Metastatic medulloblastoma in adults: outcome of patients treated according to the HIT2000 protocol

Molecular testing for adolescent and young adult central nervous system tumors: A Canadian guideline

The 2021 World Health Organization (WHO) classification of CNS tumors incorporates molecular signatures with histology and has highlighted differences across pediatric vs adult-type CNS tumors. However, adolescent and young adults (AYA; aged 15–39), can suffer from tumors across this spectrum and is a recognized orphan population that requires multidisciplinary, specialized care, and often through a transition phase. To advocate for a uniform testing strategy in AYAs, pediatric and adult specialists from neuro-oncology, radiation oncology, neuropathology, and neurosurgery helped develop this review and testing framework through the Canadian AYA Neuro-Oncology Consortium. We propose a comprehensive approach to molecular testing in this unique population, based on the recent tumor classification and within the clinical framework of the provincial health care systems in Canada.

The Role of Chemotherapy in the Treatment of Adult Medulloblastoma

BACKGROUND

The role of chemotherapy (CT) in the treatment of adult patients with medulloblastoma (MB) is unclear. The aim of this study is to compare the survival difference between adult patients with MB treated with and without chemotherapy.

METHODS

Data were derived from the SEER (Surveillance Epidemiology and End Results) database from 2010 to 2018. The Kaplan-Meier method with log-rank tests, univariate and multivariate Cox proportional hazard analyses, and propensity score matching (PSM) were used to investigate the association between chemotherapy and survival. We further conducted an exploratory subgroup analysis. The outcomes of interest were cancer-specific survival (CSS) and overall survival (OS).

RESULTS

We included 333 patients in this study, with 227 patients in the CT cohort and 106 in the nonchemotherapy cohort. The median follow-up time and the median age of the study population were 61 months and 30 years, respectively. The 5-year CSS of the CT cohort was superior to the nonchemotherapy cohort, whereas the 5-year OS was not. Kaplan-Meier curves after PSM supported the survival benefit of CT on CSS but not on OS. In the multivariate analysis after PSM, CT was the only prognostic factor for CSS, whereas there were no independent prognostic factors for OS. The survival of patients receiving CT who were diagnosed between 2010 and 2018 was better than that of previous patients. The subgroup analysis showed that there were interaction effects between CT and sex.

CONCLUSIONS

CT improved CSS for adult patients with MB. With therapeutic advances, adult patients with MB might benefit from the use of CT.

Clinical Audit of Survival Outcomes and Prognostic Factors in Adolescents and Adults with Medulloblastoma

Purpose: Medulloblastomas, comprising 20%-25% of all primary brain tumors in children are much rarer in adulthood. Disease biology varies substantially across different age groups; however, owing to rarity, adults with medulloblastoma are traditionally treated using pediatric protocols. This is a retrospective audit of adolescent and adult medulloblastoma from a comprehensive cancer center. Methods: Data regarding demography, clinical presentation, imaging characteristics, histopathological features, molecular profiling, risk stratification, treatment details, and outcomes were retrieved from medical records. All time-to-event outcomes were analyzed using Kaplan-Meier method and compared with the log-rank test. Univariate and multivariate analysis of relevant prognostic factors was done with p value <0.05 being considered statistically significant. Results: A total of 162 patients ≥15 years of age with medulloblastoma were included. The median age was 25 years (range: 15-59 years) with leptomeningeal metastases seen in 31 (19%) patients at initial diagnosis. Following surgery, patients were treated with appropriate risk-stratified adjuvant therapy comprising of craniospinal irradiation plus boost with or without systemic chemotherapy. At a median follow-up of 50 months, 5-year Kaplan-Meier estimates of progression-free survival and overall survival were 53.5% and 59.5%, respectively. The addition of adjuvant systemic chemotherapy did not impact upon survival in standard-risk medulloblastoma. High-risk (HR) disease and anaplastic histology emerged as significant and independent predictors of poor survival on multivariate analysis. Conclusion: Medulloblastoma is a rare tumor in adolescents and adults with key differences in disease biology and resultant outcomes compared with the pediatric population. Contemporary management comprising maximal safe resection followed by appropriate risk-stratified adjuvant therapy provides acceptable survival outcomes.

The Alliance AMBUSH Trial: Rationale and Design

Simple Summary

Medulloblastoma, the most common embryonal tumor in children, can also arise in older patients. Clinical studies in children with medulloblastoma have increased our understanding of molecular pathways and improved treatment strategies. We now know that medulloblastoma has at least four subtypes and each maybe best suited to specific therapies. The sonic hedgehog (SHH) pathway is altered in a significant proportion of older patients with medulloblastoma. The Alliance for Clinical Trials in Oncology cooperative group is developing the AMBUSH trial: Comprehensive Management of Adolescent and Young Adult (AYA) and Adult Patients with Medulloblastoma or Pineal Embryonal Tumors With A Randomized Placebo Controlled Phase II Focusing on Sonic Hedgehog Pathway Inhibition in SHH Subgroup Patients (Adult & Adolescent MedulloBlastoma Using Sonic Hedgehog Trial). The trial gives treatment directions for all patients and randomizes patients with average risk SHH-activated medulloblastoma to maintenance sonidegib, a hedgehog signaling pathway inhibitor, or placebo. This trial will establish a baseline for future trial comparison and investigate the benefit of a novel targeted agent.

Abstract

Unlike medulloblastoma (MB) in children, robust prospective trials have not taken place for older patients due to the low incidence of MB in adults and adolescent and young adults (AYA). Current MB treatment paradigms for older patients have been extrapolated from the pediatric experience even though questions exist about the applicability of these approaches. Clinical and molecular classification of MB now provides better prognostication and is being incorporated in pediatric therapeutic trials. It has been established that genomic alterations leading to activation of the sonic hedgehog (SHH) pathway occur in approximately 60% of MB in patients over the age of 16 years. Within this cohort, protein patched homolog (PTCH) and smoothened (SMO) mutations are commonly found. Among patients whose tumors harbor the SHH molecular signature, it is estimated that over 80% of patients could respond to SHH pathway inhibitors. Given the advances in the understanding of molecular subgroups and the lack of robust clinical data for adult/AYA MB, the Alliance for Clinical Trial in Oncology group developed the AMBUSH trial: Comprehensive Management of AYA and Adult Patients with Medulloblastoma or Pineal Embryonal Tumors with a Randomized Placebo Controlled Phase II Focusing on Sonic Hedgehog Pathway Inhibition in SHH Subgroup Patients (Adult & Adolescent MedulloBlastoma Using Sonic Hedgehog Trial). This trial will enroll patients 18 years of age or older with MB (any molecular subgroup and risk stratification) or pineal embryonal tumor. Patients will be assigned to one of three cohorts: (1) average risk non-SHH-MB, (2) average risk SHH-MB, and (3) high risk MB or pineal embryonal tumors. All patients will receive protocol-directed comprehensive treatment with radiation therapy and chemotherapy. Patients with SHH-MB in cohort 1 will be randomized to a smoothened inhibitor or placebo as maintenance therapy for one year.

Radiotherapy in Medulloblastoma-Evolution of Treatment, Current Concepts and Future Perspectives

Simple Summary

Craniospinal irradiation (CSI) is the backbone of medulloblastoma treatment and the first treatment to achieve a cure in many patients. Within the last decades, significant efforts have been made to enhance efficacy in combination with chemotherapy. With this approach, a majority of low- and standard-risk patients can be cured. In parallel, many clinical trials have dealt with CSI-dose reduction and reduction of boost volume in order to decrease long-term toxicity, particularly neurotoxicity. Within these trials, standardized quality assurance has helped to increase the accuracy of treatment and improve prognosis. More recently, advances of radiotherapy techniques such as proton treatment allowed for better sparing of healthy tissue in order to further diminish detrimental long-term effects. Major future challenges are the adaption of radiotherapy regimens to different molecularly defined disease groups alone or together with new targeted agents. Moreover, and even more importantly, innovative combinatorial treatments are needed in high- and very-high risk situations.

Abstract

Medulloblastoma is the most frequent malignant brain tumor in children. During the last decades, the therapeutic landscape has changed significantly with craniospinal irradiation as the backbone of treatment. Survival times have increased and treatments were stratified according to clinical and later molecular risk factors. In this review, current evidence regarding the efficacy and toxicity of radiotherapy in medulloblastoma is summarized and discussed mainly based on data of controlled trials. Current concepts and future perspectives based on current risk classification are outlined. With the introduction of CSI, medulloblastoma has become a curable disease. Due to combination with chemotherapy, survival rates have increased significantly, allowing for a reduction in radiation dose and a decrease of toxicity in low- and standard-risk patients. Furthermore, modern radiotherapy techniques are able to avoid side effects in a fragile patient population. However, high-risk patients remain with relevant mortality and many patients still suffer from treatment related toxicity. Treatment needs to be continually refined with regard to more efficacious combinatorial treatment in the future.

MEVITEM-a phase I/II trial of vismodegib + temozolomide vs temozolomide in patients with recurrent/refractory medulloblastoma with Sonic Hedgehog pathway activation

BACKGROUND

Vismodegib specifically inhibits Sonic Hedgehog (SHH). We report results of a phase I/II evaluating vismodegib + temozolomide (TMZ) in immunohistochemically defined SHH recurrent/refractory adult medulloblastoma.

METHODS

TMZ-naïve patients were randomized 2:1 to receive vismodegib + TMZ (arm A) or TMZ (arm B). Patients previously treated with TMZ were enrolled in an exploratory cohort of vismodegib (arm C). If the safety run showed no excessive toxicity, a Simon's 2-stage phase II design was planned to explore the 6-month progression-free survival (PFS-6). Stage II was to proceed if arm A PFS-6 was ≥3/9 at the end of stage I.

RESULTS

A total of 24 patients were included: arm A (10), arm B (5), and arm C (9). Safety analysis showed no excessive toxicity. At the end of stage I, the PFS-6 of arm A was 20% (2/10 patients, 95% unilateral lower confidence limit: 3.7%) and the study was prematurely terminated. The overall response rates (ORR) were 40% (95% CI, 12.2-73.8) and 20% (95% CI, 0.5-71.6) in arm A and B, respectively. In arm C, PFS-6 was 37.5% (95% CI, 8.8-75.5) and ORR was 22.2% (95% CI, 2.8-60.0). Among 11 patients with an expected sensitivity according to new generation sequencing (NGS), 3 had partial response (PR), 4 remained stable disease (SD) while out of 7 potentially resistant patients, 1 had PR and 1 SD.

CONCLUSION

The addition of vismodegib to TMZ did not add toxicity but failed to improve PFS-6 in SHH recurrent/refractory medulloblastoma. Prediction of sensitivity to vismodegib needs further refinements.

Integrated molecular analysis of adult sonic hedgehog (SHH)-activated medulloblastomas reveals two clinically relevant tumor subsets with VEGFA as potent prognostic indicator

BACKGROUND

Up to now, adult medulloblastoma (MB) patients are treated according to the protocols elaborated for pediatric MB although these tumors are different in terms of clinical outcomes and biology. Approximately 70% of adult MB disclose a sonic hedgehog (SHH) molecular signature in contrast to about 30% in pediatric cohorts. In addition, adult SHH-MB (aSHH-MB) are clinically heterogeneous but there is consensus neither on their optimal treatment nor on risk stratification. Thus, the identification of clinically relevant molecular subsets of aSHH-MB and identification of potential treatment targets remains inconclusive.

METHODS

We analyzed 96 samples of institutionally diagnosed aSHH-MB through genome-wide DNA methylation profiling, targeted DNA sequencing, and RNA sequencing to identify molecular subcategories of these tumors and assess their prognostic significance.

RESULTS

We defined two aSHH-MB numerically comparable epigenetic subsets with clinical and molecular variability. The subset "aSHH-MBI" (46%/48%) was associated with PTCH1/SMO (54%/46%) mutations, "neuronal" transcriptional signatures, and favorable outcomes after combined radio-chemotherapy (5-year PFS = 80% and OS = 92%). The clinically unfavorable "aSHH-MBII" subset (50%/52%; 5-year PFS = 24% and OS = 45%) disclosed GLI2 amplifications (8%), loss of 10q (22%), and gene expression signatures associated with angiogenesis and embryonal development. aSHH-MBII tumors revealed strong and ubiquitous expression of VEGFA both at transcript and protein levels that was correlated with unfavorable outcome.

CONCLUSIONS

(1) The histologically uniform aSHH-MB cohort exhibits clear molecular heterogeneity separating these tumors into two molecular subsets (aSHH-MBI and aSHH-MBII), which are associated with different cytogenetics, mutational landscapes, gene expression signatures, and clinical course. (2) VEGFA appears to be a promising biomarker to predict clinical course, which needs further prospective validation as its potential role in the pathogenesis of this subset.

Development of Randomized Trials in Adults with Medulloblastoma-The Example of EORTC 1634-BTG/NOA-23

Simple Summary

Medulloblastoma is rare after puberty. Among several molecular subgroups that have been described, the sonic hedgehog (SHH) subgroup is highly overrepresented in the post-pubertal population and can be targeted with smoothened (SMO) inhibitors. However, no practice-changing prospective clinical trials have been published in adults to date. Tumors often recur, and treatment toxicity is relevant. Thus, the EORTC 1634-BTG/NOA-23 trial for post-pubertal patients with standard risk medulloblastoma will aim to increase treatment efficacy and to decrease treatment toxicity. Patients will be randomized between standard-dose vs. reduced-dosed radiotherapy, and SHH-subgroup patients will also be randomized between the SMO inhibitor sonidegib (Odomzo^TM,, Sun Pharmaceuticals Industries, Inc., New York, USA) in addition to standard radio-chemotherapy vs. standard radio-chemotherapy alone. In ancillary studies, we will investigate tumor tissue, blood and cerebrospinal fluid samples, magnetic resonance images, and radiotherapy plans to gain information that may improve future treatment. Patients will also be monitored long-term for late side effects of therapy, health-related quality of life, cognitive function, social and professional live outcomes, and reproduction and fertility. In summary, EORTC 1634-BTG/NOA-23 is a unique multi-national effort that will help to council patients and clinical scientists for the appropriate design of treatments and future clinical trials for post-pubertal patients with medulloblastoma.

Abstract

Medulloblastoma is a rare brain malignancy. Patients after puberty are rare and bear an intermediate prognosis. Standard treatment consists of maximal resection plus radio-chemotherapy. Treatment toxicity is high and produces disabling long-term side effects. The sonic hedgehog (SHH) subgroup is highly overrepresented in the post-pubertal and adult population and can be targeted by smoothened (SMO) inhibitors. No practice-changing prospective randomized data have been generated in adults. The EORTC 1634-BTG/NOA-23 trial will randomize patients between standard-dose vs. reduced-dosed craniospinal radiotherapy and SHH-subgroup patients between the SMO inhibitor sonidegib (Odomzo^TM, Sun Pharmaceuticals Industries, Inc., New York, USA) in addition to standard radio-chemotherapy vs. standard radio-chemotherapy alone to improve outcomes in view of decreased radiotherapy-related toxicity and increased efficacy. We will further investigate tumor tissue, blood, and cerebrospinal fluid as well as magnetic resonance imaging and radiotherapy plans to generate information that helps to further improve treatment outcomes. Given that treatment side effects typically occur late, long-term follow-up will monitor classic side effects of therapy, but also health-related quality of life, cognition, social and professional outcome, and reproduction and fertility. In summary, we will generate unprecedented data that will be translated into treatment changes in post-pubertal patients with medulloblastoma and will help to design future clinical trials.

Typical Pediatric Brain Tumors Occurring in Adults-Differences in Management and Outcome

Adult brain tumors mostly distinguish themselves from their pediatric counterparts. However, some typical pediatric brain tumors also occur in adults. The aim of this review is to describe the differences between classification, treatment, and outcome of medulloblastoma, pilocytic astrocytoma, and craniopharyngioma in adults and children. Medulloblastoma is a WHO IV posterior fossa tumor, divided into four different molecular subgroups, namely sonic hedgehog (SHH), wingless (WNT), Group 3, and Group 4. They show a different age-specific distribution, creating specific outcome patterns, with a 5-year overall survival of 25–83% in adults and 50–90% in children. Pilocytic astrocytoma, a WHO I tumor, mostly found in the supratentorial brain in adults, occurs in the cerebellum in children. Complete resection improves prognosis, and 5-year overall survival is around 85% in adults and >90% in children. Craniopharyngioma typically occurs in the sellar compartment leading to endocrine or visual field deficits by invasion of the surrounding structures. Treatment aims for a gross total resection in adults, while in children, preservation of the hypothalamus is of paramount importance to ensure endocrine development during puberty. Five-year overall survival is approximately 90%. Most treatment regimens for these tumors stem from pediatric trials and are translated to adults. Treatment is warranted in an interdisciplinary setting specialized in pediatric and adult brain tumors.

Medulloblastoma in adults - reviewing the literature from a surgeon's point of view

Medulloblastoma is a common primary brain tumor in children but it is a rare cancer in adult patients. We reviewed the literature, searching PubMed for articles on this rare tumor entity, with a focus on tumor biology, advanced neurosurgical opportunities for safe tumor resection, and multimodal treatment options. Adult medulloblastoma occurs at a rate of 0.6 per one million people per year. There is a slight disparity between male and female patients, and patients with a fair skin tone are more likely to have a medulloblastoma. Patients present with cerebellar signs and signs of elevated intracranial pressure. Diagnostic efforts should consist of cerebral MRI and MRI of the spinal axis. Cerebrospinal fluid should be investigated to look for tumor dissemination. Medulloblastoma tumors can be classified as classic, desmoplastic, anaplastic, and large cell, according to the WHO tumor classification. Molecular subgroups include WNT, SHH, group 3, and group 4 tumors. Further molecular analyses suggest that there are several subgroups within the four existing subgroups, with significant differences in patient age, frequency of metastatic spread, and patient survival. As molecular markers have started to play an increasing role in determining treatment strategies and prognosis, their importance has increased rapidly. Treatment options include microsurgical tumor resection and radiotherapy and, in addition, chemotherapy that respects the tumor biology of individual patients offers targeted therapeutic approaches. For neurosurgeons, intraoperative imaging and tumor fluorescence may improve resection rates. Disseminated disease, residual tumor after surgery, lower radiation dose, and low Karnofsky performance status are all suggestive of a poor outcome. Extraneural spread occurs only in very few cases. The reported 5-year-survival rates range between 60% and 80% for all adult medulloblastoma patients.

Proposed Additions to the NCCN Guidelines for Adult Medulloblastoma

Medulloblastoma is a rare brain tumor that occurs in both children and adults, with patients aged 15 to 39 years accounting for 30% of all cases. In adults, guidelines for diagnosis and treatment are often based on retrospective data and extrapolated from the pediatric experience due to limited availability of prospective trials or registries involving adults. Importantly, adult patients differ from pediatric patients in many aspects, including the molecular features of the tumor and tolerance to treatment. In 2017, the NCI was granted support from the Cancer Moonshot initiative to address the challenges and unmet needs of adults with rare central nervous system (CNS) tumors through the NCI Comprehensive Oncology Network for Evaluating Rare CNS Tumors (NCI-CONNECT). On November 25, 2019, NCI-CONNECT convened a multidisciplinary workshop on adult medulloblastoma. Working groups identified unmet needs in clinical care and research and developed specific action items, including a proposal for inclusion of new items in the NCCN Guidelines for Adult Medulloblastoma, delineated in this review along with the evidence supporting their incorporation. Recommendations included facilitating referral of patients to centers of excellence; promoting patient participation in clinical trials or registries; encouraging use of DNA methylation for confirmation of diagnosis and subgrouping; offering counseling on contraception and fertility preservation; evaluating patients for symptoms and medical management of endocrine, vision, hearing, and neurocognitive deficits; providing psychosocial support and referral to neurorehabilitation; minimizing delays in therapy; and incorporating imaging standards and criteria for progression.

EANO-EURACAN clinical practice guideline for diagnosis, treatment, and follow-up of post-pubertal and adult patients with medulloblastoma

The European Association of Neuro-Oncology (EANO) and EUropean RAre CANcer (EURACAN) guideline provides recommendations for the diagnosis, treatment, and follow-up of post-pubertal and adult patients with medulloblastoma. The guideline is based on the 2016 WHO classification of tumours of the CNS and on scientific developments published since 1980. It aims to provide direction for diagnostic and management decisions, and for limiting unnecessary treatments and cost. In view of the scarcity of data in adults with medulloblastoma, we base our recommendations on adult data when possible, but also include recommendations derived from paediatric data if justified. Our recommendations are a resource for professionals involved in the management of post-pubertal and adult patients with medulloblastoma, for patients and caregivers, and for health-care providers in Europe. The implementation of this guideline requires multidisciplinary structures of care, and defined processes of diagnosis and treatment.

Neurocognitive functioning and health-related quality of life in adult medulloblastoma patients: long-term outcomes of the NOA-07 study

Background

Combined radiochemotherapy followed by maintenance chemotherapy with cisplatin, lomustine and vincristine within the NOA-07 study resulted in considerable short-term toxicity in adult medulloblastoma patients. Here we investigated the long-term impact of this treatment, focusing on neurocognitive functioning and health-related quality of life (HRQoL).

Methods

Neurocognitive functioning and HRQoL scores over time were determined, and differences between the post-treatment and follow-up assessments were calculated up to 18 months for neurocognition and 60 months for HRQoL.

Results

28/30 patients were analyzed. The three preselected HRQoL scales (role, social and cognitive functioning) showed improved scores, to a clinically relevant extent (≥ 10 points), compared to post-treatment levels up to 30 months, but decreased afterwards. Z-scores for verbal working memory were worse during follow-up compared to post-treatment scores and remained impaired during 18 months follow-up (i.e. z-score below − 1 standard deviation). Attention was impaired post-treatment, and remained impaired to a clinically relevant extent during follow-up. Coordination/processing speed and lexical verbal fluency improved compared to post-treatment scores, and remained within the normal range thereafter. Other tests of verbal fluency were stable over time, with z-scores within the normal range.

Conclusions

This long-term follow-up study showed that the NOA-07 treatment regimen was not associated with a deterioration in HRQoL in the post-treatment period. Verbal working memory deteriorated, while other neurocognitive domains did not seem to be impacted negatively by the treatment.

Electronic supplementary material

The online version of this article (10.1007/s11060-020-03502-y) contains supplementary material, which is available to authorized users.

DNA inhibitors for the treatment of brain tumors

Introduction: The worldwide incidence of central nervous system (CNS) primary tumors is increasing. Most of the chemotherapeutic agents used for treating these cancer types induce DNA damage, and their activity is affected by the functional status of repair systems involved in the detection or correction of DNA lesions. Unfortunately, treatment of malignant high-grade tumors is still an unmet medical need.Areas covered: We summarize the action mechanisms of the main DNA inhibitors used for the treatment of brain tumors. In addition, studies on new agents or drug combinations investigated for this indication are reviewed, focusing our attention on clinical trials that in the last 3 years have been completed, terminated or are still recruiting patients.Expert opinion: Much still needs to be done to render aggressive CNS tumors curable or at least to transform them from lethal to chronic diseases, as it is possible for other cancer types. Drugs with improved penetration in the CNS, toxicity profile, and activity against primary and recurrent tumors are eagerly needed. Targeted agents with innovative mechanisms of action and ability to harness the cells of the tumor microenvironment against cancer cells represent a promising approach for improving the clinical outcome of CNS tumors.

Medulloblastoma and central nervous system germ cell tumors in adults: is pediatric experience applicable?

Medulloblastoma and central nervous system (CNS) germ cell tumors are very rare in adults, while they account for 25% and 5% of brain tumors in children, respectively (Pastore et al. Eur J Cancer 42:2064-208, 2006). Pediatric experiences, mostly from randomized and controlled clinical trials, have led to different tailored treatments, based on various risk factors, including histology, and extent of disease. For medulloblastoma, biological features have recently emerged that enable therapies to be scaled down in some cases, or pursued more aggressively in the event of chromosomal and/or genetic alterations (Massimino et al. Crit Rev Oncol Hematol 105:35-51, 2016). Such refinements are still impossible for adult patients due to the lack of similar clinical trials that might provide the same or a different understanding regarding patients' prognosis, long-term survival, quality of life, and acute and late toxicities. This review aims to contribute to the debate on the treatment of adults with these two diseases and promote the creation of broad-based, national and international trials to advance our knowledge in this area and to share the skills between pediatric and adult oncologists as adolescent and young adults (AYA) brain tumor national boards are currently requiring.

Updates on Management of Adult Medulloblastoma

OPINION STATEMENT

Medulloblastoma (MB) is a malignant embryonal tumor of the posterior fossa and is the most common type of brain cancer in pediatric patients. In contrast, adult MB is very rare with an incidence of 0.6 per million per year and mostly affects young adults below the age of 40. Recent molecular analyses of pediatric and adult MB have classified these tumors into at least four individual molecular subgroups (SHH, WNT, group 3, and group 4) with distinct demographics, histology, and prognosis. The discrete biological composition of these tumors likely explains the marked heterogeneity in responses seen to conventional therapies such as radiation and cytotoxic chemotherapies. Given the low incidence of adult MB, prospective studies are challenging and scarce, and management guidelines are largely derived from the pediatric MB patient population and retrospective data. However, adult MB is clinically and molecularly distinct from pediatric MB and a comprehensive review of published literature on adult MB highlighting their differences is warranted. Here, we review the management of adult MB focusing on recent studies exploring the effectiveness of upfront chemotherapy, clinical trials in the context of molecular subgroup-specific therapies, and the potential role of immunotherapy in treating this disease.

Medulloblastoma: optimizing care with a multidisciplinary approach

Medulloblastoma is a malignant tumor of the cerebellum and the most frequent malignant brain tumor in children. The standard of care consists of maximal resection surgery, followed by craniospinal irradiation and chemotherapy. Such treatment allows long-term survival rates of nearly 70%; however, there are wide disparities among patient outcomes, and in any case, major long-term morbidity is observed with conventional treatment. In the last two decades, the molecular understanding of medulloblastoma has improved drastically, allowing us to revolutionize our understanding of medulloblastoma pathophysiological mechanisms. These advances led to an international consensus in 2010 that defined four prognostic molecular subgroups named after their affected signaling pathways, that is, WNT, SHH, Group 3 and Group 4. The molecular understanding of medulloblastoma is starting to translate through to clinical settings due to the development of targeted therapies. Moreover, recent improvements in radiotherapy modalities and the reconsideration of craniospinal irradiation according to the molecular status hold promise for survival preservation and the reduction of radiation-induced morbidity. This review is an overview of the current knowledge of medulloblastoma through a molecular approach, and therapeutic prospects currently being developed in surgery, radiotherapy and targeted therapies to optimize the treatment of medulloblastoma with a multidisciplinary approach will also be discussed.

Multicenter pilot study of radiochemotherapy as first-line treatment for adults with medulloblastoma (NOA-07)

Background

Medulloblastoma in adult patients is rare, with 0.6 cases per million. Prognosis depends on clinical factors and medulloblastoma entity. No prospective data on the feasibility of radiochemotherapy exist. The German Neuro-Oncology Working Group (NOA) performed a prospective descriptive multicenter single-arm phase II trial to evaluate feasibility and toxicity of radio-polychemotherapy.

Methods

The NOA-07 trial combined craniospinal irradiation with vincristine, followed by 8 cycles of cisplatin, lomustine, and vincristine. Adverse events, imaging and progression patterns, histological and genetic markers, health-related quality of life (HRQoL), and cognition were evaluated. Primary endpoint was the rate of toxicity-related treatment terminations after 4 chemotherapy cycles, and the toxicity profile. The feasibility goal was reached if at least 45% of patients received at least 4 cycles of maintenance chemotherapy.

Results

Thirty patients were evaluable. Each 50% showed classic and desmoplastic/nodular histology. Sixty-seven percent were classified into the sonic hedgehog (SHH) subgroup without TP53 alterations, 13% in wingless (WNT), and 17% in non-WNT/non-SHH. Four cycles of chemotherapy were feasible in the majority (n = 21; 70.0%). Hematological side effects and polyneuropathy were prevalent toxicities. During the active treatment period, HRQoL and verbal fluency improved significantly. The 3-year event-free survival rate was 66.6% at the time of databank lock.

Conclusions

Radio-polychemotherapy did lead to considerable toxicity and a high amount of dose reductions throughout the first 4 chemotherapy cycles that may affect efficacy. Thus, we propose frequent patient surveillance using this regimen. Modifications of the regimen may increase feasibility of radio-polychemotherapy of adult patients with medulloblastoma.

Medulloblastomas in adolescents and adults - Can the pediatric experience be extrapolated?

Adult medulloblastomas are orphan diseases that differ from their pediatric counterpart. Most are classified as classic or desmoplastic and fall in the SHH subgroup, mainly with loss-of-function mutations in PTCH1 and some by TP53-mutation due to underlying germline mutation. Activation of the WNT pathway is sporadic, although underlying Turcot syndrome may be present. One-third of tumors are issued from group 4. Most adult studies are small non-randomized retrospective heterogeneous studies performed at a single center with short follow-up. Standard craniospinal irradiation followed by maintenance chemotherapy (CCNU, cisplatin-vincristine) results in a 4-year event-free survival (EFS) and overall survival (OS) of 68% and 89% respectively in standard-risk adults, and in a 4-year EFS and OS of 50% and 90%, respectively in high-risk adults. Several pooled analyses point out the potential role of chemotherapy in adults. The feasibility of pediatric protocols in adults is sometimes hampered because of blood and peripheral nerve toxicity. In the near future, subgroups of medulloblastomas may be treated by personalized therapies. With prolonged follow-up, adults fare worse. Long-term sequelae and second line treatment are not well defined in adults. Prospective studies are ongoing to define optimal first-line and relapse treatments.

[Medulloblastoma. Pathology]

Medulloblastomas, embryonal neuroepithelial tumors developed in the cerebellum or brain stem, are mainly observed in childhood. The treatment of WHO-Grade IV tumors depends on stratifications that are usually based on postoperative data, histopathological subtype, tumor extension and presence of MYC or NMYC amplifications. Recently, molecular biology studies, based on new technologies (i.e. sequencing, transcriptomic, methylomic) have introduced genetic subtypes integrated into the latest WHO-2016 neuropathological classification. According to this classification, the three genetic groups WNT, SHH, with or without mutated TP53 gene, and non-WNT/non-SHH, comprising subgroups 3 and 4, are recalled in this review. The contribution of immunohistochemistry to define these groups is specified. The four histopathological groups are detailed in comparison to the WHO-2007 classification and the molecular data: classic medulloblastoma, desmoplastic/nodular medulloblastoma, medulloblastoma with extensive nodularity, and large cell/anaplastic medulloblastoma. The groups defined on genetic and histopathological grounds are not strictly concordant. Depending on the age of the patients, their correlations are different, as well as their role in the management and prognosis of these tumors. Other embryonal tumors, for which new classifications are in progress and gliomas may be confused with a medulloblastoma and the elements of the differential diagnosis of these entities are discussed. This evolution in classification fully justifies ongoing structuring procedures such as histopathological review (RENOCLIP) and the organization of molecular biology platforms.

Medulloblastoma in adults : A retrospective single institution analysis

PURPOSE

Adult medulloblastoma is a rare disease treated according to the current pediatric treatment guidelines. This retrospective analysis investigated the clinical outcomes and prognostic factors of adult medulloblastoma patients, who received multimodal therapy at our institution.

METHODS

Treatment charts of all patients over the age of 15 years of age with de novo medulloblastoma, who had been treated at our institution between 2001 and 2014, were retrospectively analyzed. Patients' demographic parameters, initial symptoms, treatment modalities, toxicities, and survival outcomes were investigated.

RESULTS

In all, 21 patients with a median age of 30.2 years were identified. The most frequent histologies were desmoplastic and classic, and the most common molecular subtype was sonic hedgehog (SHH). After tumor resection, all patients received craniospinal irradiation (median dose 35.2 Gy) and a boost to the posterior fossa (median dose 19.8 Gy). Simultaneous chemotherapy with vincristine was given to 20 patients and sequential chemotherapy to 15 patients. The most common side effects were hematological toxicities. Median overall survival (OS) has not been reached after a median follow-up of 92 months. Estimated 5‑ and 10-year OS was 89 and 80%, respectively. Estimated 5‑ and 10-year progression-free survival (PFS) was 89 and 81%, respectively. In univariate analysis, a shorter interval between tumor resection and end of irradiation was significantly associated with improved OS and PFS, anaplastic histology with worse OS and PFS.

CONCLUSIONS

The combined modality treatment showed a good outcome in adults with medulloblastoma. Treatment time was revealed to be prognostic and should be kept as short as possible.

Adjuvant chemotherapy and overall survival in adult medulloblastoma

Background

Although chemotherapy is used routinely in pediatric medulloblastoma (MB) patients, its benefit for adult MB is unclear. We evaluated the survival impact of adjuvant chemotherapy in adult MB.

Methods

Using the National Cancer Data Base, we identified patients aged 18 years and older who were diagnosed with MB in 2004-2012 and underwent surgical resection and adjuvant craniospinal irradiation (CSI). Patients were divided into those who received adjuvant CSI and chemotherapy (CRT) or CSI alone (RT). Predictors of CRT compared with RT were evaluated with univariable and multivariable logistic regression. Survival analysis was limited to patients receiving CSI doses between 23 and 36 Gy. Overall survival (OS) was evaluated using the Kaplan-Meier estimator, log-rank test, multivariable Cox proportional hazards modeling, and propensity score matching.

Results

Of the 751 patients included, 520 (69.2%) received CRT, and 231 (30.8%) received RT. With median follow-up of 5.0 years, estimated 5-year OS was superior in patients receiving CRT versus RT (86.1% vs 71.6%, P < .0001). On multivariable analysis, after controlling for risk factors, CRT was associated with superior OS compared with RT (HR: 0.53; 95%CI: 0.32-0.88, P = .01). On planned subgroup analyses, the 5 year OS of patients receiving CRT versus RT was improved for M0 patients (P < .0001), for patients receiving 36 Gy CSI (P = .0007), and for M0 patients receiving 36 Gy CSI (P = .0008).

Conclusions

This national database analysis demonstrates that combined postoperative chemotherapy and radiotherapy are associated with superior survival for adult MB compared with radiotherapy alone, even for M0 patients who receive high-dose CSI.

Brain tumors - other treatment modalities

Management of tumors of the central nervous system is challenging for clinicians for various reasons, including complex diagnostic procedures, limited penetration of drugs into brain tissue, and the prerequisite to preserve brain function in any case of therapeutic intervention. Therapeutic success is dependent on the efforts, skills, and cooperation of involved specialists and disciplines. Knowledge and ability to apply adequate therapeutic modalities in an interdisciplinary approach in due time are crucial, necessitating coordination of diagnostic procedures and therapeutic interventions by means of multidisciplinary brain tumor boards. In this chapter we present in brief the essential current standards and future perspectives for therapy modalities that complement surgery of brain tumors.

Posterior Fossa Intra-Axial Tumors in Adults

BACKGROUND

The posterior fossa is the site of many types of tumors, and brain metastases are the most common malignancies in that location among adults. Other brain tumors, such as ependymomas, medulloblastomas, and juvenile pilocytic astrocytomas, mostly occur during childhood and are relatively rare in adults. Most primary malignant brain tumors, such as gliomas and lymphomas, tend to be located in the supratentorial compartment.

METHODS

This review summarizes prognostic factors, therapeutic management, and molecular data of intra-axial posterior fossa tumors in adults, including ependymomas, medulloblastomas, and pilocytic astrocytomas.

RESULTS

The literature on intra-axial posterior fossa tumors in adults relies mainly on limited retrospective clinical studies, and such studies employ a wide range of treatment approaches that are usually based on therapies developed specifically for children or for supratentorial brain tumors.

CONCLUSIONS

The clinical course and surgical outcome of adult patients with intra-axial brain tumors in the posterior fossa are summarized in this review. The prognostic factors and therapeutic management of patients with these tumors are controversial because of their rarity, their heterogeneity, and the lack of sufficient data in the literature.