Treatment of younger children with medulloblastoma

The 5-year event-free survival (EFS) rates for young children with medulloblastoma, arbitrarily described in the past as aged 3 years and younger at diagnosis, have ranged between 30% and 70%. There is no consensus as to what age constitutes a younger population of children with medulloblastoma who are best treated with immediate postsurgery chemotherapy and delayed or no radiation therapy. Most studies agree that in patients aged 3 years and younger, initial chemotherapy should be strongly considered. In patients between the ages of 3 and 4 years, and possibly as old as age 5 years, some investigators have recommended that radiation therapy be delayed or omitted entirely. Such decisions are based on multiple factors, including histological subtype, molecular subtype, extent of disease at diagnosis, preexisting neurological and neurodevelopmental status, and family preferences. Most long-term survivors who have been successfully treated with chemotherapy alone have had nondisseminated completely resected tumors.[81,103,105]; [106][Level of evidence B4] Several studies that have used chemotherapy alone for younger patients have observed that the finding of desmoplasia (seen in patients with desmoplastic medulloblastoma or MBEN) and/or molecular evidence of SHH signaling suggests a significantly better prognosis than the finding of classic or large cell/anaplastic medulloblastoma.[7,27,66-68]; [82][Level of evidence B4]

The treatment of younger children with newly diagnosed medulloblastoma continues to evolve. Results have been variable, and comparison across studies has been difficult because of differences in the drug regimens used and the utilization of craniospinal and local boost radiation therapy at the end of chemotherapy or when children reached age 3 years in some studies.

Standard treatment options for younger children with newly diagnosed medulloblastoma include the following: