Age-Dependent Toxicity Patterns in Medulloblastoma: A Comparative Analysis of Treatment-Related Adverse Events Between Pediatric and Adult Populations

Background/Objectives: to compare and characterize the frequency and severity of treatment-related adverse events (TRAEs) experienced by pediatric and adult patients with medulloblastoma receiving the same pediatric-based treatments. Methods: a retrospective comparative study of TRAEs was conducted on 18 adult patients and 45 pediatric patients with medulloblastoma treated at the same institution with craniospinal/local radiotherapy and chemotherapy delivered according to pediatric regimens (i.e., PNET3, PNET4, PNET5 or high-risk protocols). Results: Grade ≥ 3 hematological TRAEs were significantly more frequent in adults (61.1% vs. 33.3%, p = 0.038). Adults also more frequently suffered from weight loss > 10% than children (72.2% vs. 40%, p = 0.018). The incidence of chemotherapy-induced peripheral neuropathy did not differ significantly between the two groups (27.7% in adults versus 22.2% in children, p = 0.65). These findings suggest that adult patients treated with pediatric-derived protocols may benefit from more proactive hematologic and nutritional supportive care to safely maintain treatment intensity. Objective severe ototoxicity was 22.2% and 17.8% in adults and children (p = 0.69), respectively. There were significantly more adults than children who needed a dose reduction (55.6% vs. 28.9% in children, p = 0.042) and who stopped treatment prematurely (44.4% vs. 20.1% in children, p = 0.048). There was no difference in 5-year overall survival between adults and the pediatric population (88.8% vs. 86.7%, p = 0.82). Conclusions: Adults are at an increased risk of hematological and nutritional toxicities when treated for medulloblastoma with identical treatment regimens. These age-related patterns of sensitivity demand protocol modifications (such as more supportive care, nutritional support, and possibly lower dose intensities). Although there were more treatment modifications due to more severe toxicity, adults had the same survival rates as children, suggesting pediatric-based protocols should still be employed with modifications to supportive care.