Abstract 1P
Background
Medulloblastoma in adults is a rare entity. Data addressing this disease in adults are scarce. We reviewed the clinicopathological, molecular characteristics and treatment outcomes of patients treated at our center.
Methods
Patients with medulloblastoma were retrospectively analyzed from our database from 2007-2019. Data included were age at diagnosis, gender, and risk stratification including the status of metastasis, type of surgery, radiotherapy, and chemotherapy status. Overall survival (OS) and progression-free survival (PFS) were calculated using Kaplan Meier Method. Log-rank test and Cox proportional hazard models were performed to identify predictors of OS and PFS. In addition, molecular sub-grouping was conducted on 29 patients.
Results
A total of 54 patients were eligible for the study. Median age at diagnosis was 26 years. Most (77.8%) patients were non-metastatic at presentation (M0 Chang stage). Complete resection was achieved in 81.5% of patients and all received adjuvant radiation. Chemotherapy was administered at the time of progression or recurrence. 59.3% were standard risk. The most common molecular subtype, Sonic hedgehog (SHH), was identified in 79.3% (23/29) of patients, followed by WNT and Group 4 each account for 10.3%. With a median follow-up of 53 months, 15 patients (27.8%) developed relapses, seven relapses were distant, three were local and five had both local and distant relapses. Five-year OS and PFS were 68.4%, and 70.0%, respectively. Patients in SHH subgroup had 5-year OS (61.4%) and PFS (59.0%), whereas 5-year OS and PFS were 100% for both Group 4 and WNT subgroups. 66.7% of distant and combined relapses were from the high-risk cohort. On univariate analysis, high-risk group and the presence of metastases conferred poor OS (p=0.007, p=0.008) and PFS (p=0.03, p=0.03). However, on multivariate analysis, none of the variables retained significance.
Conclusions
Our study is among the largest reports on adult medulloblastoma. Distant relapse is the predominant pattern in high-risk patients supporting the need for treatment intensification. SHH is the most common molecular subtype in adults and their survival outcome appears to be worse compared to pediatrics with the same molecular subgroup.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.