Familial brain tumors: studies of two families and review of recent literature

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.

Familial brainstem glioma

Two young males with a high degree of consanguinity presented with similar brainstem gliomas. As the patients were raised separately, their presentation with similar tumors suggests a genetic basis for the occurrence of these gliomas.

Exophytic malignant brainstem mixed glioma in an adult: a case report

Anaplastic mixed gliomas are rare tumors that occur mostly in the cerebral hemispheres. They have a distinctive histological appearance characterized by the presence of two or more glial cellular constituents. The incidence of malignant mixed glioma of the brainstem and posterior fossa is extremely low. The authors report an unusual case of an exophytic malignant mixed glioma. Following subtotal resection, the patient received conventional radiotherapy, but continued to deteriorate, and died five months after surgery. The extensive literature review focuses on histopathology, clinical features, natural history, and possible treatment modalities of this unusual neoplasm.

Familial glioblastoma

The authors describe a family with three members affected by glioblastoma. The proband patient, a 7 year-old girl, developed a rare complication, a pulmonary metastasis. Chromosomal analysis of her peripheral blood lymphocytes showed a normal karyotype (46, XX), without structural abnormalities. Cytogenetic study of the tumor cells disclosed several abnormalities: 46, XX, 7q-/46, XX, -2, 4p-, 7p-, +15/46, XX. Some aspects about genetics of glial neoplasms are discussed.

Glioblastoma multiforme in four siblings: a cytogenetic and molecular genetic study

The familial occurrence of gliomas, in the absence of well-defined neurological tumor syndromes such as the neurofibromatoses, is uncommon. We present a family of ten children in which the four eldest suffered from gliomas. Three of these siblings had histologically verified glioblastoma multiforme, and one patient also had an intestinal non-Hodgkin's lymphoma, but there were no stigmata or family history of a neurological tumor syndrome. Cytogenetic studies of the proband revealed a normal karyotype. Molecular genetic analysis of the proband's glioblastoma revealed two mutations in the p53 tumor suppressor gene, but these were not present in the germline DNA, mutations were not detected in the MTS1 gene in the tumors or in the germline DNA. These findings suggest that a genetic factor may be responsible for the clustering of glial tumors in this family, but it is unlikely that the genetic alteration is mutation of the p53 gene. The data are discussed in light of the literature on familial brain tumors.

The risk of cancer in relatives of patients with brain neoplasm

The family trees of 142 patients, suffering from histologically proven brain tumour, were compared to those of an equal number of sex and age matched controls. The results showed no statistically significant differences in the occurrence of malignant neoplasm between the two groups. These results indicate that the risk of cancer among relatives of patients with brain tumours does not exceed that of healthy controls.

Familial occurrence of polymorphous oligodendroglioma

A case of familial polymorphous oligodendroglioma, occurring in a brother and sister, is presented. Polymorphous oligodendrogliomas have a characteristic histopathology consisting of scattered multinucleated giant cells against a typical oligodendroglial background. The oligodendroglial character of the tumors was underlined by positive immunostaining for antigalactocerebroside, anticarbonic anhydrase, and anti-leu-7, without expression of glial fibrillary acidic protein. Both tumors were immunopositive for p53, suggesting a mutation in the p53 gene. No incidence of cancer was recorded in the family. This is the first report of familial occurrence of this particular subtype of oligodendroglioma.

Simultaneous presentation of symptomatic subependymomas in siblings: case reports and review

Two young adult siblings independently developed similar neurological complaints that included headaches, photophobia, nausea, and intermittent lancinating facial pains. Magnetic resonance imaging revealed fourth ventricular lesions that required surgery in both patients. A pathological review revealed subependymomas with virtually identical histological features. The clinical features and common pathological findings of both patients suggest that familial subependymomas may have a maldevelopmental origin with genetic implications.

Familial CNS tumors

A family with central nervous system tumors in five individuals in two generations is reported. Of five sisters, two had an isolated meningioma and one an ependymoma. Amongst the four children of those affected there was a son with two cerebral meningiomas and a daughter with a spinal meningioma. Signs typical of von Recklinghausen neurofibromatosis (NF1) or bilateral acoustic neurofibromatosis (NF2) were not present. The pattern is consistent with autosomal dominant inheritance with relatively high penetrance.

Familial cancer syndromes and clusters

Familial aggregation has been reported for virtually every form of cancer in humans. In general, close relatives of a cancer patient appear to have a twofold to threefold increase in risk for that tumor. Among cancer families, however, the level of excess risk is heterogeneous and ranges up to 1000-fold. Familial clusters of cancer are often due to inherited susceptibility, but environmental influences and chance association also must be considered. The effect of chance is large, due to the 50% lifetime risk of developing cancer that is present in the general U.S. population. Thus, a family history of cancer is the rule rather than the exception, and special studies are needed to distinguish predisposition from chance. An inherited susceptibility to cancer often becomes apparent through the occurrence of the same neoplasm among multiple blood relatives. These neoplasms tend to occur at earlier ages than usual, to appear bilaterally in paired organs, and to develop in multiple primary foci within the predisposed organ. Hereditary cancers can also develop as multiple primary tumors in organs that share the same embryological origins, as in the multiple endocrine neoplasia (MEN) syndromes. In addition, neoplasia occurs as a feature of diverse inherited diseases, such as neurofibromatosis types 1 and 2, which predispose to tumors of the peripheral nerves and brain. Recent advances in molecular biology have greatly enhanced the importance of studying cancer families. Newly developed molecular probes have been applied to map the loci of several human cancer genes. The studies have also revealed a new class of human oncogenes, the tumor suppressor genes. These genes normally function by suppressing the tumor phenotype. When inactivated or deleted in germinal cells, they can be transmitted to subsequent generations and predispose to cancer among carriers in the family. At the molecular level, these carriers have inherited a structural abnormality in one allele of a recessive oncogene, and loss of the second allele at the locus results in tumor development. The first tumor suppressor that has been isolated is the retinoblastoma gene on chromosome 13q14. Studies indicate that this gene is involved in the development of many more human cancers than had been appreciated previously on the basis of clinical observations. Presently, the identification of cancer families can be applied to genetic counseling, the in-utero diagnosis of carriers, and early disease detection. In familial cancers that are triggered by environmental carcinogens, patient education regarding the avoidance of harmful exposures can help prevent or delay the onset of neoplasia.

Potential risk factors for brain tumors in children. An analysis of 200 cases

Two hundred cases of verified brain tumors occurring in patients under 15 years of age were studied in relation to possible etiologic, genetic, and environmental risk factors. They were compared with 100 age-matched patients harboring solid neoplasms outside the nervous system, as well as with 100 normal children. In our study, first-degree relatives of a brain tumor child did not show a higher incidence of either tumors or of epilepsy and strokes as compared with controls. First-born children (46%) with higher birth weights showed a greater tendency to present brain tumors. Dystocia (18.5%), previous miscarriages (18%), and dietary restrictions during pregnancy (3%) were also noted in this study and compared with data in the literature. No evidence of a role of maternal chickenpox and toxoplasmosis could be found. The pharmacological risk also seemed to be minimal. The mother's hormonal profile is deduced from the age at menarche and delivery, as well as from a tendency to miscarriages and complicated pregnancies. With regard to the immunologic aspect, it is worth noting that 15% of the mothers complained of allergies. Live polio vaccine and zoonosis might suggest a possible role of virus-related factors in the oncogenesis of brain tumors in children. Radiation-related risk is possibly present in less than 5% of cases. Parental occupation is not relevant in this series.

Supratentorial astrocytic tumours of childhood: a clinicopathologic study of 41 cases

Forty-one patients with ages from 0 to 16 years harbouring supratentorial astrocytic tumours were treated between 1964 and 1986. Twenty-four of them were located in the cerebral hemisphere or in the ventricle, and 17 were in the basal ganglia, thalamus, and/or optico-hypothalamic region. There were nine glioblastomas multiforme, four anaplastic astrocytomas, 11 fibrillary astrocytomas, 12 pilocytic astrocytomas, two pleomorphic xanthoastrocytomas, two subependymal giant cell astrocytomas and one primitive astrocytic tumour. Low grade tumours tended to occur in young subjects near the midline, and high grade one in older patients in the hemisphere. Initial treatment in most the patients was a resection or biopsy followed by radiation therapy. Eleven patients were retreated for their recurrent tumours with combinations of surgical removal of the tumour, radiotherapy, and/or chemotherapy. After a follow-up of 3 months to 17 years, 51% of the patients survived with a median survival of 7 years. Outcome of the patients with supratentorial astrocytomas correlated mostly with the histological grade of malignancy of the tumour, and to a lesser degree with the tumour location. The biological behavior and treatment of supratentorial astrocytomas in childhood are discussed.

Supratentorial malignant gliomas in childhood: a review of fifty cases

From 1977 to 1986, 50 children aged 15 months to 18 years were treated for supratentorial malignant gliomas at the Memorial Sloan-Kettering Cancer Center and the New York University Medical Center. Thirteen patients had glioblastoma multiforme, 29 had anaplastic astrocytomas, and 8 had malignant gliomas. In 10 patients the tumor evolved from a low-grade lesion. Seven patients, including 2 patients with neurofibromatosis, developed multiple primary malignant neoplasms. The median time to tumor progression after surgery was 31 weeks, with local recurrence representing the mode of treatment failure in nearly all patients. Notable clinical features included symptomatic leptomeningeal metastasis (13 patients) and intratumoral hemorrhage (9 patients). The estimated median survival time for all 50 patients was 98 weeks, with a 3-year survival rate of 32%. A trend toward longer survival was seen in patients 12 years of age or younger at diagnosis. There was no apparent correlation between survival and tumor histology or tumor location. Recommendations for management are presented.

Familial glioma: occurrence within the "familial cancer syndrome" and systemic malformations

The family pedigree across eight generations is presented with an association of osteochondrodysplasia, other skeletal abnormalities, familial glial tumours in a father and his son, colonic and other adenomatous disease, and pigment changes. This family cluster of diseases is considered to be a dysontogenetic process with blastomatous features and grouped within the phakomastoses. A review of the literature indicates that some "familial gliomas" show additional malformations, thus resembling phakomatoses. Others are found to be members within a "familial cancer syndrome". A trait of "hereditary glioma" apart from these syndromes is difficult to identify, especially if only sibships are considered which are likely to share common environmental factors.

Familial subependymomas

A family of eleven siblings is presented, five of whom developed a brain tumour. Three siblings had a subependymoma, one had an ependymoma and in one case the tumour was unverified histologically. The significance of familial brain tumours is discussed.

Synchronous occurrence of glioblastoma multiforme in a husband and wife

Glioblastomas developed within two years of each other in an otherwise unrelated married couple in their fifties. There was a daughter who died of Hodgkin's disease but no other unusual incidence of cancer in either siblings, parents or other children. No clear etiology of risk factors for brain tumor were identified. The development of such conjugal tumors, although apparently rare, raises important etiologic questions.

Occurrence of glioblastoma multiforme in three closely related patients

Three cases of glioblastoma multiforme are presented. These cases have in common the fact that all three patients were relatives but not blood relatives. There had been prolonged intimate contact between them before the development of the neoplastic lesion.

Familial glioblastoma multiforme without neurofibromatosis

Glioblastoma multiforme is a rapidly growing anaplastic primary tumor of the central nervous system. It is frequently associated with neurofibromatosis or other hamartomatous syndromes, and in such kindreds may be found in several generations. We describe a highly inbred family in which glioblastoma multiforme presents in males only as an isolated central nervous system neoplasm on the right side, without evidence of other underlying genetic disease. It is speculated that in this family the tumor develops as the consequence of an autosomal recessive or an X-linked recessive mutation. In addition, the gene for cystic fibrosis segregates in this family and an undefined autosomal recessive malformation syndrome was detected.

Concomitant conjugal gliomas with similar histologic features

Conjugal tumors are rarely reported; but nevertheless, raise important questions of possible etiologic factors. In this report, the presentation of grade 2 gemistocytic astrocytomas in an unrelated married couple in their early thirties within 18 months of each other is described. In both cases the left frontal region of the brain was involved and histologically the tumors were very similar. Although there are no accurate figures on the true incidence of gliomas, an estimate can be derived from reliable epidemiologic studies of primary brain tumors as a whole. Using such data, it is calculated that the risk of two designated persons developing a grade 1 to 2 astrocytoma while in the fourth decade within the same year is approximately 1 in 30 billion (10(9)) and, for this couple, over a period of 15 years, at least 1 in 185 million. No specific causative environmental factors were identified in the patients, and results of conventional tests for viral and other infections were negative. It is postulated that apart from remote chance, such conjugal lesions implicate the action of an environmental agent. In the absence of other factors, involvement of a slow, unconventional virus is a possibility that must be strongly considered.

Familial oligodendroglioma. Case report

A case of familial oligodendroglioma, occurring in a mother and her daughter, is presented.