Proposed Additions to the NCCN Guidelines for Adult Medulloblastoma

Virtual multi-institutional tumor board: a strategy for personalized diagnoses and management of rare CNS tumors

PURPOSE

Multidisciplinary tumor boards (MTBs) integrate clinical, molecular, and radiological information and facilitate coordination of neuro-oncology care. During the COVID-19 pandemic, our MTB transitioned to a virtual and multi-institutional format. We hypothesized that this expansion would allow expert review of challenging neuro-oncology cases and contribute to the care of patients with limited access to specialized centers.

METHODS

We retrospectively reviewed records from virtual MTBs held between 04/2020-03/2021. Data collected included measures of potential clinical impact, including referrals to observational or therapeutic studies, referrals for specialized neuropathology analysis, and whether molecular findings led to a change in diagnosis and/or guided management suggestions.

RESULTS

During 25 meetings, 32 presenters discussed 44 cases. Approximately half (n = 20; 48%) involved a rare central nervous system (CNS) tumor. In 21% (n = 9) the diagnosis was changed or refined based on molecular profiling obtained at the NIH and in 36% (n = 15) molecular findings guided management. Clinical trial suggestions were offered to 31% (n = 13), enrollment in the observational NCI Natural History Study to 21% (n = 9), neuropathology review and molecular testing at the NIH to 17% (n = 7), and all received management suggestions.

CONCLUSION

Virtual multi-institutional MTBs enable remote expert review of CNS tumors. We propose them as a strategy to facilitate expert opinions from specialized centers, especially for rare CNS tumors, helping mitigate geographic barriers to patient care and serving as a pre-screening tool for studies. Advanced molecular testing is key to obtaining a precise diagnosis, discovering potentially actionable targets, and guiding management.

Adult medulloblastoma in an Australian population

Medulloblastoma in adult patients is a rare condition with limited contemporary demographic and treatment outcome data available in an Australian population. We conducted a retrospective review of patterns of care and outcomes of adult patients diagnosed with medulloblastoma treated at major neuro-oncology centres across Australia between January 2010 and December 2019. A total of 80 patients were identified and the median follow-up after diagnosis was 59.2 (range 0.5-204) months. A variety of chemotherapy regimens were used in the adjuvant and recurrent settings. The median overall survival (mOS) was 78 months (IQR 17.5-94.8). Patients who had no residual disease post-resection or with SHH-subtype tumours had a numerically longer 5-year survival rate than those with residual disease post resection or non-SHH subtypes respectively. The median time to recurrence from diagnosis was 18.4 months. The median OS from 1st relapse was 22.1 months (95% CI 11.7-31.4) and mOS from second relapse was 10.2 months (95% CI 6.6 - NR). This is the largest dataset examining patterns of care of adult patients with medulloblastoma in an Australian population. Substantial variation existed in the chemotherapy agents used in the adjuvant and recurrent setting. As has been demonstrated in a paediatric population, trials such as the upcoming EORTC 1634-BTG/NOA-23 trial (PersoMed-1 study) which are tailoring treatments to molecular profiles are likely to improve outcome in adult medulloblastoma.

Prognostic factors related to overall survival in adolescent and young adults with medulloblastoma: a systematic review

Background

Medulloblastoma is a rare diagnosis among adolescents and young adults (AYA). Though prognostic factors and treatment are well characterized among children with medulloblastoma, equivalent data for AYA are sparse. We conducted a systematic review to identify predictors of survival among AYA with medulloblastoma.

Methods

We searched for primary studies of AYA (age 15–39 at diagnosis) with medulloblastoma in high-income countries within OVID MEDLINE, EMBASE, and EBM Reviews-Cochrane library databases from inception to August 2020. Patient demographics, primary outcomes, and univariate and multivariable data on all prognostic factors were collected from included studies. Prognosticators were characterized as patient, disease, or treatment-related.

Results

We identified 18 articles. 5-year overall survival ranged between 40% and 89%, while disease-free survival ranged from 49% to 89%. Study quality was low as assessed by the Quality in Prognostic factor Studies tool. Though meta-analyses were not possible due heterogeneity, narrative summaries suggested that lower disease burden, superior postoperative functional status, and higher doses and larger fields of radiation were associated with improved survival. Reported chemotherapy regimens were heterogeneous in timing, agents, and relationship with radiation, precluding meaningful comparisons. Only one study included molecular subgroups for analysis, with the majority (76.5%) of tumors classified as Sonic Hedgehog (SHH).

Conclusions

Prognostication and treatment of AYA medulloblastoma is limited by a dearth of primary evidence and lack of specificity for patients aged 15–39. Dedicated prospective trials to delineate the benefit of various chemotherapy and radiation regimens are required in this population to identify prognosticators and ideal treatment regimens.

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.