Familiality in brain tumors

Enhancing patient representation learning with inferred family pedigrees improves disease risk prediction

BACKGROUND

Machine learning and deep learning are powerful tools for analyzing electronic health records (EHRs) in healthcare research. Although family health history has been recognized as a major predictor for a wide spectrum of diseases, research has so far adopted a limited view of family relations, essentially treating patients as independent samples in the analysis.

METHODS

To address this gap, we present ALIGATEHR, which models inferred family relations in a graph attention network augmented with an attention-based medical ontology representation, thus accounting for the complex influence of genetics, shared environmental exposures, and disease dependencies.

RESULTS

Taking disease risk prediction as a use case, we demonstrate that explicitly modeling family relations significantly improves predictions across the disease spectrum. We then show how ALIGATEHR's attention mechanism, which links patients' disease risk to their relatives' clinical profiles, successfully captures genetic aspects of diseases using longitudinal EHR diagnosis data. Finally, we use ALIGATEHR to successfully distinguish the 2 main inflammatory bowel disease subtypes with highly shared risk factors and symptoms (Crohn's disease and ulcerative colitis).

CONCLUSION

Overall, our results highlight that family relations should not be overlooked in EHR research and illustrate ALIGATEHR's great potential for enhancing patient representation learning for predictive and interpretable modeling of EHRs.

Differences in tumor size, clinical, demographic, and socioeconomic profiles of central nervous system tumors among a racially diverse cohort: A retrospective case-control study

Background

One avenue to improve outcomes among brain tumor patients involves the mitigation of healthcare disparities. Investigating clinical differences among brain tumors across socioeconomic and demographic strata, such can aid in healthcare disparity identification and, by extension, outcome improvement.

Methods

Utilizing a racially diverse population from Hawaii, 323 cases of brain tumors (meningiomas, gliomas, schwannomas, pituitary adenomas, and metastases) were matched by age, sex, and race to 651 controls to investigate the associations between tumor type and various demographic, socioeconomic, and medical comorbidities. Tumor size at the time of diagnosis was also compared across demographic groups.

Results

At the time of diagnosis for benign meningiomas, Native Hawaiians and Pacific Islanders (NHPI; P < 0.05), Asians, and Hispanics exhibited nearly two-fold larger tumor volumes than Whites. For gliomas, NHPI similarly presented with larger tumor volumes relative to Whites (P = 0.04) and Asians (P = 0.02), while for vestibular schwannomas, NHPI had larger tumor sizes compared to Asians (P < 0.05). Benign meningiomas demonstrated greater odds of diagnosis (P < 0.05) among Native American or Alaskan Natives, patients comorbid with obesity class I, hypertension, or with a positive Alcohol Use Disorders Identification Test-Consumption (AUDIT-C). Malignant meningiomas demonstrated greater odds (P < 0.05) among patients from higher median household income and urban geography. Gliomas overall exhibited increased odds (P < 0.05) of diagnosis among Whites and reduced odds among Asians, with greater comorbidity with obesity class III; for glioblastoma specifically, there were reduced odds of asthma diagnosis. Patients with vestibular schwannomas were at increased odds (P < 0.05) of being from the highest income quartile and having a positive AUDIT-C, yet reduced odds of psychiatric disorders. Pituitary adenomas exhibited reduced odds of diagnosis among Whites, yet greater odds among NHPI, military personnel, obesity class I, and psychiatric disorders. Intracranial metastases were more common in patients with pre-obesity, asthma, a positive AUDIT-C, and living in more affluent regions. Benign meningiomas are most often presented with seizures, while malignant meningiomas have the addition of cognitive difficulty. Gliomas often present with seizures, cognitive difficulty, dizziness/nausea/vomiting (DNV), vestibular schwannomas with DNV, and metastases with seizures.

Conclusion

Brain tumors exhibit unique sociodemographic disparities and clinical comorbidities, which may have implications for diagnosis, treatment, and healthcare policy.

Oncolytic Virotherapies and Adjuvant Gut Microbiome Therapeutics to Enhance Efficacy Against Malignant Gliomas

Glioblastoma (GBM) is the most prevalent malignant brain tumor. Current standard-of-care treatments offer limited benefits for patient survival. Virotherapy is emerging as a novel strategy to use oncolytic viruses (OVs) for the treatment of GBM. These engineered and non-engineered viruses infect and lyse cancer cells, causing tumor destruction without harming healthy cells. Recent advances in genetic modifications to OVs have helped improve their targeting capabilities and introduce therapeutic genes, broadening the therapeutic window and minimizing potential side effects. The efficacy of oncolytic virotherapy can be enhanced by combining it with other treatments such as immunotherapy, chemotherapy, or radiation. Recent studies suggest that manipulating the gut microbiome to enhance immune responses helps improve the therapeutic efficacy of the OVs. This narrative review intends to explore OVs and their role against solid tumors, especially GBM while emphasizing the latest technologies used to enhance and improve its therapeutic and clinical responses.

Previously reported CCDC26 risk variant and novel germline variants in GALNT13, AR, and MYO10 associated with familial glioma in Finland

Predisposing factors underlying familial aggregation of non-syndromic gliomas are still to be uncovered. Whole-exome sequencing was performed in four Finnish families with brain tumors to identify rare predisposing variants. A total of 417 detected exome variants and 102 previously reported glioma-related variants were further genotyped in 19 Finnish families with brain tumors using targeted sequencing. Rare damaging variants in GALNT13, MYO10 and AR were identified. Two families carried either c.553C>T (R185C) or c.1214T>A (L405Q) on GALNT13. Variant c.553C>T is located on the substrate-binding site of GALNT13. AR c.2180G>T (R727L), which is located on a ligand-binding domain of AR, was detected in two families, one of which also carried a GALNT13 variant. MYO10 c.4448A>G (N1483S) was detected in two families and c.1511C>T (A504V) variant was detected in one family. Both variants are located on functional domains related to MYO10 activity in filopodia formation. In addition, affected cases in six families carried a known glioma risk variant rs55705857 in CCDC26 and low-risk glioma variants. These novel findings indicate polygenic inheritance of familial glioma in Finland and increase our understanding of the genetic contribution to familial glioma susceptibility.

Identifying brain tumor patients' subtypes based on pre-diagnostic history and clinical characteristics: a pilot hierarchical clustering and association analysis

Introduction

Central nervous system (CNS) tumors are severe health conditions with increasing incidence in the last years. Different biological, environmental and clinical factors are thought to have an important role in their epidemiology, which however remains unclear.

Objective

The aim of this pilot study was to identify CNS tumor patients' subtypes based on this information and to test associations with tumor malignancy.

Methods

90 patients with suspected diagnosis of CNS tumor were recruited by the Neurosurgery Unit of IRCCS Neuromed. Patients underwent anamnestic and clinical assessment, to ascertain known or suspected risk factors including lifestyle, socioeconomic, clinical and psychometric characteristics. We applied a hierarchical clustering analysis to these exposures to identify potential groups of patients with a similar risk pattern and tested whether these clusters associated with brain tumor malignancy.

Results

Out of 67 patients with a confirmed CNS tumor diagnosis, we identified 28 non-malignant and 39 malignant tumor cases. These subtypes showed significant differences in terms of gender (with men more frequently presenting a diagnosis of cancer; p = 6.0 ×10-3) and yearly household income (with non-malignant tumor patients more frequently earning ≥25k Euros/year; p = 3.4×10-3). Cluster analysis revealed the presence of two clusters of patients: one (N=41) with more professionally active, educated, wealthier and healthier patients, and the other one with mostly retired and less healthy men, with a higher frequency of smokers, personal history of cardiovascular disease and cancer familiarity, a mostly sedentary lifestyle and generally lower income, education and cognitive performance. The former cluster showed a protective association with the malignancy of the disease, with a 74 (14-93) % reduction in the prevalent risk of CNS malignant tumors, compared to the other cluster (p=0.026).

Discussion

These preliminary data suggest that patients' profiling through unsupervised machine learning approaches may somehow help predicting the risk of being affected by a malignant form. If confirmed by further analyses in larger independent cohorts, these findings may be useful to create potential intelligent ranking systems for treatment priority, overcoming the lack of histopathological information and molecular diagnosis of the tumor, which are typically not available until the time of surgery.

Brain Tumor Causes, Symptoms, Diagnosis and Radiotherapy Treatment

The strategy used for the treatment of given brain cancer is critical in determining the post effects and survival. An oncological diagnosis of tumor evaluates a range of parameters such as shape, size, volume, location and neurological complexity that define the symptomatic severity. The evaluation determines a suitable treatment approach chosen from a range of options such as surgery, chemotherapy, hormone therapy, radiation therapy and other targeted therapies. Often, a combination of such therapies is applied to achieve superior results. Radiotherapy serves as a better treatment strategy because of a higher survival rate. It offers the flexibility of synergy with other treatment strategies and fewer side effects on organs at risk. This review presents a radiobiological perspective in the treatment of brain tumor. The cause, symptoms, diagnosis, treatment, post-treatment effects and the framework involved in its elimination are summarized.

Genome-wide analysis of high-risk primary brain cancer pedigrees identifies PDXDC1 as a candidate brain cancer predisposition gene

BACKGROUND

There is evidence for an inherited contribution to primary brain cancer. Linkage analysis of high-risk brain cancer pedigrees has identified candidate regions of interest in which brain cancer predisposition genes are likely to reside.

METHODS

Genome-wide linkage analysis was performed in a unique set of 11 informative, extended, high-risk primary brain cancer pedigrees identified in a population genealogy database, which include from 2 to 6 sampled, related primary brain cancer cases. Access to formalin-fixed paraffin embedded tissue samples archived in a biorepository allowed analysis of extended pedigrees.

RESULTS

Individual high-risk pedigrees were singly informative for linkage at multiple regions. Suggestive evidence for linkage was observed on chromosomes 2, 3, 14, and 16. The chromosome 16 region in particular contains a promising candidate gene, pyridoxal-dependent decarboxylase domain-containing 1 (PDXDC1), with prior evidence for involvement with glioblastoma from other previously reported experimental settings, and contains the lead single nucleotide polymorphism (rs3198697) from the linkage analysis of the chromosome 16 region.

CONCLUSIONS

Pedigrees with a statistical excess of primary brain cancers have been identified in a unique genealogy resource representing the homogeneous Utah population. Genome-wide linkage analysis of these pedigrees has identified a potential candidate predisposition gene, as well as multiple candidate regions that could harbor predisposition loci, and for which further analysis is suggested.

Depression Risk Is Associated With Weakened Synchrony Between the Amygdala and Experienced Emotion

BACKGROUND

Major depressive disorder (MDD) is associated with aberrant limbic neural responses to emotional stimuli. We assessed how self-generated emotions modulate trial-by-trial limbic activity and whether this brain-emotion synchrony varies by familial MDD risk (regardless of personal MDD history) and neuroticism.

METHODS

Participants (n = 74, mean age = 34 years) were later-generation family members of depressed or nondepressed probands as part of a longitudinal cohort study. Using an emotion induction task, we examined participant-specific modulation of anatomically defined limbic neurobiology. Neuroticism, mental health, and familial parenting style were assessed, and MDD assessments were routinely collected throughout the previous longitudinal assessments of the study.

RESULTS

Participant-specific emotional arousal modulated amygdala and hippocampal activity. Lasso regression identified attenuated right amygdala arousal modulation as being relatively more associated with neuroticism (even though neuroticism was not associated with arousal ratings). Attenuated amygdala modulation and neuroticism were significantly more likely in offspring of parents with MDD. Parental MDD, but not personal history of MDD, predicted attenuated amygdala modulation.

CONCLUSIONS

Attenuated right amygdala modulation by emotional arousal was associated with neuroticism, indicating that the amygdala was less synchronous with emotional experiences in individuals higher in neuroticism. This neurophenotype was predicted by participants' parental MDD history but not by their own MDD history; that is, it was observed in unaffected and affected offspring of parents with MDD. These data suggest that weak amygdala-emotion synchrony may be a predisposing risk factor for MDD, rather than a result of the illness, and they suggest pathways by which this risk factor for depression is passed intergenerationally.

Genetic alterations in non-syndromic, familial gliomas in first degree relatives: A systematic review

OBJECTIVE

Despite numerous reports in syndromic gliomas, the underlying genetic and molecular basis of familial, non-syndromic gliomas, in first degree relatives, remains unclear. This rare cohort of patients harboring invasive primary brain tumors with poor prognosis may provide a potential substrate of understanding the complex genetic cascade triggering tumorigenesis.

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) 2015 and The Cochrane Handbook of Systematic Reviews of Interventions. PubMed/MEDLINE, Embase and CENTRAL databases were accessed with set inclusion and exclusion criteria.

RESULTS

Following returns of 6756 articles, systematic analysis resulted in 48 papers, with 18 case series, 4 linkage analysis, 3 case-control studies, 1 cohort study, and 22 case reports. A total of 164 first degree relatives of 72 families were analyzed. The most common genetic alterations associated with non-syndromic familial gliomas reported to affect chromosomes 17 (51.1 % germline and 9.3 % tumor mutations), 22 (15.6 % germline and 6 % tumor mutations) and 1 and 19 (4.4 % germline and 9.3 % tumor mutations), with the most commonly affected genes TP53 (8.5 %) and NF2 (3.7 %). Tumor suppressors or cell-cycle regulators, cell signaling and transcription regulation or methylation were the most common gene function categories.

CONCLUSION

Four specific chromosomes (17, 22, 1 and 19) and two specific genes (TP53 and NF2) appear to be most commonly involved. This appears to be the first systematic review of genetic factors underlying non-syndromic glioma clustering in families. The defined list of genetic abnormalities, linked to familial gliomas, may facilitate therapeutic targets and future treatment design.

Childhood central nervous system tumors and leukemia: Incidence and familial risk. A comparative population-based study in Utah and Norway

BACKGROUND

In this study, we aimed to evaluate incidence rates and family risk of the most common childhood cancers, tumors in the central nervous system (CNS), and leukemia among individuals from Norway and individuals with Scandinavian ancestry living in Utah.

METHODS

We used the Utah Population Database and the Norwegian National Population Register linked to Cancer registries to identify cancers in children born between 1966 and 2015 and their first-degree relatives. We calculated incidence rates and hazards ratios.

RESULTS

The overall incidence of CNS tumors increased with consecutive birth cohorts similarly in Utah and Norway (both P < 0.001). Incidence rates of leukemia were more stable and similar in both Utah and in Norway with 4.6/100 000 person-years among children (<15 years) born in the last cohort. A family history of CNS tumors was significantly associated with risk of childhood CNS tumors in Utah HR = 3.05 (95% CI 1.80-5.16) and Norway HR = 2.87 (95% CI 2.20-3.74). In Norway, children with a first-degree relative diagnosed with leukemia had high risk of leukemia (HR = 2.39, 95% CI 1.61-3.55).

CONCLUSION

Despite geographical distance and assumed large lifestyle differences, two genetically linked pediatric populations show similar incidences of CNS tumors and leukemia in the period 1966-2015. CNS tumors and leukemia aggregated in families in both countries.

Multifaceted transforming growth factor-beta (TGFβ) signalling in glioblastoma

Glioblastoma (GBM) is an aggressive and devastating primary brain cancer which responds very poorly to treatment. The average survival time of patients is only 14-15 months from diagnosis so there is a clear and unmet need for the development of novel targeted therapies to improve patient outcomes. The multifunctional cytokine TGFβ plays fundamental roles in development, adult tissue homeostasis, tissue wound repair and immune responses. Dysfunction of TGFβ signalling has been implicated in both the development and progression of many tumour types including GBM, thereby potentially providing an actionable target for its treatment. This review will examine TGFβ signalling mechanisms and their role in the development and progression of GBM. The targeting of TGFβ signalling using a variety of approaches including the TGFβ binding protein Decorin will be highlighted as attractive therapeutic strategies.

Elucidating the molecular pathogenesis of glioma: integrated germline and somatic profiling of a familial glioma case series

Background

The genomic characterization of sporadically arising gliomas has delineated molecularly and clinically distinct subclasses of disease. However, less is known about the molecular nature of gliomas that are familial in origin. We performed molecular subtyping of 163 tumor specimens from individuals with a family history of glioma and integrated germline and somatic genomic data to characterize the pathogenesis of 20 tumors in additional detail.

Methods

Immunohistochemical analyses were performed on formalin-fixed, paraffin-embedded tumor sections to determine molecular subtypes of glioma. For 20 cases, tumor DNA was exome sequenced on an Illumina HiSeq 2000 platform and copy number profiling was performed on the Illumina HumanOmniExpress BeadChip. Genotypes at glioma risk polymorphisms were determined from germline DNA profiled on the Illumina Infinium OncoArray and deleterious germline mutations were identified from germline sequencing data.

Results

All 3 molecular subtypes of sporadic glioma were represented in the overall case series, including molecular glioblastoma (n = 102), oligodendroglioma (n = 21), and astrocytoma (n = 20). Detailed profiling of 20 of these cases showed characteristic subtype-specific alterations at frequencies comparable to sporadic glioma cases. All 20 cases had alterations in genes regulating telomere length. Frequencies of common glioma risk alleles were similar to those among sporadic cases, and correlations between risk alleles and same-gene somatic mutations were not observed.

Conclusions

This study illustrates that the molecular characteristics of familial tumors profiled largely recapitulate what is known about sporadic glioma and that both germline and somatic molecular features target common core pathways involved in gliomagenesis.

Key Points

1. Familial and sporadic gliomas display highly comparable molecular landscapes. 2. Germline and somatic molecular events target common core pathways involved in gliomagenesis. 3. Carriage of germline glioma risk variants is not associated with somatic events in the same gene.

Immune factors preceding diagnosis of glioma: a Prostate Lung Colorectal Ovarian Cancer Screening Trial nested case-control study

Background

Epidemiological studies of adult glioma have identified genetic and environmental risk factors, but much remains unclear. The aim of the current study was to evaluate anthropometric, disease-related, and prediagnostic immune-related factors for relationship with glioma risk.

Methods

We conducted a nested case–control study among the intervention arm of the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial. One hundred and twenty-four glioma cases were identified and each matched to four controls. Baseline characteristics were collected at enrollment and were evaluated for association with glioma status. Serum specimens were collected at yearly intervals and were analyzed for immune-related factors including TGF-β1, TNF-α, total IgE, and allergen-specific IgE. Immune factors were evaluated at baseline in a multivariate conditional logistic regression model, along with one additional model that incorporated the latest available measurement.

Results

A family history of glioma among first-degree relatives was associated with increased glioma risk (OR = 4.41, P = .002). In multivariate modeling of immune factors at baseline, increased respiratory allergen-specific IgE was inversely associated with glioma risk (OR for allergen-specific IgE > 0.35 PAU/L: 0.59, P = .03). A logistic regression model that incorporated the latest available measurements found a similar association for allergen-specific IgE (P = .005) and showed that elevated TGF-β1 was associated with increased glioma risk (P-value for trend <.0001).

Conclusion

The results from this prospective prediagnostic study suggest that several immune-related factors are associated with glioma risk. The association observed for TGF-β1 when sampling closer to the time of diagnosis may reflect the nascent brain tumor’s feedback on immune function.

Genomic Correlates of Disease Progression and Treatment Response in Prospectively Characterized Gliomas

PURPOSE

The genomic landscape of gliomas has been characterized and now contributes to disease classification, yet the relationship between molecular profile and disease progression and treatment response remain poorly understood.Experimental Design: We integrated prospective clinical sequencing of 1,004 primary and recurrent tumors from 923 glioma patients with clinical and treatment phenotypes.

RESULTS

Thirteen percent of glioma patients harbored a pathogenic germline variant, including a subset associated with heritable genetic syndromes and variants mediating DNA repair dysfunctions (29% of the total) that were associated with somatic biallelic inactivation and mechanism-specific somatic phenotypes. In astrocytomas, genomic alterations in effectors of cell-cycle progression correlated with aggressive disease independent of IDH mutation status, arose preferentially in enhancing tumors (44% vs. 8%, P < 0.001), were associated with rapid disease progression following tumor recurrence (HR = 2.6, P = 0.02), and likely preceded the acquisition of alkylating therapy-associated somatic hypermutation. Thirty-two percent of patients harbored a potentially therapeutically actionable lesion, of whom 11% received targeted therapies. In BRAF-mutant gliomas, response to agents targeting the RAF/MEK/ERK signaling axis was influenced by the type of mutation, its clonality, and its cellular and genomic context.

CONCLUSIONS

These data reveal genomic correlates of disease progression and treatment response in diverse types of glioma and highlight the potential utility of incorporating genomic information into the clinical decision-making for patients with glioma.

Familial aggregation of early-onset cancers

This registry‐linkage study evaluates familial aggregation of cancer among relatives of a population‐based series of early‐onset (≤40 years) cancer patients in Finland. A cohort of 376,762 relatives of early‐onset cancer patients diagnosed between 1970 and 2012 in 40,538 families was identified. Familial aggregation of early‐onset breast, colorectal, brain and other central nervous system (CNS) cancer and melanoma was explored by standardized incidence ratios (SIR), stratified by relatedness. Gender‐, age‐ and period‐specific population cancer incidences were used as reference. Cumulative risks for siblings and offspring of the proband up to age ≤40 years were also estimated. Almost all early‐onset cancers were sporadic (98% or more). Among first‐degree relatives, SIR was largest in colorectal cancer (14, 95% confidence interval 9.72–18), and lowest in melanoma (1.93, 1.05–3.23). Highest relative‐specific SIRs were observed for siblings in families, where also parent had concordant cancer, 90 (43–165) for colorectal cancer and 29 (11–64) for CNS cancer. In spouses, all SIRs were at population level. Cumulative risk of colorectal cancer by age 41 was 0.98% in siblings and 0.10% in population, while in breast cancer the corresponding risks were 2.05% and 0.56%. In conclusion, early‐onset cancers are mainly sporadic. Findings support high familial aggregation in early‐onset colorectal and CNS cancers. Familial aggregation in multiplex families with CNS cancers was mainly attributed to neurofibromatosis and in colorectal cancer to FAP‐ and HNPCC‐syndromes. The pattern of familial aggregation of early‐onset breast cancer could be seen to support very early exposure to environmental factors and/or rare genetic factors.

What's new?

The tendency for certain cancer types to cluster in families generally is explained by shared environmental exposures or inherited mutations. In particular, early‐onset cancer, diagnosed between ages 0 and 40, is considered indicative of familial factors. Here, investigation of cancer risk among more than 376,760 relatives of probands, or individuals with early‐onset cancer, shows that the likelihood of early‐onset cancer affecting even just one other relative in addition to the proband is exceedingly rare. Nearly all early‐onset cancers in the study population were sporadic. Estimated cumulative risks observed for specific cancers may prove useful in the context of genetic counseling.

The contribution of the rs55705857 G allele to familial cancer risk as estimated in the Utah population database

BACKGROUND

IDH1/2 mutated glioma has been associated with a germline risk variant, the rs55705857 G allele. The Utah Population Database (UPDB), a computerized genealogy of people in Utah, is a unique resource to evaluate cancer risk in related individuals.

METHODS

One hundred and two individuals with IDH1/2 mutant or 1p/19q co-deleted glioma were genotyped and linked to the UPDB. DNA came from blood (21), tumor tissue (43), or both (38). We determined congruence between somatic and germline samples and estimated the relative risk for developing cancer to first and second-degree relatives of G and A allele carriers at rs55705857.

RESULTS

Somatic (glioma) DNA had 85.7% sensitivity (CI 57.2-98.2%) and 95.8% specificity (CI 78.9-99.89%) for germline rs55705857 G allele. Forty-one patients were linked to pedigrees in the UPDB with at least three generations of data. First-degree relatives of rs55705857 G allele carriers were at significantly increased risk for developing cancer (RR = 1.72, p = 0.045, CI 1.02-2.94), and specifically for oligodendroglioma (RR = 57.61, p = 0.017, CI 2.96-320.98) or prostate cancer (RR = 4.10, p = 0.008, CI 1.62-9.58); relatives of individuals without the G allele were not at increased risk. Second-degree relatives of G allele carriers also had significantly increased risk for developing cancer (RR = 1.50, p = 0.007, CI 1.15-2.01).

CONCLUSIONS

Tumor DNA may approximate genotype at the rs55705857 locus. We confirmed this locus confers an increased risk of all cancers and especially of oligodendroglioma. No increased cancer or brain tumor risk is seen in family members of individuals without the high-risk G allele.

Family history of cancer and the risk of childhood solid tumours: a Norwegian nationwide register-based cohort study

Background:

It is not clear if family history of cancer increases risk of cancer in children.

Methods:

We followed-up a total of 2 610 937 children born between 1960 and 2001 for cancer risk, and their parents and siblings. In this period, 2477 primary childhood solid tumours (except lymphoma) were diagnosed. The data from the Norwegian Family and Life Course Study and from the Norwegian Cancer Register were used. Classification of hereditary cancer syndromes was based on tumour histology, pedigrees and Chompret’s criteria.

Results:

An association between risk of childhood tumours and first-degree family history of early onset of solid tumours was observed for central nervous system tumours (2.3-fold), neuroblastoma (2.3-fold), retinoblastoma (6.1-fold), hepatic tumours (4.0-fold), and melanomas (8.3-fold). Elevated risk was also seen for osteosarcomas (1.5-fold) when considering first-degree family history of cancer diagnosed at any age. The risk of hepatic tumours, neuroblastomas and melanomas remained elevated even after controlling for probable hereditary cancer syndromes.

Conclusions:

The increased risk for several childhood solid site cancers among those with first-degree relatives diagnosed with solid cancer suggests that genetic or environmental factors are involved. The fact that these associations remained after controlling for hereditary cancer syndromes indicates other genetic mechanisms might be involved.

A Comparative Study of the Molecular Characteristics of Familial Gliomas and Other Cancers

BACKGROUND

Familial cancers are those that co-occur among first-degree relatives without showing Mendelian patterns of inheritance.

MATERIALS AND METHODS

In this analysis, we compare the genomic characteristics of familial and sporadic cancers, with a focus on low-grade gliomas (LGGs) using sequence and expression data from the Cancer Genome Atlas.

RESULTS

Familial cancers show similar genomic and molecular biomarker profiles to sporadic cancers, consistent with the similarity in their clinical features. There are no statistically significant differences among somatic mutation, copy number variant, or gene expression patterns between familial and sporadic cancers; methylation profiles are the only class of molecular data to show significant differences.

CONCLUSION

Familial cancers are likely driven by multiple, individually weak contributions to familiality (i.e. large numbers of alleles and/or shared environmental risks). Consequently, these risk factors tend to be obscured by stronger confounding variables such as clinical or molecular variation among cancer subtypes.

Increased Default Mode Network Connectivity in Individuals at High Familial Risk for Depression

Research into the pathophysiology of major depressive disorder (MDD) has focused largely on individuals already affected by MDD. Studies have thus been limited in their ability to disentangle effects that arise as a result of MDD from precursors of the disorder. By studying individuals at high familial risk for MDD, we aimed to identify potential biomarkers indexing risk for developing MDD, a critical step toward advancing prevention and early intervention. Using resting-state functional connectivity MRI (rs-fcMRI) and diffusion MRI (tractography), we examined connectivity within the default mode network (DMN) and between the DMN and the central executive network (CEN) in 111 individuals, aged 11-60 years, at high and low familial risk for depression. Study participants were part of a three-generation longitudinal, cohort study of familial depression. Based on rs-fcMRI, individuals at high vs low familial risk for depression showed increased DMN connectivity, as well as decreased DMN-CEN-negative connectivity. These findings remained significant after excluding individuals with a current or lifetime history of depression. Diffusion MRI measures based on tractography supported the findings of decreased DMN-CEN-negative connectivity. Path analyses indicated that decreased DMN-CEN-negative connectivity mediated a relationship between familial risk and a neuropsychological measure of impulsivity. Our findings suggest that DMN and DMN-CEN connectivity differ in those at high vs low risk for depression and thus suggest potential biomarkers for identifying individuals at risk for developing MDD.

New insights into the genetics of glioblastoma multiforme by familial exome sequencing

Glioblastoma multiforme (GBM) is the most aggressive and malignant subtype of human brain tumors. While a family clustering of GBM has long been acknowledged, relevant hereditary factors still remained elusive. Exome sequencing of families offers the option to discover respective genetic factors.We sequenced blood samples of one of the rare affected families: while both parents were healthy, both children were diagnosed with GBM. We report 85 homozygous non-synonymous single nucleotide variations (SNVs) in both siblings that were heterozygous in the parents. Beyond known key players for GBM such as ERBB2, PMS2, or CHI3L1, we identified over 50 genes that have not been associated to GBM so far. We also discovered three accumulative effects potentially adding to the tumorigenesis in the siblings: a clustering of multiple variants in single genes (e.g., PTPRB, CROCC), the aggregation of affected genes on specific molecular pathways (e.g., Focal adhesion or ECM receptor interaction) and genomic proximity (e.g., chr22.q12.2, chr1.p36.33). We found a striking accumulation of SNVs in specific genes for the daughter, who developed not only a GBM at the age of 12 years but was subsequently diagnosed with a pilocytic astrocytoma, a common acute lymphatic leukemia and a diffuse pontine glioma.The reported variants underline the relevance of genetic predisposition and cancer development in this family and demonstrate that GBM has a complex and heterogeneous genetic background. Sequencing of other affected families will help to further narrow down the driving genetic causes for this disease.

SRL-Coated PAMAM Dendrimer Nano-Carrier for Targeted Gene Delivery to the Glioma Cells and Competitive Inhibition by Lactoferrin

Glioma, as a primary tumor of central nervous system, is the main cause of death in patients with brain cancer. Therefore, development of an efficient strategy for treatment of glioma is worthy. The aim of the current study was to develop a SRL peptide-coated dendrimer as a novel dual gene delivery system for targeting the LRP receptor, an up-regulated gene in both BBB and glioma cells. To perform this investigation, our newly developed nanocarrier (PAMAM-PEG-SRL) was used for gene delivery to C6 glioma cell lines. DNA (GFP) was loaded in these functionalized nanoparticles and their cellular uptake/distribution and gene transfection efficacy was evaluated by fluorescence and confocal microscopy. In vitro studies showed that SRL-modified nanoparticles have good transfection efficacy. Results revealed improved gene transfection efficiency of newly-synthesized delivery system. We also found that lactoferrin, as a LRP ligand, reduced the gene transfection efficacy of the delivery system due to its higher affinity compared to SRL peptides (Competitive inhibition). The present results suggest that the synthesized delivery system has the potential to be used as an alternative targeted drug delivery system for brain tumors.

Discriminating risk and resilience endophenotypes from lifetime illness effects in familial major depressive disorder

IMPORTANCE

The neural systems that confer risk or vulnerability for developing familial depression, and those that protect against or confer resilience to becoming ill, can be disentangled from the effects of prior illness by comparing brain imaging measures in previously ill and never ill persons who have either a high or low familial risk for depression.

OBJECTIVE

To distinguish risk and resilience endophenotypes for major depression from the effects of prior lifetime illness.

DESIGN, SETTING, AND PARTICIPANTS

We used functional magnetic resonance imaging to measure and compare brain function during performance of an attentional, self-regulatory task across a large sample of multigenerational families ascertained specifically to be at either high or low risk for developing major depression. Study procedures were performed in a university setting. A total of 143 community participants were followed up prospectively for more than 20 years in a university setting. The sample was enriched with persons who were at higher or lower familial risk for developing depression based on being biological offspring of either a clinical sample of persons with major depression or a community control sample of persons with no discernible lifetime illness.

MAIN OUTCOMES AND MEASURES

Task-related change in blood oxygen level-dependent functional magnetic resonance imaging signal.

RESULTS

A risk endophenotype included greater activation of cortical attention circuits. A resilience endophenotype included greater activation of the dorsal anterior cingulate cortex. The effects of prior lifetime illness were common to both risk groups and included greater deactivation of default-mode circuits.

CONCLUSIONS AND RELEVANCE

These findings identify neural systems that increase risk for depression, those that protect from illness, and those that endure following illness onset, and they suggest circuits to target for developing novel preventive and therapeutic interventions.

High incidence of benign brain meningiomas among Iranian- born Jews in Israel may be linked to both hereditary and environmental factors

BACKGROUND

Following research demonstrating an increased risk for meningiomas in the Jewish population of Shiraz (Iran) we conducted a cohort analysis of meningiomas among Jews originating in Iran and residing in Israel.

MATERIALS AND METHODS

We use the population-based registry data of the Israeli National Cancer Registry (INCR) for the main analysis. All benign meningioma cases diagnosed in Israel from January 2000 to the end of 2009 were included. Patients that were born in Iran, Iraq, Turkey, Bulgaria and Greece were used for the analysis, whereby we calculated adjusted incidence rates per 100,000 people and computed standardized incidence ratios (SIRs) comparing the Iranian-born to each of the three other groups.

RESULTS

Iranian-born Jews had statistically significant higher meningioma rates rates compared to other Jews originating in Balkan states: 1.46 fold compared to Turkish Jews and 1.86 fold compared to the Bulgaria-Greece group. There was a small increase in risk for the Iranian born group compared to those who were born in Iraq (1.06, not significant).

CONCLUSIONS

Higher rates of meningiomas were seen in Jews originating in Iran that are living in Israel as compared to rates in neighboring countries of origin. These differences can be in part attributed to early life environmental exposures in Iran but probably in larger amount are due to genetic and hereditary factors in a closed community like the Iranian Jews. Some support for this conclusion was also found in other published research.

Nationwide registry-based analysis of cancer clustering detects strong familial occurrence of Kaposi sarcoma

Many cancer predisposition syndromes are rare or have incomplete penetrance, and traditional epidemiological tools are not well suited for their detection. Here we have used an approach that employs the entire population based data in the Finnish Cancer Registry (FCR) for analyzing familial aggregation of all types of cancer, in order to find evidence for previously unrecognized cancer susceptibility conditions. We performed a systematic clustering of 878,593 patients in FCR based on family name at birth, municipality of birth, and tumor type, diagnosed between years 1952 and 2011. We also estimated the familial occurrence of the tumor types using cluster score that reflects the proportion of patients belonging to the most significant clusters compared to all patients in Finland. The clustering effort identified 25,910 birth name-municipality based clusters representing 183 different tumor types characterized by topography and morphology. We produced information about familial occurrence of hundreds of tumor types, and many of the tumor types with high cluster score represented known cancer syndromes. Unexpectedly, Kaposi sarcoma (KS) also produced a very high score (cluster score 1.91, p-value <0.0001). We verified from population records that many of the KS patients forming the clusters were indeed close relatives, and identified one family with five affected individuals in two generations and several families with two first degree relatives. Our approach is unique in enabling systematic examination of a national epidemiological database to derive evidence of aberrant familial aggregation of all tumor types, both common and rare. It allowed effortless identification of families displaying features of both known as well as potentially novel cancer predisposition conditions, including striking familial aggregation of KS. Further work with high-throughput methods should elucidate the molecular basis of the potentially novel predisposition conditions found in this study.

A comprehensive survey of cancer risks in extended families

PURPOSE

Cancer is familial; yet known cancer predisposition genes, as well as recognized environmental factors, explain only a small percentage of familial cancer clusters. This population-based description of cancer clustering describes patterns of cancer coaggregation suggestive of a genetic predisposition.

METHODS

Using a computerized genealogy of Utah families linked to a statewide cancer registry, we estimated the relative risks for 36 different cancer sites in first-, second-, and third-degree relatives of cancer cases, for each cancer site individually, and between cancer sites. We estimated the sex- and birth-year-specific rates for cancer using 1 million individuals in the resource. We applied these rates to groups of cases or relatives and compared the observed and expected numbers of cancers to estimate relative risks.

RESULTS

Many cancer sites show significantly elevated relative risks among distant relatives for cancer of the same site, strongly supporting a heritable contribution. Multiple combinations of cancer sites were observed among first-, second-, and third-degree relatives, suggesting the existence of heritable syndromes involving more than one cancer site.

CONCLUSION

This complete description of coaggregation of cancer by site in a well-defined population provides a set of observations supporting heritable cancer predispositions and may support the existence of genetic factors for many different cancers.

Significant evidence for a heritable contribution to cancer predisposition: a review of cancer familiality by site

BACKGROUND/AIMS

Sound and rigorous well-established, and newly extended, methods for genetic epidemiological analysis were used to analyze population evidence for genetic contributions to risk for numerous common cancer sites in Utah. The Utah Population Database (UPDB) has provided important illumination of the familial contribution to cancer risk by cancer site.

METHODS

With over 15 years of new cancer data since the previous comprehensive familial cancer analysis, we tested for excess familial clustering using an expanded Genealogical Index of Familiality (dGIF) methodology that provides for a more informative, but conservative test for the existence of a genetic contribution to familial relatedness in cancer.

RESULTS

Some new cancer sites have been analyzed for the first time, having achieved sufficiently large sample size with additions to the UPDB. This new analysis has identified 6 cancer sites with significant evidence for a heritable contribution to risk, including lip, chronic lymphocytic leukemia, thyroid, lung, prostate, and melanoma.

CONCLUSIONS

Both environmentally and genetically-based familial clustering have clinical significance, and these results support increased surveillance for cancer of the same sites among close relatives of affected individuals for many more cancers than are typically considered.

Familial glioblastoma: A case report of glioblastoma in two brothers and review of literature

Background:

Gliomas that aggregate in families with history of malignancy may have an inheritable genetic basis. Gliomas can occur in several well known tumor syndromes. However, their occurrence in the absence of these syndromes is quite rare. High-grade gliomas, such as glioblastoma multiforme (GBM), are the most common and most lethal primary cancers of the central nervous system (CNS).

Case Description:

We present a case of two brothers both diagnosed with GBM. Both siblings underwent biopsy with debulking of the tumors by different surgeons. Only one sibling elected to undergo chemotherapy and radiation. Cytogenetic studies were possible only on one sibling and the tumor specimen revealed multiple chromosomal abnormalities, including triploidies 4, 8, 12, 22 and loss of heterozygosity of 1p, 9p, and 10. Histological samples for both tumors were similar, both revealing increased cellularity consisting of gemistocytic astrocytes, central necrosis, and microvascularization.

Conclusion:

We present two brothers who display a rare familial relationship in the development of their GBMs. Supplementary and improved genetic studies may allow for specific treatment modalities as certain genetic abnormalities have better response to tailored treatments and carry better prognoses.

Downregulation of CDKN2A and suppression of cyclin D1 gene expressions in malignant gliomas

Background

Malignant gliomas are the most common in central nervous system cancer. Genome-wide association study identifies that CDKN2A was a susceptibility loci for glioma. The CDKN2A/cyclin-dependent kinase 4, 6/Retinoblastoma protein (Rb) pathway is thought to play a crucial role in malignant gliomas pathogenesis. We have investigated the expression of CDKN2A for potential correlations with malignant gliomas grade and potential role of CDKN2A on malignant gliomas pathogenesis.

Methods

Tumour tissue samples from 61 patients suffering from malignant gliomas were investigated. The expression levels of CDKN2A were detected using immunohistochemical staining and western blot. Overexpression and knockdown of CDKN2A were performed in human glioma cell lines. Subsequently, colony formation, growth curves and CDKN2A-Cyclin-Rb pathway were analyzed.

Results

Here we show that a lower expression of CDKN2A and a higher expression of cyclin D1 in the patients with high-grade malignant gliomas than low-grade gliomas, respectively. Moreover, overexpression of CDKN2A inhibits growth of glioma cell lines by suppression of cyclin D1 gene expression.

Conclusions

Our study suggests that CDKN2A as a malignant gliomas suppressor gene, appears to be useful for predicting behaviour of high-grade malignant gliomas. CDKN2A-Cyclin-Rb pathway plays a key role on malignant gliomas formation and that therapeutic targeting of this pathway may be useful in malignant gliomas treatment.

Association study of xenobiotic detoxication and repair genes with malignant brain tumors in children

This study presents the results of research on DNA polymorphism in children with malignant brain tumors (172 patients, 183 in the control group). Genotyping was performed using an allele-specific tetraprimer reaction for the genes of the first (CYP1A1 (2 sites)) and second phases of xenobiotic detoxication (GSTM1, GSTT1, GSTP1, GSTM3), DNA repair genesXRCC1, XPD(2 sites),OGG1, as well asNOS1andMTHFR.The increased risk of disease is associated with a minor variant ofCYP1A1(606G) (p = 0.009; OR = 1.50) and a deletion variant ofGSTT1, (p = 0.013, OR = 1.96). Maximum disease risk was observed in carriers of double deletions inGSTT1-GSTM1(p = 0.017, OR = 2.42). The obtained results are discussed in reference to literary data on the risk of malignant brain tumor formation in children and adults.

Familial risks in nervous system tumours: joint Nordic study

Background:

Familial nervous system cancers are rare and limited data on familial aspects are available particularly on site-specific tumours.

Methods:

Data from five Nordic countries were used to analyse familial risks of nervous system tumours. Standardised incidence ratios (SIRs) were calculated for offspring of affected relatives compared with offspring of non-affected relatives.

Results:

The total number of patients with nervous system tumour was 63 307, of whom 32 347 belonged to the offspring generation. Of 851 familial patients (2.6%) in the offspring generation, 42 (4.7%) belonged to the families of a parent and at least two siblings affected. The SIR of brain tumours was 1.7 in offspring of affected parents; it was 2.0 in siblings and 9.4 in families with a parent and sibling affected. For spinal tumours, the SIRs were much higher for offspring of early onset tumours, 14.0 for offspring of affected parents and 22.7 for siblings. The SIRs for peripheral nerve tumours were 16.3 in offspring of affected parents, 27.7 in siblings and 943.9 in multiplex families.

Conclusion:

The results of this population-based study on medically diagnosed tumours show site-, proband- and age-specific risks for familial tumours, with implications for clinical genetic counselling and identification of the underlying genes.

Inherited predisposition to glioma

In gliomas, germline gene alterations play a significant role during malignant transformation of progenitor glial cells, at least for families with occurrence of multiple cancers or with specific hereditary cancer syndromes. Scientific evidence during the last few years has revealed several constitutive genetic abnormalities that may influence glioma formation. These germline abnormalities are manifested as either gene polymorphisms or hemizygous mutations of key regulatory genes that are involved either in DNA repair or in apoptosis. Such changes, among others, include hemizygous alterations of the neurofibromatosis 1 (NF1) and p53 genes that are involved in apoptotic pathways, and alterations in multiple DNA repair genes such as mismatch repair (MMR) genes, x-ray cross-complementary genes (XRCC), and O6-methylguanine-DNA methyltransferase (MGMT) genes. Subsequent cellular changes include somatic mutations in cell cycle regulatory genes and genes involved in angiogenesis and invasion, leading eventually to tumor formation in various stages. Future molecular diagnosis may identify new genomic regions that could harbor genes important for glioma predisposition and aid in the early diagnosis of these patients and genetic counseling of their families.

Advances in the genetics of glioblastoma: are we reaching critical mass?

Glioblastoma is the most common and highest-grade brain tumor, causing over 10,000 deaths each year in the US alone. Given the resistance of this tumor to standard surgery, radiation and chemotherapy, an understanding of the underlying genetic lesions is vital. Recent efforts to comprehensively profile glioblastomas using the latest technologies, both by The Cancer Genome Atlas (TCGA) project and by other groups, are addressing this need. Some genetic aberrations in glioblastoma have been known for decades, but early output from the new profiling initiatives has further illuminated the relevant genetics in this disease. Some genetic lesions, such as TP53 mutation, NF1 deletion or mutation, and ERBB2 amplification, have been found to be more common than was previously reported. New and unexpected discoveries have also been made, such as frequent mutations of the IDH1 and IDH2 genes in secondary glioblastoma. We might be tempted to speculate that we are approaching a comprehensive knowledge of the genetic lesions involved in glioblastoma, although other major discoveries doubtless remain to be made. In addition, the complex task of incorporating our updated knowledge into new--and possibly personalized--therapies for patients with glioblastoma still lies ahead.

Familial risks in nervous-system tumours: a histology-specific analysis from Sweden and Norway

BACKGROUND

There are limited data available on tumour subtype-specific familial risks for nervous-system tumours. We aimed to provide such data at the population level.

METHODS

We used data from the nationwide Swedish and Norwegian databases on familial cancer to calculate standardised incidence ratios (SIRs) for the familial risk of developing a nervous-system tumour in offspring born after 1931 (Sweden) or 1900 (Norway) whose parents or siblings were probands.

FINDINGS

54 195 patients had nervous-system tumours, 22 331 of whom belonged to the offspring generation aged 0-72 years in Sweden and 0-51 years in Norway. Of 709 familial patients in the offspring generation, 438 (61.8%) had a parent affected by a nervous-system tumour (SIR 1.66; 95% CI 1.51-1.82), 236 (33.3%) had a sibling affected by a nervous-system tumour (SIR 2.01; 95% CI 1.76-2.28), and 35 (4.9%) belonged to families with a parent and at least two siblings affected by a nervous-system tumour (multiplex families; SIR 13.40; 95% CI 9.33-18.66). The SIR for glioma was 1.8 (1.5-2.0) when a parent was a proband, but increased to 11.2 (5.7-19.5) in multiplex families. Early-onset neurinoma and haemangioma showed high familial risks; with an SIR for neurinoma of 1.7 (1.4-2.2) for offspring of affected parents, 2.7 (2.0-3.5) for siblings, and 27.2 (13.5-48.8) for multiplex families, and an SIR for haemangioma of 2.4 (1.4-3.8) for offspring of affected parents. Histology-specific population-based familial risks were shown for meningioma (1.6 for offspring of affected parents; 95% CI 1.3-2.0), ependymoma (2.7 for young offspring <20 years; 1.1-5.5), medulloblastoma (4.1 for siblings; 1.7-8.1), and neuroblastoma (3.2 for siblings; 1.1-6.9).

INTERPRETATION

Our results suggest a complex genetic background for nervous-system tumours, which differs depending on the age of onset and histological subtype of the tumour. High sibling risks might suggest recessive inheritance. As the high-penetrant multiplex families only accounted for about 5% of familial nervous-system tumours, most familial cases are probably caused by low-penetrance genes.

FUNDING

The Nordic Cancer Union, Deutsche Krebshilfe, the Swedish Cancer Society, and the Swedish Council for Working Life and Social Research.