INSERM, CESP Environmental Epidemiology of Cancer, University of Paris-Sud 11, France.
Eur J Cancer Prev. 2012 Jul;21(4):367-74. doi: 10.1097/CEJ.0b013e32834e31d8.
Childhood acute leukaemia (AL) accounts for a third of childhood cancers. Analysing the spatial distribution of the incidence of AL and its lymphoblastic and myeloblastic subtypes may contribute to the identification of risk factors. This national registry-based study aimed to evaluate global spatial heterogeneity in the incidence rates of AL and to detect clusters in France over the period 1990-2006 on the 'living-zone' scale. Between 1990 and 2006, 7675 cases of AL were registered in the National Registry of Childhood Haematopoietic malignancies. Their spatial distribution in the 1895 'living zone' was first evaluated with two tests for global spatial heterogeneity (Potthoff-Witthinghill and Rogerson's tests) and then with the SaTScan and FleXScan methods, which aim to locate spatial and space-time clusters. Over 1990-2006, no spatial heterogeneity of AL or its subtypes was evidenced. In addition, none of the most likely clusters identified with SaTScan and FleXScan over the whole period was significant, and the systematic search for space-time clusters yielded nonsignificant results. However, when three subperiods were considered, five statistically significant nonoverlapping spatial clusters were identified. This study did not find evidence of any global spatial heterogeneity of AL incidence rates in France over the period 1990-2006. Although no significant spatial cluster was detected over the whole period, the study identified a few significant spatial clusters in specific periods. Even though the significance levels of those clusters do not strongly support the existence of local risk factors, the clusters may still reflect a slight impact of shared risk factors, including background environmental exposures, which require further investigation.
儿童急性白血病（AL）约占儿童癌症的三分之一。分析 AL 及其淋巴母细胞和髓母细胞亚型的发病率的空间分布情况，可能有助于确定风险因素。本基于全国性注册的研究旨在评估法国 1990-2006 年期间 AL 发病率的全球空间异质性，并检测出该病的聚类现象。1990 年至 2006 年间，国家儿童血液恶性肿瘤注册处共登记了 7675 例 AL 病例。首先，利用全球空间异质性的两种检验方法（Potthoff-Witthinghill 检验和 Rogerson 检验），评估 AL 及其亚型在 1895 个“生活区域”的空间分布情况，然后使用 SaTScan 和 FleXScan 方法定位空间和时空聚类。1990-2006 年间，未发现 AL 或其亚型存在空间异质性。此外，SaTScan 和 FleXScan 识别出的最可能聚类在整个时期内均不显著，对时空聚类的系统搜索也未得出显著结果。然而，当考虑三个亚时期时，发现了五个具有统计学意义且不重叠的空间聚类。本研究未发现 1990-2006 年期间法国 AL 发病率存在任何全球空间异质性的证据。尽管整个时期内未检测到任何显著的空间聚类，但研究在特定时期内发现了一些具有统计学意义的空间聚类。尽管这些聚类的显著水平并不能强烈支持存在局部风险因素，但这些聚类仍可能反映出共同风险因素（包括背景环境暴露）的轻微影响，这需要进一步调查。
