Management and outcomes of treating pediatric medulloblastoma: an eight years' experience in an Iranian pediatric center

Treatment Outcomes of Childhood Medulloblastoma with the SIOP/UKCCSG PNET-3 Protocol

OBJECTIVES

To retrospectively compare the overall and event-free survival rates of patients with standard and high risk medulloblastoma who received postoperative radiotherapy (RT) followed by maintenance chemotherapy.

METHODS

The study included 48 patients with medulloblastoma who were treated and followed-up between 2005 and 2021. Patients were classified according to the Chang classification because no molecular analysis was done. Immediately after surgery all patients received postoperative RT followed by eight cycles of chemotherapy (SIOP/UKCCSG PNET-3 protocol); if thrombocytopenia developed, carboplatin was replaced by cisplatin to avoid treatment delay. The clinical characteristics, risk categories and treatment outcomes of all patients were analyzed.

RESULTS

The mean age of the 48 patients (26 males, 22 females) at diagnosis was 7.27±4.21 y. The median start time of RT after surgery was 37 (range 19-80) d. The median follow-up was 56 (3-216) mo. The 5-year event-free survival was 61.2±10% in the high-risk group and 82.5±11.5% in the standard-risk group. The 5-year overall survival was 73.2±7.1%; it was 61.2±10% and 92.9±6.9% for high- and standard-risk patients, respectively (p = 0.026).

CONCLUSIONS

The outcomes of patients who were started on the modified SIOP/UKCCSG PNET-3 chemotherapy protocol, in which RT was begun as soon as possible after surgery, were comparable to those of current treatment protocols. Although a definitive conclusion is difficult, given the limited number of patients in the present study, authors suggest that their treatment protocol is a viable option for centers with limited facilities (such as an inability to perform molecular analysis).

Current Strategies for Management of Medulloblastoma

Medulloblastoma (MB) is the most common malignant central nervous system tumor of childhood, which includes multiple molecular subgroups (4) and subtypes (8 to 12), each with different outcomes and potential therapy options. Long-term survival remains poor for many of the subtypes, with high late mortality risks and poor health-related quality of life. Initial treatment strategies integrate molecular subgroup information with more standard clinical and phenotypic factors to risk stratify newly diagnosed patients. Clinical trials treating relapsed disease, often incurable, now include multiple new approaches in an attempt to improve progression-free and overall survival.

Current studies and future directions for medulloblastoma: A review from the pacific pediatric neuro-oncology consortium (PNOC) disease working group

Medulloblastoma (MB) is the most common malignant central nervous system tumor of childhood, comprising a heterogenous group of tumors each with distinct biology, clinical behavior, and prognosis. Long-term survival remains unacceptable, and those who do survive face high late mortality risk, new chronic treatment-related medical conditions, neurocognitive impairments, and poor health-related quality of life. Up-front treatment strategies now integrate molecular subgrouping with standard clinico-radiological factors to more actually risk stratify newly-diagnosed patients. To what extent this new stratification will lead to improvements in treatment outcome will be determined in the coming years. In parallel, discovery and appreciation for medulloblastoma's inter- and intra-tumoral heterogeneity continues growing. Clinical trials treating relapsed disease now encompass precision medicine, epigenetic modification, and immune therapy approaches. The Pacific Pediatric Neuro-Oncology (PNOC) Medulloblastoma Working Group is committed to developing clinical trials based on these evolving therapeutic strategies and supports translational efforts by PNOC researchers and the multi-stakeholder medulloblastoma community at large.

Epidemiological characteristics and survival outcomes of children with medulloblastoma treated at the National Cancer Institute (INCA) in Rio de Janeiro, Brazil

BACKGROUND

Medulloblastoma (MB),the most common malignant brain tumor of childhood has survival outcomes exceeding 80% for standard-risk and 60% for high-risk patients in high-income countries (HICs). These results have not been replicated in low- and middle-income countries (LMICs), where 80% of children with cancer live.

METHODS

This is a retrospective review of 114 children aged 3-18 years diagnosed with MB from 1997 to 2016 at National Cancer Institute (INCA). Sociodemographic, clinical, and treatment data were extracted from the medical records and summarized descriptively. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method.

RESULTS

The male-to-female ratio was 1.32 and the median age at diagnosis was 8.2 years. Headache (83%) and nausea/vomiting (78%) were the most common presenting symptoms. Five-year OS was 59.1% and PFS was 58.4%. The OS for standard-risk and high-risk patients was 69% and 53%, respectively. The median time to diagnosis interval was 50.5 days and the median time from surgery to radiation therapy initiation was 50.4 days. Patients who lived >40 km from INCA fared better (OS = 68.2% vs. 51.1%, p = .032). Almost 20% of families lived below the Brazilian minimum wage. Forty-five patients (35%) had metastatic disease at admission. Gross total resection was achieved in 57% of the patitents.

CONCLUSIONS

Although there are considerable barriers to deliver effective MB treatment in countries like Brazil, the OS seen in the present study demonstrates that good outcomes are not only feasible but can and should be increased with appropriate interventions.

Molecular Subgroup Is the Strongest Predictor of Medulloblastoma Outcome in a Resource-Limited Country

PURPOSE

Medulloblastoma is composed of four clinically and prognostically distinct molecular subgroups (WNT, SHH, group 3, and group 4). However, the clinical implications of these subgroups in the context of the unique challenges of low- to middle-income countries are rarely reported.

METHODS

We assembled an institutional cohort of children (3-18 years) diagnosed with medulloblastoma and treated in Jordan between 2003 and 2016. Tumors were subgrouped by NanoString and correlated with clinical and radiologic characteristics.

RESULTS

Eighty-eight patients were identified (63% male); median age was 6.9 years (interquartile range 4.8-9.2) and median symptom duration was 6 weeks (interquartile range 4-11). Radiotherapy was implemented as standard-risk in 41 patients (47%) and high-risk in 47 patients (53%). Subgrouping revealed 17 WNT (19%), 22 SHH (25%), 21 group 3 (24%), and 28 group 4 tumors (32%). Median time between craniotomy and radiotherapy was 45 days (17-155); 44% of them > 49 days. Median duration of radiotherapy was 44 days (36-74). Seventy-two patients (82%) received chemotherapy afterward. With a median follow-up of 4.6 years (0.2-14.9), 5-year progression-free survival (PFS) and overall survival were 73.5% and 69.4%, respectively, with no statistically significant survival difference between standard-risk and high-risk patients. Metastasis was significant for overall survival (P = .011). Patients with SHH and group 4 tumors had very good PFS (83.4% and 87.0%, respectively) and those with group 3 tumors had dismal outcomes (PFS 44.9%), whereas WNT tumors had less-than expected PFS (70.5%). PFS was statistically significant in patients with nonmetastatic tumors receiving radiotherapy ≤ 49 days (P = .011), particularly group 3 tumors.

CONCLUSION

Patients with SHH and group 4 medulloblastoma had excellent survival comparable with high-income countries. Compliance with treatment protocols and avoiding radiotherapy delays are important in achieving adequate survival in low- to middle-income country settings. Subgroup-driven treatment protocols should be considered in countries with limited resources.

Improving Pediatric Neuro-Oncology Survival Disparities in the United States-Mexico Border Region: A Cross-Border Initiative Between San Diego, California, and Tijuana, Mexico

PURPOSE

Treatment of children with CNS tumors (CNSTs) demands a complex, interdisciplinary approach that is rarely available in low- and middle-income countries. We established the Cross-Border Neuro-Oncology Program (CBNP) between Rady Children's Hospital, San Diego (RCHSD), and Hospital General, Tijuana (HGT), Mexico, to provide access to neuro-oncology care, including neurosurgic services, for children with CNSTs diagnosed at HGT. Our purpose was to assess the feasibility of the CBNP across the United States-Mexico border and improve survival for children with CNSTs at HGT by implementing the CBNP.

PATIENTS AND METHODS

We prospectively assessed clinicopathologic profiles, the extent of resection, progression-free survival, and overall survival (OS) in children with CNSTs at HGT from 2010 to 2017.

RESULTS

Sixty patients with CNSTs participated in the CBNP during the study period. The most common diagnoses were low-grade glioma (24.5%) and medulloblastoma (22.4%). Of patients who were eligible for surgery, 49 underwent resection at RCHSD and returned to HGT for collaborative management. Gross total resection was achieved in 78% of cases at RCHSD compared with 0% at HGT (P < .001) and was a predictor of 5-year OS (hazard ratio, 0.250; 95% CI, 0.067 to 0.934; P = .024). Five-year OS improved from 0% before 2010 to 52% in 2017.

CONCLUSION

The CBNP facilitated access to complex neuro-oncology care for underserved children in Mexico through binational exchanges of resources and expertise. Survival for patients in the CBNP dramatically improved. Gross total resection at RCHSD was associated with higher OS, highlighting the critical role of experienced neurosurgeons in the treatment of CNSTs. The CBNP model offers an attractive alternative for children with CNSTs in low- and middle-income countries who require complex neuro-oncology care, particularly those in close proximity to institutions in high-income countries with extensive neuro-oncology expertise.

Medulloblastoma has a global impact on health related quality of life: Findings from an international cohort

Background

Understanding the global impact of medulloblastoma on health related quality of life (HRQL) is critical to characterizing the broad impact of this disease and realizing the benefits of modern treatments. We evaluated HRQL in an international cohort of pediatric medulloblastoma patients.

Methods

Seventy‐six patients were selected from 10 sites across North America, Europe, and Asia, who participated in the Medulloblastoma Advanced Genomics International Consortium (MAGIC). The Health Utilities Index (HUI) was administered to patients and/or parents at each site. Responses were used to determine overall HRQL and attributes (ie specific subdomains). The impact of various demographic and medical variables on HRQL was considered—including molecular subgroup.

Results

The majority of patients reported having moderate or severe overall burden of morbidity for both the HUI2 and HUI3 (HUI2 = 60%; HUI3 = 72.1%) when proxy‐assessed. Self‐care in the HUI2 was rated as higher (ie better outcome) for patients from Western versus Eastern sites, P = .02. Patients with nonmetastatic status had higher values (ie better outcomes) for the HUI3 hearing, HUI3 pain, and HUI2 pain, all P < .05. Patients treated with a gross total resection also had better outcomes for the HUI3 hearing (P = .04). However, those who underwent a gross total resection reported having worse outcomes on the HUI3 vision (P = .02). No differences in HRQL were evident as a function of subgroup.

Conclusions

By examining an international sample of survivors, we characterized the worldwide impact of medulloblastoma. This is a critical first step in developing global standards for evaluating long‐term outcomes.

The magnitude and predictors of therapy abandonment in pediatric central nervous system tumors in low- and middle-income countries: Systematic review and meta-analysis

BACKGROUND

Outcomes of pediatric central nervous system (CNS) tumors in low- to middle-income countries (LMIC) are poorer than their high-income counterparts. Abandonment of therapy is increasingly recognized as a key contributor to this disparity, but has been poorly quantified. We performed a meta-analysis to determine the magnitude of abandonment in pediatric CNS tumors in LMIC, and risk factors and interventions aimed at reducing this.

PATIENTS AND METHODS

We searched seven databases for pediatric CNS tumor cohorts followed up from diagnosis and treated in LMIC. All languages were included. Two reviewers independently selected articles and extracted data on abandonment rates (ARs) and predictors. The authors were contacted for additional information.

RESULTS

Of 50 660 publications, 643 in five languages met criteria for full review; 131 met analysis inclusion criteria. ARs were not reported in the majority, and a small number were available from the authors. Available ARs ranged from 0% to 59%, from 38 studies (2497 children in 14 countries), and these were quantitatively analyzed. Lower-middle-income countries had higher ARs than upper-middle-income countries (27%, 95% confidence interval [CI] 20%-36% vs 9%, 95% CI 6%-14%, P < 0.0001), with significant heterogeneity within each (LMIC I₂  = 78%, P < 0.00001, UMIC I₂  = 85%, P < 0.00001). Common predictors for abandonment included distance to treatment centers, financial hardship, and prognostic misconceptions.

CONCLUSION

In LMICs, ARs are highest in lower-MICs. However, the paucity of published data limits further evaluation. Given the increasing burden of pediatric CNS tumors in LMIC, addressing deficits in abandonment reporting is critical. Consistent reporting is needed for developing interventions to improve outcomes.