High-dose busulfan-thiotepa with autologous stem cell transplantation followed by posterior fossa irradiation in young children with classical or incompletely resected medulloblastoma

Evolution of Systemic Therapy in Medulloblastoma Including Irradiation-Sparing Approaches

The management of medulloblastoma in children has dramatically changed over the past four decades, with the development of chemotherapy protocols aiming at improving survival and reducing long-term toxicities of high-dose craniospinal radiotherapy. While the staging and treatment of medulloblastoma were until recently based on the modified Chang's system, recent advances in the molecular biology of medulloblastoma have revolutionized approaches in the management of this increasingly complex disease. The evolution of systemic therapies is described in this review.

High dose craniospinal irradiation as independent risk factor of permanent alopecia in childhood medulloblastoma survivors: cohort study and literature review

PURPOSE

Our aim was to determine the main risk factors related to the occurrence of permanent alopecia in childhood medulloblastoma (MB) survivors.

METHODS

We retrospectively analyzed the clinical features of all consecutive MB survivors treated at our institute. We divided the patients into 3 groups depending on the craniospinal irradiation (CSI) dose received and defined permanent alopecia first in terms of the skin region affected (whole scalp and nape region), then on the basis of the toxicity degree (G). Any relationship between permanent alopecia and other characteristics was investigated by a univariate and multivariate analysis and Odds ratio (OR) with confidence interval (CI) was reported.

RESULTS

We included 41 patients with a mean10-year follow-up. High dose CSI resulted as an independent factor leading to permanent hair loss in both groups: alopecia of the whole scalp (G1 p-value 0.030, G2 p-value 0.003) and of the nape region (G1 p-value 0.038, G2 p-value 0.006). The posterior cranial fossa (PCF) boost volume and dose were not significant factors at multivariate analysis neither in permanent hair loss of the whole scalp nor only in the nuchal region.

CONCLUSION

In pediatric patients with MB, the development of permanent alopecia seems to depend only on the CSI dose ≥ 36 Gy. Acute damage to the hair follicle is dose dependent, but in terms of late side effects, constant and homogeneous daily irradiation of a large volume may have a stronger effect than a higher but focal dose of radiotherapy.

A Holistic Review on the Current and Future Status of Biology-Driven and Broad-Spectrum Therapeutic Options for Medulloblastoma

With a thorough investigation of the etiology of medulloblastomas, a comprehensive review was done to categorize available clinical trials in order to discuss the future potential of breakthroughs in treatment options. The pertinent issues of medulloblastoma therapy with radiation being inapplicable to children under the age of 3, and therapies causing toxicity are detailed and discussed in the context of understanding how the current therapies may address these suboptimal treatment modalities. This study aggregated published studies from the US government clinical trials website and filtered them based on their direct treatment towards medulloblastomas. Thirty-two clinical trials were applicable to be analyzed and the treatment mechanisms were discussed along with the efficacy; molecular groupings of medulloblastomas were also investigated. The investigated therapies tend to target sonic hedgehog (SHH)-subtype medulloblastomas, but there is a necessity for group 3 subtype and group 4 subtype to be targeted as well. Due to the heterogeneous nature of tumor relapse in groups 3 and 4, there are less specified trials towards those molecular groupings, and radiation seems to be the main scope of treatment. Medulloblastomas being primarily a pediatric tumor require treatment options that minimize radiation to increase the quality of living in children and to prevent long-term symptoms of over radiation. Exploring symptomatic treatment with donepezil in children with combination therapies may be a potential route for future trials; immunotherapies seem to hold potential in treating patients reacting adversely to radiation therapy.

Vorinostat and isotretinoin with chemotherapy in young children with embryonal brain tumors: A report from the Pediatric Brain Tumor Consortium (PBTC-026)

BACKGROUND

Embryonal tumors of the CNS are the most common malignant tumors occurring in the first years of life. This study evaluated the feasibility and safety of incorporating novel non-cytotoxic therapy with vorinostat and isotretinoin to an intensive cytotoxic chemotherapy backbone.

METHODS

PBTC-026 was a prospective multi-institutional clinical trial for children <48 months of age with newly diagnosed embryonal tumors of the CNS. Treatment included three 21-day cycles of induction therapy with vorinostat and isotretinoin, cisplatin, vincristine, cyclophosphamide, and etoposide; three 28-day cycles of consolidation therapy with carboplatin and thiotepa followed by stem cell rescue; and twelve 28-day cycles of maintenance therapy with vorinostat and isotretinoin. Patients with M0 medulloblastoma (MB) received focal radiation following consolidation therapy. Molecular classification was by DNA methylation array.

RESULTS

Thirty-one patients with median age of 26 months (range 6-46) received treatment on study; 19 (61%) were male. Diagnosis was MB in 20 and supratentorial CNS embryonal tumor in 11. 24/31 patients completed induction therapy within a pre-specified feasibility window of 98 days. Five-year progression-free survival (PFS) and overall survival (OS) for all 31 patients were 55 ± 15 and 61 ± 13, respectively. Five-year PFS was 42 ± 13 for group 3 MB (n = 12); 80 ± 25 for SHH MB (n = 5); 33 ± 19 for embryonal tumor with multilayered rosettes (ETMR, n = 6).

CONCLUSION

It was safe and feasible to incorporate vorinostat and isotretinoin into an intensive chemotherapy regimen. Further study to define efficacy in this high-risk group of patients is warranted.

Prognostic Clinical and Biologic Features for Overall Survival after Relapse in Childhood Medulloblastoma

Simple Summary

Despite progress in the biology and upfront treatment of childhood medulloblastoma, relapse is almost universally fatal. No standardized treatment has so far been established for these patients. By determining which characteristics are prognostic after relapse, treatment strategies may be optimized for each of these children. We demonstrated that molecular subgroup at diagnosis is a relevant prognostic factor of outcome after relapse. Moreover, we showed that time to relapse and the use of salvage radiotherapy at relapse might have a potential impact on post-relapse survival. Our data suggest that ongoing efforts toward a better understanding of the biology, timing and type of relapse would be important to understand the determinants of tumor behavior at relapse. This could help us address more specific questions on the best surveillance strategies after completion of the treatment and the introduction of risk-stratified second-line treatment strategies.

Abstract

Given the very poor prognosis for children with recurrent medulloblastoma, we aimed to identify prognostic factors for survival post-relapse in children with childhood medulloblastoma. We retrospectively collected clinico-biological data at diagnosis and main clinical characteristics at relapse of children newly diagnosed with a medulloblastoma between 2007 and 2017 at Gustave Roussy and Necker Hospital. At a median follow-up of 6.6 years (range, 0.4–12.3 years), relapse occurred in 48 out 155 patients (31%). The median time from diagnosis to relapse was 14.3 months (range, 1.2–87.2 months). Relapse was local in 9, metastatic in 22 and combined (local and metastatic) in 17 patients. Second-line treatment consisted of chemotherapy in 31 cases, radiotherapy in 9, SHH-inhibitor in four and no treatment in the remaining four. The 1-year overall survival rate post-relapse was 44.8% (CI 95%, 31.5% to 59.0%). While molecular subgrouping at diagnosis was significantly associated with survival post-relapse, the use of radiotherapy at relapse and time to first relapse (>12 months) might also have a potential impact on post-relapse survival.

Strategy to minimize radiation burden in infants and high-risk medulloblastoma using intrathecal methotrexate and high-dose chemotherapy: A prospective registry study in Japan

BACKGROUND

Most childhood medulloblastoma (MB) cases are curable using multimodal treatment, including craniospinal irradiation (CSI). However, late effects are a serious problem for survivors. This prospective registry study evaluated Japanese patients to determine whether a reduced radiation dose was feasible.

PATIENTS AND METHODS

Patients with MB were classified as an infant group (<3 years old) and a high-risk (HR) group (≥3 years old with metastasis). The HR group received intrathecal methotrexate (IT-MTX) and high-dose chemotherapy (HDC) using thiotepa and melphalan, as well as concomitant radiotherapy with a recommended CSI dose of 18 Gy and a total local dose of 50 Gy. Radiotherapy was only considered for infants if residual tumors were present after the HDC.

RESULTS

Between 1997 and 2006, we identified 28 HR patients (M1: 9, M2/3: 19) and 17 infant patients (M0: 11, M1: 3, M2/3: 3). During the median follow-up of 9.4 years for the entire HR group, the 5-year progression-free survival (PFS) rate was 82.1 ± 7.2% and the 5-year overall survival (OS) rate was 85.7 ± 6.6%. Subanalyses of the patients who received the recommended treatment revealed that the 5-year PFS and OS rates were both 90.5 ± 6.4%. In the infant group, the 5-year PFS rate was 52.9 ± 12.1% and the 5-year OS rate was 51.8 ± 12.4%. There were no serious adverse events associated with the IT-MTX and HDC treatments.

CONCLUSION

Intensified chemotherapy using HDC and IT-MTX might allow for a reduced prophylactic radiation dose in patients with MB with metastases. Further studies are needed to validate these findings.

Double-conditioning regimen consisting of high-dose thiotepa and melphalan with autologous stem cell rescue for high-risk pediatric solid tumors: A second report

BACKGROUND

Pediatric patients with high-risk, relapsed, or refractory solid tumors have a poor prognosis. We have previously reported a dose-finding experience of high-dose chemotherapy consisting of thiotepa and melphalan ("double-conditioning regimen"). Using doses derived from that study, we have treated patients since 2005. We now report a retrospective review of patients treated by this fixed dose.

PROCEDURE

We reviewed 50 patients (median 4 years; range 0-15 years) with high-risk or relapsed/refractory solid tumors treated by this dose-fixed, double-conditioning regimen from April 2005 to May 2014. Doses were thiotepa 800 mg/m² and melphalan 280 mg/m² for children ≥2 years of age, and 32 mg/kg and 6 mg/kg, respectively, for children <2 years of age. Further, doses were reduced according to creatinine clearance with poor renal function.

RESULTS

Nonhematological toxicity was mainly gastrointestinal-grade 3 mucositis (n = 41) and grade 3-4 diarrhea (n = 10). Neurological, renal, and endothelial cell toxicity and sinusoidal obstruction syndrome were not observed. There were two toxic deaths (interstitial viral pneumonia). This regimen demonstrated antitumor activity against several types of tumors. Although the frequency of gastrointestinal toxicity was high, other severe toxicity was not observed.

CONCLUSIONS

Our double-conditioning regimen was very well tolerated and demonstrated antitumor activity. We are moving forward with multi-institutional trials now.

Tandem high-dose chemotherapy with topotecan-thiotepa-carboplatin and melphalan-etoposide-carboplatin regimens for pediatric high-risk brain tumors

BACKGROUND

High-dose chemotherapy (HDC) and autologous stem-cell transplantation (auto-SCT) are used to improve the survival of children with high-risk brain tumors who have a poor outcome with the standard treatment. This study aims to evaluate the outcome of HDC/auto-SCT with topotecan-thiotepa-carboplatin and melphalan-etoposide-carboplatin (TTC/MEC) regimens in pediatric brain tumors.

METHODS

We retrospectively analyzed the data of 33 children (median age 6 years) who underwent HDC/auto-SCT (18 tandem and 15 single) with uniform conditioning regimens.

RESULTS

Eleven patients aged < 3 years at diagnosis were eligible for HDC/auto-SCT to avoid or defer radiotherapy. In addition, nine patients with high-risk medulloblastoma (presence of metastasis and/or postoperative residual tumor ≥ 1.5 cm²), eight with other high-risk brain tumor (six CNS primitive neuroectodermal tumor, one CNS atypical teratoid/rhabdoid tumor, and one pineoblastoma), and five with relapsed brain tumors were enrolled. There were three toxic deaths, and two of which were due to pulmonary complications. The main reason for not performing tandem auto-SCT was due to toxicities and patient refusal. The event-free survival (EFS) and overall survival (OS) rates of all patients were 59.4% and 80.0% at a median follow-up with 49.1 months from the first HDC/auto-SCT, respectively. The EFS/OS rates of patients aged < 3 years at diagnosis, high-risk medulloblastoma, other high-risk brain tumor, and relapsed tumors were 50.0/81.8%, 87.5/85.7%, 66.7/88.9%, and 20.0/60.0%, respectively.

CONCLUSIONS

Although tandem HDC/auto-SCT with TTC/MEC regimens showed promising survival rates, treatment modifications are warranted to reduce toxicities. The survival rates with relapsed brain tumors were unsatisfactory despite HDC/auto-SCT, and further study is needed.

Safety and feasibility of outpatient autologous stem cell transplantation in pediatric patients with primary central nervous system tumors

High-dose chemotherapy with autologous hematopoietic stem cell transplantation (autoHSCT) is a well-established treatment for pediatric central nervous system (CNS) tumors. Given the risks of toxicity and infection, pediatric autoHSCT has been historically performed on hospitalized children. As our practice evolved, some patients were transplanted as outpatients. We performed a retrospective cohort analysis of 37 patients who received 90 transplant procedures (49 outpatient and 41 inpatient) at Children’s Hospital Colorado. The most common primary diagnosis was medulloblastoma (51.4%). Of the patients transplanted as outpatients, 69.4% were admitted for fever and neutropenia and had a median time to hospitalization of day +6, with fever and neutropenia being the most common reasons for admission. The median time to neutrophil engraftment was the same in both cohorts, 11 days. Median time to platelet engraftment was 13 days (8–82 days) vs 16 days (8–106 days) (p = 0.0008). At day +100, the transplant-related mortality (TRM) was 0% for both the cohorts. At a median follow-up of 1.7 years, overall survival (OS) for all patients was 66.1% and TRM was 0% for both the cohorts. Outpatient autoHSCT for properly selected children with CNS tumors is safe and effective.

Intellectual, educational, and situation-based social outcome in adult survivors of childhood medulloblastoma

PURPOSE

To investigate intellectual and situation-based social outcome and educational achievement in adult survivors of childhood medulloblastoma and analyse factors influencing outcome Methods: We collected demographic, medical and cognitive data, and social and educational outcome at a mean time since the end of treatments of 14.9 years in 58 adults, aged 19-35 years, consecutively treated in a single cancer center between 1989 and 2005.

RESULTS

Ten survivors had severe intellectual disability, 12 were still studying, 23 had a regular employment and 13 were unemployed. Full Scale Intellectual Quotient, assessed 6.6 years after the end of treatments, ranged from 46 to 131. It was strongly associated with educational achievement and significantly lower in patients who experienced postoperative cerebellar mutism, and when parental education level was low.

CONCLUSION

These factors should be systematically considered at diagnosis in order to offer adequate and timely assessments and interventions.

Late effects of craniospinal irradiation for medulloblastomas in paediatric patients

Along with surgery, radiation therapy (RT) remains an essential option to cure patients suffering from medulloblastoma. However, its long-term adverse effects, particularly due to craniospinal irradiation (CSI), which is necessary to eradicate microscopic spread, are a limiting factor. The most frequent sequelae involve neurocognitive and endocrine impairment, which occurs in nearly all patients. Recent progress achieved through genetic and molecular biology offers the possibility to better stratify patients according to risk factors such as age, post-resection tumour residue and metastasis. Thus, new therapeutic studies assess the possibility to reduce radiation dose and/or radiation field size for patients with the most favourable prognosis. New radiotherapy techniques are also used such as Intensity-Modulated Radiotherapy (IMRT), tomotherapy and proton therapy, which aim at reducing the dose delivered to normal tissue. Conventional photon-based therapy has a relatively high exit dose in contrast with proton therapy which causes less damage to surrounding healthy tissue. It is noteworthy that each technique requires a long follow-up in order to prove that late effects could be reduced without compromising survival rates. Dosimetric comparison theoretically suggests that proton therapy may be the superior method for CSI in terms of late effects, but further research is needed to firmly establish this. Whatever the technique used, the great complexity of CSI requires discipline and expertise along with an external quality control online before the first RT session.

Clinical, Pathological, and Molecular Characterization of Infant Medulloblastomas Treated with Sequential High-Dose Chemotherapy

BACKGROUND

High-dose chemotherapy (HDC) strategies were developed to avoid unacceptable neurotoxicity associated with craniospinal irradiation in infants with embryonal brain tumors. However, the impact of molecular and pathological characterizations in such approaches and long-term outcome have not been widely described in young children.

METHODS

We retrospectively collected information from seven North American institutions, on young children with medulloblastoma (MB) treated with sequential HDC, as per the CCG 99703 protocol. Data collection included clinical presentation, histology, molecular subgroup, irradiation, ototoxicity, and neurocognitive evaluations.

RESULTS

The cohort included 53 patients diagnosed at a median age of 24 months (2.9-63.2). Seventeen patients (32.1%) had nodular desmoplatic MB, all belonging to the sonic Hedgehog (SHH) subgroup, as did 30% of classic MB. The 5-year progression-free survival (PFS) and overall survival (OS) was 69.6% (±6·9%) and 76.1% (±6.5%), respectively. Seventeen (32.1%) patients received irradiation (nine adjuvant radiotherapy [RT]). Patients with SHH and group 3 MB had a 5-year PFS of 86·2% (±7.4%) and 49·1% (±14%), respectively (P = 0.03). The 5-year PFS radiation free for group 3 MB was 46.4%. Patients with macroscopic metastasis (M2 and M3) had a worst survival. Fifteen (45.5%) patients had significant ototoxicity. Mean Full Scale Intellectual Quotient (FSIQ) for 24 survivors was 91.6 (range 52-119).

CONCLUSIONS

This HDC strategy led to an encouraging OS while only 20% of the patients received adjuvant RT. SHH MB, irrespective of histological subgroup, had an excellent outcome. Such intensive therapy may not be needed for this subgroup. Patients with classic histology or group 3 had an encouraging PFS of 58% and 46.4%, respectively, in the absence of adjuvant RT. The neurocognitive profile of the survivors appears to be within the normal range.

Novel role of hematopoietic stem cells in immunologic rejection of malignant gliomas

Adoptive cellular therapy (ACT) after lymphodepletive conditioning can induce dramatic clinical responses, but this approach has been largely limited to melanoma due to a lack of reliable methods for expanding tumor-specific lymphocytes from the majority of other solid cancers. We have employed tumor RNA-pulsed dendritic cells (DCs) to reliably expand CD4⁺ and CD8⁺ tumor-reactive T lymphocytes for curative ACT in a highly-invasive, chemotherapy- and radiation-resistant malignant glioma model. Curative treatment of established intracranial tumors involved a synergistic interaction between myeloablative (MA) conditioning, adoptively transferred tumor-specific T cells, and tumor RNA-pulsed DC vaccines. Hematopoietic stem cells (HSCs), administered for salvage from MA conditioning, rapidly migrated to areas of intracranial tumor growth and facilitated the recruitment of tumor-specific lymphocytes through HSC-elaborated chemokines and enhanced immunologic rejection of intracranial tumors during ACT. Furthermore, HSC transplant under non-myeloablative (NMA) conditions also enhanced immunologic tumor rejection, indicating a novel role for the use of HSCs in the immunologic treatment of malignant gliomas and possibly other solid tumors.