A very rare cancer in Down syndrome: medulloblastoma. Epidemiological data from 13 countries

Primary Central Nervous System Lymphoma in a Patient with Down Syndrome

Intracranial tumors are rare in persons with Down syndrome. Although germ cell tumors and gliomas have been reported in Down syndrome, primary central nervous system lymphoma (PCNSL) has not. We report a case of PCNSL in a 48-year-old man with Down syndrome and no history of malignant tumors. He visited our hospital for evaluation of left hemiparesis and gait disturbance. A thorough examination revealed brain tumors, and analysis of a biopsy specimen of the tumor confirmed a diagnosis of PCNSL. The final pathological diagnosis was diffuse large B-cell lymphoma of the central nervous system. Chemotherapy with rituximab, methotrexate, procarbazine, and vincristine was administered, and whole-brain irradiation was planned in conjunction with chemotherapy. It is unclear whether chromosomal abnormalities related to Down syndrome were involved in the development of PCNSL. Further molecular biological analysis may clarify the mechanism of combined Down syndrome and PCNSL.

Medulloblastoma and Down Syndrome: An Extremely Rare Association

Medulloblastoma has a reduced incidence in Down syndrome (DS). This protective characteristic has not been clarified yet. Here, we report the second case of SHH medulloblastoma and DS documented in the literature. A complete surgery was performed followed by reduced craniospinal irradiation dose and adjuvant chemotherapy. No evidence of tumor recurrence was observed. The overall survival was 9.1 years. No family history or physical stigma of other hereditary predisposition syndrome was found. In the elucidation of this extremely rare association, future case reports play an important role in defining the spectrum of brain tumors and their peculiar features in DS.

Ten Reasons Why People With Down Syndrome are Protected From the Development of Most Solid Tumors -A Review

People with Down syndrome have unique characteristics as a result of the presence of an extra chromosome 21. Regarding cancer, they present a unique pattern of tumors, which has not been fully explained to date. Globally, people with Down syndrome have a similar lifetime risk of developing cancer compared to the general population. However, they have a very increased risk of developing certain tumors (e.g., acute leukemia, germ cell tumors, testicular tumors and retinoblastoma) and, on the contrary, there are some other tumors which appear only exceptionally in this syndrome (e.g., breast cancer, prostate cancer, medulloblastoma, neuroblastoma and Wilms tumor). Various hypotheses have been developed to explain this situation. The genetic imbalance secondary to the presence of an extra chromosome 21 has molecular consequences at several levels, not only in chromosome 21 but also throughout the genome. In this review, we discuss the different proposed mechanisms that protect individuals with trisomy 21 from developing solid tumors: genetic dosage effect, tumor suppressor genes overexpression, disturbed metabolism, impaired neurogenesis and angiogenesis, increased apoptosis, immune system dysregulation, epigenetic aberrations and the effect of different microRNAs, among others. More research into the molecular pathways involved in this unique pattern of malignancies is still needed.

Medulloblastoma Associated with Down Syndrome: From a Rare Event Leading to a Pathogenic Hypothesis

Down syndrome (DS) is the most common chromosome abnormality with a unique cancer predisposition syndrome pattern: a higher risk to develop acute leukemia and a lower incidence of solid tumors. In particular, brain tumors are rarely reported in the DS population, and biological behavior and natural history are not well described and identified. We report a case of a 10-year-old child with DS who presented with a medulloblastoma (MB). Histological examination revealed a classic MB with focal anaplasia and the molecular profile showed the presence of a CTNNB1 variant associated with the wingless (WNT) molecular subgroup with a good prognosis in contrast to our case report that has shown an early metastatic relapse. The nearly seven-fold decreased risk of MB in children with DS suggests the presence of protective biological mechanisms. The cerebellum hypoplasia and the reduced volume of cerebellar granule neuron progenitor cells seem to be a possible favorable condition to prevent MB development via inhibition of neuroectodermal differentiation. Moreover, the NOTCH/WNT dysregulation in DS, which is probably associated with an increased risk of leukemia, suggests a pivotal role of this pathway alteration in the pathogenesis of MB; therefore, this condition should be further investigated in future studies by molecular characterizations.

RELA Fusion-Positive Ependymoma in a Child with Down Syndrome: A Case Report

INTRODUCTION

Down syndrome (DS) is the most common multiple malformation syndrome in humans and is associated with an increased risk of childhood malignancy, particularly leukemia. Incidence of brain tumors in patients with DS is limited to sporadic cases. We report the first case of a RELA fusion-positive ependymoma in a 3-year-old boy with DS.

CASE PRESENTATION

Imaging prompted by new left-sided hemiparesis demonstrated an 8-cm hemorrhagic right temporal-parietal mass. Subsequent image-complete resection confirmed a RELA fusion-positive anaplastic ependymoma with 90% OLIG2 staining. Postoperatively, the patient, unfortunately, experienced fatal recurrence and drop metastases with leptomeningeal involvement.

CONCLUSION

To our knowledge, this is the first reported case of a confirmed RELA fusion-positive ependymoma in a child with DS. We discuss this finding in the context of intracranial tumors in children with DS, as well as the finding of 90% positive OLIG2 expression and its potential as a prognostic marker.

Vemurafenib Treatment of Pleomorphic Xanthoastrocytoma in a Child With Down Syndrome

Brain tumors are the most common solid neoplasms of childhood, but they are very rarely reported in children with Down Syndrome (DS), who develop more commonly different types of malignancies. In particular, we hereby report the case of an 8-years-old child with DS that presented to our attention for neurological and endocrinological issues. Brain imaging revealed the presence of a mass that was partially resected revealing a histological diagnosis of Pleomorphic Xanthoastrocytoma (PXA), a rare WHO grade II tumor extending from the diencephalic region into the surrounding brain tissue. These tumors can harbor the BRAF mutation p.V600E, targetable by the specific inhibitor Vemurafenib. After confirming the presence of the mutation in the tumor, the patient was treated with Vemurafenib. The treatment proved to be effective, leading to a partial response and a stabilization of the disease. Usually, in patients with DS a reduction of the dose of chemotherapeutic drugs is necessary. Vemurafenib was instead well-tolerated as the only observed adverse effect was grade I skin toxicity. This is, to our knowledge, the first case of a PXA reported in a child with DS and the first DS patient treated with Vemurafenib.

The Pattern of Malignancies in Down Syndrome and Its Potential Context With the Immune System

The immune surveillance theory of cancer posits that the body's immune system detects and destroys randomly occurring malignant cells. This theory is based on the observation of the increased frequency of malignancies in primary and secondary immunodeficiencies, and is supported by the successful demonstration of immune augmentation in current oncological immune therapy approaches. We review this model in the context of Down syndrome (DS), a condition with a unique tumor profile and various immune defects. Children and adults with DS are more prone to infections due to anatomical reasons and a varying degree of T- and B-cell maturation defects, NK cell dysfunction, and chemotactic or phagocytic abnormalities. However, despite an increased incidence of lymphoblastic and myeloblastic leukemia of infants and children with DS, individuals with DS have a globally decreased incidence of solid tumors as compared to age-adjusted non-DS controls. Additionally, cancers that have been considered “proof of immune therapy principles,” such as renal carcinoma, small cell lung carcinoma, and malignant melanoma, are less frequent in adults with DS compared to the general population. Thus, despite the combination of an increased risk of leukemia with detectable immune biological abnormalities and a clinical immunodeficiency, people with DS appear to be protected against many cancers. This observation does not support the immune surveillance theory in the context of DS and indicates a potential tumor-suppressive role for trisomy 21 in non-hematological malignancies.

Trisomy 21 Represses Cilia Formation and Function

Trisomy 21 (T21) is the most prevalent human chromosomal disorder, causing a range of cardiovascular, musculoskeletal, and neurological abnormalities. However, the cellular processes disrupted by T21 are poorly understood. Consistent with the clinical overlap between T21 and ciliopathies, we discovered that T21 disrupts cilia formation and signaling. Cilia defects arise from increased expression of Pericentrin, a centrosome scaffold and trafficking protein encoded on chromosome 21. Elevated Pericentrin is necessary and sufficient for T21 cilia defects. Pericentrin accumulates at centrosomes and dramatically in the cytoplasm surrounding centrosomes. Centrosome Pericentrin recruits more γ-tubulin and enhances microtubules, whereas cytoplasmic Pericentrin assembles into large foci that do not efficiently traffic. Moreover, the Pericentrin-associated cilia assembly factor IFT20 and the ciliary signaling molecule Smoothened do not efficiently traffic to centrosomes and cilia. Thus, increased centrosome protein dosage produces ciliopathy-like outcomes in T21 cells by decreasing trafficking between the cytoplasm, centrosomes, and cilia.

Childhood cancer research in Oxford II: The Childhood Cancer Research Group

BACKGROUND

We summarise the work of the Childhood Cancer Research Group, particularly in relation to the UK National Registry of Childhood Tumours (NRCT).

METHODS

The Group was responsible for setting up and maintaining the NRCT. This registry was based on notifications from regional cancer registries, specialist children's tumour registries, paediatric oncologists and clinical trials organisers. For a large sample of cases, data on controls matched by date and place of birth were also collected.

RESULTS

Significant achievements of the Group include: studies of aetiology and of genetic epidemiology; proposals for, and participation in, international comparative studies of these diseases and on a classification system specifically for childhood cancer; the initial development of, and major contributions to, follow-up studies of the health of long-term survivors; the enhancement of cancer registration records by the addition of clinical data and of birth records. The Group made substantial contributions to the UK government's Committee on Medical Aspects of Radiation in the Environment.

CONCLUSION

An important part of the ethos of the Group was to work in collaboration with many other organisations and individuals, both nationally and internationally: many of the Group's achievements described here were the result of such collaborations.

Desmoid-type fibromatosis in a boy with Down syndrome

Patients with Down syndrome (DS) have a markedly higher incidence of childhood leukemia, but a lower incidence of most solid tumors, compared with age-matched euploid individuals. Trisomy 21 might be protective against tumorigenesis because of several tumor suppressive mechanisms. Desmoid-type fibromatosis (DF) is a rare monoclonal, fibroblastic proliferation characterized by a variable clinical course. In recent reports, almost all cases of DF involved genomic alterations associated with activation of the Wnt/β-catenin pathway. Here, we report the case of a boy with DS who developed DF without activation of the Wnt/β-catenin pathway. To the best of our knowledge, this is the first case of DS involving DF.

SHH desmoplastic/nodular medulloblastoma and Gorlin syndrome in the setting of Down syndrome: case report, molecular profiling, and review of the literature

INTRODUCTION

Individuals with Down syndrome (DS) have an increased risk of acute leukemia compared to a markedly decreased incidence of solid tumors. Medulloblastoma, the most common malignant brain tumor of childhood, is particularly rare in the DS population, with only one published case. As demonstrated in a mouse model, DS is associated with cerebellar hypoplasia and a decreased number of cerebellar granule neuron progenitor cells (CGNPs) in the external granule cell layer (EGL). Treatment of these mice with sonic hedgehog signaling pathway (Shh) agonists promote normalization of CGNPs and improved cognitive functioning.

CASE REPORT

We describe a 21-month-old male with DS and concurrent desmoplastic/nodular medulloblastoma (DNMB)-a tumor derived from Shh dysregulation and over-activation of CGNPs. Molecular profiling further classified the tumor into the new consensus SHH molecular subgroup. Additional testing revealed a de novo heterozygous germ line mutation in the PTCH1 gene encoding a tumor suppressor protein in the Shh pathway.

DISCUSSION

The developmental failure of CGNPs in DS patients offers a plausible explanation for the rarity of medulloblastoma in this population. Conversely, patients with PTCH1 germline mutations experience Shh overstimulation resulting in Gorlin (Nevoid Basal Cell Carcinoma) syndrome and an increased incidence of malignant transformation of CGNPs leading to medulloblastoma formation. This represents the first documented report of an individual with DS simultaneously carrying PTCH1 germline mutation.

CONCLUSION

We have observed a highly unusual circumstance in which the PTCH1 mutation appears to "trump" the effects of DS in causation of Shh-activated medulloblastoma.

A tumor profile in Edwards syndrome (trisomy 18)

Constitutional trisomy 18 causes Edwards syndrome, which is characterized by intellectual disability and a particular set of malformations. Although this condition carries high mortality during prenatal and early postnatal life, some of the rare infants who survive the first months develop benign and malignant tumors. To determine the tumor profile associated with Edwards syndrome, we performed a systematic review of the literature. This review reveals a tumor profile differing from those of Down (trisomy 21) and Patau (trisomy 13) syndromes. The literature covers 45 malignancies: 29 were liver cancers, mainly hepatoblastomas found in Japanese females; 13 were kidney tumors, predominantly nephroblastomas; 1 was neuroblastoma; 1 was a Hodgkin disease; and 1 was acute myeloid leukemia in an infant with both trisomy 18 and type 1 neurofibromatosis. No instances of the most frequent malignancies of early life-cerebral tumors, germ cell tumors, or leukemia--are reported in children with pure trisomy 18. Tumor occurrence does not appear to correlate with body weight, tissue growth, or cancer genes mapping to chromosome 18. Importantly, the most recent clinical histories report successful treatment; this raises ethical concerns about cancer treatment in infants with Edwards syndrome. In conclusion, knowledge of the Edwards' syndrome tumor profile will enable better clinical surveillance in at-risk organs (i.e., liver, kidney). This knowledge also provides clues to understanding oncogenesis, including the probably reduced frequency of some neoplasms in infants and children with this genetic condition. © 2016 Wiley Periodicals, Inc.

Meningioma in Down Syndrome

BACKGROUND

Down syndrome comprises multiple malformations and is due to trisomy of chromosome 21. There is epidemiologic evidence that individuals with Down syndrome are at decreased risk for solid tumors including brain tumors. It has been suggested that some genes expressed on the extra copy of chromosome 21 act as tumor suppressor genes and contribute to protection against tumorigenesis.

CASE DESCRIPTION

We report the first case to our knowledge of a patient with Down syndrome, an 8-year-old boy, with an intracranial meningioma, in which the status of chromosome 21 was examined. The diagnosis was based on histologic examination of the surgically resected tumor. Postoperatively, the patient's neurologic status improved, and there was no tumor regrowth in the next 2 years. Fluorescence in situ hybridization for chromosome 22 confirmed high allele loss involving the neurofibromin 2 gene locus, a finding typical in meningiomas. Fluorescence in situ hybridization also revealed chromosome 21 heterogeneity in tumor cells; not only cells with trisomy 21 but also cells with disomy and monosomy 21 were present. All blood cells from the patient manifested trisomy 21.

CONCLUSIONS

Deletion of the chromosome 21 allele may be associated with tumorigenesis of meningioma in Down syndrome. This supports the hypothesis that some genes whose expression is increased on the extra copy of chromosome 21 function as tumor suppressor genes and that they contribute to the reduced tumor incidence in individuals with Down syndrome.

Chronic up-regulation of the SHH pathway normalizes some developmental effects of trisomy in Ts65Dn mice

Down Syndrome (DS) is a highly complex developmental genetic disorder caused by trisomy for human chromosome 21 (Hsa21). All individuals with DS exhibit some degree of brain structural changes and cognitive impairment; mouse models such as Ts65Dn have been instrumental in understanding the underlying mechanisms. Several phenotypes of DS might arise from a reduced response of trisomic cells to the Sonic Hedgehog (SHH) growth factor. If all trisomic cells show a similar reduced response to SHH, then up-regulation of the pathway in trisomic cells might ameliorate multiple DS phenotypes. We crossed Ptch1tm1Mps/+ mice, in which the canonical SHH pathway is expected to be up-regulated in every SHH-responsive cell due to the loss of function of one allele of the pathway suppressor, Ptch1, to the Ts65Dn DS model and assessed the progeny for possible rescue of multiple DS-related phenotypes. Down-regulation of Ptch produced several previously unreported effects on development by itself, complicating interpretation of some phenotypes, and a number of structural or behavioral effects of trisomy were not compensated by SHH signaling. However, a deficit in a nest-building task was partially restored in Ts;Ptch+/- mice, as were the structural anomalies of the cerebellum seen in Ts65Dn mice. These results extend the body of evidence indicating that reduced response to SHH in trisomic cells and tissues contributes to various aspects of the trisomic phenotype.

Intracranial teratoma in children: the role of chromosome 21 trisomy

Teratomas are very rare intracranial tumors and cytogenetic information on this group remains rare. We report a case of a mature teratoma with abnormal +21 trisomy in tumor karyotype ocurring in a non-Down syndrome(DS) infant. Additionally, the evidence for the contribution of chromosome 21 trisomy in this neoplasia are briefly reviewed. The 6-month-old male baby presented with a posterior fossa tumor. Histological evaluation of tumor specimen showed a mature teratoma composed of fully differentiated ectodermal, mesodermal and endodermal components. Although somatic karyotyping of the index case was normal, composite tumor karyotype depicted 47,XY,+21[6]/46,XY[6]. Besides previous reports of children with DS and intracranial teratomas, this is the first report to describe the occurrence of an isolated chromosome 21 trisomy within the tumor of a non-DS child. The participation of chromosome 21 in this rare pediatric tumor, either somatic or restricted to tumor specimen,may deserve special interest and further investigation.