CHILDHOOD BRAIN TUMORS AND N-NITROSO EXPOSURES

儿童脑肿瘤(CBT)是世界上最常见的实体肿瘤 0-19岁的儿童。迄今已完成的CBT流行病学研究 提示长期怀疑的Bt电离等危险因素 辐射、头部创伤和已知的遗传易感性 只有一小部分事件的案例。令人信服的 实验模型表明，N-亚硝基化合物(NOC) 可能会导致人类患上BT，特别是当暴露在 经胎盘的。因为由这些物质引起的肿瘤 非人灵长类动物经胎盘暴露NOC发生在 在年轻的成年动物和未成熟的动物中，这似乎是合理的 我们的CBT研究包括所有被诊断到20岁的病例。 拟议的美国研究，与同时进行的 国际研究，将首先关注NOC/CBT 假设。 我们建议研究自1984年以来诊断的所有原发Bt病例- 1990年在生活在西部所有地区的0-19岁儿童中 以人口为基础的肿瘤登记覆盖的海岸；这 包括洛杉矶(LA)、旧金山(SF)的19个县 和西雅图地区。在旧金山和西雅图，我们都希望采访 年确诊的105例BT患儿的生母情况 这7年的时间；在洛杉矶，我们预计将采访300个案例 母亲们。在每个区域中，随机数字拨号控件按以下方式分层 年龄和性别的选择将与对照：病例比例为2：1的SF 西雅图和洛杉矶1：1。我们希望完成与以下人员的采访 510例CBT患者的母亲和720例对照的母亲和1000名父亲。 调查问卷询问NOC暴露的来源，例如 饮食、饮用水、药品、化妆品、橡胶制品和 父母的职业暴露。 所有病例的病理切片将由一名儿科医生审查 神经病理学家。西海岸3个地区的数据将 被单独分析，也将被汇集在一起。合并后的 西海岸研究将有足够的统计力量进行 对两种最常见的CBT组织学类型的单独分析- 星形细胞瘤和髓母细胞瘤。数据也将具有可比性 数据来自一项同时进行的国际研究。数据来自 拟议的西海岸研究将与来自 国际研究，以实现对几个 较少见的组织学类型。

Childhood brain tumors (CBT) are the most common solid tumor in children ages 0-19. Epidemiologic studies of CBT done to date suggest that long suspected BT risk factors such as ionizing radiation, head trauma and known genetic predispositions account for only a small proportion of incident cases. A compelling experimental model suggests that N-nitroso compounds (NOC) may cause BT in humans, particularly when exposure is transplacental. Since the tumors that are induced by transplacental NOC exposure of non-human primates occur in young adult as well as in immature animals it seems reasonable in our CBT study to include all cases diagnosed to age 20. This proposed U.S. study, in conjunction with the concurrent international study, will be the first to focus on the NOC/CBT hypothesis. We propose to study all cases of primary BT diagnosed from 1984- 1990 among children ages 0-19 living in all areas of the West Coast that are covered by population-based tumor registries; this includes 19 counties in the Los Angeles (LA), San Francisco (SF) and Seattle areas. In both SF and Seattle we expect to interview the biological mothers of 105 children with BT diagnosed during this 7 year period; in LA we expect to interview 300 case mothers. In each region random digit dial controls stratified by age and sex will be selected with a control:case ratio of 2:1 for SF and Seattle and 1:1 in LA. We expect to complete interviews with mothers of 510 CBT cases and 720 controls and with 1000 fathers. The questionnaire asks about sources of NOC exposure such as diet, drinking water, drugs, cosmetics, rubber products and parental occupational exposures. Pathology slides of all cases will be reviewed by a single pediatric neuropathologist. Data for each of the 3 West Coast regions will be analyzed separately and will also be pooled. The combined West Coast study will have sufficient statistical power to conduct separate analyses for the 2 most common histologic types of CBT- astrocytoma and medulloblastoma. Data will also be comparable with data from a concurrent international study. Data from the proposed West Coast study will be combined with data from the international study to enable separate analyses for several of the less common histologic types.