Nonmetastatic Medulloblastoma of Early Childhood: Results From the Prospective Clinical Trial HIT-2000 and An Extended Validation Cohort

PURPOSE

The HIT-2000-BIS4 trial aimed to avoid highly detrimental craniospinal irradiation (CSI) in children < 4 years of age with nonmetastatic medulloblastoma by systemic chemotherapy, intraventricular methotrexate, and risk-adapted local radiotherapy.

PATIENTS AND METHODS

From 2001-2011, 87 patients received systemic chemotherapy and intraventricular methotrexate. Until 2006, CSI was reserved for nonresponse or progression. After 2006, local radiotherapy was introduced for nonresponders or patients with classic medulloblastoma (CMB) or large-cell/anaplastic medulloblastoma (LCA). DNA methylation profiles of infantile sonic hedgehog-activated medulloblastoma (SHH-INF) were subdivided into iSHH-I and iSHH-II subtypes in the HIT-2000-BIS4 cohort and a validation cohort (n = 71) from the HIT group and Russia.

RESULTS

Five years after diagnosis, patients with desmoplastic medulloblastoma (DMB) or medulloblastoma with extensive nodularity (MBEN; n = 42) had 93% progression-free survival (5y-PFS), 100% overall survival (5y-OS), and 93% CSI-free (5y-CSI-free) survival. Patients with CMB/LCA (n = 45) had 37% 5y-PFS, 62% 5y-OS, and 39% 5y-CSI-free survival. Local radiotherapy did not improve survival in patients with CMB/LCA. All DMB/MBEN assessed by DNA methylation profiling belonged to the SHH-INF subgroup. Group 3 patients (5y-PFS, 36%; n = 14) relapsed more frequently than the SHH-INF group (5y-PFS, 93%; n = 28) or group 4 patients (5y-PFS, 83%; n = 6; P < .001). SHH-INF split into iSHH-I and iSHH-II subtypes in HIT-2000-BIS4 and the validation cohort, without prognostic impact (5y-PFS: iSHH-I, 73%, v iSHH-II, 83%; P = .25; n = 99). Intelligence quotient (IQ) was significantly lower in patients after CSI (mean IQ, 90 [no radiotherapy], v 74 [CSI]; P = .012).

CONCLUSION

Systemic chemotherapy and intraventricular methotrexate led to favorable survival in both iSHH subtypes of SHH-activated DMB/MBEN with acceptable neurotoxicity. Survival in patients with non-wingless (WNT)/non-SHH disease with CMB/LCA was not improved by local radiotherapy. Patients with group 4 disease had more favorable survival rates than those with group 3 medulloblastoma.

Desmoplastic nodular medulloblastoma in young children: a management dilemma

Background

Children with desmoplastic nodular medulloblastoma (DNMB) have excellent survival, leading multiple groups globally to attempt reduction of treatment-related morbidity. In 2013, the Children's Oncology Group began a clinical trial (ACNS1221) eliminating both radiation therapy (RT) and intraventricular methotrexate for children under 3 years of age with localized DNMB, aiming to build upon the excellent outcomes of the German HIT trials. ACNS1221 has recently closed due to increased incidence of recurrences noted at the 2-year interim analysis, raising important questions regarding optimal therapy for DNMB.

Methods

A review of major clinical trials that included children with DNMB was performed through July 2017.

Results

One hundred and eighty-eight DNMB patients enrolled on 11 prospective clinical trials were identified. The use of marrow-ablative chemotherapy and autologous hematopoietic cell rescue (AuHCR) or treatment with intraventricular methotrexate has been associated with excellent outcomes. RT was usually required for patients with evidence of disease at the end of therapy.

Conclusions

The minimal intensity and duration of chemotherapy required to maximally cure children with DNMB without need of RT remains unknown. Further trials are required to better identify a subset of DNMB patients who can be cured without marrow-ablative chemotherapy or intraventricular methotrexate.