Benefits of screening in von Hippel-Lindau disease--comparison of morbidity associated with initial tumours in affected parents and children

Comprehensive characterization and building of National Registry of von Hippel-Lindau disease in Brazil

BACKGROUND

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder caused by pathogenic variants in VHL gene. The common manifestations include hemangioblastomas (HB) of the central nervous system (CNS) and retina (RH); pheochromocytoma (PHEO); clear cell renal cell carcinoma (ccRCC); pancreatic and renal cysts (PRC) and pancreatic neuroendocrine neoplasm (PNEN).

METHODS

The first characterization of VHL in Brazil was published in 2003 and included 20 families with a history of VHL. The aim of this study was to expand the previous Brazilian cohort to include more families, as well as to collect prospectively both clinical and molecular characteristics of patients with VHL to build the VHL Brazilian Registry (VHLBR). Patients with VHL were selected through review of data from medical records of experts and from social networks of support for families with VHL in Brazil.

RESULTS

A total of 142 subjects representing 62 unrelated Brazilian families with VHL were registered. The mean age of VHL onset was 28.78 years old and 128 individuals (90.1%) had at least one VHL-related lesion. CNS HB was the most common manifestation occurring in 91 (71%) patients, followed by multiple PRC (48.4%), RH (39.8%), ccRCC (28.9%), PHEO (12.5%) and PNEN (7.8%). Of the 97 subjects whose presence of VHL variants was confirmed, 51 (52.6%) had missense variants, 22 (22.7%) large deletions, 10 (10.3%) frameshift, 7 (7.2%) splice site, 4 (4.1%) nonsense and 3 (3.1%) in-frame deletions. Regarding surveillance, 115 (81%) participants had at least one physician responsible for their outpatient follow-up; however, 69 (60%) of them did not report a regular frequency of tests.

CONCLUSION

We built the largest prospective VHLBR with organized collections of clinical and genetic data from families with VHL, which will be helpful to guide policies for VHL care and oncogenetics in Brazil. Although there have been improvements in diagnosis and clinical screening methods, VHL care in Brazil is still deficient, especially regarding surveillance and regular medical appointments with experts.

Pheochromocytomas and paragangliomas in von Hippel-Lindau disease: not a needle in a haystack

OBJECTIVE

Pheochromocytomas are a hallmark feature of von Hippel-Lindau disease (vHL). To our knowledge, this is the first systematic review with meta-analysis evaluating the frequency of pheochromocytomas and/or paragangliomas (PPGLs) in patients with vHL, as well as among patients with different vHL subtypes.

DESIGN

Systematic review with meta-analysis.

METHODS

We searched on MEDLINE, Scopus, and Web of Science. We included primary studies assessing participants with vHL and reporting on the frequency of PPGL. We performed random-effects meta-analysis to quantitatively assess the frequency of PPGL, followed by meta-regression and subgroup analysis. Risk of bias analysis was performed to assess primary studies' methodological quality.

RESULTS

We included 80 primary studies. In 4263 patients with vHL, the pooled frequency of PPGL was 19.4% (95% CI = 15.9-23.6%, I2 = 86.1%). The frequency increased to 60.0% in patients with vHL type 2 (95% CI = 53.4-66.3%, I2 = 54.6%) and was determined to be of 58.2% in patients with vHL type 2A (95% CI = 49.7-66.3%, I2 = 36.2%), compared to 49.8% in vHL type 2B (95% CI = 39.9-59.7%, I2 = 42.7%), and 84.1% in vHL type 2C (95% CI = 75.1-93.1%, I2 = 0%). In meta-regression analysis, more recent studies were associated with a higher frequency of PPGL. All studies had at least one internal validity item classified as 'high risk of bias,' with 13% studies having low risk of bias in all external validity items.

CONCLUSIONS

PPGLs are a common manifestation of vHL. Despite methodological limitations and differences across primary studies, our results point to the importance of PPGL screening in patients with vHL.

Molecular characterisation of sporadic endolymphatic sac tumours and comparison to von Hippel-Lindau disease-related tumours

AIMS

Although inactivation of the von Hippel-Lindau gene (VHL) on chromosome 3p25 is considered to be the major cause of hereditary endolymphatic sac tumours (ELSTs), the genetic background of sporadic ELST is largely unknown. The aim of this study was to determine the prevalence of VHL mutations in sporadic ELSTs and compare their characteristics to VHL-disease-related tumours.

METHODS

Genetic and epigenetic alterations were compared between 11 sporadic and 11 VHL-disease-related ELSTs by targeted sequencing and DNA methylation analysis.

RESULTS

VHL mutations and small deletions detected by targeted deep sequencing were identified in 9/11 sporadic ELSTs (82%). No other cancer-related genetic pathway was altered except for TERT promoter mutations in two sporadic ELST and one VHL-disease-related ELST (15%). Loss of heterozygosity of chromosome 3 was found in 6/10 (60%) VHL-disease-related and 10/11 (91%) sporadic ELSTs resulting in biallelic VHL inactivation in 8/10 (73%) sporadic ELSTs. DNA methylation profiling did not reveal differences between sporadic and VHL-disease-related ELSTs but reliably distinguished ELST from morphological mimics of the cerebellopontine angle. VHL patients were significantly younger at disease onset compared to sporadic ELSTs (29 vs. 52 years, p < 0.0001, Fisher's exact test). VHL-disease status was not associated with an increased risk of recurrence, but the presence of clear cells was found to be associated with shorter progression-free survival (p = 0.0002, log-rank test).

CONCLUSION

Biallelic inactivation of VHL is the main mechanism underlying ELSTs, but unknown mechanisms beyond VHL may rarely be involved in the pathogenesis of sporadic ELSTs.

Inherited syndromes involving pancreatic neuroendocrine tumors

Inherited syndromes are important to recognize in the setting of a pancreatic neuroendocrine tumor (PNET) as there are significant implications for the patient's medical management and opportunity for early detection of subsequent manifestations. Although most PNETs are sporadic, approximately 10% are due to an inherited syndrome, which include multiple endocrine neoplasia type 1 (MEN1), multiple endocrine neoplasia type 4 (MEN4), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC). The general hallmarks of a hereditary endocrine neoplasia predisposition syndrome include any one of the following: multiple primary tumors (in the same or different organs), rare tumors (prevalence of less than 1 in 1,000 people in the general population), earlier age of diagnosis (usually under the age of 40), characteristic pattern of disease in the individual or family (phenotype and inheritance pattern). These syndromes are monogenic (due to a single gene disorder), highly penetrant (with all carriers of the disease exhibiting at least part of the phenotype) and can display variable expressivity (where affected individuals may have different presentations and features of the disease). A thoughtful approach to management is required, even if the presenting symptom is resolved, as these syndromes often involve multi-organ disease with a lifelong risk for tumor development. Additionally, the natural history of tumors in the setting of a hereditary condition may be different than would be expected in a sporadic form of the disease. For example, in some circumstances the risk of metastatic disease is lower, and therefor longer observation is the preferred approach over early surgical intervention. The unique aspects to management, challenges in hereditary disease recognition and accurate diagnosis, and rarity of these syndromes are all reasons to support referral to high-volume centers with the experience and knowledge to treat patients with hereditary endocrine neoplasia syndromes.

Imaging surveillance for children with predisposition to renal tumors

Effective surveillance is necessary for early detection of tumors in children with cancer predisposition syndromes. Instituting a surveillance regimen in children comes with practical challenges that include determining imaging modality and timing, and considering cost efficiency, accessibility, and the significant consequences of false-positive and false-negative results. To address these challenges, the American Association for Cancer Research has recently published consensus recommendations that focus on surveillance of cancer predisposition syndromes in children. This review condenses the imaging surveillance recommendations for syndromes that carry a predisposition to renal tumors in childhood, and includes summaries of the predisposition syndromes and discussion of considerations of available imaging modalities.

Evidence for genetic anticipation in vonHippel-Lindau syndrome

BACKGROUND

von Hippel-Lindau (vHL) syndrome is a rare autosomal-dominant disorder that confers a lifelong risk for developing both benign and malignant tumours in multiple organs. Recent evidence suggests that vHL may exhibit genetic anticipation (GA). The aim of this study was to determine if GA occurs in vHL, and if telomere shortening may be a factor in GA.

METHODS

A retrospective chart review of vHL families seen at The Hospital for Sick Children between 1984 and 2016 was performed. Age of onset (AOO, defined as the age of first physician-diagnosed vHL-related manifestation) was confirmed for 96 patients from 20 unrelated families (80 clinically affected and 16 unaffected carriers). Flow-FISH(flow cytometry sorting of cells whose telomeres are labeled by Fluorescence In Situ Hybridization) was used to measure mean telomere length of six white blood cell subtypes from 14 known VHL pathogenic variant carriers.

RESULTS

The median AOO for generations I, II and III were 32.5, 22.5 and 12.0 years, respectively. The differences in the AOO between generations were highly significant using a Cox proportional hazards model (P=6.00×10^-12). Telomere lengths were significantly different for granulocytes and natural killer lymphocytes of patients with vHL compared with age-matched controls. For six vHL parent-child pairs, median white blood cell telomere lengths between parent and child were not significantly different.

CONCLUSIONS

Our results suggest that vHL telomere abnormalities may be primarily somatic in origin rather than a cause of GA. As tumour development exhibits GA in our cohort, vHL surveillance guidelines may need to account for a patient's generational position within a vHL pedigree.

von Hippel-Lindau development in children and adolescents

The autosomal dominant von Hippel-Lindau disease (vHL) is associated with a lifelong risk of tumor development, especially retinal and CNS hemangioblastomas, pheochromocytoma, and renal cell carcinoma. Knowledge of paediatric vHL development is limited, and current surveillance guidelines are based on expert opinions. We aimed to describe the course of vHL development in children and adolescents, focusing on age at first manifestation, manifestation frequencies, and types. The prevalence of vHL diagnosis as well as manifestations in childhood were evaluated based on 99 patients, who had started surveillance before 18 years: 37 Danish patients from the national vHL research database and 62 international patients reported in 15 articles. Overall, 70% (69 of 99) developed manifestations before 18 years (median age at first manifestation: 12 years (range: 6-17 years)). Thirty per cent (30 of 99) had developed more than one manifestation type; the most frequent were retinal (34%) and CNS (30%) hemangioblastomas. Among the 37 Danish patients, 85% (97 of 116) of their tumors were asymptomatic. Vision outcome is significantly improved in hemangioblastomas that are treated while still asymptomatic. We agree with current guidelines that retinal surveillance be performed from birth. The patients had their first CNS hemangioblastomas at the median ages of 13-14 years (range: 6-17 years). Further, 11% (4 of 37) of the Danish patients had CNS surgery in their teenage years. Although the cohort is too small to make definite conclusions about specific initiation ages, regular CNS surveillance from vHL patients' teenage years seems clinically relevant.

Renal Cell Carcinoma in a Young Adult - Do We Need Further Investigations?

Renal cell carcinomas (RCC), mostly occurring in adults aged 60-70 years, can result from well-known factors like cigarette smoking, obesity and hypertension. However, they have been associated with genetic alterations in children and young adults. A 28 year-old male patient with a confirmed RCC underwent biomolecular and immunohistochemical analyses due to his young age. A point mutation of the von Hippel-Lindau tumor suppressor gene was identified. Young patients under 40 years with diagnosed RCC should undergo additional diagnostic investigation, hence the discovery of an underlying cause. This could be important for further treatment and counseling of these young patients.

What the neurosurgeon should know about hemangioblastoma, both sporadic and in Von Hippel-Lindau disease: A literature review

BACKGROUND

Hemangioblastomas are associated with Von Hippel-Lindau disease (VHLD) in 10-40% of cases. Based upon a literature review we state the core features the neurosurgeon should be aware of.

METHODS

We performed a selective literature (Cochrane and Medline) search for hemangioblastoma, both sporadic and VHL associated. We reviewed general characteristics (epidemiology, symptomatology, diagnosis, and management) and focused on follow-up as well as screening modalities for sporadic and VHL associated lesions.

RESULTS

Based upon our literature search, we established guidelines for screening and follow-up in both sporadic and VHL associated hemangioblastoma patients.

CONCLUSIONS

Screening for retinal angiomas, abdominal masses, and pheochromocytomas as well as genetic analysis is recommended for every patient with a newly diagnosed hemangioblastoma. Follow-up is by magnetic resonance imaging (MRI) of the clinical neuronal region at 6 and at 12-24 months postoperatively. For VHL-associated hemangioblastomas yearly investigation for craniospinal hemangioblastoma by MRI and yearly screening and follow-up for retinal angiomas is recommended. Annual abdominal ultrasound with triennial computed tomography (CT) imaging for abdominal masses is postulated. Annual audiometry is to be performed for possible endolymphatic sac tumor, detailed radiographic imaging of the skull base should be performed upon abnormality in auditory testing. Investigations for cystadenomas of the epidydimis and broad ligament only are mandatory on indication. Annual investigation for pheochromocytoma is recommended.

Unintended diagnosis of Von Hippel Lindau syndrome using Array Comparative Genomic Hybridization (CGH): counseling challenges arising from unexpected information

Array Comparative Genomic Hybridization (array CGH) is a powerful tool for identifying genomic imbalances and providing a diagnosis in individuals with a normal karyotype. It has been particularly useful in the investigation of individuals with developmental delay +/-, dysmorphic features and/or multiple congenital abnormalities. However, this non-targeted method of scanning the whole genome can reveal unexpected information. We present a case where array CGH identified the cause of a proband's moderate mental retardation by discovery of a de novo deletion of chromosome 3p25.3. This deletion was shown to contain at least 25 genes including the VHL gene, the deletion or mutation of which leads to Von Hippel Lindau (VHL) syndrome. Presymptomatic testing for VHL is usually offered after appropriate genetic counseling about the implications of this condition. Therefore, scanning the genome by array CGH presents a number of challenges for the genetic counselor. We suggest that further understanding of the psychosocial effects of array CGH is needed in order for appropriate pre- and post-test counseling to be provided.

von Hippel-Lindau disease: surveillance strategy for endolymphatic sac tumors

PURPOSE

: Up to 16% of patients with the hereditary von Hippel-Lindau disease develop endolymphatic sac tumors of the inner ear. Early diagnosis and treatment of endolymphatic sac tumors can prevent audiovestibular morbidity, but optimal endolymphatic sac tumor surveillance strategy has yet to be determined. We aimed to evaluate endolymphatic sac tumor surveillance to determine the best surveillance strategy.

METHODS

: In a national prospective study, 40 VHL mutation carriers were interviewed about audiovestibular symptoms and had audiological examinations and magnetic resonance imaging of the inner ear. Further, we performed a meta-analysis including all reported endolymphatic sac tumor von Hippel-Lindau disease cases in the literature (N = 140 with 156 endolymphatic sac tumors).

RESULTS

: In the prospective study, endolymphatic sac tumors were suspected based on audiovestibular symptoms, audiometry, and magnetic resonance imaging in 34%, 30%, and 12.5% of subjects, respectively. In total, more than 90% of radiologically diagnosed endolymphatic sac tumors were associated with abnormal audiometric findings. No endolymphatic sac tumor genotype-phenotype correlations were found.

CONCLUSION

: We recommend annual audiometry as a first-line endolymphatic sac tumor screening tool, and in countries where periodic surveillance magnetic resonance imaging of the central nervous system is performed, specific images of the inner ear should be included. Audiometric abnormalities in patients with von Hippel-Lindau disease without magnetic resonance imaging-visible endolymphatic sac tumors could be due to microscopic endolymphatic sac tumors. Determination of audiometric endolymphatic sac tumor characteristics could further target screening and improve endolymphatic sac tumor diagnosis.

Pediatric endocrine screening for von Hippel-Lindau disease: benefits and the challenge of compliance

Fifteen children and adolescents (4 male) with a median age of 5.4 yr (range 1.2 -13.6 yr) were entered into a screening protocol to identify lesions of von Hippel-Lindau (VHL) disease. Fourteen had an affected first-degree relative and one had a previous VHL lesion. Screening during the period of 2000 to 2008 followed published guidelines and consisted of measurement of urinary catecholamines, adrenal and renal imaging and ophthalmological and central nervous system examinations and imaging. Screening identified 8 VHL lesions in 6 asymptomatic patients with confirmed genetic mutations. Five patients had elevated urinary noradrenaline excretion and in each case the presence of a pheochromocytoma was identified on adrenal magnetic resonance imagin scan. In one patient a left-sided tumor was identified 1 yr after a right-sided tumor had been removed. In a sixth patient a retinal capillary hemangioma and a cerebellar hemangioblastoma were identified. Patient compliance with the screening protocol was variable reflecting its time-intensive nature. A formal screening programme for this at-risk population of pediatric patients, despite being intensive, can identify VHL lesions during a pre-morbid phase and may thus have a beneficial impact on prognosis in this serious disorder.

Educational paper: screening in cancer predisposition syndromes: guidelines for the general pediatrician

Improvements in our understanding of the genetic basis of human disease and increased utilization of genetic testing have identified a variety of heritable disorders associated with the onset of benign or malignant neoplasms during childhood. In many cases, the optimal management of affected children is dependent upon the early detection and treatment of tumors. Surveillance strategies based on the natural history of these lesions are often complex, requiring clinical examinations and radiologic and laboratory studies that evolve over a patient's lifetime. A general pediatrician may be the first to suspect one of these disorders in a patient, or may be faced with questions regarding genetic testing, cancer risk, and cancer screening. The pediatrician may also coordinate and interpret the results of specific surveillance studies. In this review, we present the genetic etiology, presentation, natural history, and surveillance recommendations for four disparate hereditary tumor predisposing syndromes, including Beckwith-Wiedemann syndrome/idiopathic hemihyperplasia, von Hippel-Lindau disease, Li-Fraumeni syndrome, and rhabdoid tumor/schwannomatosis. These examples are meant to offer the clinician practical recommendations as well as a framework upon which to base the understanding and management of other conditions associated with an increased risk to develop tumors in childhood.

Two pediatric patients with Von Hippel-Lindau disease type 2b: from patient to screening, from screening to patient

Von Hippel-Lindau (VHL) disease is an autosomal dominantly inherited tumor susceptibility disease characterized by the development of hemangioblastomas of the brain, spinal cord and retina; pheochromocytomas and renal cell carcinoma. The disease is caused by mutations in the VHL tumor suppressor gene located on chromosome 3p26-p25. In this paper, we present two patients with VHL disease type 2B confirmed by genetic analysis. Diagnosis in the first patient was based on demonstration of retinal hemangioblastoma in association with bilateral pheochromocytoma. Family screening revealed renal cell carcinoma in her father and uncle. The second patient was discovered during family screening of another index case in adult age. VHL disease should be clinically suspected in any individual with a pheochromocytoma especially when there is bilateral and/or multifocal disease or family history. Screening of patients and at-risk family members for VHL-associated tumors should be essential in management of VHL.

VHL disease

von Hippel-Lindau disease (VHL) disease increases susceptibility to several malignancies, including renal cell carcinoma, haemangioblastomas of the central nervous system or retina and phaeochromocytomas. The VHL tumour suppressor gene, responsible for the disease, encodes for a major regulator of the hypoxic response by targeting the transcription factor hypoxia inducible factor (HIF) for degradation. In this review, we present a synopsis of clinical features of the disease and emphasise unique aspects of VHL syndrome in the paediatric population. Genotype-phenotype associations based on the risk of phaeochromocytoma have pointed to the existence of additional, HIF-independent functions of VHL that remain underexplored. We also examine the progress on these pleiotropic roles of VHL, which contribute to explain clinical features of VHL disease. These advances have important translational implications and are likely to offer a new host of therapeutic options to individuals affected by the disease in the future.

Genetic Counseling in Renal Masses

All urologists have faced patients suffering a renal cancer asking for the occurrence of the disease in their offspring and very often the answer to this question has not been well founded from the scientific point of view, and only in few cases a familial segregation tree is performed. The grate shift seen in the detection of small renal masses and renal cancer in the last decades will prompt us to know the indications for familial studies, which and when are necessary, and probably to refer those patients with a suspected familial syndrome to specialized oncological centers where the appropriate molecular and familial studies could be done. Use of molecular genetic testing for early identification of at-risk family members improves diagnostic certainty and would reduce costly screening procedures in at-risk members who have not inherited disease-causing mutations. This review will focus on the molecular bases of familial syndromes associated with small renal masses and the indications of familial studies in at-risk family members.