Telethon Institute for Child Health Research, University of Western Australia, PO Box 855, West Perth, WA, 6872, Australia,
Cancer Causes Control. 2014 Mar;25(3):375-83. doi: 10.1007/s10552-014-0338-x. Epub 2014 Jan 21.
Childhood brain tumors (CBT) are the second most common type of childhood cancer and the leading cause of childhood cancer mortality. Few causes of CBT are known, but parental, fetal, and early life exposures are likely to be important given the early age at diagnosis of many cases. We aimed to investigate whether parents' diagnostic radiological procedures before conception, in the mother during pregnancy or the child's procedures were associated with an increased risk of CBT.
This population-based case-control study was conducted between 2005 and 2010. Cases were identified through all ten Australian pediatric oncology centers, and controls via nationwide random-digit dialing; frequency-matched to cases on age, sex and state of residence. Information on radiological exposures in the time periods of interest was obtained for 306 case and 950 control families through mailed questionnaires. Analysis used unconditional logistic regression, adjusting for matching variables and potential confounders.
We found no evidence of positive associations between risk of CBT overall and childhood or parental pre-pregnancy radiological procedures. Increased ORs for high-grade gliomas associated with childhood radiological procedures were based on small numbers and may be due to chance.
Given the evidence for an increased risk of CBT in cohort studies of computed tomography (CT) in childhood, the lack of such an association in our study may be due to the reduced intensity of CTs after 2001. Future research to investigate the safety of fetal exposure to more intense procedures like CT scans is needed.
儿童脑肿瘤（CBT）是儿童中第二常见的癌症类型，也是儿童癌症死亡的主要原因。尽管 CBT 的病因知之甚少，但鉴于许多病例的诊断年龄较早，父母、胎儿和生命早期的暴露可能很重要。我们旨在研究父母在受孕前、母亲在怀孕期间或孩子的诊断性放射程序是否与 CBT 风险增加有关。
本研究是一项基于人群的病例对照研究，于 2005 年至 2010 年进行。通过澳大利亚的十个儿科肿瘤中心确定病例，通过全国范围内的随机拨号确定对照；病例和对照按年龄、性别和居住州进行频数匹配。通过邮寄问卷获得了 306 例病例和 950 例对照家庭在感兴趣时间段内的放射暴露信息。分析采用非条件逻辑回归，调整了匹配变量和潜在混杂因素。
我们没有发现 CBT 总体风险与儿童或父母孕前放射程序之间存在正相关的证据。与儿童放射程序相关的高级别胶质瘤的 OR 增加基于少数病例，可能是偶然的。
鉴于队列研究中 CT 检查与 CBT 风险增加的证据，我们的研究中没有这种关联可能是由于 2001 年后 CT 检查强度降低所致。需要进一步研究胎儿暴露于 CT 扫描等更强烈程序的安全性。
