Von Hippel-Lindau disease

Characterization of the Pheochromocytoma-Predominant Subgroup of von Hippel-Lindau Disease

OBJECTIVE

To define a classification schema for von Hippel-Lindau (VHL) patients who have a pheochromocytoma predominant phenotyope.

MATERIALS AND METHODS

VHL patients who underwent adrenalectomy with pathology-proven pheochromocytoma at our institution were included. We defined pheochromocytoma-predominant VHL a priori as patients with one or more of the following traits: early onset [age at first pheochromocytoma below the cohort's median age (28.2years)], family history of pheochromocytomas, multiple pheochromocytomas, and paraganglioma(s). Patients with pheochromocytoma-predominant disease were compared to the remaining cohort to determine differences in genotype and phenotype.

RESULTS

One-hundred thirty-nine VHL patients were examined. Preliminary analysis showed that three characteristics (early onset, family history, and multiple pheochromocytomas) were associated. Having paraganglioma(s) did not correlate with the other factors, so it was excluded from the definition of pheochromocytoma-predominant disease. The majority of our patients (110/139, 79%) met the final definition. Pheochromocytoma-predominant patients were less likely to have most additional VHL tumor types, including renal cell carcinoma (P<.001) whereas they were more likely to have missense mutations (P<.001) than the remaining cohort. Overall, pheochromocytoma-predominant patients were most likely to have 0 (P<.001) or 1 (P=.008) extra-adrenal tumor types while non-pheochromocytoma-predominant patients were most likely to have 4 (P=.02) or 5 (P=.02).

CONCLUSION

Pheochromocytoma-predominant VHL patients are phenotypically distinct from their non-pheochromocytoma-predominant counterparts and are significantly less likely to have more than one other VHL manifestation, including renal carcinoma.

Protacs in cancer therapy: mechanisms, design, clinical trials, and future directions

Cancer develops as a result of changes in both genetic and epigenetic mechanisms, which lead to the activation of oncogenes and the suppression of tumor suppressor genes. Despite advancements in cancer treatments, the primary approach still involves a combination of chemotherapy, radiotherapy, and surgery, typically providing a median survival of approximately five years for patients. Unfortunately, these therapeutic interventions often bring about substantial side effects and toxicities, significantly impacting the overall quality of life for individuals undergoing treatment. Therefore, urgent need of research required which comes up with effective treatment of cancer. This review explores the transformative role of Proteolysis-Targeting Chimeras (PROTACs) in cancer therapy. PROTACs, an innovative drug development strategy, utilize the cell's protein degradation machinery to selectively eliminate disease-causing proteins. The review covers the historical background, mechanism of action, design, and structure of PROTACs, emphasizing their precision in targeting oncogenic proteins. The discussion extends to the challenges, nanotechnology applications, and ongoing clinical trials, showcasing promising results and clinical progress. The review concludes with insights into patents, future directions, and the potential impact of PROTACs in addressing dysregulated protein expression across various diseases. Overall, it provides a concise yet comprehensive overview for researchers, clinicians, and industry professionals involved in developing targeted therapies.

Fibroblast growth factor receptor expression in hemangioblastomas: A novel therapeutic target

Hemangioblastoma is a highly vascularized, benign tumor in the central nervous system, frequently associated with von Hippel-Lindau (VHL) disease. Hemangioblastoma may cause tumor-associated hemorrhage or exert pressure on nearby structures, leading to life-threatening complications. Although surgical resection is the primary treatment, complete removal is not always feasible. Accordingly, there is a need to explore targeted or anti-angiogenic therapies. The fibroblast growth factor receptor (FGFR) family has roles in tumorigenesis and angiogenesis, making it a potential target in personalized therapy. The distribution and significance of FGFRs in hemangioblastoma have yet to be investigated. We examined 139 formalin-fixed, paraffin-embedded hemangioblastoma samples from 111 patients, including sporadic cases and those associated with VHL disease. Immunohistochemistry revealed positive staining for FGFR2 (95%) and FGFR4 (61%), while FGFR1 (0%) and FGFR3 (12%) were mainly negative. FGFR2 expression was significantly increased in VHL-mutated tumors (75%, p = 0.034) and in male patients (68%, p = 0.020). Tumors located in the cerebrum (n = 6, 5%) had a higher likelihood of positive FGFR4 staining (100%, p = 0.009). Additionally, a larger tumor diameter was associated with a higher likelihood of FGFR4 expression (median 12.0 mm vs 17.5 mm, p = 0.018), suggesting its contribution in tumor growth. Our study revealed the expression of FGFR2 and FGFR4 in a significant number of hemangioblastomas. This finding demonstrates the potential of FGFRs as promising therapeutic targets for patients with hemangioblastoma.

Key roles of ubiquitination in regulating critical regulators of cancer stem cell functionality

The ubiquitin (Ub) system, a ubiquitous presence across eukaryotes, plays a crucial role in the precise orchestration of diverse cellular protein processes. From steering cellular signaling pathways and orchestrating cell cycle progression to guiding receptor trafficking and modulating immune responses, this process plays a crucial role in regulating various biological functions. The dysregulation of Ub-mediated signaling pathways in prevalent cancers ushers in a spectrum of clinical outcomes ranging from tumorigenesis and metastasis to recurrence and drug resistance. Ubiquitination, a linchpin process mediated by Ub, assumes a central mantle in molding cellular signaling dynamics. It navigates transitions in biological cues and ultimately shapes the destiny of proteins. Recent years have witnessed an upsurge in the momentum surrounding the development of protein-based therapeutics aimed at targeting the Ub system under the sway of cancer stem cells. The article provides a comprehensive overview of the ongoing in-depth discussions regarding the regulation of the Ub system and its impact on the development of cancer stem cells. Amidst the tapestry of insights, the article delves into the expansive roles of E3 Ub ligases, deubiquitinases, and transcription factors entwined with cancer stem cells. Furthermore, the spotlight turns to the interplay with pivotal signaling pathways the Notch, Hedgehog, Wnt/β-catenin, and Hippo-YAP signaling pathways all play crucial roles in the regulation of cancer stem cells followed by the specific modulation of Ub-proteasome.

Genetics and current research models of Mendelian tumor predisposition syndromes with ocular involvement

In this review, we aim to provide a survey of hereditable tumor predisposition syndromes with a Mendelian inheritance pattern and ocular involvement. We focus our discussion on von Hippel-Lindau disease, neurofibromatosis type 1, NF2-related schwannomatosis, tuberous sclerosis complex, retinoblastoma, and the BAP1 tumor predisposition syndrome. For each of the six diseases, we discuss the clinical presentation and the molecular pathophysiology. We emphasize the genetics, current research models, and therapeutic developments. After reading each disease section, readers should possess an understanding of the clinical presentation, genetic causes and inheritance patterns, and current state of research in disease modeling and treatment.

Belzutifan for von Hippel-Lindau disease-associated renal cell carcinoma and other neoplasms (LITESPARK-004): 50 months follow-up from a single-arm, phase 2 study

BACKGROUND

Hypoxia-inducible factor-2α inhibitor belzutifan is approved for von Hippel-Lindau disease-associated renal cell carcinoma, CNS haemangioblastomas, and pancreatic neuroendocrine tumours, based on previously published initial results from the LITESPARK-004 study. Updated results are presented here after a median follow-up of nearly 50 months.

METHODS

In this single-arm, phase 2 study, participants were enrolled at 11 centres in Denmark, France, the UK, and the USA. Oral belzutifan 120 mg once daily was given to eligible adults aged 18 years or older with a diagnosis of von Hippel-Lindau disease (based on germline VHL alterations), at least one measurable renal cell carcinoma tumour, no tumour larger than 3 cm that necessitated immediate surgery, no metastatic disease, no previous systemic anticancer treatment, and an Eastern Cooperative Oncology Group performance status score of 0 or 1. The primary endpoint was the proportion of participants with an objective response in von Hippel-Lindau disease-associated renal cell carcinoma per Response Evaluation Criteria in Solid Tumours, version 1.1, determined by an independent review committee, and assessed in all participants who received at least one dose of belzutifan. This ongoing study is no longer recruiting and is registered at ClinicalTrials.gov, NCT03401788.

FINDINGS

Between May 31, 2018, and Mar 29, 2019, 61 participants were enrolled; 36 (59%) were continuing treatment as of April 3, 2023. The median age of all enrolled participants was 41·0 years (IQR 29·0-51·0); 32 (52%) of 61 participants were male and 29 (48%) were female; most were White (n=55; 90%). Median study follow-up was 49·9 months (IQR 48·9-52·2). 41 (67%; 95% CI 54-79) of 61 participants with renal cell carcinoma had an objective response; seven (11%) had a complete response and 34 (56%) a partial response. 13 grade 3 treatment-related adverse events occurred in 11 (18%) participants (anaemia: seven [11%]; fatigue: three [5%]; urinary tract infection: one [2%]; hypoxia: one [2%]; and blister: one [2%]). None of the participants had a grade 4 or 5 treatment-related adverse event. Four (7%) participants had serious treatment-related adverse events (one participant each: anaemia, urinary tract infection, intracranial haemorrhage, and hypoxia).

INTERPRETATION

Updated results support the use of belzutifan as systemic treatment for von Hippel-Lindau disease-associated renal cell carcinoma.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA; the Intramural Research Program of the National Institutes of Health, National Cancer Institute Center for Cancer Research; and a grant from the National Cancer Institute.

Von Hippel-Lindau Disease : A Comprehensive Review of Diagnosis, Genetics, Clinical Challenges, and Surveillance

von Hippel-Lindau (VHL) disease is a genetic condition predisposing individuals to the development of benign and malignant tumors across various organs. This review explores the intricate genetic underpinnings of VHL disease, its clinical manifestations, and the associated malignancy risks. The latest diagnostic criteria, surveillance guidelines, and advancements in therapeutic strategies, including the Food and Drug Administration-approved hypoxia-inducible factor-2α inhibitor, belzutifan, are focused on. Through a multidisciplinary approach, tailored surveillance programs aim to improve patient outcomes while balancing intervention risks. Emerging technologies such as wholebody magnetic resonance imaging and liquid biopsies hold promises for enhancing non-invasive surveillance. This review underscores the significance of ongoing research and interdisciplinary care in managing this complex syndrome.

Neurological Outcome of Spinal Hemangioblastomas: An International Observational Multicenter Study About 35 Surgical Cases

INTRODUCTION

Hemangioblastomas (HBs) are benign, highly vascular tumors that can be found intracranially or in the spinal region, representing around 2-15% of primary intramedullary tumors. They can occur sporadically or in association with Von Hipple-Lindau (VHL) disease. Despite recent of advancement of nonsurgical treatments, complete surgical resection remains the gold standard of care for the spinal HBs.

MATERIALS AND METHODS

We conducted an international multicenter retrospective analysis of adult patients surgically treated for spinal HBs in four European referral centers between January 2000 and September 2024, with a minimum post-operative follow-up duration of 6 months. Patients' sex and age at surgical intervention, clinical presentation, and duration symptoms prior to clinical diagnosis were identified. The pre- and post-operative neurological status at 1 and 6 months and at the last visit was assessed using the modified McCormick score (MCS). The extent of surgical resection was divided into gross total resection (GTR) and subtotal resection (STR). Finally, post-operative complications were inspected as well, namely cerebrospinal fluid leaks, infections, hemorrhages and post-operative spinal stability.

RESULTS

A total of 35 patients were included in the cohort, with an age median of 52 years (34.5-60) and a slight male predominance (21/35, i.e., 60%). The median follow-up period was 37.5 months (12-75). More than half were located in the cervical region, making it the most common (54.3%). Syrinxes were observed in 23 cases (72%), and HBs were more commonly intramedullary (80%). GTR was achievable in around 88% of cases. Post-operative complications were observed in nine patients (25.7%). Nearly half of patients were discharged into rehabilitations centers (48.5%). Tumor recurrence was seen in 10.3% only. At the last follow-up, an excellent overall post-operative neurological status (positive ∆ McCormick) was observed in most of patients (88%) and was found to be associated with a relatively younger age group. Tumor location and presence of syrinxes did not show any statistical significance regarding clinical outcome. In patients having benefited from intra-operative monitoring, only D-wave changes showed statistical significance regarding post-operative outcome (p < 0.05).

CONCLUSIONS

A large majority of patients operated for a spinal HB demonstrated favorable outcome after surgery, with unchanged or improved neurological status. Advanced age could have an impact on the post-operative neurological outcome. Other factors such as tumor size, location, and the presence of syrinx did not seem to significantly impact the neurological outcome. Finally, the surgery of these vascular lesions with no possibility of debulking or piece-meal removal and requiring "en bloc" resection is technically demanding and should be performed by experienced teams in spine and spinal cord surgery only.

Molecular dynamics reveal potential effects of novel VHL variants on VHL-Elongin C binding in ccRCC patients from Eastern India

Renal cell carcinoma (RCC) is the one of the most fatal and frequent form of urological malignancy worldwide. The von Hippel-Lindau (VHL) tumour suppressor gene is a critical component of the VHL-Cullin2-ElonginB/C (VCB) complex that regulates the ubiquitin-mediated proteasomal degradation of proteins with mutations consistently associated with the development of clear cell renal cell carcinoma (ccRCC). Despite extensive investigations conducted worldwide, there is a notable lack of data concerning VHL mutations in sporadic ccRCC patients from India. Our study aimed to investigate the sporadic VHL mutations within the tumours of 210 ccRCC patients without a familial history of VHL disease. We extracted genomic DNA from tumour and adjacent normal tissues, PCR amplified and sequenced the VHL gene. In silico tools were used assess the damaging potential of missense variants on pVHL structure and stability. Protein-protein docking and protein flexibility molecular docking simulation study were employed to study the interaction between wild-type and mutated VHL models with Elongin C. Sequence analysis revealed seven novel missense mutations in patient tumour tissues p.(Val170Phe), p.(Arg69Cys), p.(Phe76Leu), p.(Glu173Asp), p.(Leu201Val), p.(His208Leu), p.(Arg205Pro). I-Mutant 2.0 indicated these mutations reduced pVHL stability (ΔΔG < -0.5 kcal/mol). Protein Flexibility-Molecular Dynamic (MD) Simulation study indicated that mutations weaken the interaction of VHL with Elongin C, with V170F showing the most significant reduction in binding quality and stability. In conclusion, this study introduces novel genetic data from an understudied population and highlights the impact of VHL mutations on its interaction with Elongin C. These findings contribute to our understanding of the molecular basis of VHL-related pathologies and may guide future therapeutic strategies targeting these interactions.

Global Incidence, Risk Factors, and Temporal Trends of Adrenal Cancer: A Systematic Analysis of Cancer Registries

OBJECTIVE

Adrenal gland cancer (AGC) is a rare cancer with a poor prognosis. Studies on this cancer have been limited. This study, for the first time, aims to analyze the global disease burden and trends of AGC in country level and examine lifestyle and socioeconomic risk factors to generate hypotheses.

METHODS

The Global Cancer Observatory database was used to extract the incidence rate of AGC in 2020. Age-standardized rates (ASRs) of AGC incidence and lifestyle/metabolic risk factor prevalence were obtained from databases. Linear regression and Joinpoint regression were used to assess associations with risk factors and Average Annual Percentage Change of AGC incidence.

RESULTS

Globally, there were an estimated 16 961 new AGC cases in 2020 (ASR: 0.14 per 100 000 persons). Higher disease burden was observed mainly in European regions. ASRs were comparable between sexes (males: 0.16; females: 0.14). The higher ASR was observed among the older population aged 50 to 74 years with an ASR of 0.31 compared with the younger population aged 15 to 49 years with an ASR of 0.07. Higher AGC incidence was associated with higher Human Development Index, gross domestic product, and lifestyle-related factors such as physical inactivity, obesity, hypertension, and lipid disorder (β = 0.005-0.052).

CONCLUSION

The overall incidence trend showed a decrease, with 3 countries reporting significant decreases and 1 country reporting a significant increase. Similar patterns were observed by sex and age group, except for an overall increase among the younger population.

Von Hippel-Lindau syndrome: clinical features, genetic foundations, and management strategies

Von Hippel-Lindau Syndrome (VHL) is a rare, hereditary disorder characterized by the development of multiple tumors and cysts in various parts of the body due to mutations in the VHL gene on chromosome 3p25-26. Patients with VHL are at increased risk for hemangioblastomas of the brain, spinal cord, and retina, renal cell carcinomas, pheochromocytomas, pancreatic neuroendocrine tumors, and endolymphatic sac tumors. Clinical manifestations vary widely, and early diagnosis through genetic testing and regular surveillance is crucial for effective management. Treatment involves monitoring for tumor development, surgical removal of tumors, and targeted therapies for advanced cases. Recent advances in understanding the VHL pathway have led to new targeted treatments, particularly those involving the hypoxia-inducible factors and vascular endothelial growth factor pathways, which have improved patient outcomes. This article reviews the clinical features, genetic foundations, genotype/phenotype relationship and current management strategies for VHL, emphasizing recent advances that have enhanced prognosis and quality of life for patients.

Case report: Endolymphatic sac tumor with blurred vision

Introduction

Endolymphatic sac tumor (ELST) is a rare neoplasm that exhibits aggressive growth primarily in the endolymphatic capsule and can potentially affect nearby neurovascular structures. The diagnosis of ELST poses challenges due to its low prevalence, gradual progression, and nonspecific symptomatology. It is currently believed that prompt surgical intervention is recommended for endolymphatic sac tumors upon diagnosis. In cases where the lesion is complex or in close proximity to vital blood vessels and nerves, making complete resection challenging, adjuvant therapy may be employed postoperatively. This approach aims to enhance treatment outcomes.

Case presentation

A case of a 53-year-old male was admitted to the Department of Neurosurgery of Shenzhen People's Hospital with the main cause of dizziness and blurred vision, and was found to have an occupation in the pontocerebellar angle for about 20 days. Preoperative cranial CT suggested that the temporal bone mastoid was widely damaged with worm-like bone, and some of them showed honeycomb changes. MRI suggested that shadow was seen in the posterior part of the left internal auditory canal, temporal bone mastoid and jugular foramen, with a size of about 28x21x27mm.The T1-weighted image showed low and equal signals, and the T2-weighted image showed equal and slightly low signals in the center with multicompartmental cystic high signals in the margin. The center of the mass strengthened significantly after enhancement. The patient had no other clinical manifestations and no family history. The clinical diagnosis was left-sided pontocerebellar angle occupation - nature to be determined. The occupation was resected microscopically using the distal lateral combined anterior approach to the sigmoid sinus. Due to the extremely rich blood supply of the tumor, the tumor was embedded in the petrous humerus, which was soft and tough, and the surrounding structures were not clearly displayed, making surgical resection extremely difficult. postoperative pathology and immunohistochemistry confirmed that this lesion was an endolymphatic cystic tumor. After surgery, most of the tumor was successfully resected while preserving neurological function well, and the residual tumor was treated with adjuvant gamma knife with good results.

Conclusion

ELST is a rare, low-grade, locally aggressive tumor that is difficult to diagnose early. During the surgery, it was observed that the tumor had a significant blood supply, which made its removal challenging. Preoperative embolization of the tumor's blood supply artery would facilitate surgical resection and help avoid massive intraoperative bleeding. Complete surgical resection is the treatment of choice, and any remaining tumor remnants can be managed with adjuvant radiotherapy post-surgery, necessitating long-term follow-up to monitor any developments.

Pediatric patients with von Hippel-Lindau and hemangioblastomas treated successfully with belzutifan

Hemangioblastoma is the most common tumor associated with von Hippel-Lindau (VHL), and are a leading cause of mortality. We present five pediatric patients with VHL-associated hemangioblastomas treated with belzutifan, a hypoxia-inducible factor 2a (HIF2a) inhibitor. Three patients were started on belzutifan due to vision loss from progressive retinal hemangioblastomas. Within one year of treatment, all three patients had improvement in hemangioblastoma size and visual acuity. For patients with intracranial lesions, belzutifan resulted in an improvement in neurologic symptoms and hemangioblastoma size. Four patients experienced grade 1-2 anemia and two patients required a dose reduction. Our report suggests that belzutifan can be an effective therapy for pediatric, adolescent, and young adult patients with VHL-associated hemangioblastomas.

Unique properties of clinical manifestation and magnetic resonance imaging for differential diagnosis of optic nerve hemangioblastoma

BACKGROUND

To investigate the unique properties of clinical manifestation and radiological imaging for differential diagnosis of optic nerve hemangioblastoma (ONH) from adult optic nerve glioma (ONG) prior to surgical resection.

METHODS

ONH and adult ONG patients were recruited from 2012 to 2022.

RESULTS

A total of seven ONH patients (8 eyes) and 23 adult ONG patients (24 eyes) were assessed. The median onset age of ONH patients was older than that of adult ONG patients (p = 0.007). There were 42.9% (3/7) of ONH patients closely associated with the diagnosis of Von Hippel-Lindau (VHL) syndrome. Notably in Magnetic Resonance Imaging (MRI), the retrobulbar hemangioblastomas in all ONH patients were primarily intraorbital (100%, 8/8), canalicular (87.5%, 7/8), and anterior intracranial (12.5%, 1/8), especially concentrated in the orbital apex, with little posterior optic pathway involvement. Nearly all affected parts of optic nerve in the ONH group (75.0%, 6/8) presented with circumscribed cystic-solid components, characterized by cystic lesions (peritumoral oedema) anteriorly and solid tumours posteriorly, with significant heterogeneous enhancement. Adult ONG lesions prior to extend from the anterior portion to the whole length of the optic nerve, with relatively innocent enlargement in the postcontrast study.

CONCLUSION

Optic nerve tumours in those with older ages at diagnosis (>30 years) or those diagnosed with VHL syndrome are more likely to be indicative of ONH. In the absence of associated VHL syndrome, a distinguishing MRI feature is the concentration of tumours in the orbital apex, characterized by circumscribed cystic-solid components and heterogeneous enhancement of the solid portion.

EAF2: a tumor suppressor gene with multi-aspect functions

Since ELL-associated factor 2 (EAF2) was identified in 1997 as an androgen response gene, it has been of medical and scientific interest. Early studies demonstrated the tumor-suppressing function of EAF2 in the prostate. Sequencing studies indicated an association between EAF2 and several other malignant diseases and multiple physiological processes, such as transcription, apoptosis, embryogenesis, and DNA repair. Further understanding of EAF2 will provide new opportunities and therapeutic approaches for cancers, especially prostate cancer. This narrative review summarizes the existing knowledge of EAF2 and outlines its potential significance. To our knowledge, this is the first review of the role of this novel tumor suppressor gene and its possible functions.

Spinal cord hemangioblastomas in von Hippel-Lindau disease

Background

von Hippel-Lindau disease (VHL) is an autosomal dominant familial neoplasia syndrome. The most common manifestation of VHL is central nervous system hemangioblastomas. VHL patients will often develop multiple hemangioblastomas along their craniospinal axis over their lifetime. Spinal cord hemangioblastomas account for nearly half of all nervous system hemangioblastomas in VHL.

Methods

The authors conducted a literature review and summation of available articles on spinal cord hemangioblastomas associated with VHL.

Results

The embryological origins, epidemiology, natural history, surgical outcomes, nonsurgical treatments, and future directions in spinal cord hemangioblastomas are discussed.

Conclusions

Hemangioblastomas in VHL are optimally managed with a multidisciplinary approach that includes surgical resection of symptomatic lesions. Novel treatments are gaining traction, but must be studied further for efficacy and safety.

Endolymphatic Sac Tumors Associated With von Hippel-Lindau: A Case Report Highlighting Opportunity for Novel Orphan Drug Therapy

OBJECTIVE

To discuss the potential benefit of belzutifan therapy in a patient with von Hippel-Lindau (VHL) disease-associated endolymphatic sac tumor (ELST).

PATIENTS

Case report.

INTERVENTIONS

Clinical details of a patient with residual ELST after hearing preservation surgery who initiated belzutifan therapy postoperatively for concurrent renal cell carcinoma, as well as literature review of belzutifan and ELST.

MAIN OUTCOME MEASURES

The patient remained without radiologic evidence of growth of her residual tumor at 17 months post-initiation of belzutifan. It is unknown whether this represents therapeutic drug effect, nonviability of residual tumor, or slow tumor growth not captured radiographically within the duration of follow-up.

CONCLUSIONS

Belzutifan could have direct therapeutic benefit in patients with VHL-associated ELST.

Belzutifan for patients with von Hippel-Lindau disease-associated CNS haemangioblastomas (LITESPARK-004): a multicentre, single-arm, phase 2 study

BACKGROUND

The first-in-class hypoxia-inducible factor-2α inhibitor, belzutifan, showed clinically meaningful antitumour activity in von Hippel-Lindau (VHL) disease-associated neoplasms in the ongoing, single-arm, phase 2 LITESPARK-004 study. We aimed to investigate antitumour activity with an additional 16 months of follow-up and present updated results for the subgroup of patients with CNS haemangioblastomas.

METHODS

In the multicentre, single-arm, phase 2 LITESPARK-004 study, adults (aged ≥18 years) from 11 cancer centres or hospitals in the USA, Denmark, France, and the UK, with germline VHL alterations, at least one measurable renal cell carcinoma tumour, no renal cell carcinoma tumour greater than 3 cm requiring immediate surgical intervention, an Eastern Cooperative Oncology Group performance status 0 or 1, and no previous systemic therapy received oral belzutifan 120 mg once daily until unacceptable toxicity, disease progression, or patient decision to withdraw. The primary endpoint, evaluated in patients with CNS haemangioblastomas, was the proportion of patients with an objective response per RECIST version 1.1 by an independent review committee. We assessed response using two approaches. In approach 1, we evaluated all measurable (≥1 cm maximum diameter) or non-measurable lesions at baseline, including both the solid lesion and the associated cystic component if present. In approach 2, we evaluated only baseline lesions with a measurable (≥1 cm maximum diameter) solid lesion. Antitumour activity was assessed in all patients who received at least one dose of belzutifan. This study is no longer recruiting but is ongoing, and is registered with Clinicaltrials.gov, NCT03401788.

FINDINGS

Between May 31, 2018, and March 29, 2019, of 67 patients screened, 61 (32 [52%] male and 29 [48%] female) were enrolled; 50 (82%) had at least one CNS haemangioblastoma evaluable at baseline (184 total lesions). Median follow-up for the 50 patients with CNS haemangioblastomas was 38·0 months (IQR 36·7-40·1). In approach 1, 22 of 50 patients (44% [95% CI 30-59]) had an objective response. In approach 2, 19 of 25 patients (76% [55-91] had an objective response. 23 (46%) of 50 patients had a grade 3-5 all-cause adverse event. 19 (38%) patients reported grade 3 adverse events, the most common of which was anaemia (in 6 [12%] patients). Two of 50 patients (4%) reported grade 4 events (retinal vein occlusion and embolism). Two patients died owing to adverse events not considered treatment-related (suicide and toxicity to various agents).

INTERPRETATION

Belzutifan showed meaningful antitumour activity in VHL disease-associated CNS haemangioblastomas that was sustained for more than 3 years of treatment. These results continue to support belzutifan as a systemic treatment option for patients with VHL disease-related CNS haemangioblastomas.

FUNDING

Merck Sharp & Dohme, National Institutes of Health, and National Cancer Institute.

In Silico Exploration of AHR-HIF Pathway Interplay: Implications for Therapeutic Targeting in ccRCC

The oxygen-sensing pathway is a crucial regulatory circuit that defines cellular conditions and is extensively exploited in cancer development. Pathogenic mutations in the von Hippel-Lindau (VHL) tumour suppressor impair its role as a master regulator of hypoxia-inducible factors (HIFs), leading to constitutive HIF activation and uncontrolled angiogenesis, increasing the risk of developing clear cell renal cell carcinoma (ccRCC). HIF hyperactivation can sequester HIF-1β, preventing the aryl hydrocarbon receptor (AHR) from correctly activating gene expression in response to endogenous and exogenous ligands such as TCDD (dioxins). In this study, we used protein-protein interaction networks and gene expression profiling to characterize the impact of VHL loss on AHR activity. Our findings reveal specific expression patterns of AHR interactors following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and in ccRCC. We identified several AHR interactors significantly associated with poor survival rates in ccRCC patients. Notably, the upregulation of the androgen receptor (AR) and retinoblastoma-associated protein (RB1) by TCDD, coupled with their respective downregulation in ccRCC and association with poor survival rates, suggests novel therapeutic targets. The strategic activation of the AHR via selective AHR modulators (SAhRMs) could stimulate its anticancer activity, specifically targeting RB1 and AR to reduce cell cycle progression and metastasis formation in ccRCC. Our study provides comprehensive insights into the complex interplay between the AHR and HIF pathways in ccRCC pathogenesis, offering novel strategies for targeted therapeutic interventions.

Molecular Genetics of Pheochromocytoma/Paraganglioma

Pheochromocytomas and paragangliomas (PPGL) are neuroendocrine tumors which secrete catecholamines, causing cardiovascular compromise. While isolated tumors and locoregional disease can be treated surgically, treatment options for metastatic disease are limited, and no targeted therapies exist. Approximately 25% of PPGL are causatively associated with germline pathogenic variants, which are known risk factors for multifocal and metastatic PPGL. Knowledge of somatic driver mutations continues to evolve. Molecular classification of PPGL has identified three genomic subtypes: Cluster 1 (pseudohypoxia), Cluster 2 (kinase signaling) and Cluster 3 (Wnt-altered). This review summaries recent studies characterizing the tumor microenvironment, genomic drivers of tumorigenesis and progression, and current research on molecular targets for novel diagnostic and therapeutic strategies in PPGL.

Genetics, Pathophysiology, and Current Challenges in Von Hippel-Lindau Disease Therapeutics

This review article focuses on von Hippel-Lindau (VHL) disease, a rare genetic disorder characterized by the development of tumors and cysts throughout the body. It discusses the following aspects of the disease.

GENETICS

VHL disease is caused by mutations in the VHL tumor suppressor gene located on chromosome 3. These mutations can be inherited or occur spontaneously. This article details the different types of mutations and their associated clinical features.

PATHOPHYSIOLOGY

The underlying cause of VHL disease is the loss of function of the VHL protein (pVHL). This protein normally regulates hypoxia-inducible factors (HIFs), which are involved in cell growth and survival. When pVHL is dysfunctional, HIF levels become elevated, leading to uncontrolled cell growth and tumor formation.

CLINICAL MANIFESTATIONS

VHL disease can affect various organs, including the brain, spinal cord, retina, kidneys, pancreas, and adrenal glands. Symptoms depend on the location and size of the tumors.

DIAGNOSIS

Diagnosis of VHL disease involves a combination of clinical criteria, imaging studies, and genetic testing.

TREATMENT

Treatment options for VHL disease depend on the type and location of the tumors. Surgery is the mainstay of treatment, but other options like radiation therapy may also be used.

CHALLENGES

This article highlights the challenges in VHL disease management, including the lack of effective therapies for some tumor types and the need for better methods to monitor disease progression. In conclusion, we emphasize the importance of ongoing research to develop new and improved treatments for VHL disease.

Advances in Molecular Mechanisms of Kidney Disease: Integrating Renal Tumorigenesis of Hereditary Cancer Syndrome

Renal cell carcinoma (RCC) comprises various histologically distinct subtypes, each characterized by specific genetic alterations, necessitating individualized management and treatment strategies for each subtype. An exhaustive search of the PubMed database was conducted without any filters or restrictions. Inclusion criteria encompassed original English articles focusing on molecular mechanisms of kidney cancer. On the other hand, all non-original articles and articles published in any language other than English were excluded. Hereditary kidney cancer represents 5-8% of all kidney cancer cases and is associated with syndromes such as von Hippel-Lindau syndrome, Birt-Hogg-Dubè syndrome, succinate dehydrogenase-deficient renal cell cancer syndrome, tuberous sclerosis complex, hereditary papillary renal cell carcinoma, fumarate hydratase deficiency syndrome, BAP1 tumor predisposition syndrome, and other uncommon hereditary cancer syndromes. These conditions are characterized by distinct genetic mutations and related extra-renal symptoms. The majority of renal cell carcinoma predispositions stem from loss-of-function mutations in tumor suppressor genes. These mutations promote malignant advancement through the somatic inactivation of the remaining allele. This review aims to elucidate the main molecular mechanisms underlying the pathophysiology of major syndromes associated with renal cell carcinoma. By providing a comprehensive overview, it aims to facilitate early diagnosis and to highlight the principal therapeutic options available.

The genetic differences between types 1 and 2 in von Hippel-Lindau syndrome: comprehensive meta-analysis

BACKGROUND

Patients with von Hippel-Lindau (VHL) disease are at risk of developing tumors in the eye, brain, kidney, adrenal gland, and other organs based on their gene mutations. The VHL tumor suppressor gene contains pathogenic variants responsible for these events. This meta-analysis aims to investigate the genetic differences among the various types of VHL syndrome and their correlation with the location of mutations (exons and domains) in the VHL gene.

METHOD

Papers eligible for publication until September 2023 were identified using the electronic databases of PubMed, Google Scholar, Scopus, and EMBASE. The Random Effect model was utilized to evaluate the genetic differences between type 1 and type 2 VHL syndromes.

RESULTS

The prevalence of missense mutations (MSs) was found to be 58.9% in type 1, while it was 88.1% in type 2. Interestingly, the probability of observing MSs in type 1 was 0.42 times lower compared to type 2. The mutation hotspots of the VHL gene were R167Q/W, Y98H, R238W, and S65L, respectively. Although type 2 had a high presentation of Y98H and R238W, it did not have a higher S65L than type 1. The analysis demonstrated a statistically significant higher prevalence of truncated mutations (PTMs) in type 1. Among type 1, large/complete deletions (L/C DELs) were found in 16.9% of cases, whereas in type 2 only 3.7%. This difference was statistically significant with a p-value < 0.001. Overall, the probability of identifying mutations in domain 2 compared to domain 1 was found to be 2.13 times higher in type 1 (p-value < 0.001). Furthermore, the probability of detecting exon 1 in comparison with observing exon 2 in type 1 was 2.11 times higher than type 2 and revealed a statistically significant result (p-value < 0.001). The detection of exon 2 was 2.18 times higher in type 1 (p-value < 0.001). In addition, the likelihood of discovering exon 2 compared with others was significantly lower in type 1 compared with type 2 VHL (OR = 0.63, p-value = 0.015).

CONCLUSIONS

We have revealed a comprehensive genetic difference between types 1 and 2 of VHL syndrome. The significant differences in MS, PTMs, L/C DELs, and the location of the mutations between type 1 and type 2 VHL patients in the Asian, European, and American populations emphasize the genetic heterogeneity of the syndrome. These findings may pave the way for the diagnosis, treatment, and further investigation of the mechanisms behind this complex genetic disorder.

Trigeminal nerve hemangioblastoma in the setting of undiagnosed von Hippel-Lindau disease: illustrative case

BACKGROUND

Von Hippel-Lindau disease (VHL) is an autosomal dominant tumor predisposition syndrome caused by mutations in the VHL gene. Patients with VHL are predisposed to developing numerous neoplasms, including central nervous system hemangioblastomas that typically arise within the cerebellum, brainstem, or spinal cord. The authors present the unusual case of a 69-year-old patient with a hemangioblastoma of the trigeminal nerve as his initial presentation of VHL.

OBSERVATIONS

A 69-year-old male presented with progressive right-sided V3 paresthesias, gait disturbance, and diplopia. Magnetic resonance imaging demonstrated an enhancing 0.5-cm nodule within the right trigeminal nerve and an associated peritumoral cyst exerting mass effect on the cerebral peduncle. Neural axis imaging demonstrated pia-based enhancing lesions concerning for multiple spinal hemangioblastomas. The patient underwent an uncomplicated retrosigmoid craniotomy for trigeminal nerve hemangioblastoma resection. The patient had postoperative improvement in his gait, diplopia, and facial paresthesias. Genetic testing revealed that the patient was heterozygous for a pathological mutation in the VHL gene.

LESSONS

Hemangioblastomas in adults over 50 years of age should prompt a workup for VHL. Recognizing that cranial nerves are a possible site of hemangioblastoma occurrence is important for neurosurgeons and radiologists alike. Resection of cranial nerve hemangioblastomas is technically challenging but can lead to symptom improvement for patients. https://thejns.org/doi/10.3171/CASE24149.

Cauda equina myxopapillary ependymoma in von Hippel-Lindau disease: A case report

Background

Patients affected by Von Hippel-Lindau (VHL) are prone to develop central nervous system neoplasms such as hemangioblastomas (HBs). Myxopapillary ependymoma (MPE) is not commonly associated with VHL disease.

Case Description

We present the first case of a VHL patient affected by simultaneous silent cauda equina MPE and a symptomatic conus medullaris HB. The patient was first operated for systemic tumors and followed for asymptomatic HBs. Simple surveillance was maintained until neurological symptoms appeared. Regular follow-up demonstrated objective growth of the cystic conus medullaris tumor while the cauda equina lesion remained stable. Surgery was performed to avoid further neurological worsening. Histopathological examination showed conus medullaris HB and a nearby cauda equina MPE.

Conclusion

Simultaneous spinal HBs and isolated MPE may exceptionally occur in VHL patients.

A Von Hippel-Lindau Syndrome Case Diagnosed While Hospitalized for Major Depression

Von Hippel-Lindau syndrome (VHL) is a rare genetic disorder inherited in an autosomal dominant manner. It progresses with the presence of cranial and visceral organ tumors. Psychiatric symptoms may be accompanied by tumor location and hormonal changes. However, it is rare for the disease to first appear with psychiatric symptoms, which may delay the diagnosis of the disease. In this article, a case of VHL, first presenting with major depression, is discussed. The diagnosis and treatment of major depression may obscure the diagnosis of VHL due to the similar mean age at diagnosis and the confounding effect of neurovegetative symptoms accompanying depression.

Prevalence and prognosis of hypoxia-inducible factor-2α (HIF-2α) pathway gene mutations across advanced solid tumors

INTRODUCTION

Hypoxia-inducible factor-2α (HIF-2α) modulates the hypoxic response pathway in tumors; however, mutations in pathways (including SDHA, SDHB, SDHC, SDHD, FH, and VHL genes) that are suspected to activate HIF-2α are poorly understood, with limited understanding of the prevalence and clinical prognosis.

METHODS

This retrospective observational study used a de-identified nationwide (US-based) clinico-genomic database (CGDB) across 15 available tumor types.

RESULTS

Among the 9467 adult patients with advanced/metastatic solid tumors included in the analysis, any mutation at the above-mentioned six genes was observed in 1.8% (95% CI: 1.5-2.1) of patients. The mutation prevalence ranged from 0.05% of SDHD to 0.93% of VHL. When further stratified by tumor type, the prevalence of gene mutation in each tumor type was well below 1%, except for VHL with 44% in renal cell carcinomas (RCC). Excluding RCC, the prevalence of any HIF-2α gene mutations in the study population was 0.9% (95% CI: 0.8-1.2). The median overall survival (OS) from 1 and 2 L therapy among patients with any HIF-2α gene mutation was 14.5 (95% CI: 11.5-24.2) and 9.3 (95% CI: 6.0-18.1) months, respectively, compared with 13.4 (95% CI: 12.9-13.9) and 9.8 (95% CI: 9.3-10.4) months among patients without HIF-2α gene mutations.

DISCUSSION AND CONCLUSIONS

The prevalence of HIF-2α related gene mutations was generally low (<1%) across the 15 solid tumor types, except for VHL in RCC. No significant association between HIF-2α gene mutation status and OS was identified among patients evaluated in this study.

MFN2 suppresses the accumulation of lipid droplets and the progression of clear cell renal cell carcinoma

Dissolving the lipid droplets in tissue section with alcohol during a hematoxylin and eosin (H&E) stain causes the tumor cells to appear like clear soap bubbles under a microscope, which is a key pathological feature of clear cell renal cell carcinoma (ccRCC). Mitochondrial dynamics have been reported to be closely associated with lipid metabolism and tumor development. However, the relationship between mitochondrial dynamics and lipid metabolism reprogramming in ccRCC remains to be further explored. We conducted bioinformatics analysis to identify key genes regulating mitochondrial dynamics differentially expressed between tumor and normal tissues and immunohistochemistry and Western blot to confirm. After the target was identified, we created stable ccRCC cell lines to test the impact of the target gene on mitochondrial morphology, tumorigenesis in culture cells and xenograft models, and profiles of lipid metabolism. It was found that mitofusin 2 (MFN2) was downregulated in ccRCC tissues and associated with poor prognosis in patients with ccRCC. MFN2 suppressed mitochondrial fragmentation, proliferation, migration, and invasion of ccRCC cells and growth of xenograft tumors. Furthermore, MFN2 impacted lipid metabolism and reduced the accumulation of lipid droplets in ccRCC cells. MFN2 suppressed disease progression and improved prognosis for patients with ccRCC possibly by interrupting cellular lipid metabolism and reducing accumulation of lipid droplets.

A Cerebellar Tumor-to-Tumor Metastasis in a Patient With Von Hippel-Lindau Disease

Tumor-to-tumor metastasis in the central nerve system is uncommon in our routine practice. Most reports include metastatic breast cancer into meningioma. Here we report a metastatic clear cell renal cell carcinoma (ccRCC) into a cerebellar hemangioblastoma in a patient with von Hippel-Lindau (VHL) disease. Imaging cannot distinguish metastatic ccRCC from primary cerebellar hemangioblastoma. Immuno-molecular studies are proven to be diagnostic. We also reviewed previously documented tumor-to-tumor metastasis of ccRCC to cerebellar hemangioblastoma in VHL disease. Lastly, we discussed potential mechanisms involved in the metastasis of ccRCC to hemangioblastoma in the cerebellum in patients with VHL.

Ocular manifestations of renal ciliopathies

Renal ciliopathies are a common cause of kidney failure in children and adults, and this study reviewed their ocular associations. Genes affected in renal ciliopathies were identified from the Genomics England Panels. Ocular associations were identified from Medline and OMIM, and the genes additionally examined for expression in the human retina ( https://www.proteinatlas.org/humanproteome/tissue ) and for an ocular phenotype in mouse models ( http://www.informatics.jax.org/ ). Eighty-two of the 86 pediatric-onset renal ciliopathies (95%) have an ocular phenotype, including inherited retinal degeneration, oculomotor disorders, and coloboma. Diseases associated with pathogenic variants in ANK6, MAPKBP1, NEK8, and TCTN1 have no reported ocular manifestations, as well as low retinal expression and no ocular features in mouse models. Ocular abnormalities are not associated with the most common adult-onset "cystic" kidney diseases, namely, autosomal dominant (AD) polycystic kidney disease and the AD tubulointerstitial kidney diseases (ADTKD). However, other kidney syndromes with cysts have ocular features including papillorenal syndrome (optic disc dysplasia), Hereditary Angiopathy Nephropathy, Aneurysms and muscle Cramps (HANAC) (tortuous retinal vessels), tuberous sclerosis (retinal hamartomas), von Hippel-Lindau syndrome (retinal hemangiomas), and Alport syndrome (lenticonus, fleck retinopathy). Ocular abnormalities are associated with many pediatric-onset renal ciliopathies but are uncommon in adult-onset cystic kidney disease. However the demonstration of ocular manifestations may be helpful diagnostically and the features may require monitoring or treatment.

Belzutifan for von Hippel-Lindau Disease: Pancreatic Lesion Population of the Phase 2 LITESPARK-004 Study

PURPOSE

Primary analysis of the ongoing, single-arm, phase 2 LITESPARK-004 study (NCT03401788) showed clinically meaningful antitumor activity in von Hippel-Lindau (VHL) disease-associated renal cell carcinoma (RCC) and other neoplasms with belzutifan treatment. We describe results of belzutifan treatment for VHL disease-associated pancreatic lesions [pancreatic neuroendocrine tumors (pNET) and serous cystadenomas].

PATIENTS AND METHODS

Adults with VHL diagnosis based on germline VHL alteration, ≥1 measurable RCC tumor, no renal tumor >3 cm or other VHL neoplasm requiring immediate surgery, Eastern Cooperative Oncology Group performance status of 0 or 1, and no prior systemic anticancer treatment received belzutifan 120 mg once daily. End points included objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), and linear growth rate (LGR) in all pancreatic lesions and pNETs per RECIST version 1.1 by independent review committee, and safety.

RESULTS

All 61 enrolled patients (100%) had ≥1 pancreatic lesion and 22 (36%) had ≥1 pNET measurable at baseline. Median follow-up was 37.8 months (range, 36.1-46.1). ORR was 84% [51/61; 17 complete responses (CR)] in pancreatic lesions and 91% (20/22; 7 CRs) in pNETs. Median DOR and median PFS were not reached in pancreatic lesions or pNETs. After starting treatment, median LGR for pNETs was -4.2 mm per year (range, -7.9 to -0.8). Eleven patients (18%) had ≥1 grade 3 treatment-related adverse event (AE). No grade 4 or 5 treatment-related AEs occurred.

CONCLUSIONS

Belzutifan continued to show robust activity and manageable safety in VHL disease-associated pNETs.

DNA methyltransferase 3A induces the occurrence of oral submucous fibrosis by promoting the methylation of the von Hippel-Lindau

BACKGROUND

Oral submucous fibrosis (OSF) is associated with malignant disorders. DNA methyltransferase 3A (DNMT3A) is a DNA methylesterase reported to be upregulated in multiple organs and shown to inhibit fibrosis. However, the detailed effect of DNMT3A on OSF remains unclear.

METHODS

To mimic OSF in vitro, oral fibroblasts were exposed to arecoline and molecular biological experiments were performed to detect the function of DNMT3A in OSF.

RESULTS

We found that von Hippel-Lindau (VHL) was downregulated and highly methylated in OSF. Arecoline remarkably increased the viability, invasiveness, and migration of oral fibroblasts, but upregulation of VHL partially reversed these effects. DNMT3A induces DNA hypermethylation in the VHL promoter, and VHL markedly inhibits the level of tenascin-C (TNC) by inducing the ubiquitination of TNC. TNC reversed the inhibitory effect of VHL upregulation on the differentiation of oral fibroblasts into myofibroblasts.

CONCLUSION

DNMT3A induces OSF by promoting methylation of the VHL promoter. Hence, our study provides novel insights into the discovery of novel strategies that can be employed against OSF.

Unveiling a TGFBI Variant in the Retinal Capillary Hemangioblastoma, Type II Granular Corneal Dystrophy, and Von Hippel-Lindau Families: Unlocking Potential for Early Intervention and Targeted Therapy

Purpose

To identify the potential genetic factors responsible for retinal capillary hemangioblastoma (RCH) and Type II granular corneal dystrophy (GCDII), with autosomal dominant inheritance. We used whole-exome sequencing (WES) in an Iranian family to identify the possible genetic etiology of RCH and GCDII with other manifestations of von Hippel-Lindau (VHL) disease.

Methods

This study included one Iranian family for WES in index patients and Sanger sequencing in all available individuals.

Results

Clinical presentations of these patients included RCH, GCD, central nervous system hemangioblastoma as well as pancreatic cyst. WES disclosed a heterozygous known pathogenic variant c.371G>A (p.R124H) in exon 4 of gene TGFBI.

Conclusions

For the first time, our research identified the potential involvement of TGFBI: c.371G>A (p.R124H) in an Iranian family with RCH, GCDII, and other symptoms of VHL disease. In the future, TGFBI could offer a new understanding and a promising therapeutic approach for both GCDII and VHL diseases simultaneously. Before using the variant in genetic counseling, it is recommended to conduct functional analysis using appropriate animal models to understand its pathogenesis mechanism.

A novel immune-related lncRNA signature predicts the prognosis and immune landscape in ccRCC

BACKGROUND

As one of the most common tumors, the pathogenesis and progression of clear cell renal cell carcinoma (ccRCC) in the immune microenvironment are still unknown.

METHODS

The differentially expressed immune-related lncRNA (DEirlncRNA) was screened through co-expression analysis and the limma package of R, which based on the ccRCC project of the TCGA database. Then, we designed the risk model by irlncRNA pairs. In RCC patients, we have compared the area under the curve, calculated the Akaike Information Criterion (AIC) value of the 5-year receiver operating characteristic curve, determined the cut-off point, and established the optimal model for distinguishing the high-risk group from the low-risk group. We used the model for immune system assessment, immune point detection and drug sensitivity analysis after verifying the feasibility of the above model through clinical features.

RESULTS

In our study, 1541 irlncRNAs were included. 739 irlncRNAs were identified as DEirlncRNAs to construct irlncRNA pairs. Then, 38 candidate DEirlncRNA pairs were included in the best risk assessment model through improved LASSO regression analysis. As a result, we found that in addition to age and gender, T stage, M stage, N stage, grade and clinical stage are significantly related to risk. Moreover, univariate and multivariate Cox regression analysis results reveals that in addition to gender, age, grade, clinical stage and risk score are independent prognostic factors. The results show that patients in the high-risk group are positively correlated with tumor infiltrating immune cells when the above model is applied to the immune system. But they are negatively correlated with endothelial cells, macrophages M2, mast cell activation, and neutrophils. In addition, the risk model was positively correlated with overexpressed genes (CTLA, LAG3 and SETD2, P<0.05). Finally, risk models can also play as an important role in predicting the sensitivity of targeted drugs.

CONCLUSIONS

The new risk model may be a new method to predict the prognosis and immune status of ccRCC.

Neurocutaneous Diseases: Diagnosis, Management, and Treatment

Neurocutaneous disorders, also known as phakomatoses, are congenital and acquired syndromes resulting in simultaneous neurologic and cutaneous involvement. In several of these conditions, the genetic phenomenon is understood, providing a pivotal role in the development of therapeutic options. This review encompasses the discussion of the genetic and clinical involvement of neurocutaneous disorders, and examines clinical management and treatment options. With the current advances in genetics, the role of precision medicine and targeted therapy play a substantial role in addressing the management of these conditions. The interconnectedness between therapeutic options highlights the importance of precision medicine in treating each disorder's unique molecular pathway. This review provides an extensive synthesis of ongoing and current therapeutics in the management of such clinically unique and challenging conditions.

New Prospects on Neuroimaging in Von Hippel Lindau Disease-A Narrative Review

(1) Background: Hemangiomas in Von Hippel-Lindau (VHL) syndrome patients are typically benign but pose threats due to their vital locations involving the central nervous system and the retina. An MRI is currently recommended as the gold standard for tumors associated with VHL in the head region. This narrative review aims to comprehensively outline current standards and recent findings related to imaging of retinal and CNS hemangiomas in Von Hippel-Lindau syndrome. (2) Material and Methods: A review in adherence to PRISMA guidelines using the search string "Von Hippel-Lindau hemangioblastoma imaging" was conducted on PUBMED and SCOPUS databases. (3) Results: After reviewing 455 titles and abstracts, 20 publications fulfilling the inclusion criteria were analyzed. The analysis included studies describing MRI, CT, optical coherence tomography, and PET/CT. (4) Conclusion: While MRI remains the gold standard for diagnosing head tumors in Von Hippel-Lindau syndrome, various PET/CT methods show promise as alternative imaging modalities.

Characterizing and predicting ccRCC-causing missense mutations in Von Hippel-Lindau disease

BACKGROUND

Mutations within the Von Hippel-Lindau (VHL) tumor suppressor gene are known to cause VHL disease, which is characterized by the formation of cysts and tumors in multiple organs of the body, particularly clear cell renal cell carcinoma (ccRCC). A major challenge in clinical practice is determining tumor risk from a given mutation in the VHL gene. Previous efforts have been hindered by limited available clinical data and technological constraints.

METHODS

To overcome this, we initially manually curated the largest set of clinically validated VHL mutations to date, enabling a robust assessment of existing predictive tools on an independent test set. Additionally, we comprehensively characterized the effects of mutations within VHL using in silico biophysical tools describing changes in protein stability, dynamics and affinity to binding partners to provide insights into the structure-phenotype relationship. These descriptive properties were used as molecular features for the construction of a machine learning model, designed to predict the risk of ccRCC development as a result of a VHL missense mutation.

RESULTS

Analysis of our model showed an accuracy of 0.81 in the identification of ccRCC-causing missense mutations, and a Matthew's Correlation Coefficient of 0.44 on a non-redundant blind test, a significant improvement in comparison to the previous available approaches.

CONCLUSION

This work highlights the power of using protein 3D structure to fully explore the range of molecular and functional consequences of genomic variants. We believe this optimized model will better enable its clinical implementation and assist guiding patient risk stratification and management.

von Hippel-Lindau disease-related neoplasia with an emphasis on renal manifestations

von Hippel-Lindau (VHL) disease is characterized by biallelic inactivation of the VHL gene leading to abnormal or absent VHL protein function, and constitutive activation of hypoxia-inducible factors (HIF) that leads to pro-tumorigenic signaling. Individuals with VHL disease develop numerous cysts and tumors involving multiple organs including the kidneys, central nervous system, endolymphatic sac, lungs, pancreatobiliary system, adrenal glands, epididymis, and/or broad ligament. On histologic examination, these lesions show morphologic overlap as they are frequently characterized by cells with clear cytoplasm and prominent vascularity. In addition to distinguishing non-renal tumors from metastatic clear cell renal cell carcinoma, understanding site-specific histopathologic and immunophenotypic features of these tumors has several applications. This includes distinguishing VHL-related tumors from those that arise sporadically and lack VHL gene alterations, guiding further genetic workup, and helping distinguish between different genetic predisposition syndromes. In this context, immunohistochemical studies for markers such as paired box 8 (PAX-8), carbonic anhydrase 9 (CA9), and glucose transporter 1 (GLUT-1) have an important role in routine clinical practice and represent cost-effective diagnostic tools. The recent development of targeted therapeutics directed against HIF-mediated signaling represents a significant milestone in the management of VHL disease and highlights the importance of accurately diagnosing and characterizing the wide spectrum of VHL disease-associated lesions.

Neurocutaneous Disorders in Pregnancy

Importance

Neurocutaneous disorders have significant implications for care of the pregnant patient. As neurocutaneous disorders are uncommon, obstetricians may be unfamiliar with these disorders and with recommendations for appropriate care of this population.

Objective

This review aims to summarize existing literature on the interaction between neurocutaneous disorders and pregnancy and to provide a guide for physicians caring for an affected patient.

Evidence Acquisition

A PubMed, MEDLINE, and Google Scholar search was carried out with a broad range of combinations of the medical subject headings (MeSH) terms "pregnancy," "Sturge -Weber," "Neurofibromatosis Type 1," "neurofibromatosis type 2," "von Hippel Lindau," "Tuberous Sclerosis," "neurocutaneous disorder," "treatment," "congenital malformations," "neurodevelopmental defects," "miscarriage," "breastfeeding," "autoimmune," "pathophysiology," and "management." References of included articles were searched to identify any articles that may have been missed after the above method was used.

Results

Neurocutaneous disorders are associated with increased pregnancy-associated maternal and fetal/neonatal morbidity, largely surrounding hypertensive disorders, epilepsy, and medication exposure. Some features of neurocutaneous disorders may be worsened or accelerated by pregnancy. Neurocutaneous disorders can often be diagnosed prenatally. Therefore, directed assessment should be offered to affected individuals with a personal or family history of a neurocutaneous disorder.

Conclusion and Relevance

Patients affected by neurocutaneous disorders who are pregnant or planning for future pregnancy should be carefully followed by a multidisciplinary team, which could include maternal-fetal medicine, neurology, and anesthesia, as well as other relevant subspecialists. Additional research is required regarding optimal counseling and management of these patients.

68Ga-DOTANOC PET/CT for Screening and Surveillance of Von Hippel-Lindau (VHL) disease

Purpose

Hereditary tumor syndrome Von Hippel-Lindau (VHL) disease is characterized by various benign and malignant tumors that are known to express somatostatin receptors (SSTR). We evaluated the role of 68Ga-DOTANOC PET/CT scan in patients with positive germline mutation of the VHL gene, presented initially or on follow-up, for the detection of recurrent or synchronous/metachronous lesions.

Methods

Fourteen patients (8 males; 6 females) with mean age 30 ± 9.86 years were retrospectively analyzed, were tested positive for VHL on gene dosage analysis, and underwent 68 Ga-DOTANOC PET/CT scan for disease evaluation. The number and site of lesions were determined. The tracer uptake was analyzed semi-quantitatively by calculating the maximum standardized uptake values (SUVmax) of lesion.

Results

Four of the 14 patients underwent scan for initial diagnosis as baseline, 6 patients for post-therapy disease status, and 4 patients for initial diagnosis as well as follow-up evaluation of the disease. A total of 67 lesions were detected in 14 patients. The sites of lesions were cerebellar/vertebral/spinal (17; mean SUVmax = 7.85); pancreatic neuroendocrine tumor (NET) (11; mean SUVmax = 20.64); retina (3; mean SUVmax = 10.46); pheochromocytoma (10; mean SUVmax = 16.32); paragangliomas (3; mean SUVmax = 10.65); pancreatic cyst (9; mean SUVmax = 2.54); and renal cyst (8; mean SUVmax = 1.56) and miscellaneous lesions constituted 6 lesions.

Conclusion

Our results show that 68 Ga-DOTANOC PET/CT may be a useful modality for screening and follow-up of associated tumors in patients with germline gene mutation for VHL. It can be used as a one-stop imaging modality for VHL patients and may substitute for separate radiological investigations, making it more convenient for patients in terms of time and cost.

Targeting HIF-2 Alpha in Renal Cell Carcinoma

OPINION STATEMENT

Current treatment options for patients with metastatic renal cell carcinoma (mRCC) are limited to immunotherapy with checkpoint inhibitors and targeted therapies that inhibit the vascular endothelial growth factor receptors (VEFG-R) and the mammalian target of rapamycin (mTOR). Despite significantly improved outcomes over the last few decades, most patients with mRCC will ultimately develop resistance to these therapies, thus highlighting the critical need for novel treatment options. As part of the VHL-HIF-VEGF axis that rests at the foundation of RCC pathogenesis, hypoxia-inducible factor 2α (HIF-2α) has been identified as a rationale target for mRCC treatment. Indeed, one such agent (belzutifan) is already approved for VHL-associated RCC and other VHL-associated neoplasms. Early trials of belzutifan indicate encouraging efficacy and good tolerability in sporadic mRCC as well. The potential inclusion of belzutifan and other HIF-2α inhibitors into the mRCC treatment armamentarium either as a single agent or as combination therapy would be a welcome addition for patients with mRCC.

Von Hippel-Lindau Disease (VHL): Characteristic Lesions with Classic Imaging Findings

Von Hippel-Lindau disease (VHL) is a multisystem cancer syndrome caused by the inactivation of the VHL tumor suppressor gene and involves various organ systems including the central nervous system (CNS), endocrine system, and the kidneys. Tumors seen in patients with VHL disease can be benign or malignant and are usually multifocal, bilateral, and hypervascular in nature. As most lesions associated with VHL are asymptomatic initially, early diagnosis and the institution of an evidence-based surveillance protocol are of paramount importance. Screening, surveillance, and genetic counseling are key aspects in the management of patients diagnosed with VHL disease and often require a multidisciplinary approach and referral to specialized centers. This article will discuss the characteristic lesions seen with VHL disease, their diagnosis, screening protocols and management strategies, as well as an illustrative case to demonstrate the natural progression of the disease with classic imaging findings.

Von Hippel-Lindau Disease (VHL): Characteristic Lesions with Classic Imaging Findings

Von Hippel-Lindau disease (VHL) is a multisystem cancer syndrome caused by the inactivation of the VHL tumor suppressor gene and involves various organ systems including the central nervous system (CNS), endocrine system, and the kidneys. Tumors seen in patients with VHL disease can be benign or malignant and are usually multifocal, bilateral, and hypervascular in nature. As most lesions associated with VHL are asymptomatic initially, early diagnosis and the institution of an evidence-based surveillance protocol are of paramount importance. Screening, surveillance, and genetic counseling are key aspects in the management of patients diagnosed with VHL disease and often require a multidisciplinary approach and referral to specialized centers. This article will discuss the characteristic lesions seen with VHL disease, their diagnosis, screening protocols and management strategies, as well as an illustrative case to demonstrate the natural progression of the disease with classic imaging findings.

Total pancreatoduodenectomy for multiple pancreatic cysts in von Hippel-Lindau disease presenting as obstructive jaundice: A case report

INTRODUCTION

Von Hippel-Lindau (VHL) disease can be known as a rare autosomal dominant syndrome that affects some organ systems and is characterized by the growth of both benign and malignant tumors. Diagnosis and management of VHL were needed to have better outcomes.

CASE PRESENTATION

A 39-year-old male with a history of VHL disease and positive family history presented with jaundice and pruritus. He had a history of craniotomy thrice. Laboratory workup revealed elevated total bilirubin level with conjugated bilirubin predominant. The contrast-enhanced MRI showed dilatation of biliary tree with suspicion of partial obstruction by multiple cysts in the pancreas, with ±0.5-5 cm in diameter. A PET/CT scan showed multiple lesions corresponding to VHL disease. The patient underwent total pancreatoduodenectomy. The histopathology finding was multicystic pancreatic hamartoma with neuroendocrine cell hyperplasia.

CLINICAL DISCUSSION

Multiple pancreatic cysts without prior pancreatic inflammatory episodes should suggest VHL disease and prompt a genetic test, according to clinical presentation. As soon as the diagnosis is made, all potential family members must be screened, and those who are affected must receive genetic counseling and strict follow-up care to treat the disease's potentially fatal CNS and visceral manifestations. Total pancreatoduodenectomy was performed according to jaundice, risk of pancreas malignancy, and the existence of endocrine pancreatic insufficiency.

CONCLUSION

Total pancreatoduodenectomy could be performed to relieve the symptom severity and avoid the possibility of malignant changes in VHL.

Belzutifan in adults with VHL-associated central nervous system hemangioblastoma: a single-center experience

PURPOSE

Belzutifan is a selective inhibitor of hypoxia-inducible factor 2 alpha (HIF-2a) that has emerged as a targeted therapy option for Von Hippel-Lindau (VHL) syndrome-associated tumors with recent FDA approval. There is limited real-world evidence regarding safety and efficacy in CNS hemangioblastoma. Our objective was to report on our clinical experience with belzutifan in adult patients with VHL-associated CNS hemangioblastoma.

METHODS

We retrospectively reviewed our institutional experience of belzutifan in adult patients (> 18 years of age at time of therapy) with VHL and craniospinal CNS hemangioblastomas not amenable to surgical resection. The period for study review was October 2021 to March 2023.

RESULTS

4 patients (all female) with a median age of 36 years at time of belzutifan initiation were included. Median duration of therapy at last follow-up was 11 months (6-17 months). All patients had radiographic response to therapy after a median of 3 months (2-5 months), with maximal response to therapy after a median of 8 months (3-17 months). Therapy was well tolerated, with the most common adverse effect being anemia. No patients had treatment pauses or dose adjustments due to belzutifan-related toxicity. No patients experienced hypoxia.

CONCLUSION

We showed that belzutifan is safe and well-tolerated with strong disease response for CNS hemangioblastoma in adults with VHL, supporting continued use of belzutifan in this patient population. Future studies should assess duration of treatment, effects of cessation after long-term use, and markers of therapeutic response.

Hereditary Cancer Syndromes: A Comprehensive Review with a Visual Tool

Hereditary cancer syndromes account for nearly 10% of cancers even though they are often underdiagnosed. Finding a pathogenic gene variant could have dramatic implications in terms of pharmacologic treatments, tailored preventive programs, and familiar cascade testing. However, diagnosing a hereditary cancer syndrome could be challenging because of a lack of validated testing criteria or because of their suboptimal performance. In addition, many clinicians are not sufficiently well trained to identify and select patients that could benefit from a genetic test. Herein, we searched the available literature to comprehensively review and categorize hereditary cancer syndromes affecting adults with the aim of helping clinicians in their daily clinical practice through a visual tool.

β-Adrenoreceptors as Therapeutic Targets for Ocular Tumors and Other Eye Diseases-Historical Aspects and Nowadays Understanding

β-adrenoreceptors (ARs) are members of the superfamily of G-protein-coupled receptors (GPCRs), and are activated by catecholamines, such as epinephrine and norepinephrine. Three subtypes of β-ARs (β₁, β₂, and β₃) have been identified with different distributions among ocular tissues. Importantly, β-ARs are an established target in the treatment of glaucoma. Moreover, β-adrenergic signaling has been associated with the development and progression of various tumor types. Hence, β-ARs are a potential therapeutic target for ocular neoplasms, such as ocular hemangioma and uveal melanoma. This review aims to discuss the expression and function of individual β-AR subtypes in ocular structures, as well as their role in the treatment of ocular diseases, including ocular tumors.

Investigation of germline VHL variants in Iranian patients with retinal capillary hemangioblastoma and genotype-phenotype analysis

BACKGROUND

Retinal capillary hemangioblastoma (RCH), while sporadic in some cases, is the most common and earliest manifestation of von Hippel-Lindau disease (VHL). This is the first report on different types of VHL variants and genotype-phenotype correlations in Iranian families with RCH.

MATERIALS AND METHODS

In this prospective observational case series study, 17 families with RCH were included. PCR was performed to amplify 3 exons of VHL gene. Afterward, Sanger sequencing was performed on all PCR products. For the detection of VHL copy number variations, MLPA was used.

RESULTS

Our study identified 10 different types of VHL variants. Missense mutations were the most common variants found and affected the structure of α domain of the VHL protein (pVHL). The majority of mutations (72.7%) in the patients with RCH and central nervous system hemangioblastoma (CNS-HB) were located on α domain.

CONCLUSION

α domain of VHL may play a potential role in the pathogenesis of RCH. Our findings suggest that genotype-phenotype characteristics in those variants in α- domain may predispose patients to RCH with CNS-HB.

Síndrome de von Hippel-Lindau em um Serviço Privado de Câncer em São Paulo: Relato de Caso

Introdução: A síndrome de von Hippel-Lindau (VHL) é uma patologia hereditária autossômica dominante que envolve o crescimento de tumores em diversas regiões do corpo humano em razão da mutação no gene VHL. Relato do caso: Paciente, sexo masculino, 38 anos, há três anos queixava-se de cefaleia recorrente, com piora progressiva. Foi diagnosticado com uma lesão em cerebelo cuja ressonância magnética cerebral encontrou uma formação expansiva na porção posteroinferior do hemisfério cerebelar esquerdo. Foi realizada tomografia multislice de abdome, que evidenciou formação nodular esplênica com realce marginal. A imagem da coluna cervical demonstrou pequeno nódulo localizado na medula cervical (intramedular) adjacente à vértebra cervical 3 (C3). Diante dos achados, o paciente foi submetido à ressecção macroscópica total da lesão do cerebelo, com laudo anatomopatológico de hemangioblastoma cerebelar grau 1, de acordo com a classificação da Organização Mundial da Saúde (OMS), que é um tumor benigno com baixa agressividade e recorrência. O teste imuno-histoquímico mostrou cluster of differentiation 34 (CD 34) positivo, índice de proliferação celular (Ki67) positivo (<5%), alfa inibina positiva e epithelial membrane antigen (EMA) negativo. Como o paciente não tinha história familiar de câncer, em função dos achados radiológicos, foi realizado sequenciamento de nova geração identificando a variante patogênica VHL c.292T>C, constatado em linhagem germinativa que, apesar do desconhecimento de história familiar positiva para a síndrome, confirmou o diagnóstico do paciente. Conclusão: O conjunto de achados clínicos e a variante no gene VHL confirmam o diagnóstico da síndrome.