Treatment of Childhood Embryonal Tumors With Multilayered Rosettes or Medulloepithelioma

A registry-based review of 159 patients with a confirmed molecular diagnosis of ETMR reported survival results for different treatments.[11]

In a separate, but possibly overlapping, international retrospective review, 49 patients with histologically confirmed (by the treating institution) ETMRs were treated between 1988 to 2017 in a variety of ways.[35] The 5-year progression-free survival rate was 18% (± 6%), and the OS rate was 24% (± 6%). Most survivors received radiation therapy, including both local and craniospinal treatment, and there was no clear difference in outcomes between the types and extent of radiation therapy. The relative benefits of conventional chemotherapy compared with high-dose chemotherapy could not be assessed.[5]

In a subsequent publication, likely including some of the patients from the retrospective study, treatment was limited to only those who received chemotherapy and radiation therapy on the prospective P-HIT study or per the study protocol. The P-HIT study included postsurgery chemotherapy, high-dose chemotherapy, and radiation for some patients. In 35 patients with ETMRs, 8 long-term survivors were identified, 6 of whom had received either craniospinal or local radiation therapy, in addition to induction and high-dose chemotherapy. None of the patients who presented with brain stem disease survived. The 5-year survival was best for patients with localized disease, possibly for those treated with both induction and high-dose chemotherapy. The role of radiation therapy or the optimal volume of radiation therapy (local versus craniospinal) could not be determined.[10]

These studies suggest that the outcome for children with ETMRs may not be as dire as suggested by initial studies, which found a 5-year survival rate of 25% or lower. Outcome is more favorable in children with localized disease at the time of diagnosis and those who were treated with aggressive postsurgical chemotherapy, including induction and high-dose consolidation treatment. The role of radiation therapy is still unproven, and there is no evidence that craniospinal radiation in patients with localized disease is superior to focal radiation therapy.[5,10,11]