Long-term results of combined preradiation chemotherapy and age-tailored radiotherapy doses for childhood medulloblastoma

Optimizing reirradiation for relapsed medulloblastoma: identifying the ideal patient and tumor profiles

BACKGROUND

First-line therapies for medulloblastoma(MBL) are obtaining higher survival-rates while decreasing late-effects, but treatment at relapse is not standardized. We report here the experience with MBL re-irradiation(re-RT), its timing and outcome in different clinical settings and tumor groups.

METHODS

Patient's staging/treatment at diagnosis, histotypes/molecular subgroups, relapse site/s, re-treatments outcome are reported.

RESULTS

25 patients were included, with a median age of 11.4 years; 8 had metastases. According to 2016-2021 WHO-classification, 14 had SHH subgroup tumors(six TP53 mutated,one + MYC,one + NMYC amplification), 11 non-WNT/non-SHH (two with MYC/MYCN amplification).Thirteen had received HART-CSI, 11 standard-CSI, one HFRT; all post-radiation chemotherapy(CT), 16 also pre-RT. Median time to relapse (local-LR in nine, distant-DR in 14, LR + DR in two) was 26 months. Fourteen patients were re-operated, in five cases excising single DR-sites, thereafter three received CT, two after re-RT; out of 11 patients not re-operated, four had re-RT as first treatment and seven after CT. Re-RT was administered at median 32 months after first RT: focally in 20 cases, craniospinal-CSI in five. Median post-relapse-PFS/after re-RT was 16.7/8.2 months, while overall survival-OS was 35.1/23.9 months, respectively. Metastatic status both at diagnosis/relapse negatively affected outcome and re-surgery was prognostically favorable. PD after re-RT was however significantly more frequent in SHH (with a suggestive association with TP53 mutation, p = 0.050). We did not observe any influence of biological subgroups on PFS from recurrence while SHH showed apparently worse OS compared to non-WNT/non-SHH group.

CONCLUSIONS

Re-surgery + reRT can prolong survival; a substantial fraction of patients with worse outcome belongs to the SHH-subgroup.

Automatic Machine Learning to Differentiate Pediatric Posterior Fossa Tumors on Routine MR Imaging

BACKGROUND AND PURPOSE

Differentiating the types of pediatric posterior fossa tumors on routine imaging may help in preoperative evaluation and guide surgical resection planning. However, qualitative radiologic MR imaging review has limited performance. This study aimed to compare different machine learning approaches to classify pediatric posterior fossa tumors on routine MR imaging.

MATERIALS AND METHODS

This retrospective study included preoperative MR imaging of 288 patients with pediatric posterior fossa tumors, including medulloblastoma (n = 111), ependymoma (n = 70), and pilocytic astrocytoma (n = 107). Radiomics features were extracted from T2-weighted images, contrast-enhanced T1-weighted images, and ADC maps. Models generated by standard manual optimization by a machine learning expert were compared with automatic machine learning via the Tree-Based Pipeline Optimization Tool for performance evaluation.

RESULTS

For 3-way classification, the radiomics model by automatic machine learning with the Tree-Based Pipeline Optimization Tool achieved a test micro-averaged area under the curve of 0.91 with an accuracy of 0.83, while the most optimized model based on the feature-selection method χ2 score and the Generalized Linear Model classifier achieved a test micro-averaged area under the curve of 0.92 with an accuracy of 0.74. Tree-Based Pipeline Optimization Tool models achieved significantly higher accuracy than average qualitative expert MR imaging review (0.83 versus 0.54, P < .001). For binary classification, Tree-Based Pipeline Optimization Tool models achieved an area under the curve of 0.94 with an accuracy of 0.85 for medulloblastoma versus nonmedulloblastoma, an area under the curve of 0.84 with an accuracy of 0.80 for ependymoma versus nonependymoma, and an area under the curve of 0.94 with an accuracy of 0.88 for pilocytic astrocytoma versus non-pilocytic astrocytoma.

CONCLUSIONS

Automatic machine learning based on routine MR imaging classified pediatric posterior fossa tumors with high accuracy compared with manual expert pipeline optimization and qualitative expert MR imaging review.

Social attainment in survivors of pediatric central nervous system tumors: a systematic review and meta-analysis from the Children's Oncology Group

PURPOSE

Improved therapies for pediatric central nervous system (CNS) tumors have increased survival rates; however, many survivors experience significant long-term functional limitations. Survivors of pediatric CNS tumors can experience deficits in social attainment. The aim of this review was to systematically amalgamate findings pertaining to social attainment (i.e., educational attainment, marriage, employment outcomes) in survivors of pediatric CNS tumors.

METHODS

PubMed (web-based), PsycINFO (EBSCO), EMBASE (Ovid), and Web of Science (Thomson Reuters) were used to identify articles published between January 2011 and September 2018. Eligible studies reported outcomes for survivors of pediatric CNS tumors diagnosed before age 21 years and > 5 years from diagnosis and/or > 2 years off therapy. All data were independently abstracted by two reviewers. Random-effects meta-analyses were performed using Review Manager 5.0.

RESULTS

The search yielded 7021 unique publications. Forty-six were included in the current review. Meta-analyses revealed survivors of CNS tumors were significantly more likely to have completed compulsory education only (OR = 1.87, 95% CI = 1.66, 2.12, p < 0.00001), less likely to be married (OR = 4.70, 95% CI = 3.89, 5.68, p < 0.00001), and more likely to be unemployed (OR = 2.84, 95% CI = 2.62, 3.08, p < 0.00001) compared to non-cancer controls. Cranial radiation therapy, neurocognitive deficits, and younger age at diagnosis were associated with poorer outcomes. Hearing loss and bilateral blindness were also related to poorer outcomes. Sex did not impact social attainment outcomes.

CONCLUSIONS

Survivors of pediatric CNS tumors are at elevated risk for poor attainment of key adult social outcomes.

IMPLICATIONS FOR CANCER SURVIVORS

There is a critical need to develop interventions to support survivors in becoming independent and productive adults.

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.

Targeting inhibitors of apoptosis proteins suppresses medulloblastoma cell proliferation via G2/M phase arrest and attenuated neddylation of p21

Medulloblastoma (MB) is the most common type of malignant childhood brain tumor. We previously showed that inhibitors of apoptosis proteins (IAP) small‐molecule inhibitors (LCL161 or LBW242) combined with chemotherapy have synergistic antiproliferative effects on MB cells. The synergistic antitumor effects of combination treatments happen through induction of autophagy and caspase‐3/7‐activated apoptosis. Here, we investigated the effects of IAP inhibitors or silencing IAP on cell cycle regulation. We discovered that treatment with IAP inhibitors or their combination with conventional chemotherapy (vincristine or cisplatin), as well as RNAi knockdown of cIAP1/2 or XIAP arrested MB cells in the G2/M phase through downregulation of cyclin B1‐CDK1 and cyclin A‐CDK1/2. Among these three IAPs, only silencing cIAP1 expression enhanced p21 dependent‐G2/M phase accumulation. IAP inhibitors reduced cIAP1 expression and increased p21 expression in time course experiments. Furthermore, cIAP1 can govern p21 proteasomal degradation via neddylation in lieu of ubiquitination. Inhibition of IAPs significantly abrogated cIAP1‐mediated p21 degradation. We also observed an inverse correlation between nuclear cIAP1 and nuclear p21 expressions in MB tumor tissues. These findings provide new mechanistic evidence of the influence of IAP inhibitors on MB cell proliferation through disruption of the cell cycle.

Blocking interleukin-6 signaling inhibits cell viability/proliferation, glycolysis, and colony forming activity of human medulloblastoma cells

Elevated levels of the pro-inflammatory cytokine interleukin-6 (IL-6) have tumor-promoting activity and are associated with poor survival outcomes in many cancers. Additionally, the IL-6/GP130/STAT3 axis has been widely studied due to its pivotal role in tumor development and maintenance in a number of tissue types, including the cerebellum. However, the connection between IL-6 signaling and medulloblastoma progression is largely unexplored. In the present study, we observed that IL-6 induced medulloblastoma cell viability, cell proliferation and glycolysis. Furthermore, it also upregulated the expression of phosphorylated STAT3, indicating that the IL-6/GP130/STAT3 pathway plays a central role in medulloblastoma. The FDA-approved drug bazedoxifene, a blocker of the formation of the hexameric IL-6/IL-6R/GP130 complex, was re-purposed in this study to inhibit the IL-6/GP130/STAT3 signaling pathway. Bazedoxifene not only inhibited IL-6 mediated cell viability and cell proliferation, and increased phosphorylated STAT3 expression, but it also decreased cell glycolysis, demonstrating a certain level of therapeutic efficacy in vitro. Collectively, our findings offer new insight into the molecular mechanism underlying the biological aggressiveness of medulloblastoma, the roles of IL-6 in these processes and a possible efficacious adjuvant therapy for medulloblastoma.

Synergistic anti-cancer effects of epigenetic drugs on medulloblastoma cells

PURPOSE

Medulloblastomas are aggressive brain malignancies. While considerable progress has been made in the treatment of medulloblastoma patients with respect to overall survival, these patients are still at risk of developing neurologic and cognitive deficits as a result of anti-cancer therapies. It is hypothesized that targeted molecular therapies represent a better treatment option for medulloblastoma patients. Therefore, the aim of the present study was to test a panel of epigenetic drugs for their effect on medulloblastoma cells under mild hypoxic conditions that reflect the physiological concentrations of oxygen in the brain.

METHODS

Protein levels of histone deacetylase 1 (HDAC1) and DNA methyltransferase 1 (DNMT1) in medulloblastoma-derived cells (Daoy and D283 Med), as well as in developing and differentiated brain cells, were determined and compared. Class I and II histone deacetylase inhibitors (HDACi) and a DNMT inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC), were applied to Daoy and D283 Med cells, and their effects were studied using viability, apoptosis and cancer sphere assays.

RESULTS

We found that in HDAC1 and DNMT1 overexpressing medulloblastoma-derived cells, cell death was induced under various epigenetic drug conditions tested. At low HDACi concentrations, however, a pro-proliferative effect was observed. Parthenolide, a drug that affects cancer stem cells, was found to be efficient in inducing cell death in both cell lines tested. In contrast, we found that Daoy cells were more resistant to 5-aza-dC than D283 Med cells. When suberoylanilide hydroxamic acid (SAHA) and parthenolide were individually applied to both cell lines in combination with 5-aza-dC, a synergistic effect on cell survival was observed.

CONCLUSIONS

Our current results suggest that the application of HDACi in combination with drugs that target DNMT may represent a promising option for the treatment of medulloblastoma.

Blockade of Inhibitors of Apoptosis Proteins in Combination with Conventional Chemotherapy Leads to Synergistic Antitumor Activity in Medulloblastoma and Cancer Stem-Like Cells

Background

Medulloblastoma (MB) is the most common pediatric primary malignant brain tumor. Approximately one-third of MB patients succumb to treatment failure and some survivors suffer detrimental side effects. Hence, the purpose of this study is to explore new therapeutic regimens to overcome chemotherapeutic agent resistance or reduce chemotherapy-induced toxicity.

Methods

We detected the expression of inhibitors of apoptosis proteins (IAPs) in MB and CD133+ MB cell lines and MB tissues using immunoblotting and immunohistochemical staining. The antitumor effects of inhibitors against IAPs on MB or CD133+ MB cells were evaluated by MTT assay, Annexin V/PI analysis, and caspase-3/7 activity. Autophagy was assessed by the conversion of light chain (LC) 3-I to LC3-II and Cyto-ID autophagy detection kit.

Results

MB cells showed higher expression of IAPs compared to normal astrocytes and normal brain tissues. Conventional chemotherapeutic agents combined with small-molecule IAP inhibitors (LCL161 or LBW242) showed a synergistic effect in MB cells. Combined treatments triggered apoptosis in MB cells through activation of caspase-3/7 and autophagic flux simultaneously. In addition, we found that CD133+ MB cells with features of cancer stem cells displayed higher levels of X-linked inhibitor of apoptosis (XIAP) and cellular inhibitor of apoptosis 1/2 (cIAP1/2), and were hypersensitive to treatment with IAP inhibitors.

Conclusions

These results shed light on the biological effects of combination therapy on MB cells and illustrate that IAP inhibitors are more effective for CD133+ stem-like MB cells.

Critical combinations of radiation dose and volume predict intelligence quotient and academic achievement scores after craniospinal irradiation in children with medulloblastoma

PURPOSE

To prospectively follow children treated with craniospinal irradiation to determine critical combinations of radiation dose and volume that would predict for cognitive effects.

METHODS AND MATERIALS

Between 1996 and 2003, 58 patients (median age 8.14 years, range 3.99-20.11 years) with medulloblastoma received risk-adapted craniospinal irradiation followed by dose-intense chemotherapy and were followed longitudinally with multiple cognitive evaluations (through 5 years after treatment) that included intelligence quotient (estimated intelligence quotient, full-scale, verbal, and performance) and academic achievement (math, reading, spelling) tests. Craniospinal irradiation consisted of 23.4 Gy for average-risk patients (nonmetastatic) and 36-39.6 Gy for high-risk patients (metastatic or residual disease >1.5 cm(2)). The primary site was treated using conformal or intensity modulated radiation therapy using a 2-cm clinical target volume margin. The effect of clinical variables and radiation dose to different brain volumes were modeled to estimate cognitive scores after treatment.

RESULTS

A decline with time for all test scores was observed for the entire cohort. Sex, race, and cerebrospinal fluid shunt status had a significant impact on baseline scores. Age and mean radiation dose to specific brain volumes, including the temporal lobes and hippocampi, had a significant impact on longitudinal scores. Dichotomized dose distributions at 25 Gy, 35 Gy, 45 Gy, and 55 Gy were modeled to show the impact of the high-dose volume on longitudinal test scores. The 50% risk of a below-normal cognitive test score was calculated according to mean dose and dose intervals between 25 Gy and 55 Gy at 10-Gy increments according to brain volume and age.

CONCLUSIONS

The ability to predict cognitive outcomes in children with medulloblastoma using dose-effects models for different brain subvolumes will improve treatment planning, guide intervention, and help estimate the value of newer methods of irradiation.

Pemetrexed and gemcitabine as combination therapy for the treatment of Group3 medulloblastoma

We devised a high-throughput, cell-based assay to identify compounds to treat Group3 medulloblastoma (G3 MB). Mouse G3 MBs neurospheres were screened against a library of approximately 7,000 compounds including US Food and Drug Administration-approved drugs. We found that pemetrexed and gemcitabine preferentially inhibited G3 MB proliferation in vitro compared to control neurospheres and substantially inhibited G3 MB proliferation in vivo. When combined, these two drugs significantly increased survival of mice bearing cortical implants of mouse and human G3 MBs that overexpress MYC compared to each agent alone, while having little effect on mouse MBs of the sonic hedgehog subgroup. Our findings strongly suggest that combination therapy with pemetrexed and gemcitabine is a promising treatment for G3 MBs.

Relapse in medulloblastoma: what can be done after abandoning high-dose chemotherapy? A mono-institutional experience

PURPOSE

We retrospectively report strategies used for medulloblastoma patients progressing after craniospinal irradiation where we aimed for: symptom control, a satisfactory quality of life, accrual in phase 1-2 trials, when available, and the first two conditions could no longer be satisfied by already experienced second-line strategies.

METHODS

Surgery was used in cases of doubtful relapse or when only one site was affected. Radiotherapy was given whenever possible, especially to relieve symptoms. The main chemotherapy regimens were oral temozolomide/etoposide, intravenous (iv.) cisplatin/etoposide, iv. gemcitabine/oxaliplatin, an oral sonic hedgehog pathway inhibitor and oral melphalan.

RESULTS

Between 1998 and 2011, we treated 18 patients relapsed after median 20 months. Nine had relapsed locally, four had dissemination, three single metastases, and two had one synchronous local and metastatic recurrence. Responses to chemotherapy were seen in 32% of cases. The median hospital stay for treatments/complications was 19 days. The 1- and 3-year progression-free survival (PFS) rates were 28 ± 10% and 0%, respectively, for OS, they were 44 ± 12% and 22 ± 10% but no patient was cured. The median PFS after a first relapse was 7 months (range 1-29); the median OS was 7 months (range 4-44). No patients died due to treatment toxicity. Late recurrence (more than 1-2 years after diagnosis) and involvement of single sites were favorable prognostic factors.

CONCLUSIONS

Without succeeding in patients cure, we ensured them further treatment with short hospital stay thus affording low personal and social costs. The chances of cure may emerge from tailored therapies according to genetic stratification.