Treatment of early childhood medulloblastoma by postoperative chemotherapy and deferred radiotherapy

Abstract

To investigate the utility of postoperative chemotherapy in delaying radiotherapy and to identify prognostic factors in early childhood medulloblastoma, we studied children younger than 3 years of age registered to the HIT-SKK'87 (Therapieprotokoll für Säuglinge und Kleinkinder mit Hirntumoren [Brain Tumor Radiotherapy for Infants and Toddlers with Medulloblastoma] 1987) trial who received systemic interval chemotherapy until craniospinal radiotherapy was applied at 3 years of age or at relapse, from 1987 to 1993. Children with postoperative residual tumor or metastatic disease received systemic induction chemotherapy prior to interval chemotherapy. Twenty-nine children were eligible for analyses (median age, 1.7 years; median follow-up, 12.6 years). In children without macroscopic metastases, rates (+/-SEM) for 10-year progression-free survival (PFS) and overall survival (OS) were 52.9% +/- 12.1% and 58.8% +/- 11.9% (complete resection), and 55.6% +/- 16.6% and 66.7% +/- 15.7% (incomplete resection), compared with 0% and 0% in children with macroscopic metastases. Survival was superior in nine children with desmoplastic or extensive nodular histology compared with 20 children with classic medulloblastoma (10-year PFS, 88.9% +/- 10.5% and 30.0% +/- 10.3%, p = 0.003; OS, 88.9% +/- 10.5% and 40.0% +/- 11.0%, p = 0.006). Eleven of 12 children with tumor progression during chemotherapy had classic medulloblastoma. After treatment, IQ scores were inferior compared with nonirradiated children from the subsequent study, HIT-SKK'92. Classic histology, metastatic disease, and male gender were independent adverse risk factors for PFS and OS in 72 children from HIT-SKK'87 and HIT-SKK'92 combined. In terms of survival, craniospinal radiotherapy was successfully delayed especially in young children with medulloblastoma of desmoplastic/extensive nodular histology, which was a strong independent favorable prognostic factor. Because of the neurocognitive deficits of survivors, the emerging concepts to avoid craniospinal radiotherapy should rely on the histological medulloblastoma subtype.

Fig. 1

Treatment regimens HIT-SKK’87 and HIT-SKK’92. Abbreviations: OP, operation; HR, high risk; Ifo, ifosfamide; VP, etoposide; hd MTX, high-dose methotrexate; CDDP, cisplatinum; SR, standard risk; VCR, vincristine; d, day; post., posterior; CP, cyclophosph-amide; Carbo, carboplatin; I.ventr., intraventricular; CR, complete response.

Fig. 2

Survival rates according to staging (HIT-SKK’87). (A) Progression-free survival (PFS) for stage M0/M1 disease with (R+) and without (R0) postoperative residual tumor (10-year PFS, 52.9% and 55.6%, p = 0.986) and in children with macroscopic metastases (M2/M3; PFS, 0%; p < 0.001). (B) Overall survival (OS) in M0/M1 disease with and without postoperative residual tumor (10-year OS, 58.8% and 66.7%, p = 0.704) and in children with macroscopic metastases (0%; p = 0.001).

Fig. 3

Survival rates according to histological subtype (HIT-SKK’87). (A) Progression-free survival (PFS) in children with desmoplastic medulloblastoma (DMB) or medulloblastoma with extensive nodularity (MBEN), compared with classic medulloblastoma (CMB) (10-year PFS, 88.9% and 30.0%, p = 0.003). (B) Overall survival (OS) in children with desmoplastic DMB or MBEN compared with children with CMB (10-year OS, 88.9% and 40.0%, p = 0.006).

Fig. 4

HIT-SKK’87 compared with HIT-SKK’92: 8-year progression-free survival (PFS). (A) Children with M0/M1 disease and complete tumor resection (93.3% and 52.9%, p = 0.011). (B) Children with macroscopic metastases (M2/M3) (33.3% and 0%, p = 0.012). (C) Children with classic medulloblastoma (29.0% and 30.0%, p = 0.666). (D) Children with desmoplastic medulloblastoma and medulloblastoma with extensive nodularity (85.0% and 88.9%, p = 0.827).

Fig. 5

HIT-SKK’87 and HIT-SKK’92: Pooled analyses according to histology. (A and B) Eight-year progression-free survival (PFS) (A) and 8-year overall survival (OS) (B) of children from both studies with medulloblastoma with extensive nodularity (MBEN; 100% and 100%), with desmoplastic medulloblastoma (DMB; 76.5% and 88.2%; not significant) and classic medulloblastoma (CMB; 29.5% and 38.8%; both p < 00.001).