McNally R J Q, Pearce M S, Parker L
School of Clinical Medical Sciences (Child Health), University of Newcastle Upon Tyne, Newcastle upon Tyne, United Kingdom.
Eur J Epidemiol. 2006;21(2):139-44. doi: 10.1007/s10654-005-5698-9.
There has been speculation that environmental exposures may be involved in the aetiology of testicular cancer in adolescent boys and young men. Indirect evidence for this hypothesis would be provided by the finding of space-time clustering. To examine this we have looked for evidence of space-time clustering using data from a population-based cancer registry from Northern England. All cases of testicular cancer diagnosed in males aged 15-24 years during the period 1968-2002 were included in the study. Tests for space-time interactions between cases were applied with fixed thresholds of close in space and close in time. Addresses at birth and diagnosis were used in the analyses. To adjust for the effect of varying population density tests were repeated replacing fixed geographical distances with nearest neighbour thresholds. A total of 257 cases of testicular cancer were identified for analysis. Overall there was no evidence for space-time clustering. However, there was statistically significant space-time clustering for 15-19-year-old based on time of birth and place of diagnosis (p<0.001). The very limited finding of space-time clustering may provide tentative evidence for an environmental, or infectious component to aetiology. However, it may well be a chance finding. A larger study based on national data is required.
有人推测，环境暴露可能与青春期男孩和年轻男性睾丸癌的病因有关。时空聚集性的发现将为这一假说提供间接证据。为了对此进行研究，我们利用来自英格兰北部一个基于人群的癌症登记处的数据，寻找时空聚集性的证据。该研究纳入了1968年至2002年期间诊断出的所有15至24岁男性睾丸癌病例。对病例之间的时空相互作用进行了检验，采用了空间接近和时间接近的固定阈值。分析中使用了出生地址和诊断地址。为了调整人口密度变化的影响，重复进行检验，用最近邻阈值取代固定的地理距离。总共确定了257例睾丸癌病例进行分析。总体而言，没有时空聚集性的证据。然而，基于出生时间和诊断地点，15至19岁人群存在统计学上显著的时空聚集性（p<0.001）。时空聚集性这一非常有限的发现可能为病因中的环境或感染因素提供初步证据。然而，这很可能是一个偶然发现。需要开展一项基于全国数据的更大规模研究。
