Medulloblastoma in the Second Decade of Life: a Specific Group with Respect to Toxicity and Management: a Canadian Pediatric Brain Tumor Consortium Study

Background: Most reported data of chemoradiotherapy protocols for the treatment of medulloblastoma describe children who were treated in the first decade of life. To consider the feasibility of this approach in adolescents, the authors studied their clinical course with specific emphasis on toxicity, tolerability, and prognosis.

Methods: In this retrospective study, the authors examined the toxicity profiles and outcomes of children age 10-20 years with medulloblastoma who were treated at centers throughout Canada between 1986 and 2003. Detailed toxicity data from 2 chemotherapy protocols were collected for teenagers and were compared with data from a group of control patients age 5-10 years.

Results: In total, 72 teenagers were analyzed. Grade >/= 2 ototoxicity and neurotoxicity occurred in 45% and 71% of chemotherapy-treated patients, respectively. Grade 3-4 hematotoxicty occurred in 95% of patients. Toxicity resulted in delay of treatment for 73% of patients and dose modification in 75% of patients, including protocol discontinuation in 25% of patients. Weight loss > 10% was encountered in 73% of patients and required intervention in 45% of patients. Teenagers had significantly more hematotoxicity and neurotoxicity compared with controls on both chemotherapeutic protocols. Ototoxicity was similar in both age groups. Toxicity resulted in significantly more treatment delays and dose modifications in teenager patients compared with controls. The 5-year overall and event-free survival rates (+/- standard deviation) were 78% +/- 6% and 70% +/- 6%, respectively. The mean time (+/- standard deviation) to disease recurrence was 3.2 +/- 2.2 years.

Conclusions: The increased toxicity rate and high incidence of treatment modifications in this study suggested that current pediatric protocols may require modifications for teenagers with medulloblastoma. The results highlighted several issues that should be addressed in future prospective trials.