Ziegler R G, Blot W J, Hoover R, Blattner W A, Fraumeni J F
Cancer Res. 1981 Sep;41(9 Pt 2):3724-6.
Colon cancer shows a distinct geographic pattern in the United States, with mortality rates in the Northeast exceeding those in the South by about 50%. The North-South gradient remains even after adjustment for differences in urbanization and socioeconomic status. Those counties in the South that attract large numbers of retirees from the North retain the low colon mortality rates characteristic of the South, even at older ages. This observation implies either that certain life-style changes associated with migration at retirement rapidly reduce the risk of colon cancer or that individuals migrate selectively, based on some correlate of health. A specific hypothesis related to the former possibility is that consumption of fruits and vegetables, and the associated vitamin C, carotene, and fiber, is elevated in the South and related to the reduced risk of colon cancer. A protocol is presented for a case-control interview study in Southern retirement areas to assess these possible explanations. A detailed residential history, as well as information on frequency of consumption of specific foods, food groups, and micronutrients, will be collected by interview and will be complemented by selected serum micronutrient determinations and fecal mutagenicity assays.
结肠癌在美国呈现出明显的地理分布模式，东北部的死亡率比南部高出约50%。即使在对城市化和社会经济地位的差异进行调整之后，南北梯度仍然存在。南部那些吸引大量北方退休人员的县，即使在老年人中也保持着南部特有的低结肠癌死亡率。这一观察结果表明，要么是与退休后移民相关的某些生活方式的改变迅速降低了患结肠癌的风险，要么是个人基于某种健康相关因素进行了选择性移民。与前一种可能性相关的一个具体假设是，南部水果和蔬菜以及相关的维生素C、胡萝卜素和纤维的摄入量较高，这与结肠癌风险降低有关。本文介绍了一项在南部退休地区进行的病例对照访谈研究的方案，以评估这些可能的解释。通过访谈将收集详细的居住史以及关于特定食物、食物组和微量营养素消费频率的信息，并将通过选定的血清微量营养素测定和粪便致突变性检测加以补充。
