Muir C S, Storm H H, Polednak A
Cancer Registration in Scotland, Information and Statistics Division, Edinburgh.
Cancer Surv. 1994;19-20:369-92.
Interpretation of time trends in incidence rates for cancers of brain and other and unspecified parts of nervous system is complicated by variation in registration efficiency over time and place, statistical instability of rates, changes in the ICD classification of the tumours, variation in registration practice for the benign and unspecified tumours over time and changes in methods of diagnosis. The reader will undoubtedly have the impression that in this chapter there are too many differences in the content of the data over time and place to have confidence in any of the conclusions drawn. To derive a well documented and sustainable assessment on secular trends will require an international collaborative study collecting incidence data for the malignant, benign, uncertain and unspecified tumours of the brain and other parts of the nervous system by histology and by method of diagnosis. By providing a separate rubric for the meninges, the 10th Revision of the ICD (WHO, 1993) should--combined with the morphology rubrics of the second edition of the International Classification of Diseases-Oncology (Percy et al 1990)--make such an endeavour somewhat easier. The data presented above nevertheless suggest that, as for several other cancer sites, on the whole there has been a slow overall increase in the incidence of brain and other and unspecified nervous system neoplasms on the order of 1-2% per year over the past 30 years. Increases appear to have been greater in older people. The extent to which these increases are due to the unquestioned improvements in methods and precision of diagnosis is not clear. Birth cohort data suggest that in recent years, this influence may have been greatest for those birth cohorts born prior to 1900, and this effect is unlikely to disappear until cohorts born about 1910-1920 have passed on. There is currently little evidence to support the contention that the recent increase in older people cannot be largely explained by improvements in diagnostic methods, wider access to medical care and more intensive investigation. Further work is needed.
脑癌以及神经系统其他未明确部位癌症发病率随时间变化趋势的解读较为复杂，原因包括登记效率随时间和地点的变化、发病率的统计不稳定性、肿瘤国际疾病分类（ICD）的变化、良性和未明确肿瘤登记实践随时间的变化以及诊断方法的改变。读者无疑会觉得，在本章中，数据内容在时间和地点上存在太多差异，以至于对得出的任何结论都难以信服。要得出一份有充分记录且可持续的长期趋势评估，需要开展一项国际合作研究，按组织学和诊断方法收集脑及神经系统其他部位恶性、良性、不确定和未明确肿瘤的发病率数据。国际疾病分类第10版（世界卫生组织，1993年）通过为脑膜提供单独的类目，应能与《国际疾病分类肿瘤学》第二版（珀西等人，1990年）的形态学类目相结合，使这项工作变得稍容易一些。然而，上述数据表明，与其他几个癌症部位一样，总体而言，在过去30年里，脑及其他未明确神经系统肿瘤的发病率每年以1%-2%的速度缓慢上升。老年人的发病率上升幅度似乎更大。这些上升在多大程度上归因于诊断方法和精度的无疑改进尚不清楚。出生队列数据表明，近年来，这种影响对1900年以前出生的队列可能最大，而且在大约1910 - 1920年出生的队列去世之前，这种影响不太可能消失。目前几乎没有证据支持这样的观点，即老年人近期发病率的上升不能主要由诊断方法的改进、更广泛的医疗服务获取和更深入的检查来解释。还需要进一步开展工作。
