Whittemore A S
Stanford University School of Medicine, Department of Health Research and Policy, California 94305-5092.
Int J Epidemiol. 1989 Sep;18(3):563-8. doi: 10.1093/ije/18.3.563.
Age-specific incidence rates for cancers of the colon and rectum are presented for Chinese in the western United States and Canada (high risk area), and in Shanghai, the People's Republic of China (low risk area). These rates are compared to those among North American whites. Among Chinese, rate differences between high and low risk areas are greater for colon cancer than rectal cancer, are greater for men than women, and increase with age. The most striking finding is the high colon cancer incidence among older Chinese-American men, compared to Chinese-American women. Colon cancer rates among elderly Chinese-American men equal those of whites, which are seven times the corresponding rates in China. By contrast, colon cancer rates among older Chinese-American women are intermediate between those of whites and those in China, and are only three to four times the rates in China. Rectal cancer rate differences for Chinese men also exceed those for Chinese women. However, they are less dramatic than for colon cancer, with elderly Chinese-American men having roughly double the rates in China, and with women exhibiting little variation between continents or ethnic groups. Male:female (M:F) rate ratios increase with age for both continents, both ethnic groups, and both colon and rectum. The colon cancer M:F ratios among Chinese-Americans exceed the others, reaching two in the older age groups. These observations suggest sex-specific aetiological exposures, or sex-specific susceptibilities to common exposures, among Chinese-Americans.(ABSTRACT TRUNCATED AT 250 WORDS)
本文呈现了美国西部和加拿大（高风险地区）的华裔以及中华人民共和国上海地区（低风险地区）结肠直肠癌的年龄别发病率，并将这些发病率与北美白人的发病率进行了比较。在华裔人群中，结肠癌的高风险地区与低风险地区之间的发病率差异大于直肠癌，男性大于女性，且随年龄增长而增加。最显著的发现是，与华裔美国女性相比，老年华裔美国男性的结肠癌发病率很高。老年华裔美国男性的结肠癌发病率与白人相当，是中国相应发病率的七倍。相比之下，老年华裔美国女性的结肠癌发病率介于白人和中国女性之间，仅为中国发病率的三到四倍。华裔男性的直肠癌发病率差异也超过了华裔女性。然而，与结肠癌相比，差异并不那么显著，老年华裔美国男性的发病率约为中国的两倍，而女性在不同大陆或种族群体之间的差异很小。两个大陆、两个种族群体以及结肠和直肠的男性:女性（M:F）发病率比均随年龄增长而增加。华裔美国人的结肠癌M:F比超过其他群体，在老年组中达到2。这些观察结果表明，华裔美国人存在性别特异性的病因暴露，或对常见暴露的性别特异性易感性。（摘要截选至250字）
