standards of care and clinical trials.

Biological Behaviour of Craniopharyngiomas

Jakob Erdheim (1874-1937) first described craniopharyn-giomas (CPs) as "hypophyseal duct tumours" and postulated the existence of two tumour types based on their histological features: (1) an aggressive type showing similarities to adamantinomas (tumours of the jaw) and (2) a more benign form characterised by the presence of papillary structures. More than a century later, these initial observations have been confirmed; based on their distinct genetic, epigenetic, and histological features, the WHO classifies CPs into two types: adamantinomatous CPs (ACPs) and papillary CPs (PCPs). Considerable knowledge has been generated on the biology of CPs in the last 20 years. Mutations in CTNNB1 (encoding β-catenin) are prevalent in ACP, whilst PCPs frequently harbour mutations in BRAF (p.BRAF-V600E). The consequence of these mutations is the activation of either the WNT/β-catenin (ACP) or the MAPK/ERK (PCP) pathway. Murine models support a critical role for these mutations in tumour formation and have provided important insights into tumour pathogenesis, mostly in ACP. A critical role for cellular senescence has been uncovered in murine models of ACP with relevance to human tumours. Several gene profiling studies of human and murine ACP tumours have identified potential targetable pathways, and novel therapeutic agents are being used in clinical and pre-clinical research, in some cases with excellent results. In this review, we will present the accumulated knowledge on the biological features of these tumours and summarise how these advances are being translated into potential novel treatments.

Clinical outcomes following proton therapy for adult craniopharyngioma: a single-institution cohort study

BACKGROUND

Craniopharyngioma is a benign tumor that commonly develops within the suprasellar region. The tumor and treatment can have debilitating consequences for pediatric and adult patients, including vision loss and pituitary/hypothalamic dysfunction. Most craniopharyngioma series focus on treatment of the pediatric population. We evaluated the outcomes of all adult craniopharyngioma patients treated at our institution using proton therapy to report outcomes for disease control, treatment-related toxicity, and tumor response.

METHODS

We analyzed 14 adult patients (≥ 22 years old). All patients had gross disease at the time of radiotherapy. Five were treated for de novo disease and 9 for recurrent disease. Patients received double-scattered conformal proton therapy to a mean dose of 54 GyRBE in 1.8 GyRBE/fraction (range 52.2-54 GyRBE). Weekly magnetic resonance imaging (MRI) helped to evaluate tumor changes during radiotherapy.

RESULTS

With median clinical and radiographic follow-up of 29 and 26 months, respectively, the 3-year local control and overall survival rates were both 100%. There were no grade 3 or greater acute or late radiotherapy-related side effects. There was no radiotherapy-related vision loss or optic neuropathy. No patients required intervention or treatment replanning due to tumor changes during radiotherapy. Two patients experienced transient cyst expansion at their first post-radiotherapy MRI. Both patients were followed closely clinically and radiographically and had subsequent dramatic tumor/cyst regression, requiring no interventions.

CONCLUSIONS

Our data support the safety and efficacy of proton therapy in the treatment of adult craniopharyngioma as part of primary or salvage treatment. We recommend early consideration of radiotherapy. This trial was registered at www.clinicaltrials.gov as #NCT03224767.

The Inflammatory Milieu of Adamantinomatous Craniopharyngioma and Its Implications for Treatment

Pediatric Adamantinomatous Craniopharyngiomas (ACPs) are histologically benign brain tumors that often follow an aggressive clinical course. Their suprasellar location leaves them in close proximity to critical neurological and vascular structures and often results in significant neuroendocrine morbidity. Current treatment paradigms, involving surgical resection and radiotherapy, confer significant morbidity to patients and there is an obvious need to discover effective and safe alternative treatments. Recent years have witnessed significant efforts to fully detail the genomic, transcriptomic and proteomic make-up of these tumors, in an attempt to identify potential therapeutic targets. These studies have resulted in ever mounting evidence that inflammatory processes and the immune response play a critical role in the pathogenesis of both the solid and cystic portion of ACPs. Several inflammatory and immune markers have been identified in both the cyst fluid and solid tumor tissue of ACP. Due to the existence of effective agents that target them, IL-6 and immune checkpoint inhibitors seem to present the most likely immediate candidates for clinical trials of targeted immune-related therapy in ACP. If effective, such agents may result in a paradigm shift in treatment that ultimately reduces morbidity and results in better outcomes for our patients.

Histopathology of Parasellar Neoplasms

The anatomical and histological complexity of the parasellar region as well as the presence of embryonic remnants determine the huge diversity of parasellar neoplasms. Some of them are only located in the parasellar region, whereas others can occur elsewhere, within or outside the central nervous system. Their spectrum ranges from histologically benign and low-grade malignant to high-grade malignant tumours. Although rare, metastases can pose differential diagnostic dilemmas. The severity of the clinical picture, the challenges of surgery and the risk of adverse sequelae related to surgery or radiotherapy make parasellar tumours interesting entities for the clinicians irrespective of their histological malignancy grade. Due to the different cell origins of parasellar tumours, the World Health Organization classification system does not categorise them as a distinct group. Detailed criteria for classification and malignancy grading are presented in the classification systems covering central nervous system tumours, haematological malignancies and tumours of the soft tissue and bone. In the last few years, molecular genetic features have been integrated into the diagnosis of several types of the parasellar tumours enhancing diagnostic accuracy and providing information of the value for targeting therapies. In this review, we will present histopathological and molecular genetic features, updated classification criteria and recent advances in the diagnostics and rationale for novel pharmacological therapies of selected types of parasellar neoplasms.

The Medical Therapy of Craniopharyngiomas: The Way Ahead

CONTEXT

Craniopharyngiomas, which are categorized as adamantinomatous (ACPs) or papillary (PCPs), have traditionally been treated with surgery and/or radiotherapy, although when the tumors progress or recur, therapeutic possibilities are very limited. Following recent advances in their molecular pathogenesis, new medical therapeutic options have emerged.

EVIDENCE ACQUISITION

The search strategy that we selected to identify the appropriate evidence involved the following medical subject headings (MeSH) terms: ("Craniopharyngioma" [MeSH] AND "Craniopharyngioma/drug therapy" [MeSH]) NOT ("review" [Publication Type] OR "review literature as topic" [MeSH Terms] OR "review" [All Fields]) AND ("2009/05/01" [PDat]: "2019/04/28" [PDat]).

EVIDENCE SYNTHESIS

Mutations of β-catenin causing Wnt activation with alterations of the MEK/ERK pathway are encountered in the great majority of patients with ACPs; specific alterations also stratify patients to a more aggressive behavior. In most PCPs there is primary activation of the Ras/Raf/MEK/ERK pathway secondary to BRAF-V600E mutations. BRAF inhibitors, such as dabrafenib or vemurafenib, either alone or in combination with the MEK inhibitors trametinib and cobimetinib, have been administered to patients with PCPs producing clinically useful and, in some cases, sustained responses. In contrast to PCPs, drugs targeting β-catenin and its downstream MAPK pathway in ACPs have so far only been used in in vitro studies, but there appear to be promising new targets clinically.

CONCLUSIONS

The identification of specific genetic alterations in patients with craniopharyngiomas has expanded the therapeutic options, providing evidence for a customized approach using newer molecular agents. More studies including a larger number of carefully selected patients are required to evaluate the response to currently available and evolving agents alone and in combination.

Using personalized medicine in gliomas: a genomic approach to diagnosis and overcoming treatment resistance in a case with pleomorphic xanthoastrocytoma

INTRODUCTION

A patient who was initially considered to have a glioblastoma (GBM) had molecular analysis, showing that it was a pleomorphic xanthoastrocytoma (PXA). Up to 78% of PXA tumors have BRAF V600E mutations. Primary brain tumors with BRAF mutations can have a good response to BRAF MEK inhibitors (BRAF MEKi), and there may be a synergistic response when combined with autophagy inhibitors.

PRESENTATION OF THE CASE

A 20-year-old man found to have a large brain mass with midline shift underwent resection. He was diagnosed with "GBM" and treated with radiation and temozolomide with subsequent disease recurrence. Review of histology showed malignant PXA with BRAF V600E mutation. Treatment with Dabrafenib and Trametinib was started, and tumor size increased in size after 14 months of treatment. Given studies showing that resistance to BRAF inhibition can be overcome by autophagy inhibition, chloroquine was added. Patient has been on "triple" therapy for 15 months and has radiographically Stable Disease. At MCC, 3% of patients with gliomas have BRAF mutations who could potentially benefit from this combination therapy.

CONCLUSION

This is the first report of a PXA patient receiving therapy with BRAF MEKi and an autophagy inhibitor with prolonged stable disease. This patient highlights the importance of a molecular interrogation in gliomas to provide an integrated diagnosis and effective treatment. This may be useful in up to 3% of glioma patients with BRAF mutations. Molecular testing in neuro-oncology is providing new avenues of diagnosis and treatment, and detailed molecular interrogation should be considered routine.

Craniopharyngioma

Craniopharyngiomas are rare malformational tumours of low histological malignancy arising along the craniopharyngeal duct. The two histological subtypes, adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP), differ in genesis and age distribution. ACPs are diagnosed with a bimodal peak of incidence (5-15 years and 45-60 years), whereas PCPs are restricted to adults mainly in the fifth and sixth decades of life. ACPs are driven by somatic mutations in CTNNB1 (encoding β-catenin) that affect β-catenin stability and are predominantly cystic in appearance. PCPs frequently harbour somatic BRAFV600E mutations and are typically solid tumours. Clinical manifestations due to increased intracranial pressure, visual impairment and endocrine deficiencies should prompt imaging investigations, preferentially MRI. Treatment comprises neurosurgery and radiotherapy; intracystic chemotherapy is used in monocystic ACP. Although long-term survival is high, quality of life and neuropsychological function are frequently impaired due to the close anatomical proximity to the optic chiasm, hypothalamus and pituitary gland. Indeed, hypothalamic involvement and treatment-related hypothalamic lesions frequently result in hypothalamic obesity, physical fatigue and psychosocial deficits. Given the rarity of these tumours, efforts to optimize infrastructure and international collaboration should be research priorities.

Insights into pituitary tumorigenesis: from Sanger sequencing to next-generation sequencing and beyond

Introduction: This review explores insights provided by next-generation sequencing (NGS) of pituitary tumors and the clinical implications.Areas covered: Although syndromic forms account for just 5% of pituitary tumours, past Sanger sequencing studies pragmatically focused on them. These studies identified mutations in MEN1, CDKN1B, PRKAR1A, GNAS and SDHx causing Multiple Endocrine Neoplasia-1 (MEN1), MEN4, Carney Complex-1, McCune Albright Syndrome and 3P association syndromes, respectively. Furthermore, linkage analysis of single-nucleotide polymorphisms identified AIP mutations in 20% with familial isolated pituitary adenomas (FIPA). NGS has enabled further investigation of sporadic tumours. Thus, mutations of USP8 and CABLES1 were identified in corticotrophinomas, BRAF in papillary craniopharyngiomas and CTNNB1 in adamantinomatous craniopharyngiomas. NGS also revealed that pituitary tumours occur in the DICER1 syndrome, due to DICER1 mutations, and CDH23 mutations occur in FIPA. These discoveries revealed novel therapeutic targets and studies are underway of BRAF inhibitors for papillary craniopharyngiomas, and EGFR and USP8 inhibitors for corticotrophinomas.Expert opinion: It has become apparent that single-nucleotide variants and small insertion/deletion DNA mutations cannot explain all pituitary tumorigenesis. Integrated and improved analyses including whole-genome sequencing, copy number, and structural variation analyses, RNA sequencing and epigenomic analyses, with improved genomic technologies, are likely to further define the genomic landscape.

Advances in the management of craniopharyngioma in children and adults

Background Childhood and adult-onset craniopharyngioma is a rare embryogenic tumor of the sellar, suprasellar, and parasellar region. Survival rates are high; however, tumor location and treatment sequalae including endocrine deficits, visual impairment, metabolic complications, cognitive and psychosocial deficits can significantly impair patient's quality of life. There is considerable controversy regarding the optimal management of craniopharyngiomas. Subtotal resection of the tumor followed by targeted irradiation to avoid further hypothalamic damage is currently indicated. Novel insights in the tumor's molecular pathology present the possibility for targeted therapy possibly decreasing the rate and severity of treatment-associated morbidity. Conclusions Craniopharyngioma should be seen as a chronic disease. To achieve optimal outcomes a multidisciplinary team of specialized neurosurgeons, neuro-radiologists, neuro-oncologists, pathologists and endocrinologists should be involved in the diagnosis, planning of the surgery, irradiation and long-term follow-up.

Craniopharyngioma: a roadmap for scientific translation

OBJECTIVE Craniopharyngiomas are among the most challenging of intracranial tumors to manage because of their pattern of growth, associated morbidities, and high recurrence rate. Complete resection on initial encounter can be curative, but it may be impeded by the risks posed by the involved neurovascular structures. Recurrent craniopharyngiomas, in turn, are frequently refractory to additional surgery and adjuvant radiation or chemotherapy. METHODS The authors conducted a review of primary literature. RESULTS Recent advances in the understanding of craniopharyngioma biology have illuminated potential oncogenic targets for pharmacotherapy. Specifically, distinct molecular profiles define two histological subtypes of craniopharyngioma: adamantinomatous and papillary. The discovery of overactive B-Raf signaling in the adult papillary subtype has led to reports of targeted inhibitors, with a growing acceptance for refractory cases. An expanding knowledge of the biological underpinnings of craniopharyngioma will continue to drive development of targeted therapies and immunotherapies that are personalized to the molecular signature of each individual tumor. CONCLUSIONS The rapid translation of genomic findings to medical therapies for recurrent craniopharyngiomas serves as a roadmap for other challenging neurooncological diseases.

Newly diagnosed papillary craniopharyngioma with BRAF V600E mutation treated with single-agent selective BRAF inhibitor dabrafenib: a case report

We report a case of a patient with newly diagnosed, locally extensive and cystic, suprasellar papillary craniopharyngioma successfully treated with single-agent Dabrafenib. The patient was symptomatic with gait imbalance with falls, lethargic episodes, fatigue and incontinence. Diagnostic imaging demonstrated a cystic suprasellar tumor extending into the third ventricle causing obstructive hydrocephalus. The tumor was partially debulked, and bilateral shunts were placed. NGS sequencing demonstrated BRAF V600E mutation, and the patient was prescribed dual agent Dabrafenib and Trametinib. However, due to insurance denial for Trametinib, he only received single-agent Dabrafenib (150mg BID). The treatment resulted in a major response (over two years), including reduction of the tumor cyst, and improvement of the clinical symptoms. No adverse events have been reported. The patient continues on Dabrafenib (150 mg BID) with a steady reduction in tumor size, and improvement in cognitive function leading to independent living.

Multiplexed immunofluorescence reveals potential PD-1/PD-L1 pathway vulnerabilities in craniopharyngioma

Background

Craniopharyngiomas are neoplasms of the sellar/parasellar region that are classified into adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP) subtypes. Surgical resection of craniopharyngiomas is challenging, and recurrence is common, frequently leading to profound morbidity. BRAF V600E mutations render PCP susceptible to BRAF/MEK inhibitors, but effective targeted therapies are needed for ACP. We explored the feasibility of targeting the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint pathway in ACP and PCP.

Methods

We mapped and quantified PD-L1 and PD-1 expression in ACP and PCP resections using immunohistochemistry, immunofluorescence, and RNA in situ hybridization. We used tissue-based cyclic immunofluorescence to map the spatial distribution of immune cells and characterize cell cycle and signaling pathways in ACP tumor cells which intrinsically express PD-1.

Results

All ACP (15 ± 14% of cells, n = 23, average ± SD) and PCP (35 ± 22% of cells, n = 18) resections expressed PD-L1. In ACP, PD-L1 was predominantly expressed by tumor cells comprising the cyst lining. In PCP, PD-L1 was highly expressed by tumor cells surrounding the stromal fibrovascular cores. ACP also exhibited tumor cell-intrinsic PD-1 expression in whorled epithelial cells with nuclear-localized beta-catenin. These cells exhibited evidence of elevated mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) signaling. Profiling of immune populations in ACP and PCP showed a modest density of CD8+ T cells.

Conclusions

ACP exhibit PD-L1 expression in the tumor cyst lining and intrinsic PD-1 expression in cells proposed to comprise an oncogenic stem-like population. In PCP, proliferative tumor cells express PD-L1 in a continuous band at the stromal-epithelial interface. Targeting PD-L1 and/or PD-1 in both subtypes of craniopharyngioma might therefore be an effective therapeutic strategy.

BRAF Mutations and the Utility of RAF and MEK Inhibitors in Primary Brain Tumors

BRAF mutations have been identified as targetable, oncogenic mutations in many cancers. Given the paucity of treatments for primary brain tumors and the poor prognosis associated with high-grade gliomas, BRAF mutations in glioma are of considerable interest. In this review, we present the spectrum of BRAF mutations and fusion alterations present in each class of primary brain tumor based on publicly available databases and publications. We also summarize clinical experience with RAF and MEK inhibitors in patients with primary brain tumors and describe ongoing clinical trials of RAF inhibitors in glioma. Sensitivity to RAF and MEK inhibitors varies among BRAF mutations and between tumor types as only class I BRAF V600 mutations are sensitive to clinically available RAF inhibitors. While class II and III BRAF mutations are found in primary brain tumors, further research is necessary to determine their sensitivity to third-generation RAF inhibitors and/or MEK inhibitors. We recommend that the neuro-oncologist consider using these drugs primarily in the setting of a clinical trial for patients with BRAF-altered glioma in order to advance our knowledge of their efficacy in this patient population.

Dramatic response of BRAF V600E-mutant epithelioid glioblastoma to combination therapy with BRAF and MEK inhibitor: establishment and xenograft of a cell line to predict clinical efficacy

Epithelioid glioblastoma is a rare aggressive variant of glioblastoma (GBM) characterized by a dismal prognosis of about 6 months and frequent leptomeningeal dissemination. A recent study has revealed that 50% of epithelioid GBMs harbor three genetic alterations - BRAF V600E mutation, TERT promoter mutations, and homozygous deletions of CDKN2A/2B. Emerging evidence support the effectiveness of targeted therapies for brain tumors with BRAF V600E mutation. Here we describe a dramatic radiographical response to combined therapy with BRAF and MEK inhibitors in a patient with epithelioid GBM harboring BRAF V600E mutation, characterized by thick spinal dissemination. From relapsed tumor procured at autopsy, we established a cell line retaining the BRAF V600E mutation, TERT promoter mutation and CDKN2A/2B loss. Intracranial implantation of these cells into mice resulted in tumors closely resembling the original, characterized by epithelioid tumor cells and dissemination, and invasion into the perivascular spaces. We then confirmed the efficacy of treatment with BRAF and MEK inhibitor both in vitro and in vivo. Epithelioid GBM with BRAF V600E mutation can be considered a good treatment indication for precision medicine, and this patient-derived cell line should be useful for prediction of the tumor response and clarification of its biological characteristics.

Exceptional Responders in Oncology: A Systematic Review and Meta-Analysis of Patient Level Data

PURPOSE

We aim to systematically review and analyze the available literature on "exceptional responders" in oncology. We hypothesize that survival or patients with an exceptional response may be predicted based on clinical factors.

MATERIALS AND METHODS

A PICOS/PRISMA/MOOSE selection protocol was used to find studies that reported oncology patients with an exceptional response. A total of 333 initial articles were screened, and 76 articles were included, accounting for 85 patients. The primary outcome was survival after exceptional response therapy (ERT). The secondary outcome was survival since diagnosis. Univariate and multivariate analyses were conducted for both outcomes with 17 covariates.

RESULTS

The median age was 52 years (interquartile range, 35-66 y), 51.8% were male individuals, 18 (21.2%) had lung cancer, and 1 patient (1%) met all National Cancer Institute criteria for exceptional response. The most common treatment resulting in exceptional response was a form of chemotherapy (49.2%) followed by targeted therapy (26.8%) and radiation therapy (7.7%). The median time from diagnosis to initiation of ERT was 7.92 months (interquartile range, 0-24.72 mo). On multivariate analysis of survival after initiation of ERT, there were no predictors of exceptional response. On multivariate analysis of survival since diagnosis, predictors of prolonged survival included time between diagnosis and ERT initiation (hazard ratio, 0.52; 95% confidence interval, 0.32-0.87; P=0.0124) and single prior surgery versus none (0.08; 95% confidence interval, 0.01-0.98; P=0.04853).

CONCLUSIONS

There were no clinically apparent patient or treatment factors that predicted favorable survival following ERT; instead, reporting of exceptional response appears to be biased.