Faculty Bibliography

PURPOSE: High-grade gliomas of the CNS are characterized by poor treatment response and prognosis for long-term survival. The Children's Oncology Group (COG) L991 study investigated the neuropsychological, behavioral, and quality of life (QoL) outcomes after treatment on the Children's Cancer Group (CCG) trial for high-grade gliomas (CCG-945). PATIENTS AND METHODS: Fifty-four patients (29 males, 25 females) with a median age of 8.8 years at diagnosis (range, 0.2 to 19.5 years) were enrolled at 25 institutions in North America, representing 81% of available survivors; median length of follow-up was 15.1 years (range, 9.5 to 19.2 years), and median age at study evaluation was 23.6 years (range, 11.3 to 36 years). Standardized tests of neuropsychological functioning and QoL were performed. Descriptive statistics summarized principal findings, and one-way analysis of variance identified potential predictors of outcomes. RESULTS: With an average follow-up time of 15 years, survivors demonstrated intellectual functioning within the low-average range. Executive functioning and verbal memory were between the low-average and borderline ranges. In contrast, visual memory and psychomotor processing speed were between the borderline and impaired ranges, respectively. Approximately 75% of patient reported overall QoL within or above normal limits for both physical and psychosocial domains. Nonhemispheric tumor location (midline or cerebellum), female sex, and younger age at treatment emerged as independent risk factors. CONCLUSION: These results serve as a benchmark for comparison with future pediatric high-grade glioma studies, in addition to identifying at-risk cohorts that warrant further research and proactive interventions to minimize late effects while striving to ensure survival.

We performed a single institution retrospective analysis of 114 patients treated with BU-based pretransplant conditioning regimens. Oral BU was administered to 76 patients (total dose 16 mg/kg or 8 mg/kg) and i.v. BU to 38 others (total dose 12.8 mg/kg or 6.4 mg/kg). Either CY (n=74) or fludarabine (n=40) was given in combination with BU. Median age was 35 years in the oral BU group and 48.5 years with i.v. BU (P<0.001). OS and PFS rates at 3-years post HSCT were not different in patients who received either i.v. or oral BU (OS: 41.3 vs 44.0% (P=0.981); PFS: 52.7 vs 54.7% (P=0.526), respectively). The i.v. BU, however, was associated with a significantly shorter time to engraftment (13.5 days vs 16 days, respectively; P<0.001). There were no significant differences in survival or 100-day mortality for patients who received either CY or fludarabine, in combination with BU. After adjustment for confounders, multivariate analysis showed that age of transplant (P=0.002), donor type (sibling or unrelated; P=0.003), GVHD (P<0.05) and route of administration (P=0.023) were significant risk factors for OS. The i.v. BU used in an older age group yielded equivalent survival compared with oral BU used in a younger population.

Recent studies highlight the importance of BRAF alterations resulting in mitogen activated protein kinase (MAK/ERK) pathway activation in low-grade CNS tumors. We studied 106 low-grade CNS neoplasms in a cohort of primarily pediatric patients to identify the prevalence and clinicopathologic significance of these alterations. Polymerase chain reaction testing identified KIAA1549:BRAF fusions in 51 (48%) tumors overall, including 42 (60%) pilocytic astrocytomas, 4 (17%) unclassifiable low-grade gliomas, 4 (36%) low-grade glioneuronal/neuroepithelial tumors, 0 (of 5) pleomorphic xanthoastrocytomas, 0 (of 4) diffuse astrocytomas (World Health Organization grade II), and 1 (of 3, 33%) pilomyxoid astrocytoma. KIAA1549:BRAF gene fusions confirmed by sequencing included the previously reported ones involving exons 1-16/9-18 (49%), 1-15/9-18 (35%), and 1-16/11-18 (8%) and 2 fusions with novel breakpoints: 1-15/11-18 (6%) and 1-17/10-18 (1%). DNA sequencing identified BRAF mutations in 8% of tumors. BRAF mutations were absent. KIAA1549:BRAF fusions were significantly more frequent in infratentorial (57%) and optic pathway (59%) tumors versus supratentorial (19%) tumors (p = 0.001). We did not identify significantly improved progression-free survival in tumors with fusions. In summary, KIAA1549:BRAF fusions predominate in pilocytic astrocytomas but are also present in some low-grade unclassifiable gliomas and glioneuronal tumors. The prognostic and therapeutic significance of this alteration is unclear and merits further study.

A 20-year-old male with a prior history of germinoma presented 8 years after the initial diagnosis with progressive lower back pain. The preoperative diagnosis was schwannoma based on the appearances of a tumor in the lumbosacral region on MRI; however, histologically, a germinoma "drop" metastasis was seen. This report emphasizes the need for long-term follow-up in patients with germinoma. In addition, this patient is unusual in that the preoperative assessment favored schwannoma.