Higginson J, Muir C S
Bull Cancer. 1977;64(3):365-84.
The evidence in support of the assertion that 80% of human cancers are of environmental origin is reviewed. The environment is used in its broadest sense and is taken to include the widespread general exposures of air and water pollution, the work environment, exposures resulting from personal choice such as smoking and drinking, and the diet. Several examples are chosen to show that a wide range of environmental agents can cause cancer. Consideration of descriptive epidemiological data relating to migrants, geographical variation in incidence, changes in risk over time, correlation studies, clusters and case reports, supports an environmental etiology for many cancers the cause of which is at present unkown. The same data can be used to show that a large proportion of cancer is likely to be due to environmental factors. If the lowest rate observed in a series of populations be regarded as representing a residuum of cancers due to non-environmental causes then it is possible to imagine a hypothetical population with a very low rate indeed. However, it is unlikely that such a level could be achieved even if all causal mechanisms were understood as it is possible that factors leading to one cancer may protect against another. Until evidence to the contrary is aduced it is held that the vast majority of human cancers are due to the environment: the reasons why there has been reluctance to accept this conclusion are discussed.
本文综述了支持“80%的人类癌症源于环境”这一论断的证据。这里的环境是最广义的，包括广泛存在的空气和水污染、工作环境、吸烟和饮酒等个人选择导致的暴露以及饮食。文中选取了几个例子来说明多种环境因素可引发癌症。对与移民相关的描述性流行病学数据、发病率的地理差异、风险随时间的变化、相关性研究、聚集性病例和病例报告的考量，支持了许多目前病因不明的癌症具有环境病因这一观点。同样的数据也可用于表明很大一部分癌症可能归因于环境因素。如果将一系列人群中观察到的最低发病率视为非环境因素导致的癌症残余率，那么可以设想一个发病率极低的假设人群。然而，即便所有因果机制都已明了，这样的低发病率水平也不太可能实现，因为导致一种癌症的因素可能对另一种癌症起到预防作用。在有相反证据出现之前，人们认为绝大多数人类癌症是由环境所致，并讨论了为何一直有人不愿接受这一结论。
