Intracranial germ cell tumors in Adolescents and Young Adults: European and North American consensus review, current management and future development

The incidence of intracranial germ cell tumors (iGCT) is much lower in European and North American (E&NA) than in Asian population. However, E&NA cooperative groups have simultaneously developed with success treatment strategies with specific attention paid to long-term sequelae. Neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or cerebrospinal fluid (CSF) and/or serum analysis, deferring the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated as either germinoma or non-germinomatous germ cell tumors (NGGCT). Metastatic disease is defined by a positive CSF cytology and/or distant drops in craniospinal MRI. The combination of surgery and/or chemotherapy and radiation therapy is tailored according to grouping and staging. With more than 90% 5-year event-free survival (EFS), localized germinomas can be managed without aggressive surgery, and benefit from chemotherapy followed by whole ventricular irradiation with local boost. Bifocal germinomas are treated as non-metastatic entities. Metastatic germinomas may be cured with craniospinal irradiation. With a 5-year EFS over 70%, NGGCT benefit from chemotherapy followed by delayed surgery in case of residual disease, and some form of radiotherapy. Future strategies will aim at decreasing long-term side effects while preserving high cure rates.

Marrow-ablative chemotherapy followed by tandem autologous hematopoietic cell transplantation in pediatric patients with malignant brain tumors

To improve survival in young children with malignant brain tumors, irradiation-avoiding or -minimizing marrow-ablative chemotherapy (HDCx) with autologous hematopoietic cell transplantation (AuHCT) has been investigated. We evaluated the outcome of 44 children with malignant brain tumors treated with HDCx and tandem AuHCT at Children's Hospital Los Angeles between June 1999 and July 2012. Forty-four children with malignant brain tumors were studied. Twenty-one had medulloblastoma/primitive neuro-ectodermal tumor, eight atypical teratoid/rhabdoid tumor (ATRT), five high-grade glioma, four malignant germ cell tumor, three ependymoma and three choroid plexus carcinoma. Twenty-nine patients received three tandem transplants and 15 received two tandem transplants, respectively. The 5-year PFS and overall survivals (OS) for all patients were 46.3±8.2% and 51.7±8.5%, respectively. The PFS and OS for 27 newly diagnosed patients were 68.9±9.9% and 73.5±9.3%, respectively, compared with 17 transplanted at relapse 11.8±9.8% (P<0.001) and 15.1±12.3% (P=0.0231), respectively. The 5-year PFS and OS in 13 previously unirradiated patients were 74±13% and 74±13% versus 33.2±9.8% and 40.2±10.6% in 31 irradiated patients (P=0.11 and P=0.239), respectively. One patient died of transplant-related toxicity. HDCx with tandem AuHCT is feasible and safe in children with malignant brain tumors with encouraging irradiation-free survival in newly diagnosed children.

Apparent diffusion and fractional anisotropy of diffuse intrinsic brain stem gliomas

BACKGROUND AND PURPOSE

DIBSGs have the worst prognosis among pediatric brain tumors with no improvement of outcome for several decades. In this study, we determined whether diffusion imaging could improve patient stratification and our understanding of the impact of therapies.

MATERIALS AND METHODS

Nine baseline and 24 follow-up DTI studies performed in 9 patients on a 1.5T clinical MR imaging scanner were reviewed. ADC and FA were measured for the whole lesion and at 5 anatomic levels: the rostral medulla, caudal pons, midpons, rostral pons, and caudal midbrain. Reference data were obtained from 8 controls with normal brain stem, 6 patients with medulloblastoma, and 7 patients with pilocytic astrocytoma.

RESULTS

ADC was higher in untreated DIBSG than in normal brain stem and medulloblastoma (1.14 ± 0.18 [×10⁻³ mm²/s] versus 0.75 ± 0.06 and 0.56 ± 0.05, both P < .001). FA was lower in DIBSG than in normal brain stem (0.24 ± 0.04 versus 0.43 ± 0.02, P < .001) but was higher than that in pilocytic astrocytoma (0.17 ± 0.05, P < .05). Lower baseline ADC and higher FA correlated with a worse clinical course. Correlations were more significant at the caudal midbrain than in other regions. ADC decreased and FA increased after RT. Changes of FA after RT at the caudal midbrain correlated with event-free survival.

CONCLUSIONS

Baseline ADC and FA of DIBSG revealed hypocellular tumors with extensive edema. Diffusion changes after therapy implied reduced edema but did not support a significant response to therapy. The significance of diffusion properties varied with anatomic locations, the caudal midbrain being particularly important.

Central nervous system (CNS) tumors in the first six months of life: the Children's Hospital Los Angeles experience, 1979-2005

BACKGROUND

The authors report the experience at the Children's Hospital Los Angeles with brain tumors diagnosed before 6 months of age, describing the characteristics of the patients, their tumors, treatment strategies, and prognostic factors.

METHODS

Thirty-three children who were identified between 1979 and 2005 were included. Twelve were female (36%). There were 11 gliomas, 9 choroid plexus tumors, 8 medulloblastomas and supratentorial primitive neuroectodermal tumors (PNET), 2 atypical teratoid/rhabdoid tumors (ATRT), and 1 each of ependymoma, craniopharyngioma, and immature teratoma. Locations of primary tumors included 21 supratentorial (64%) and 7 posterior fossa, and 5 tumors involved both compartments. The treatment strategies included 5 patients with biopsy only, 18 less than gross total resections (<GTRx), and 9 GTRx. Fourteen children (42%) received chemotherapy. Three patients (9%) received irradiation, 1 at initial diagnosis and 2 at relapse. Nine patients (27%) demonstrated metastases, 6 at diagnosis and 3 at relapse.

RESULTS

The Kaplan Meier analysis of event-free survival (EFS) and overall survival (OS) for all patients is 21 +/- 9% and 35 +/- 9% at 5 years. For the glioma patients, the 4-year OS is 48 +/- 17%, while the 5-year OS for the medulloblastoma/PNET/ATRT patients is 12 +/- 11% (p = .39). The 5-year OS for children achieving a GTRx is 64 +/- 21% and for those with <GTRx is 27 +/- 10% (p = .08).

Newly diagnosed high-risk malignant brain tumors with leptomeningeal dissemination in young children: A final update on Head Start II Regimen A2 intensified with high-dose methotrexate

9552

Background: The prognosis for young children with newly diagnosed malignant brain tumors with leptomeningeal dissemination remains poor. From Jan 1997 to Mar 2003, “Head Start II” Regimen A2, intensified with high-dose methotrexate, was offered to this high-risk population. Methods: Eligibility: patients < 10 yrs of age; confirmed diagnosis of medulloblastoma (MB), primitive neuroectodermal tumor (PNET), ependymoma and choroid plexus carcinoma (CPC); and high-risk status as determined by neuroaxis dissemination. Patients with atypical teratoid/rhabdoid tumor (ATRT), regardless of stage, were also eligible. Treatment: 5 cycles of vincristine (0.05 mg/kg/week × 3 doses), cisplatin (3.5 mg/kg), etoposide (4 mg/kg/day × 2 days), cyclophosphamide (65 mg/kg/day × 2 days), and methotrexate (400 mg/kg) with leucovorin. Children without progressive disease (PD) by the end of induction underwent a single consolidation cycle (carboplatin, etoposide, thiotepa) with autologous stem cell rescue. Reduced dose RT (2340cGy CSI and focal boost) was reserved for any with residual disease at the end of induction or for the older patient (>6 yrs of age). Results: 40 patients were enrolled (MB, 22; PNET, 6; ependymoma, 5; AT/RT, 6; CPC, 1), med age at diagnosis 38 mos (range 5 to 119 mos). Significant toxicities of this intensified regimen included GI toxicities and infections. Among the entire cohort, there were 26 CR, 6 PR, 2 with stable disease and 4 with PD (and 2 toxic deaths), for a CR +PR response rate of 82%. For disseminated MB (4 M1; 2 M2; 16 M3), the CR rate alone is 77% (17/22). The 5-year EFS and OS for disseminated MB are 45% (95% CI, 24 % to 64%) and 54% (95% CI, 31% to 72%), respectively. Of note, 6/12 MB survivors (all M3) did not receive RT and all are NED >5 years from diagnosis. In addition, there are 3 AT/RT survivors, 12, 54 and 66 mos post-diagnosis who did not receive RT. Conclusions: This intensified regimen is feasible and tolerable. For patients with disseminated MB, the majority of whom had M3 disease at diagnosis, the impressive response rate and outcomes suggest that the addition of methotrexate is justified for future studies. Long- term neuropsychological outcomes are being studied at this time.

No significant financial relationships to disclose.

Outcome of children less than three years old at diagnosis with non-metastatic medulloblastoma treated with chemotherapy on the “Head Start” I and II protocols: Final report

9507

Background: The use of dose-intensive chemotherapy with autologous hematopoietic cell rescue (AuHCR) is a potentially curative approach to the management of infants and young children with non-metastatic (M-0) medulloblastoma, with the additional benefit of avoiding the late effects of irradiation. We report the results of the “Head Start” I (1991 to 1997) and “Head Start” II (1997 to 2002) clinical trials, using this approach, to treat children with M-0 medulloblastoma, who were less than three years of age at diagnosis. Methods: Twenty one children were enrolled on these two serial studies. After surgery, patients received a uniform induction chemotherapy regimen consisting of five cycles of vincristine, cisplatin, cyclophosphamide and etoposide. Following completion of induction, all patients underwent myeloablative consolidation chemotherapy using carboplatin, thiotepa and etoposide followed by AuHCR, and did not receive irradiation. Irradiation was used only at relapse. Quality of life (QoL) and social and emotional behavior were evaluated on “Head Start” I, and cognitive functioning was evaluated on “Head Start” II survivors. Results: The five-year event-free (EFS) and overall survival (OS) rates (±SE) for all patients, patients with gross total resection, and patients with residual tumor were 52 ± 11% and 70 ± 10%, 64 ± 13% and 79 ± 17%, and 29 ± 17% and 57 ± 19%, respectively. The five-year EFS and OS (±SE) for patients with desmoplastic and classical medulloblastoma were 67 ± 16% and 78 ± 14%, and 42 ± 14 and 67 ± 14%, respectively. Young age (<2 years versus 2 to 3 years) at diagnosis did not appear to impact adversely upon outcome. There were four treatment related deaths. A majority of survivors (71%) avoided irradiation altogether. Neuropsychological functioning in children surviving without irradiation was well within the normal range for most patients. Conclusions: The strategy of brief intensive chemotherapy without irradiation for young children with M-0 medulloblastoma has eliminated the need for craniospinal irradiation in over half (52%) of the patients, with preservation of QoL and cognitive functioning in the majority.

No significant financial relationships to disclose.