Adjuvant chemotherapy for medulloblastoma: The first multi-centre control trial of the International Society of Paediatric Oncology (SIOP I)

Evolution of neurosurgical advances and nuances in medulloblastoma therapy

Medulloblastoma, the most common malignant brain tumor in children, presents a complex treatment challenge due to its propensity for infiltrative growth within the posterior fossa and its potential attachment to critical anatomical structures. Central to the management of medulloblastoma is the surgical resection of the tumor, which is a key determinant of patient prognosis. However, the extent of surgical resection (EOR), ranging from gross total resection (GTR) to subtotal resection (STR) or even biopsy, has been the subject of extensive debate and investigation within the medical community. Today, the impact of neurosurgical EOR on the prognosis of medulloblastoma patients remains a complex and evolving area of investigation. The conflicting findings in the literature, the challenges posed by critical surrounding anatomical structures, the potential for surgical complications and neurologic morbidity, and the nuanced interactions with molecular subgroups all contribute to the complexity of this issue. As the field continues to advance, the imperative to strike a delicate balance between maximizing resection and preserving quality of life remains central to the management of medulloblastoma patients.

Evolution of Systemic Therapy in Medulloblastoma Including Irradiation-Sparing Approaches

The management of medulloblastoma in children has dramatically changed over the past four decades, with the development of chemotherapy protocols aiming at improving survival and reducing long-term toxicities of high-dose craniospinal radiotherapy. While the staging and treatment of medulloblastoma were until recently based on the modified Chang's system, recent advances in the molecular biology of medulloblastoma have revolutionized approaches in the management of this increasingly complex disease. The evolution of systemic therapies is described in this review.

Posterior fossa tumors in children: current insights

While in adults most intracranial tumors develop around the cerebral hemispheres, 45 to 60% of pediatric lesions are found in the posterior fossa, although this anatomical region represents only 10% of the intracranial volume. The latest edition of the WHO classification for CNS tumors presented some fundamental paradigm shifts that particularly affected the classification of pediatric tumors, also influencing those that affect posterior fossa. Molecular biomarkers play an important role in the diagnosis, prognosis, and treatment of childhood posterior fossa tumors and can be used to predict patient outcomes and response to treatment and monitor its effectiveness. Although genetic studies have identified several posterior fossa tumor types, differing in terms of their location, cell of origin, genetic mechanisms, and clinical behavior, recent management strategies still depend on uniform approaches, mainly based on the extent of resection. However, significant progress has been made in guiding therapy decisions with biological or molecular stratification criteria and utilizing molecularly targeted treatments that address specific tumor biological characteristics. The primary focus of this review is on the latest advances in the diagnosis and treatment of common subtypes of posterior fossa tumors in children, as well as potential therapeutic approaches in the future.   Conclusion: Molecular biomarkers play a central role, not only in the diagnosis and prognosis of posterior fossa tumors in children but also in customizing treatment plans. They anticipate patient outcomes, measure treatment responses, and assess therapeutic effectiveness. Advances in neuroimaging and treatment have significantly enhanced outcomes for children with these tumors. What is Known: • Central nervous system tumors are the most common solid neoplasms in children and adolescents, with approximately 45 to 60% of them located in the posterior fossa. • Multimodal approaches that include neurosurgery, radiation therapy, and chemotherapy are typically used to manage childhood posterior fossa tumors What is New: • Notable progress has been achieved in the diagnosis, categorization and management of posterior fossa tumors in children, leading to improvement in survival and quality of life.

Questions and answers in the management of children with medulloblastoma over the time. How did we get here? A systematic review

Introduction

Treatment of children with medulloblastoma (MB) includes surgery, radiation therapy (RT) and chemotherapy (CT). Several treatment protocols and clinical trials have been developed over the time to maximize survival and minimize side effects.

Methods

We performed a systematic literature search in May 2023 using PubMed. We selected all clinical trials articles and multicenter studies focusing on MB. We excluded studies focusing exclusively on infants, adults, supratentorial PNETs or refractory/relapsed tumors, studies involving different tumors or different types of PNETs without differentiating survival, studies including <10 cases of MB, solely retrospective studies and those without reference to outcome and/or side effects after a defined treatment.

Results

1. The main poor-prognosis factors are: metastatic disease, anaplasia, MYC amplification, age younger than 36 months and some molecular subgroups. The postoperative residual tumor size is controversial.2. MB is a collection of diseases.3. MB is a curable disease at diagnosis, but survival is scarce upon relapse.4. Children should be treated by experienced neurosurgeons and in advanced centers.5. RT is an essential treatment for MB. It should be administered craniospinal, early and without interruptions.6. Craniospinal RT dose could be lowered in some low-risk patients, but these reductions should be done with caution to avoid relapses.7. Irradiation of the tumor area instead of the entire posterior fossa is safe enough.8. Hyperfractionated RT is not superior to conventional RT9. Both photon and proton RT are effective.10. CT increases survival, especially in high-risk patients.11. There are multiple drugs effective in MB. The combination of different drugs is appropriate management.12. CT should be administered after RT.13. The specific benefit of concomitant CT to RT is unknown.14. Intensified CT with stem cell rescue has no benefit compared to standard CT regimens.15. The efficacy of intraventricular/intrathecal CT is controversial.16. We should start to think about incorporating targeted therapies in front-line treatment.17. Survivors of MB still have significant side effects.

Conclusion

Survival rates of MB improved greatly from 1940-1970, but since then the improvement has been smaller. We should consider introducing targeted therapy as front-line therapy.

Ligand Installation to Polymeric Micelles for Pediatric Brain Tumor Targeting

Medulloblastoma is a life-threatening disease with poor therapeutic outcomes. In chemotherapy, low drug accumulation has been a cause of these outcomes. Such inadequate response to treatments has been associated with low drug accumulation, particularly with a limited cellular uptake of drugs. Recently, the conjugation of drugs to ligand molecules with high affinity to tumor cells has attracted much attention for enhancing drug internalization into target cells. Moreover, combining tumor-targeting ligands with nano-scaled drug carriers can potentially improve drug loading capacity and the versatility of the delivery. Herein, we focused on the possibility of targeting CD276/B7-H3, which is highly expressed on the medulloblastoma cell membrane, as a strategy for enhancing the cellular uptake of ligand-installed nanocarriers. Thus, anti-CD276 antibodies were conjugated on the surface of model nanocarriers based on polyion complex micelles (PIC/m) via click chemistry. The results showed that the anti-CD276 antibody-installed PIC/m improved intracellular delivery into CD276-expressing medulloblastoma cells in a CD276-dependent manner. Moreover, increasing the number of antibodies on the surface of micelles improved the cellular uptake efficiency. These observations indicate the potential of anti-CD276 antibody-installed nanocarriers for promoting drug delivery in medulloblastoma.

Medulloblastoma in the Modern Era: Review of Contemporary Trials, Molecular Advances, and Updates in Management

Critical discoveries over the past two decades have transformed our understanding of medulloblastoma from a single entity into a clinically and biologically heterogeneous disease composed of at least four molecularly distinct subgroups with prognostically and therapeutically relevant genomic signatures. Contemporary clinical trials also have provided valuable insight guiding appropriate treatment strategies. Despite therapeutic and biological advances, medulloblastoma patients across the age spectrum experience tumor- and treatment-related morbidity and mortality. Using an updated risk stratification approach integrating both clinical and molecular features, ongoing research seeks to (1) cautiously reduce therapy and mitigate toxicity in low-average risk patients, and (2) thoughtfully intensify treatment with incorporation of novel, biologically guided agents for patients with high-risk disease. Herein, we review important historical and contemporary studies, discuss management updates, and summarize current knowledge of the biological landscape across unique pediatric, infant, young adult, and relapsed medulloblastoma populations.

Meta of classical chemotherapy compared with high-dose chemotherapy and autologous stem cell rescue in newly diagnosed medulloblastoma after radiotherapy

BACKGROUND

High-dose chemotherapy combined with autologous stem cell rescue (HDCT + ASCR) has been used to treat newly diagnosed medulloblastoma, but there was no high-level evidence to support its efficacy.

METHODS

Databases were retrieved, and patients were divided into 2 groups: group A was radiotherapy combined with HCDT + ASCR, and group B was classical radiotherapy and chemotherapy. The clinical benefit rate, progression-free survival (PFS), overall survival (OS) and toxicities data were extracted.

RESULTS

22 clinical trials met the inclusion criteria, 416 in group A and 2331 in group B. There was no difference in CBR between 2 groups (80.0% vs 71.5%, P.262). The 3-year PFS (3-y PFS) of group A was significantly better than group B (79.0% vs 69.5%, P = .004). The analysis found that there was no difference between the 2 groups of the standard risk group or the high-risk group. In the standard risk group, the 5-y PFS of group A was significantly better than group B (83.6% vs75.6%, P = .004). Comparison of 3-y OS and 5-y OS between 2 groups of all MB patients showed no difference (P = .086; P = .507), stratified analysis was the same result. The gastrointestinal toxicity in group A was significantly higher than that in group B (P = .016), and the level 3/4 ototoxicity in high-risk group A was higher than that in group B (P = .001).

CONCLUSIONS

HDCT + ASCR can prolong 3-year PFS significantly, and prolong 5-y PFS significantly in the standard risk group, but increase gastrointestinal toxicity significantly for newly diagnosed medulloblastoma.

The Current State of Radiotherapy for Pediatric Brain Tumors: An Overview of Post-Radiotherapy Neurocognitive Decline and Outcomes

Tumors of the central nervous system are the most common solid malignancies diagnosed in children. While common, they are also found to have some of the lowest survival rates of all malignancies. Treatment of childhood brain tumors often consists of operative gross total resection with adjuvant chemotherapy or radiotherapy. The current body of literature is largely inconclusive regarding the overall benefit of adjuvant chemo- or radiotherapy. However, it is known that both are associated with conditions that lower the quality of life in children who undergo those treatments. Chemotherapy is often associated with nausea, emesis, significant fatigue, immunosuppression, and alopecia. While radiotherapy can be effective for achieving local control, it is associated with late effects such as endocrine dysfunction, secondary malignancy, and neurocognitive decline. Advancements in radiotherapy grant both an increase in lifetime survival and an increased lifetime for survivors to contend with these late effects. In this review, the authors examined all the published literature, analyzing the results of clinical trials, case series, and technical notes on patients undergoing radiotherapy for the treatment of tumors of the central nervous system with a focus on neurocognitive decline and survival outcomes.

Comparison of toxicity following single versus tandem autologous transplant regimens for pediatric medulloblastoma

BACKGROUND

Medulloblastoma outcomes have improved with craniospinal irradiation and chemotherapy, but such therapy has resulted in poor neurocognitive outcomes for young patients. Chemotherapy-only regimens with autologous transplant have been implemented with the intention of avoiding radiation. It is not yet known whether single or tandem transplantation is superior with respect to efficacy and/or safety.

METHODS

We performed a retrospective review of children with medulloblastoma treated at Dana-Farber Cancer Institute from 1996 to 2016 who received either single or tandem autologous transplantation after completion of induction chemotherapy. We compared safety and outcome data between the two groups.

RESULTS

Among 23 patients, 12 received tandem transplants. Median follow-up was 6.4 years (IQR = 0.8-10.5). There was no statistically significant difference in 5-year EFS or OS between the single (70.7 ± 14%, 80.2 ± 13%) and tandem transplant groups (57.1 ± 15%, 79.6 ± 13%). Seven tandem transplant patients received subsequent radiation while only four required radiation in the single transplant group (p = .41). In the single transplant regimen, patients experienced longer antibiotic duration (p = .03) and LOS (p = .01) and a trend toward increased number of transfusions (p = .06). Four cases of veno-occlusive disease were reported in the single transplant group (p = .04).

CONCLUSIONS

Outcomes were similar between regimens, but the single transplant regimen had more hepatic complications. These data suggest that tandem transplant regimens may have reduced toxicity compared to the single transplant regimen with similar outcome measures.

Pediatric versus Adult Medulloblastoma: Towards a Definition That Goes beyond Age

Simple Summary

Medulloblastoma is a rare brain tumor that affects children and adults. Treatment with surgery, radiation, and chemotherapy currently cures most patients; however, ~30% of all patients have poor clinical outcomes despite treatment. Prospective clinical trials have historically excluded older patients, while recent advances in molecular diagnostics have enhanced our understanding of tumorigenesis. The aim of this literature review is to discuss the history of clinical trials in medulloblastoma and to argue in favor of prioritizing molecular drivers of disease as trial inclusion features rather than an arbitrary age cutoff.

Abstract

Medulloblastoma is a rare malignant brain tumor that predominantly affects children but also occurs in adults. The incidence declines significantly after age 15, and distinct tumor molecular features are seen across the age spectrum. Standard of care treatment consists of maximal safe surgical resection followed by adjuvant radiation and/or chemotherapy. Adjuvant treatment decisions are based on individual patient risk factors and have been informed by decades of prospective clinical trials. These trials have historically relied on arbitrary age cutoffs for inclusion (age 16, 18, or 21, for example), while trials that include adult patients or stratify patients by molecular features of disease have been rare. The aim of this literature review is to review the history of clinical trials in medulloblastoma, with an emphasis on selection criteria, and argue in favor of rational and inclusive trials based on molecular features of disease as opposed to chronological age. We performed a scoping literature review for medulloblastoma and clinical trials and include a summary of those results. We also discuss some of the significant advances made in understanding the molecular biology of medulloblastoma within the past decade, most notably the identification of four distinct subgroups based on gene expression profiling. We will also cite the recent experiences of childhood leukemia and the emergence of tissue-agnostic therapies as examples of successes of rationally designed, inclusive trials translating to improved clinical outcomes for patients across the age spectrum. Despite the prior trial history and recent molecular advances outcomes remain poor for ~30% of medulloblastoma patients. We believe that defining patients by the specific molecular alterations their tumors harbor is the best way to ensure they can access potentially efficacious therapies on clinical trials.

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.

[Early and long-term outcomes of treatment in patients with medulloblastoma]

OBJECTIVE

To compare the modes of craniospinal irradiation (CSI) and to determine possible factors improving the outcome in patients with medulloblastoma.

MATERIAL AND METHODS

The study included 92 patients with medulloblastoma who were treated at the Russian Research Radiology Center between 2008 and 2019. Mean age of patients was 12 years. Classical morphological variant of medulloblastoma prevailed (48.4%). After surgery, 78 patients underwent radiotherapy (CSI + full-volume «boost» on the tumor site). Standard risk patients received CSI in a reduced dose after tumor resection. Weekly modification of radiotherapy with vincristine was performed in 73 (79.3%) patients.

RESULTS

We significantly (p<0.05) determined the total focal doses for CSI in patients with medulloblastoma. Total resection of posterior cranial fossa tumor improved relapse-free survival by several times. Complete CSI up to total dose of 36/54 Gy ensures the most positive effect compared to irradiation in reduced dose.

CONCLUSION

Relapse-free survival significantly depends on total focal dose of CSI. Single focal dose, chemotherapeutic modification of radiotherapy and M-stage had no significant effect on relapse-free survival. Perhaps, this is due to small sample size.

Adult Medulloblastoma Demographic, Tumor and Treatment Impact since 2006: A Canadian University Experience

Medulloblastoma is an aggressive primary brain tumor that is extremely rare in adults; therefore, prospective studies are limited. We reviewed the information of all MB patients treated at the CHUM between 2006 and 2017. We divided our cohort by age and further divided adult patients (53%) in two groups, those diagnosed between 2006–2012 and 2013–2017. In our adult population, median follow up was 26 months and SHH-activated MB comprised 39% of tumors. Adult 5yOS was 80% and first-line therapy led to a 5yPFS of 77%. The absence of radiosensitizing chemotherapy (100% vs. 50%; p = 0.033) negatively influenced 5yPFS. 96% of adult patients received radiotherapy and 48% of them received concomitant radiosensitizing chemotherapy. Complete surgical resection was performed on 85% of adults, but the extent of resection did not have a discernable impact on survival and did not change with time. Adjuvant chemotherapy did not clearly affect prognosis (5yOS 80% vs. 67%, p = 0.155; 5yPFS 78% vs. 67%, p = 0.114). From 2006–2012, the most common chemotherapy regimen (69%) was Cisplatinum, Lomustine and Vincristine, which was replaced in 2013 by Cisplatinum, Etoposide and Cyclophosphamide (77%) with a trend for worse survival. Nine patients recurred and seven of these (78%) were treated with palliative chemotherapy. In conclusion, we did not identify prognostic demographic or tumor factors in our adult MB population. The presence of radiosensitizing chemotherapy was associated with a more favorable PFS. Cisplatinum, Lomustine and Vincristine regimen might be a better adjuvant chemotherapy regimen.

Safety and efficacy of concurrent carboplatin during full-dose craniospinal irradiation for high-risk/metastatic medulloblastoma in a resource-limited setting

PURPOSE

To assess the safety and efficacy of concurrent carboplatin during craniospinal irradiation (CSI) in high-risk/metastatic medulloblastoma defined as either residual tumor >1.5 cm² or leptomeningeal metastases.

METHODS

This single-arm combined prospective (2005-2011) and retrospective (2011-2019) study was undertaken at a tertiary care cancer center in India. Following surgery, patients with newly diagnosed high-risk/metastatic medulloblastoma received concurrent carboplatin (35 mg/m² ) for 15 days (day 1 to day 15) during CSI plus posterior fossa/tumor bed boost, followed by six cycles of standard adjuvant chemotherapy.

RESULTS

All 97 patients completed their planned course of radiotherapy without interruptions, except for two (2.1%) patients who had brief gaps due to treatment-related toxicity. Grade 3-4 anemia, neutropenia, thrombocytopenia, and febrile neutropenia were seen in four (4.1%), 41 (42.2%) 21 (21.6%), and 18 (18.6%) patients, necessitating packed cell transfusion, granulocyte colony-stimulating factor, and platelet support in five (5.1%), 41 (42.2%), and five (5.1%) patients, respectively, during the concurrent phase. Following myelorecovery, 92 (94.9%) patients completed the planned six cycles of standard adjuvant systemic chemotherapy. There were no treatment-related deaths during the concurrent chemo-radiotherapy phase, while three (3.1%) toxic deaths were ascribed to adjuvant chemotherapy-related complications. At a median follow-up of 82 months, the 5-year Kaplan-Meier estimates of progression-free survival and overall survival were 60.2% and 62.1%, respectively. On univariate analysis, leptomeningeal metastases (M0/M1 vs. M2/M3) and histological subtype (large cell/anaplastic vs. others) emerged as significant prognostic factors for survival.

CONCLUSION

Addition of concurrent carboplatin to RT as radiosensitizing chemotherapy is a simple and effective way of treatment intensification in high-risk/metastatic medulloblastoma.

Observed-to-expected incidence ratios of second malignant neoplasms after radiation therapy for medulloblastoma: A Surveillance, Epidemiology, and End Results analysis

BACKGROUND

The authors analyzed the incidence and types of second malignant neoplasms (SMNs) in patients treated for medulloblastoma.

METHODS

The authors compared the incidence of SMNs after radiotherapy (RT) for medulloblastoma in patients treated in 1973-2014 with the incidence in the general population with the multiple primary-standardized incidence ratio function of Surveillance, Epidemiology, and End Results 9. Observed-to-expected incidence (O/E) ratios and 95% confidence intervals (CIs) were reported for the entire cohort and by disease site according to age at diagnosis, treatment era, and receipt of chemotherapy. P values < .05 were considered statistically significant.

RESULTS

Of the 1294 patients with medulloblastoma who received RT, 68 developed 75 SMNs. The O/E ratio for SMNs among all patients was 4.49 (95% CI, 3.53-5.62; P < .05). The site at highest risk was the central nervous system (CNS; O/E, 40.62; 95% CI, 25.46-61.51), which was followed by the endocrine system (O/E, 15.95; 95% CI, 9.12-25.91), bone (O/E, 14.45; 95% CI, 1.75-52.21), soft tissues (O/E, 9.01; 95% CI, 1.09-32.56), the digestive system (O/E, 5.03; 95% CI, 2.51-9.00), and the lymphatic/hematopoietic system (O/E, 3.37; 95% CI, 1.35-6.94). The O/E ratio was higher for patients given chemotherapy and RT (O/E, 5.52; 95% CI, 3.75-7.83) than for those given RT only (O/E, 3.96; 95% CI, 2.88-5.32).

CONCLUSIONS

Patients with medulloblastoma are at elevated risk for SMNs in comparison with the general population. Variations in O/E for SMNs by organ systems were found for treatment modality, age at diagnosis, and time of diagnosis. The most common site, the CNS, was involved more often in younger patients and those given chemotherapy with RT.

Surgical management of posterior fossa medulloblastoma in children: The Lyon experience

INTRODUCTION

Modern approach for the treatment of posterior fossa medulloblastomas remains a challenge for pediatric neurosurgeons and pediatric oncologists and requires a multidisciplinary approach to optimize survival and clinical results.

MATERIAL AND METHODS

We report the surgical principles of the treatment of posterior fossa medulloblastomas in children and how to avoid technical mistakes especially in very young patients. We also report our experience in a series of 64 patients operated from a medulloblastoma between 2000 and 2018 in Lyon.

RESULTS

All patients had a craniospinal MRI. Eighty-one percent of the patients (n=50) had strictly midline tumor while 19% (n=14) had lateralized one. Eleven percent (n=7) had metastasis at diagnosis on the initial MRI. Forty-one percent (n=29) had an emergency ETV to treat hydrocephaly and the intracranial hypertension. All patient underwent a direct approach and a complete removal was achieved in 78% (n=58) of the cases on the postoperative MRI realized within 48h postsurgery. Histological findings revealed classical medulloblastoma in 73% (n=46), desmoplastic medulloblastoma in 17% (n=11) and anaplastic/large cell medulloblastoma in 10% (n=7). Patients were classified as low risk in 7 cases, standard risk in 30 cases and high risk in 27 cases. Ninety-six percent (n=61) of the patient received radiotherapy. Seventy-six percent (n=48) received pre-irradiation or adjuvant chemotherapy. At last follow-up in December 2018, 65% (n=41) of the patient were in complete remission, 12% (n=8) were in relapse and 27% (n=15) had died from their disease. The overall survival at five , ten and fifteen years for all the series was of 76%, 73% and 65.7% respectively.

CONCLUSIONS

Medulloblastomas remain a chimiosensible and radiosensible disease and the complete surgical removal represents a favorable prognostic factor. The extension of surgery has also to be weighted in consideration of the new biomolecular and genetic knowledge that have to be integrated by surgeons to improve quality of life of patients.

Paediatric posterior fossa tumour resection rates in a small volume centre: the past decade's experience

BACKGROUND

Paediatric brain tumour resection rates have been shown to correlate with outcome and, it is argued, are linked to operator volume and caseload. The British paediatric neurosurgery community has previously debated centralisation of paediatric neuro-oncology. At the 2018 British Paediatric Neurosurgery Group (BPNG) meeting, a commitment was made to prospectively collect tumour resection data at each Neurosurgical Unit (NSU). Here we review our prospectively-collected 10-year database of the three commonest paediatric posterior fossa tumours - astrocytomas, medulloblastomas and ependymomas.

MATERIALS AND METHODS

Our primary outcome was extent of resection (EOR) on post-operative MRI scans reviewed by neuro-radiologists. Secondary outcomes comprised neurosurgical morbidity including infection, need for cerebrospinal fluid (CSF) diversion and the occurrence of posterior fossa syndrome (PFS).

RESULTS

55 children had 62 operations, where our complete resection rates for pilocytic astrocytomas, medulloblastomas and ependymomas were 77%, 79% and 63%, respectively. Both our primary and secondary outcomes were in keeping with the published literature and we discuss here some of the factors which may contribute towards favourable outcomes in a small volume centre.

CONCLUSION

Our results suggest that small volume centres can expect equivalent results to larger volume NSUs with regards to paediatric brain tumour surgery. Continuing efforts nationally for data collection on resection rates and operative outcomes is a key step towards optimising management in these children.

Preclinical Models of Craniospinal Irradiation for Medulloblastoma

Medulloblastoma is an embryonal tumor that shows a predilection for distant metastatic spread and leptomeningeal seeding. For most patients, optimal management of medulloblastoma includes maximum safe resection followed by adjuvant craniospinal irradiation (CSI) and chemotherapy. Although CSI is crucial in treating medulloblastoma, the realization that medulloblastoma is a heterogeneous disease comprising four distinct molecular subgroups (wingless [WNT], sonic hedgehog [SHH], Group 3 [G3], and Group 4 [G4]) with distinct clinical characteristics and prognoses has refocused efforts to better define the optimal role of CSI within and across disease subgroups. The ability to deliver clinically relevant CSI to preclinical models of medulloblastoma offers the potential to study radiation dose and volume effects on tumor control and toxicity in these subgroups and to identify subgroup-specific combination adjuvant therapies. Recent efforts have employed commercial image-guided small animal irradiation systems as well as custom approaches to deliver accurate and reproducible fractionated CSI in various preclinical models of medulloblastoma. Here, we provide an overview of the current clinical indications for, and technical aspects of, irradiation of pediatric medulloblastoma. We then review the current literature on preclinical modeling of and treatment interventions for medulloblastoma and conclude with a summary of challenges in the field of preclinical modeling of CSI for the treatment of leptomeningeal seeding tumors.

Medulloblastoma genomics in the modern molecular era

Medulloblastoma (MB) represents a spectrum of biologically and clinically distinct entities. Initially described histopathologically as a small, round blue cell tumor arising in the cerebellum, MB has emerged as a paradigm for molecular classification in cancer. Recent advances in genomic, transcriptomic and epigenomic profiling of MB have further refined molecular classification and complemented conventional histopathological diagnosis. Herein, we review the main clinical and molecular features of the four consensus subgroups of MB (WNT, SHH, Group 3 and Group 4). We also highlight hereditary predisposition syndromes associated with increased risk of MB. Finally, we explore advances in the classification of the consensus molecular groups while also presenting cutting-edge frontiers in identifying intratumoral heterogeneity and cellular origins of MB.

Management of high-risk medulloblastoma

Medulloblastoma is the most common malignant brain tumors in children. Current management combines surgery, radiotherapy, and chemotherapy. Current treatment of medulloblastoma is based on a clinical risk-stratification system that takes into account age, extent of resection and metastatic status. High-risk medulloblastoma patients are defined by the presence of metastatic disease and/or an incomplete resection with a residual amount of tumour>1.5 cm². This review describes the evolution in the management of high-risk medulloblastoma patients during recent 4 decades and recent changes in the definition of high-risk patients as a result of major advances in the understanding of the molecular heterogeneity of medulloblastomas.

Twenty years experience in treating childhood medulloblastoma: Between the past and the present

PURPOSE

Medulloblastoma is the most common primary malignant central nervous system tumour in children. These last decades, treatment modalities have largely evolved resulting in better survival rates. Nevertheless, long-term toxicity is a major concern in this setting. The purpose of this study was to analyse the clinical results and medical outcomes of a cohort of paediatric patients treated for medulloblastoma in Xhinhua Hospital in Shanghai. These results are compared with those from other centres reported in literature.

PATIENTS AND METHODS

This was a retrospective study conducted at Xhinhua Hospital in Shanghai, China. It included 121 patients treated for medulloblastoma from 1993 to December 2013.

RESULTS

Mean age at diagnosis was 6.7 years (range: 1-14.3 years). Total surgical resection was achieved in 60% of the cases. Classic medulloblastoma was found in 59% of the cases. Adjuvant radiotherapy was delivered in all cases and chemotherapy concerned 70.2% of the studied cohort. The median follow-up time of the study was 84 months (range: 24-120 months). Five- and 10 years progression-free survival rates were 83.2%, and 69.5% and 5 years and 10 years. Overall survival rates were 82.5%, and 72.5%. Patient's age significantly influenced survival: patients under 3 years old had the worse outcomes (P=0.01). T and M stages also significantly impacted survival rates: advanced stages were associated with lower rates (P=0.08 and 0.05 respectively). Finally, patients receiving temezolomide had bad outcomes when compared to the new standard protocol used in the department (P=0.03). The most commonly reported late toxicity was growth suppression in 35 patients (52.2%). Hypothyroidism requiring hormone replacement was recorded in 29% of the cases. Hearing loss, and problems including poor concentration, poor memory and learning difficulties were reported in 19% and 25% of the cases respectively. Second cancers were noted in three cases.

CONCLUSION

Overall, our results are comparable to those reported in literature. Nevertheless, efforts should be made to ensure longer follow-ups and correctly assess treatment-related toxicity.

Preradiation Chemotherapy for Adult High-risk Medulloblastoma: A Trial of the ECOG-ACRIN Cancer Research Group (E4397)

OBJECTIVES

To assess the long-term outcomes and objective response (OR) to preradiation chemotherapy and radiation in adult high-risk medulloblastoma.

MATERIALS AND METHODS

In this prospective phase II trial, adults with high-risk medulloblastoma were treated with 3 cycles of preradiation cisplatin, etoposide, cyclophosphamide, and vincristine followed by craniospinal radiation (CSI). OR, progression-free survival (PFS), overall survival (OS), and toxicities were assessed.

RESULTS

Eleven patients were enrolled over a 6-year period. Six (55%) had subarachnoid metastases. Two (18%) had an OR to preradiation chemotherapy. Two (18%) progressed while on chemotherapy. Completion of CSI was not compromised. The OR rate after chemotherapy and radiation was 45% (5/11). Nonevaluable patients at both time-points weakened the response data conclusions. Median PFS was 43.8 months. Five-year PFS was 27%. Five-year OS was 55%. Nonmetastatic (M0) and metastatic (M+) patients had similar outcomes.

CONCLUSIONS

The OR to this preradiation chemotherapy regimen is lower than anticipated from the adult and pediatric literature raising a question about comparative efficacy of chemotherapy in different age groups. The OS achieved is similar to retrospective adult series, but worse than pediatric outcomes. Although this regimen can be administered without compromising delivery of CSI, our results do not provide support for the use of this neoadjuvant chemotherapy for adult medulloblastoma.

Late Morbidity and Mortality Among Medulloblastoma Survivors Diagnosed Across Three Decades: A Report From the Childhood Cancer Survivor Study

PURPOSE

Treatment of medulloblastoma has evolved from surgery and radiotherapy to contemporary multimodal regimens. However, the impact on long-term health outcomes remains unknown.

METHODS

Cumulative incidence of late mortality (5 or more years from diagnosis), subsequent neoplasms (SNs), and chronic health conditions were evaluated in the Childhood Cancer Survivor Study among 5-year survivors of medulloblastoma diagnosed between 1970 and 1999. Outcomes were evaluated by treatment exposure, including historical therapy (craniospinal irradiation [CSI] ≥ 30 Gy, no chemotherapy), high risk (CSI ≥ 30 Gy + chemotherapy), standard risk (CSI < 30 Gy + chemotherapy), and by treatment decade (1970s, 1980s, 1990s). Rate ratios (RRs) and 95% CIs estimated long-term outcomes using multivariable piecewise exponential models.

RESULTS

Among 1,311 eligible survivors (median age, 29 years [range, 6 to 60 years]; median time from diagnosis, 21 years [range, 5 to 44 years]), the 15-year cumulative incidence rate of all-cause late mortality was 23.2% (diagnosed 1970s) versus 12.8% (1990s; P = .002), with a recurrence-related mortality rate of 17.7% versus 9.6% ( P = .008). Lower late mortality rates as a result of other health-related causes were not observed. Among 997 survivors who completed a baseline survey, the 15-year cumulative incidence of SNs was higher among survivors with multimodal therapy (standard risk, 9.5%; historical, 2.8%; P = .03). Survivors treated in the 1990s had a higher cumulative incidence of severe, disabling, life-threatening, and fatal chronic health conditions (56.5% in 1990s v 39.9% in 1970s; P < .001) and were more likely to develop multiple conditions (RR, 2.89; 95% CI, 1.31 to 6.38). However, survivors of standard-risk therapy were less likely to use special education services than high-risk therapy survivors (RR, 0.84; 95% CI, 0.75 to 0.93).

CONCLUSION

Historical changes in medulloblastoma therapy that improved 5-year survival have increased the risk for SNs and debilitating health conditions for survivors yet reduced the need for special education services.

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.

Case-based review: pediatric medulloblastoma

Medulloblastoma is the most common malignant brain tumor affecting children. These tumors are high grade with propensity to metastasize within the central nervous system and, less frequently, outside the neuraxis. Recent advancements in molecular subgrouping of medulloblastoma refine diagnosis and improve counseling in regards to overall prognosis. Both are predicated on the molecular drivers of each subgroup-WNT-activated, SHH-activated, group 3, and group 4. The traditional therapeutic mainstay for medulloblastoma includes a multimodal approach with surgery, radiation, and multiagent chemotherapy. As we discover more about the molecular basis of medulloblastoma, efforts to adjust treatment approaches based on molecular risk stratification are under active investigation. Certainly, the known neurological, developmental, endocrine, and psychosocial injury related to medulloblastoma and its associated therapies motivate ongoing research towards improving treatment for this life-threatening tumor while at the same time minimizing long-term side effects.

Outcome for children treated for medulloblastoma and supratentorial primitive neuroectodermal tumor (CNS-PNET) - a retrospective analysis spanning 40 years of treatment

BACKGROUND

Medulloblastoma (MB) and supratentorial primitive neuroectodermal tumor of the central nervous system (CNS-PNET) are among the most common pediatric brain tumors. The diagnosis, treatment, and outcome of MB/CNS-PNET patients treated during the last four decades at Oslo University Hospital (OUH) are described.

MATERIAL AND METHODS

All patients younger than 20 years of age diagnosed and treated for MB/CNS-PNET at OUH between 1 January 1974 and 31 December 2013 were identified.

RESULTS

We found 175 patients. In 13 of them, the diagnosis was changed upon histopathological review and in 4 patients part of the treatment was administered at other hospitals. Thus, 158 patients were included for further analysis. Eight patients did not receive adjuvant therapy because of a dismal clinical condition. The overall 5-year survival rate for MB and CNS-PNET was 54%, for MB 57%, and for CNS-PNET 41%. Gross total resection (GTR) was achieved in 118 patients and 5-year overall survival for patients with GTR versus those with non-GTR differed significantly with 64% versus 22%. Cytological examination of the cerebrospinal fluid was performed in 52 patients. A total of 126 patients received radiotherapy as part of the primary treatment and 24 did not due to young age. Median time from surgery to start of radiotherapy was 33 days. Duration of radiotherapy was more than 48 days in 22% of patients. At the time of analysis, 63 patients were alive and disease-free, one alive with disease, and 94 patients were deceased; 84 of these due to MB/CNS-PNET and 10 due to supposed late effects from the treatment.

CONCLUSIONS

Survival was comparable to data from other population-based studies. The importance of GTR for survival was corroborated. Reporting real-world data remains crucial to know the true outcome of patients treated outside clinical trials.

Evolution of cerebral microbleeds after cranial irradiation in medulloblastoma patients

OBJECTIVE

To characterize the temporal and spatial pattern of cerebral microbleeds (CMBs) after cranial irradiation in patients with medulloblastoma.

METHODS

We retrospectively identified patients with medulloblastoma treated with craniospinal irradiation at the Massachusetts General Hospital between 1999 and 2015. Longitudinal MRI including T2*-weighted gradient-recalled echo (GRE) sequences were reviewed, and the prevalence, spatial pattern, and risk factors associated with CMBs were characterized.

RESULTS

We identified a total of 27 patients; 5 patients were children (median age 6.3 years) and 22 patients were adults (median age 28.8 years). CMBs were found in 67% (18/27) of patients, who were followed for a median of 4.1 years. Patients with CMBs had longer GRE follow-up time compared to those without CMBs (4.9 vs 1.7 years, p = 0.035). The median latency of the appearance of CMBs was 2.79 years (interquartile range 1.76-4.26). The prevalence of CMBs increased with each year from time of radiation therapy, and the cumulative prevalence was highest in patients age <20 years (100% cumulative prevalence, vs 59% in adult patients treated at age ≥20 years). CMBs were mostly found in lobar distribution and predominately in bilateral occipital lobes. Patients using antithrombotic medications developed CMBs at a significantly higher rate (p = 0.041).

CONCLUSIONS

Our data demonstrate a high prevalence of CMBs following cranial irradiation, progressively increasing with each year from time of radiation therapy.

Medulloblastoma

Medulloblastoma accounts for nearly 10% of all childhood brain tumors. These tumors occur exclusively in the posterior fossa and have the potential for leptomeningeal spread. Treatment includes a combination of surgery, radiation therapy (in patients >3 years old). Patients >3 years old are stratified based on the volume of postoperative residual tumor and the presence or absence of metastases into "standard risk" and "high risk" categories with long-term survival rates of approximately 85% and 70%, respectively. Outcomes are inferior in infants and children younger than 3 years with exception of those patients with the medulloblastoma with extensive nodularity histologic subtype. Treatment for medulloblastoma is associated with significant morbidity, especially in the youngest patients. Recent molecular subclassification of medulloblastoma has potential prognostic and therapeutic implications. Future incorporation of molecular subgroups into treatment protocols will hopefully improve both survival outcomes and posttreatment quality of life.

Childhood medulloblastoma

Medulloblastoma accounts for 15-20% of childhood nervous system tumours. The risk of dying was reduced by 30% in the last twenty years. Patients are divided in risk strata according to post-surgical disease, dissemination, histology and some molecular features such as WNT subgroup and MYC status. Sixty to 70% of patients older than 3 years are assigned to the average-risk group. High-risk patients include those with disseminated and/or residual disease, large cell and/or anaplastic histotypes, MYC genes amplification. Current and currently planned clinical trials will: (1) evaluate the feasibility of reducing both the dose of craniospinal irradiation and the volume of the posterior fossa radiotherapy (RT) for those patients at low biologic risk, commonly identified as those having a medulloblastoma of the WNT subgroup; (2) determine whether intensification of chemotherapy (CT) or irradiation can improve outcome in patients with high-risk disease; (3) find target therapies allowing tailored therapies especially for relapsing patients and those with higher biological risk.

Craniospinal irradiation with concomitant and adjuvant temozolomide--a feasibility assessment of toxicity in patients with glioblastoma with a PNET component

There is no standard treatment for glioblastoma with elements of PNET (GBM-PNET). Conventional treatment for glioblastoma is surgery followed by focal radiotherapy with concurrent temozolomide. Given the increased propensity for neuroaxial metastases seen with GBM-PNETs, craniospinal irradiation (CSI) with temozolomide (TMZ) could be a feasible treatment option but little is known regarding its toxicity. The clinical records of all patients treated at two UK neuro-oncology centres with concurrent CSI and TMZ were examined for details of surgery, radiotherapy, chemotherapy and toxicities related to the CSI-TMZ component of their treatment. Eight patients were treated with CSI-TMZ, the majority (6/8) for GBM-PNET. All patients completed radiotherapy to the craniospinal axis 35-40 Gy in 20-24 daily fractions with a focal boost to the tumour of 14-23.4 Gy in 8-13 daily fractions. Concurrent TMZ was administered at 75 mg/m(2) for seven of the cohort, with the other patient receiving 50 mg/m(2). The most commonly observed non-haematological toxicities were nausea and vomiting, with all patients experiencing at least grade 2 symptoms of either or both. All patients had at least grade 3 lymphopaenia. Two patients experience grade 4 neutropaenia and grade 3 thrombocytopaenia. Three of the eight patients required omission of TMZ for part of their chemoradiotherapy and 3/8 required hospital admission at some point during chemoradiotherapy. The addition of TMZ to CSI did not interrupt radiotherapy. Principal toxicities were neutropaenia, lymphopaenia, thrombocytopaenia, nausea and vomiting. Treatment with CSI-TMZ merits further investigation and may be suitable for patients with tumours at high-risk of metastatic spread throughout the CNS who have TMZ-sensitive pathologies.

[Pediatric medulloblastoma: Retrospective series of 52 patients]

PURPOSE

Retrospective analysis of the results of 52 children irradiated for a medulloblastoma.

PATIENTS AND METHODS

Between 1974 and 2012, 52 children with an average age of 6 years and a half (11 months-17 years and a half) were treated with surgery then with radiotherapy at the Comprehensive Cancer Centre of Strasbourg (France). For 44 children, the treatment consisted of a chemotherapy.

RESULTS

After a mean follow-up of 106.6 months (7-446 months), 13 relapses and 24 deaths were observed. Overall survival at 5 years and 10 years were 62% and 57%, respectively. Disease-free survival at 5 years and 10 years were 80% and 63%, respectively. Univariate analysis found the following adverse prognostic factors: the existence of a postoperative residue, the positivity of the cerebrospinal fluid, the metastatic status and medulloblastoma of high-risk. Positivity of the cerebrospinal fluid remains a negative factor in multivariate analysis.

CONCLUSION

These results confirm the survival rate obtained by a conventional approach (surgery then irradiation). Insufficiency of results and rarity of medulloblastoma require the establishment of international protocols.

Prognostic value of medulloblastoma extent of resection after accounting for molecular subgroup: a retrospective integrated clinical and molecular analysis

Background

Incomplete surgical resection of medulloblastoma is controversially considered a marker of high-risk disease; driving aggressive surgical resections, “second-look” surgeries, and/or intensified chemoradiotherapy. All prior publications evaluating the clinical importance of extent of resection (EOR) failed to account for molecular subgroup. We analysed the prognostic value of EOR across 787 medulloblastoma samples in a subgroup-specific manner.

Methods

We retrospectively identified patients from Medulloblastoma Advanced Genomics International Consortium (MAGIC) centres with a histological diagnosis of medulloblastoma and complete extent of resection and survival data. Specimens were collected from 35 international institutions. Medulloblastoma subgroup affiliation was determined using nanoString gene expression profiling on frozen or formalin-fixed paraffin-embedded tissues. Extent of resection (EOR) based on post-operative imaging was classified as gross total (GTR), near total (NTR, <1·5cm²), or subtotal (STR, ≥ 1·5cm²). Overall survival (OS) and progression-free survival (PFS) multivariable analyses including subgroup, age, metastatic status, geographical location of therapy (North America/Australia vs world), and adjuvant therapy regimen were performed. The primary endpoint was the impact of surgical EOR by molecular subgroup and other clinical variables on OS and PFS.

Findings

787 medulloblastoma patients (86 WNT, 242 SHH, 163 Group 3, and 296 Group 4) were included in a multivariable Cox model of PFS and OS. The marked benefit of EOR in the overall cohort was greatly attenuated after including molecular subgroup in the multivariable analysis. There was an observed PFS benefit of GTR over STR (hazard ration [HR] 1·45, 95% CI; 1·07–1·96, p=0·02) but there was no observed PFS or OS benefit of GTR over NTR (HR 1·05, 0·71–1·53, p=0·82 and HR 1·14, 0·75–1·72, p=0.55). There was no statistically significant survival benefit to greater EOR for patients with WNT, SHH, or Group 3 patients (HR 1·03, 0·67–1·58, p=0·9 for STR vs. GTR). There was a PFS benefit for GTR over STR in patients with Group 4 medulloblastoma (HR1·97, 1·22–3·17, p=0·01), particularly those with metastatic disease (HR 2·22, 1–4·93, p=0·05). A nomogram based on this multivariable cox proportional hazards model shows the comparably smaller impact of EOR on relative risk for PFS and OS than subgroup affiliation, metastatic status, radiation dose, and adjuvant chemotherapy.

Interpretation

The prognostic benefit of EOR for patients with medulloblastoma is attenuated after accounting for molecular subgroup affiliation. Although maximal safe surgical resection should remain the standard of care, surgical removal of small residual portions of medulloblastoma is not recommended when the likelihood of neurological morbidity is high as there is no definitive benefit to GTR over NTR. Our results suggest a re-evaluation of the long-term implications of intensified craniospinal irradiation (36 Gy) in children with small residual portions of medulloblastoma.

Funding

Funding Canadian Cancer Society Research Institute, Terry Fox Research Institute, Canadian Institutes of Health Research, National Institutes of Health, Pediatric Brain Tumor Foundation, Garron Family Chair in Childhood Cancer Research.

Advances in Radiation Therapy in Pediatric Neuro-oncology

Radiation therapy remains a highly effective therapy for many pediatric central nervous system tumors. With more children achieving long-term survival after treatment for brain tumors, late-effects of radiation have become an important concern. In response to this problem, treatment protocols for a variety of pediatric central nervous system tumors have evolved to reduce radiation fields and doses when possible. Recent advances in radiation technology such as image guidance and proton therapy have led to a new era of precision treatment with significantly less exposure to healthy tissues. These developments along with the promise of molecular classification of tumors and targeted therapies point to an optimistic future for pediatric neuro-oncology.

The UK Experience of a Treatment Strategy for Pediatric Metastatic Medulloblastoma Comprising Intensive Induction Chemotherapy, Hyperfractionated Accelerated Radiotherapy and Response Directed High Dose Myeloablative Chemotherapy or Maintenance Chemotherapy (Milan Strategy)

BACKGROUND

Historically, the 5-year overall survival (OS) for metastatic medulloblastoma (MMB) was less than 40%. The strategy of post-operative induction chemotherapy (IC) followed by hyperfractionated accelerated radiotherapy (HART) and response directed high dose chemotherapy (HDC) was reported in a single center study to improve 5-year OS to 73%. We report outcomes of this strategy in UK.

METHODS

Questionnaires were sent to all 20 UK pediatric oncology primary treatment centers to collect retrospective data on delivered treatment, toxicity and survival with this strategy in children aged 3-19 years with MMB.

RESULTS

Between February 2009 and October 2011, 34 patients fulfilled the entry criteria of the original study. The median age was 7 years (range 3-15). Median interval from surgery to HART was 109 versus 85 days in the original series. The incidence of grade 3 or 4 hematological toxicities with IC and HDC was 83-100%. All 16 patients who achieved complete response by the end of the regimen remain in remission but only three of 18 patients with lesser responses are still alive (P < 0.0001). With a median follow-up of 45 months for survivors, the estimated 3-year OS is 56% (95% CI 38, 71). This result is outside the 95% CI of the original study results and encompasses the historical survival result of 40%.

CONCLUSION

Within the limits of statistical significance, we did not replicate the improved survival results reported in the original series. The reasons include differences in patient sub-groups and protocol administration. International randomized phase III studies are needed.

Clinical Outcomes Among Children With Standard-Risk Medulloblastoma Treated With Proton and Photon Radiation Therapy: A Comparison of Disease Control and Overall Survival

PURPOSE

The purpose of this study was to compare long-term disease control and overall survival between children treated with proton and photon radiation therapy (RT) for standard-risk medulloblastoma.

METHODS AND MATERIALS

This multi-institution cohort study includes 88 children treated with chemotherapy and proton (n=45) or photon (n=43) RT between 2000 and 2009. Overall survival (OS), recurrence-free survival (RFS), and patterns of failure were compared between the 2 cohorts.

RESULTS

Median (range) age was 6 years old at diagnosis (3-21 years) for proton patients versus 8 years (3-19 years) for photon patients (P=.011). Cohorts were similar with respect to sex, histology, extent of surgical resection, craniospinal irradiation (CSI) RT dose, total RT dose, whether the RT boost was delivered to the posterior fossa (PF) or tumor bed (TB), time from surgery to RT start, or total duration of RT. RT consisted of a median (range) CSI dose of 23.4 Gy (18-27 Gy) and a boost of 30.6 Gy (27-37.8 Gy). Median follow-up time is 6.2 years (95% confidence interval [CI]: 5.1-6.6 years) for proton patients versus 7.0 years (95% CI: 5.8-8.9 years) for photon patients. There was no significant difference in RFS or OS between patients treated with proton versus photon RT; 6-year RFS was 78.8% versus 76.5% (P=.948) and 6-year OS was 82.0% versus 87.6%, respectively (P=.285). On multivariate analysis, there was a trend for longer RFS with females (P=.058) and higher CSI dose (P=.096) and for longer OS with females (P=.093). Patterns of failure were similar between the 2 cohorts (P=.908).

CONCLUSIONS

Disease control with proton and photon radiation therapy appears equivalent for standard risk medulloblastoma.

[Evolution of the management of pediatric and adult medulloblastoma]

Medulloblastoma are cerebellar tumours belonging to the group of primitive neuroectodermal tumours (PNET) and are the most common malignant brain tumours of childhood. These tumours are rare and heterogeneous, requiring some multicentric prospective studies and multidisciplinary care. The classical therapeutic approaches are based on clinical, radiological and surgical data. They involve surgery, radiation therapy and chemotherapy. Some histological features were added to characterize risk. More recently, molecular knowledge has allowed to devise risk-adapted strategies and helped to define groups with good outcome and reduce long-term sequelae, improve the prognostic of high-risk medulloblastoma and develop new therapeutic tools.

SIOP PODC adapted treatment recommendations for standard-risk medulloblastoma in low and middle income settings

Effective treatment of children with medulloblastoma requires a functioning multi-disciplinary team with adequate neurosurgical, neuroradiological, pathological, radiotherapy and chemotherapy facilities and personnel. In addition the treating centre should have the capacity to effectively screen and manage any tumour and treatment-associated complications. These requirements have made it difficult for many low and middle-income countries (LMIC) centres to offer curative treatment. This article provides management recommendations for children with standard-risk medulloblastoma (localised tumours in children over the age of 3-5 years) according to the level of facilities available.

Local perspective on a rare brain tumour: adult medulloblastoma

BACKGROUND

Little contemporary data are available regarding Australian patterns of care in adult medulloblastoma. It is unclear whether treatment, extrapolated from paediatric protocols despite known differences between the two groups, results in comparable efficacy.

AIM

To perform a retrospective review of patterns of care in adult medulloblastoma, especially with respect to adjuvant chemotherapy, in Australian patients.

METHODS

All medulloblastoma patients aged 15 years or older at two neuro-oncology institutions were identified from January 1995-May 2011. Patients with supratentorial or peripheral tumours were excluded. Standardised data were extracted from each institution regarding symptoms, disease staging, treatments received, toxicities and survival outcomes.

RESULTS

Seventeen eligible patients were identified. Median age was 37 years (range 20-67 years). All had good performance status (Eastern Cooperative Oncology Group 0-1). There were 11 standard-risk de novo patients, three high-risk de novo patients and three patients with recurrent disease. Median overall survival (OS) had not been reached for standard-risk patients with median follow up of 58 months. The median OS for high-risk de novo patients was 21 months, while the median OS was 15 months for patients with recurrent disease. Treatment was well tolerated, with haematological toxicities being most common.

CONCLUSIONS

Combined modality therapy (surgery followed by postoperative radiotherapy and adjuvant chemotherapy) was well tolerated and associated with good outcomes in standard-risk de novo patients. High-risk and recurrent disease patients do extremely poorly regardless of treatment and better treatment strategies are needed in these patients.

Effective childhood cancer treatment: the impact of large scale clinical trials in Germany and Austria

In Germany and Austria, more than 90% of pediatric cancer patients are enrolled into nationwide disease-specific first-line clinical trials or interim registries. Essential components are a pediatric cancer registry and centralized reference laboratories, imaging review, and tumor board assistance. The five-year overall survival rate in countries where such infrastructures are established has improved from <20% before 1950 to >80% since 1995. Today, treatment intensity is tailored to the individual patient's risk to provide the highest chances of survival while minimizing deleterious late effects. Multicenter clinical trials are internationalized and serve as platforms for further improvements by novel drugs and biologicals.

High-risk medulloblastoma: a pediatric oncology group randomized trial of chemotherapy before or after radiation therapy (POG 9031)

PURPOSE

To compare event-free survival (EFS) in children with high-risk medulloblastoma randomly assigned to receive either chemotherapy before radiation or chemotherapy after radiation.

PATIENTS AND METHODS

One hundred twelve patients were randomly assigned to each arm. Criteria used to categorize patients as high risk included M1-4 disease by modified Chang staging classification, T3b/T4 disease, or greater than 1.5 cm3 of residual tumor after surgery. Postoperatively, children with high-risk medulloblastoma were randomly assigned to two arms, either chemotherapy entailing three cycles of cisplatin and etoposide before radiation (chemotherapy first [CT1]) or the same chemotherapy regimen after radiation (radiation therapy first [RT1]). Both groups received consolidation chemotherapy consisting of vincristine and cyclophosphamide.

RESULTS

The median follow-up time was 6.4 years. Five-year EFS was 66.0% in the CT1 arm and 70.0% in the RT1 arm (P = .54), and 5-year overall survival in the two groups was 73.1% and 76.1%, respectively (P = .47). In the CT1 arm, 40 of the 62 patients with residual disease achieved either complete or partial remission.

CONCLUSION

Five-year EFS did not differ significantly whether, after surgery, patients received chemotherapy before or after radiotherapy.

Medulloblastoma in the first year of life: A report of five cases

Five infants with cerebellar medulloblastoma, who all presented within the first year of life, are presented. The initial characteristic presenting symptoms included vomiting and macrocrania, frequently followed by a delay in normal development. No patients showed any signs or symptoms of cerebellar dysfunction. One infant, who was initially diagnosed as having a congenital hydrocephalus, died 4 months after undergoing a cerebrospinal fluid shunt operation, while the remaining four patients all underwent direct surgery for their tumors and three also received an additional course of postoperative radiation therapy. Of these four patients, three died within 4 years after diagnosis, with a mean survival period of 2.7 years, whereas one is still alive after a follow-up period of more than 20 years. However, the patient does suffer from both physical and intellectual handicaps. The clinical and histological features of infantile medulloblastomas are reviewed while the therapeutic problems associated with these tumors are also discussed.

Necrosis after craniospinal irradiation: results from a prospective series of children with central nervous system embryonal tumors

PURPOSE

Necrosis of the central nervous system (CNS) is a known complication of craniospinal irradiation (CSI) in children with medulloblastoma and similar tumors. We reviewed the incidence of necrosis in our prospective treatment series.

PATIENTS AND METHODS

Between 1996 and 2009, 236 children with medulloblastoma (n = 185) or other CNS embryonal tumors (n = 51) received postoperative CSI followed by dose-intense cyclophosphamide, vincristine, and cisplatin. Average risk cases (n = 148) received 23.4 Gy CSI, 36 Gy to the posterior fossa, and 55.8 Gy to the primary; after 2003, the treatment was 23.4 Gy CSI and 55.8 Gy to the primary. All high-risk cases (n = 88) received 36-39.6 Gy CSI and 55.8 Gy primary. The primary site clinical target volume margin was 2 cm (pre-2003) or 1 cm (post-2003). With competing risk of death by any cause, we determined the cumulative incidence of necrosis.

RESULTS

With a median follow-up of 52 months (range, 4-163 months), eight cases of necrosis were documented. One death was attributed. The median time to the imaging evidence was 4.8 months and to symptoms 6.0 months. The cumulative incidence at 5 years was 3.7% ± 1.3% (n = 236) for the entire cohort and 4.4% ± 1.5% (n = 196) for infratentorial tumor location. The mean relative volume of infratentorial brain receiving high-dose irradiation was significantly greater for patients with necrosis than for those without: ≥ 50 Gy (92.12% ± 4.58% vs 72.89% ± 1.96%; P=.0337), ≥ 52 Gy (88.95% ± 5.50% vs 69.16% ± 1.97%; P=.0275), and ≥ 54 Gy (82.28% ± 7.06% vs 63.37% ± 1.96%; P=.0488), respectively.

CONCLUSIONS

Necrosis in patients with CNS embryonal tumors is uncommon. When competing risks are considered, the incidence is 3.7% at 5 years. The volume of infratentorial brain receiving greater than 50, 52, and 54 Gy, respectively, is predictive for necrosis.

Population survival from childhood cancer in Britain during 1978-2005 by eras of entry to clinical trials

BACKGROUND

Inclusion in clinical trials is generally viewed as best practice for most newly diagnosed childhood cancers, but the impact on population-based survival has rarely been examined.

PATIENTS AND METHODS

The population-based data were analysed for 25 853 children (66% of all registered childhood cancers) diagnosed in Britain during 1978-2005 with acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), Hodgkin lymphoma, non-Hodgkin lymphoma, medulloblastoma, neuroblastoma, Wilms tumour, hepatoblastoma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma and germ-cell tumours. The Kaplan-Meier survival curves were compared by log-rank tests. Time trends were analysed by Cox regression. Separate analyses were done for children with ALL, medulloblastoma and neuroblastoma according to clinically relevant age thresholds.

RESULTS

Survival increased significantly during 1978-2005 for every diagnostic category; the annual reduction in risk of death ranged from 2.7% (rhabdomyosarcoma) to 12.0% (gonadal germ-cell tumours). Survival increased steadily between trial eras for ALL (age 1-14 years) and neuroblastoma (age 1-14 years), but changed little since the mid-1980s for medulloblastoma (age 0-2 years), osteosarcoma or Ewing sarcoma.

CONCLUSIONS

Changes in survival between trial eras parallel those reported by the relevant clinical trials. The increasing level of participation in trials, facilitated by the organisation of specialist care, has underpinned the substantial improvements in survival seen at the population level.