Phase 2 study of temozolomide in children and adolescents with recurrent central nervous system tumors: a report from the Children's Oncology Group.

BACKGROUND: Effective chemotherapy is lacking for most types of central nervous system (CNS) tumors in children. Temozolomide, an agent with activity against adult brain tumors, was investigated in children and adolescents with recurrent CNS tumors. METHODS: Temozolomide was administered orally as monthly 5-day courses at doses of 200 mg/m(2)/d (patients with no prior craniospinal irradiation [CSI]) or 180 mg/m(2)/d (prior CSI). Patients with a complete (CR) or partial (PR) response or stable disease (SD) could continue temozolomide for up to 12 cycles. RESULTS: The cohort comprised 122 patients, including 113 with CNS tumors. Median age was 11 years (range, 1-23 years). Among 104 evaluable patients with CNS tumors, 5 PRs and 1 CR were observed. PRs occurred in 1 of 23 evaluable patients with high-grade astrocytoma, 1 of 21 with low-grade astrocytoma, and 3 of 25 with medulloblastoma/primitive neuroectodermal tumor (PNET). The CR occurred in an additional patient with medulloblastoma/PNET. No responses were observed in patients with ependymoma, brain-stem glioma, or other CNS tumors. Notably, 41% of patients with low-grade astrocytoma had SD through 12 courses. The most frequent toxicities were grade 3 or 4 neutropenia (19%) and thrombocytopenia (25%); nonhematologic toxicity was infrequent. CONCLUSIONS: Although overall objective responses were limited, further exploration of temozolomide may be warranted in children with medulloblastoma and other PNETs, or in patients with low-grade astrocytoma, perhaps in a setting of less pretreatment than the patients in the current study, or in the context of multiagent therapy.

Population-based study of early age-related macular degeneration: role of the complement factor H Y402H polymorphism in bilateral but not unilateral disease.

OBJECTIVE: Recently, a strong association has been observed for the complement factor H (CFH) Tyr402His polymorphism with early and advanced age-related macular degeneration (AMD) in independent non-Hispanic White, clinic-based, case-control studies. These studies suggest the CFH His402 allele is a major risk allele in early and advanced AMD, explaining 43% to 70% of all AMD in older adults. We utilized a population-based case-control study design of early AMD among Latinos/Hispanics to evaluate the CFH Tyr402His polymorphism for an association with early AMD phenotypes. DESIGN: Retrospective population-based case-control study. PARTICIPANTS: This study cohort consists of 285 early AMD cases and 570 controls matched on age, birthplace, and smoking status. METHODS: Genotype determination was performed by allele-specific digestion of polymerase chain reaction products. MAIN OUTCOME MEASURES: Complement factor H Tyr402His polymorphism. RESULTS: We observed no overall statistically significant association with early AMD among Latinos. However, a subset of early AMD cases that have bilateral, not unilateral, intermediate-to-large soft macular drusen were 1.7 times more likely to carry either the homozygous or heterozygous His402 genotype. CONCLUSIONS: Our data suggest that the CFH Tyr402His is not a major risk factor for overall early AMD in this Latino population, but may play a role in susceptibility to phenotypes of early AMD likely to progress to late AMD.

Inverse association of antioxidant and phytoestrogen nutrient intake with adult glioma in the San Francisco Bay Area: a case-control study.

BACKGROUND: Increasing evidence from epidemiologic studies suggest that oxidative stress may play a role in adult glioma. In addition to dietary antioxidants, antioxidant and weak estrogenic properties of dietary phytoestrogens may attenuate oxidative stress. Our hypothesis is that long-term consumption of dietary antioxidants and phytoestrogens such as genistein, daidzein, biochanin A, formononetin, matairesinol, secoisolariciresinol and coumestrol, may reduce the risk of adult glioma. METHODS: Using unconditional logistic regression models, we compared quartiles of consumption for several specific antioxidants and phytoestrogens among 802 adult glioma cases and 846 controls from two study series from the San Francisco Bay Area Adult Glioma Study, 1991-2000, controlling for vitamin supplement usage, age, socioeconomic status, gender, ethnicity and total daily calories. For cases, dietary information was either self-reported or reported by a proxy. For controls, dietary information was self-reported. Gender- and series-specific quartiles of average daily nutrient intake, estimated from food-frequency questionnaires, were computed from controls. RESULTS: Significant p-values (trend test) were evaluated using significance levels of either 0.05 or 0.003 (the Bonferroni corrected significance level equivalent to 0.05 adjusting for 16 comparisons). For all cases compared to controls, statistically significant inverse associations were observed for antioxidant index (p < 0.003), carotenoids (alpha- and beta-carotene combined, p < 0.05), daidzein (p = 0.003), matairesinol (p < 0.05), secoisolariciresinol (p < 0.003), and coumestrol (p < 0.003). For self-reported cases compared to controls, statistically significant inverse associations were observed for antioxidant index (p < 0.05) and daidzein (p < 0.05). CONCLUSION: Our results support inverse associations of glioma with higher dietary antioxidant index and with higher intake of certain phytoestrogens, especially daidzein.

MAT1-modulated cyclin-dependent kinase-activating kinase activity cross-regulates neuroblastoma cell G1 arrest and neurite outgrowth.

Cyclin-dependent kinase-activating kinase (CAK) regulates cell cycle G1 exit, where cells commonly commit either to proliferate or to differentiate. CAK activity in G1 regulation is determined by its assembly factor and targeting subunit, ménage à trois 1 (MAT1). The precise mechanism of how proliferation/differentiation transition is induced from cancer cell G1 arrest remains unknown. We present evidence that in neuroblastoma CHP126 cells, CAK interacts with and phosphorylates retinoblastoma tumor suppressor protein (pRb) and retinoid X receptor alpha (RXRalpha). Retinoic acid (RA)-induced neuroblastoma cell proliferation/differentiation transition is associated with decreased CAK activity, as evidenced by a switch from CAK hyperphosphorylation of pRb and RXRalpha to hypophosphorylation of pRb and RXRalpha. Manipulation of MAT1 abundance shows that MAT1 reduction mimics RA-induced hypophosphorylation of pRb/RXRalpha, proliferation inhibition, and neurite outgrowth, whereas MAT1 overexpression resists these RA actions. Thus, these findings reveal an important mechanism by which MAT1-modulated CAK activity is crucial in the switch from proliferation to differentiation in neuroblastoma cells.

Burkitt's and Burkitt-like lymphoma in children and adolescents: a review of the Children's Cancer Group experience.

Historically, the survival of children and adolescents with Burkitt's and Burkitt-like lymphoma had been poor. Recently, short and intensive chemotherapy appears to have improved disease outcome. We therefore reviewed the results of four successive Children's Cancer Group trials conducted on 470 children with disseminated Burkitt's and Burkitt-like lymphoma. Of the patients studied, the median age was 8 years (0-21 years), the male:female ratio was 4:1, 58% had lactate dehydrogenase (LDH) > or = 500 IU/l, 23% had M2 or M3 bone marrow (BM), and 12% demonstrated central nervous system involvement. In a multivariate analysis, the 4-year event-free survival (EFS) in patients > or = 15-years-old compared with < 15-year-old was 34 +/- 7 versus 59 +/- 2% (P < 0.05), the 4-year EFS of M2/M3 compared with M1 BM was 38 +/- 5 versus 63 +/- 3% (P < 0.001), and the 4-year EFS with LDH > or = 500 IU/l compared with LDH < 500 IU/l was 49 +/- 3 versus 71 +/- 4% (P < 0.001). Furthermore, patients treated on the most recent protocol, which was short and more intensive, had a significantly improved survival compared with those on previous trials (4-year EFS 80 +/- 6 versus 54 +/- 2%, P < 0.001). In summary, the outcome for childhood Burkitt's and Burkitt-like lymphoma has recently improved with the use of short and intensive B-cell non-Hodgkin's lymphoma-directed therapy.