Edward J. Estlin

Age–incidence patterns of primary CNS tumors in children, adolescents, and adults in England

Around 25% of all tumors in those 0-14 years of age and 9% in those 15-24 years of age involve the CNS. They are the most common cause of cancer-related deaths in both age groups. In adults 25-84 years of age, the proportion of CNS tumors is 2%; 5-year overall survival is 10%-15%; and survivors have considerable morbidity. Comprehensive up-to-date population-based incidence data on these tumors are lacking. We present incidence rates for primary CNS tumors based on data derived from the high-quality national cancer registration system in England. A total of 54,336 CNS tumors of malignant, benign, and uncertain behavior were registered across the whole of England from 1995 through 2003. The age-standardized rates for all ages (0-84 years) was 9.21 per 100,000 person-years. This is higher than previously reported for England because it includes nonmalignant CNS tumors and hence gives a more accurate picture of burden of disease. The age-standardized rates for those 0-14 years of age, 15-24 years of age, and 25-84 years of age were 3.56, 3.26, and 14.57 per 100,000 person-years, respectively. In this article, we describe the changing patterns in the epidemiology of primary CNS tumors in these three age groups with respect to sex, tumor behavior, and histology using the current WHO classification. This information will provide a reference for future studies nationally and internationally and make comparisons relevant and meaningful.

Chronic hypoxia promotes hypoxia-inducible factor-1alpha-dependent resistance to etoposide and vincristine in neuroblastoma cells.

Hypoxia is widespread in solid tumors as a consequence of poorly structured tumor-derived neovasculature. Direct measurement of low oxygen levels in a range of adult tumor types has correlated tumor hypoxia with advanced stage, poor response to chemotherapy and radiotherapy, and poor prognosis. Little is known about the importance of hypoxia in pediatric tumors; therefore, we evaluated the effects of hypoxia on the response of the neuroblastoma cell lines SH-EP1 and SH-SY5Y to the clinically relevant drugs, vincristine, etoposide, and cisplatin. Short periods of hypoxia (1% O2) of up to 16 hours had no effect on drug-induced apoptosis or clonogenic survival. Prolonged hypoxia of 1 to 7 days leads to reduction in vincristine- and etoposide-induced apoptosis in SH-SY5Y and SH-EP1 cells, and this was reflected in increased clonogenic survival under these conditions. Neither short-term nor prolonged hypoxia had any effect on the clonogenic response to cisplatin in SH-SY5Y cells. Hypoxia-inducible factor-1 (HIF-1) α was stabilized in these cell lines within 2 hours of hypoxia but was no longer detectable beyond 48 hours of hypoxia. Up-regulation of carbonic anhydrase IX showed HIF-1α to be transcriptionally active. Down-regulation of HIF-1α by short hairpin RNA interference and the small-molecule 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole reduced hypoxia-induced drug resistance. These results suggest that prolonged hypoxia leads to resistance to clinically relevant drugs in neuroblastoma and that therapies aimed at inhibiting HIF-1α function may be useful in overcoming drug resistance in this tumor. [Mol Cancer Ther 2006;5(9):2241–50]

SenseCam as a rehabilitation tool in a child with anterograde amnesia

We present the case of a 13-year-old boy, CJ, with profound episodic memory difficulties following the diagnosis of a metastatic intracranial germ cell tumour and subsequent treatment with radiotherapy and chemotherapy. At the core of this study is the first application of SenseCam to a child with severe memory impairment. CJ was taken for a walk while he was wearing SenseCam. This included visiting four different locations. We manipulated the number of locations he could review on SenseCam “films” and then tested recognition memory (forced choice) for both reviewed and non-reviewed locations. We also collected his justifications for the choices he made. Our results indicate that repeated viewings of SenseCam images support the formation of personal semantic memories. Overall our results suggest that the use of SenseCam in memory rehabilitation extends beyond supporting episodic memory and recollection, and supports the feasibility of its use with children who have marked memory difficulties.

Are reported increases in incidence of primary CNS tumours real? An analysis of longitudinal trends in England, 1979–2003

Reported increases in the incidence of CNS tumours in the developed world in the 1970s to 1990s have been a cause for concern and debate. It still remains to be adequately answered whether these increases are true or an artefact of changes in diagnostic and registration practices. Using high-quality national cancer registration data, we have analysed incidence trends for each major histological subgroup of CNS tumour (2000 World Health Organisation (WHO) classification) registered in those aged 0-84 years for the whole of England during the period 1979 through 2003. 134,509 primary CNS tumours of malignant, benign and uncertain behaviour located in the brain, meninges, spinal cord, cranial nerves, other parts of the central nervous system and in the pituitary and pineal glands were registered. In summary, we present the single largest nationwide study on the longitudinal incidence trends of CNS tumours. The increase in incidence observed in the 1970s and 1980s was mainly in the young and the elderly and has now plateaued and may even be decreasing. There is however variation in trends by histology. The incidence of some histological sub-groups has continued to increase until the most recent period of analysis. Much of the initial increase can be attributed to the emergence of much more widely available neuroimaging, while the most recent incidence changes for specific sub-groups of CNS tumours appear to be due to greater diagnostic specificity leading to a shift in registered categories. However, the trends for high-grade astrocytomas and other gliomas need further observation and investigation.

Nutritional problems in children treated for medulloblastoma: Implications for enteral nutrition support

The aim of this study was to identify the nature and severity of nutritional problems associated with the current treatment of medulloblastoma and to identify any risk factors for nutritional morbidity during treatment.

Phase II study of irinotecan in combination with temozolomide (TEMIRI) in children with recurrent or refractory medulloblastoma: a joint ITCC and SIOPE brain tumor study.

BACKGROUND This multicenter phase II study investigated temozolomide + irinotecan (TEMIRI) treatment in children with relapsed or refractory medulloblastoma. METHODS Patients received temozolomide 100-125 mg/m(2)/day (days 1-5) and irinotecan 10 mg/m(2)/day (days 1-5 and 8-12) every 3 weeks. The primary endpoint was tumor response within the first 4 cycles confirmed ≥4 weeks and assessed by an external response review committee (ERRC). In a 2-stage Optimum Simon design, ≥6 responses in the first 15 evaluable patients were required within the first 4 cycles for continued enrollment; a total of 19 responses from the first 46 evaluable patients was considered successful. RESULTS Sixty-six patients were treated. Seven responses were recorded during stage 1 and 15 in the first 46 ERRC evaluated patients (2 complete responses and 13 partial responses). The objective response rate during the first 4 cycles was 32.6% (95% confidence interval [CI], 19.5%-48.0%). Median duration of response was 27.0 weeks (7.7-44.1 wk). In 63 patients evaluated by local investigators, the objective response rate was 33.3% (95% CI, 22.0%-46.3%), and 68.3% (95% CI, 55.3%-79.4%) experienced clinical benefit. Median survival was 16.7 months (95% CI, 13.3-19.8). The most common grade 3 treatment-related nonhematologic adverse event was diarrhea (7.6%). Grade 3/4 treatment-related hematologic adverse events included neutropenia (16.7%), thrombocytopenia (12.1%), anemia (9.1%), and lymphopenia (9%). CONCLUSIONS The planned study primary endpoint was not met. However, its tolerability makes TEMIRI a suitable candidate chemotherapy backbone for molecularly targeted agents in future trials in this setting.

A phase I study of nolatrexed dihydrochloride in children with advanced cancer. A United Kingdom Children's Cancer Study Group Investigation

A phase I study of nolatrexed, administered as a continuous 5 day intravenous infusion every 28 days, has been undertaken for children with advanced malignancy. 16 patients were treated at 3 dose levels; 420, 640 and 768 mg/m2 24 h−1. 8 patients were evaluable for toxicity. In the 6 patients treated at 768 mg/m2 24 h−1, dose-limiting oral mucositis and myelosuppression were observed. Plasma nolatrexed concentrations and systemic exposure, measured in 14 patients, were dose related, with mean AUC values of 36 mg−1 ml−1 min−1, 50 mg ml−1 min−1 and 80 mg ml−1 min−1 at the 3 dose levels studied. Whereas no toxicity was encountered if the nolatrexed AUC was <45 mg ml−1 min−1, Grade 3 or 4 toxicity was observed with AUC values of >60 mg ml−1 min−1. Elevated plasma deoxyuridine levels, measured as a surrogate marker of thymidylate synthase inhibition, were seen at all of the dose levels studied. One patient with a spinal primitive neuroectodermal tumour had stable disease for 11 cycles of therapy, and in two patients with acute lymphoblastic leukaemia a short-lived 50% reduction in peripheral lymphoblast counts was observed. Nolatrexed can be safely administered to children with cancer, and there is evidence of therapeutic activity as well as antiproliferative toxicity. Phase II studies of nolatrexed in children at the maximum tolerated dose of 640 mg/m2 24 h−1are warranted.

Preclinical efficacy of the bioreductive alkylating agent RH1 against paediatric tumours

Background:Despite substantial improvements in childhood cancer survival, drug resistance remains problematic for several paediatric tumour types. The urgent need to access novel agents to treat drug-resistant disease should be expedited by pre-clinical evaluation of paediatric tumour models during the early stages of drug development in adult cancer patients.Methods/results:The novel cytotoxic RH1 (2,5-diaziridinyl-3-[hydroxymethyl]-6-methyl-1,4-benzoquinone) is activated by the obligate two-electron reductase DT-diaphorase (DTD, widely expressed in adult tumour cells) to a potent DNA interstrand cross-linker. In acute viability assays against neuroblastoma, osteosarcoma, and Ewing′s sarcoma cell lines RH1 IC50 values ranged from 1-200 nM and drug potency correlated both with DTD levels and drug-induced apoptosis. However, synergy between RH1 and cisplatin or doxorubicin was only seen in low DTD expressing cell lines. In clonogenic assays RH1 IC50 values ranged from 1.5–7.5 nM and drug potency did not correlate with DTD level. In A673 Ewings sarcoma and 791T osteosarcoma tumour xenografts in mice RH1 induced apoptosis 24 h after a single bolus injection (0.4 mg/kg) and daily dosing for 5 days delayed tumour growth relative to control.Conclusion:The demonstration of RH1 efficacy against paediatric tumour cell lines, which was performed concurrently with the adult Phase 1 Trial, suggests that this agent may have clinical usefulness in childhood cancer.

The cellular adaptations to hypoxia as novel therapeutic targets in childhood cancer.

Exposure of tumour cells to reduced levels of oxygen (hypoxia) is a common finding in adult tumours. Hypoxia induces a myriad of adaptive changes within tumour cells which result in increased anaerobic glycolysis, new blood vessel formation, genetic instability and a decreased responsiveness to both radio and chemotherapy. Hypoxia correlates with disease stage and outcome in adult epithelial tumours and increasingly it is becoming apparent that hypoxia is also important in paediatric tumours. Despite its adverse effects upon tumour response to treatment hypoxia offers several avenues for new drug development. Bioreductive agents already exist, which are preferentially activated in areas of hypoxia, and thus have less toxicity for normal tissue. Additionally the adaptive cellular response to hypoxia offers several novel targets, including vascular endothelial growth factor (VEGF), carbonic anhydrase, and the central regulator of the cellular response to hypoxia, hypoxia inducible factor-1 (HIF-1). Novel agents have emerged against all of these targets and are at various stages of clinical and pre-clinical development. Hypoxia offers an exciting opportunity for new drug development that can include paediatric tumours at an early stage.

Benefits and limitations of errorless learning after surviving pediatric brain tumors: A case study

Survivors of childhood brain tumors often acquire complex cognitive difficulties including impairments in attention, processing speed, and different aspects of memory function. These impairments can affect their learning in the real world and in the classroom. However, the efficacy of memory rehabilitation techniques post treatment has not yet been assessed in these patients. We present the case of a 15-year-old boy, C.J., who acquired a profound episodic memory impairment due to a metastatic germ cell tumor and subsequent treatment. The focus of this study was the application of an errorless learning technique to a verbal learning task. We were interested to test whether C.J. would benefit from errorless learning as compared to errorful learning. Results of an experiment and a follow-up study indicated that C.J.s learning was more efficient under errorless conditions, although access to the information from long-term memory remained cue dependent. Implications for learning with or without the support of episodic memory are discussed, and future directions for memory rehabilitation of brain tumor survivors are outlined.