THYROID CANCER IN A MULTIETHNIC POPULATION

这项以人群为基础的流行病学研究将检验 营养因素与女性甲状腺癌风险的转移 特别强调亚裔美国人，这是一个高危人群。甲状腺 癌症是年轻女性中最常见的癌症之一， 在快速增长的亚裔美国人人口中。更高的发病率 在美国的亚裔移民中患甲状腺癌的比例高于 亚裔原住民群体，表明随时变化的环境 暴露，如营养因素，在疾病的后期起作用 致癌过程中，影响患甲状腺癌的风险。有限的生态， 实验和流行病学证据表明，高碘暴露 可能会增加患乳头状甲状腺癌的风险，这是最常见的 美国的组织学类型。或者，一些研究结果 可归因于高水平的碘暴露可能解释为低 硒的消耗。增加其他抗氧化剂的消费也可能 在降低患甲状腺癌的风险方面发挥作用。拟议的病例对照 旨在澄清这些关联的研究将在旧金山进行 弗朗西斯科湾区，一个种族和文化不同的人口 在饮食摄入量上提供了很大的变化。被诊断出患有 甲状腺癌将在三年内进行前瞻性鉴定。 此外，为了检验与移民相关的假设，亚洲病例被诊断为 在此之前的三年内，将追溯确定。 控制组将是从一般情况下选择的女性的概率样本 使用随机数字拨号的人口，频率与 五岁年龄组和种族/族裔(即非西班牙裔白人、 非裔美国人、西班牙裔/拉丁裔、亚裔美国人)。所有的科目都将是 确诊时年龄在20岁到74岁之间，居住在北方五个城市 由两个基于人口的癌症登记机构覆盖的加利福尼亚州县。 个人面谈将以英语、西班牙语、 粤语、他加路语或越南语。因为土壤中的碘和 硒的变化很大，并强烈影响食物水平，这些元素的摄入量 从食物频率调查问卷中得出的微量元素受到 严重的错误分类。因此，脚趾甲修剪，这提供了 与这些微量元素相关的一个相对长期的生物标记 在致癌的促进阶段暴露，将是 收集并使用中子活化分析进行分析。肿瘤综述 样本将被用于证实恶性肿瘤的病例并提供 统一的组织学分类。在对数据进行初步检查之后， 非条件Logistic回归分析，调整年龄和 将进行种族/民族调查，以检验营养假说。 有关移民的假设将在亚裔美国人中进行测试。

This population-based epidemiologic study will examine the role of nutritional factors and migration in thyroid cancer risk among women, with special emphasis on Asian Americans, a high risk population. Thyroid cancer is one of the most commonly occurring cancers among young women and in the rapidly growing population of Asian Americans. The higher incidence of thyroid cancer among Asian immigrants to the United States than among native Asian populations, suggests that readily changeable environmental exposures, such as nutritional factors, acting at a late stage in the carcinogenic process, affect thyroid cancer risk. Limited ecologic, experimental, and epidemiologic evidence suggests that high iodine exposure may increase the risk of papillary thyroid cancer, the most common histologic type in the United States. Alternatively, some of the findings attributed to high levels of iodine exposure may be explained by low selenium consumption. Increased consumption of other antioxidants may also play a role in decreasing thyroid-cancer risk. The proposed case-control study, designed to clarify these associations, will be conducted in the San Francisco Bay Area, an ethnically and culturally heterogenous population providing substantial variation in dietary intake. Women diagnosed with thyroid cancer will be prospectively identified during a three-year period. In addition, to test hypotheses related to migration, Asian cases diagnosed during the preceding three years will be retrospectively identified. Controls will be a probability sample of women selected from the general population using random-digit dialing, frequency-matched to cases on the basis of five-year age-groups and race/ethnicity (i.e., non-Hispanic White, African American, Hispanic/Latina, Asian American). All subjects will be between the ages of 20 and 74 at diagnosis and reside in five northern California counties covered by two population-based cancer registries. Personal interviews will be conducted with subjects in English, Spanish, Cantonese, Tagalog, or Vietnamese. Since soil levels of iodine and selenium vary widely and strongly influence food levels, intake of these trace elements derived from food-frequency questionnaires are subject to substantial misclassification. Therefore, toenail clippings, which provide a relatively long-term biologic marker of these trace elements correlated with exposure during the promotional phase of carcinogenesis, will be collected and analyzed using neutron activation analysis. Review of tumor specimens will be undertaken for cases to verify malignancy and provide a uniform histologic classification. After initial examination of the data, unconditional logistic regression analyses, adjusting for age and race/ethnicity, will be conducted to test nutritional hypotheses. Hypotheses regarding migration will be tested among Asian Americans.