Dietary Supplements and Lung & Colorectal Cancer Risk

描述(由申请人提供)： 维生素和矿物质补充剂是美国最常用的药物之一。许多消费者使用补充剂来预防癌症等慢性疾病，但除了极少数例外，很少有证据表明它们的好处或风险。这项研究的目的是利用之前从补充剂使用者比例较高的大型队列研究中收集的数据，检查各种膳食补充剂与肺癌和结直肠癌发病率的关系。主要目的是调查在截至基线的10年内补充维生素C、维生素E、钙和复合维生素与肺癌和结直肠癌发病率的关系。次要目标是检查1)特定的、不太常见的维生素、矿物质、植物和其他补充剂(例如叶酸、β-胡萝卜素、硒、鱼油/omega-3脂肪酸、纤维和大蒜补充剂)和2)非类固醇抗炎药(NSAID)和生活方式因素(例如饮食、体力活动)与肺癌和结直肠癌发病率的关系以及它们与补充剂的相互作用。 在2000-2002年间，来自华盛顿州西部的77,738名年龄在50-76岁的男性和女性完成了一份基线问卷，该问卷收集了过去10年中38种补充剂的使用、饮食、体力活动、健康史和癌症风险因素的详细信息。补充剂使用者是招募对象，因此，队列成员的补充剂使用率高且持续时间长：79%的人曾经使用补充剂，66%的人使用多种维生素，46%的人使用单独的维生素C，47%的人使用单独的维生素E，46%的人使用钙，通常在过去10年中的5-8年。通过与华盛顿州西部SEER癌症登记处建立联系，通过与华盛顿州死亡档案建立联系来跟踪肺癌和结直肠癌队列，通过与国家地址变更系统联系来从SEER集水区向外迁出。这项提案寻求资金，以进行针对具体目标的分析。我们预计在平均4.3年的随访期后发现540例肺癌病例，在平均随访期5.3年后确定450例结直肠癌病例。主要接触将是过去10年中被归类为不使用和使用者中三种的感兴趣的营养物质(单一补充剂和多种维生素)的平均每天摄入量，所有分析都将针对饮食和其他潜在的混杂因素和效果调节剂进行调整。这项研究的结果将增强目前关于膳食补充剂与肺癌和结直肠癌风险之间关系的科学知识，并提供信息来帮助指导1亿美国成年人服用补充剂，无论是否发现特定补充剂的保护作用、没有影响或增加风险。

DESCRIPTION (provided by applicant): Vitamin and mineral supplements are among the most commonly used drugs in the U.S. Many consumers use supplements to prevent chronic diseases such as cancer, but with few exceptions, there is sparse evidence for either their benefits or risks. The goal of this study is to examine associations of various dietary supplements with lung and colorectal cancer incidence, using previously collected data from a large cohort study with a high proportion of supplement users. The primary aim is to investigate associations of supplemental vitamin C, vitamin E, calcium, and multivitamins over the 10-year period ending at baseline with the incidence of lung and colorectal cancers. Secondary objectives are to examine associations of intakes of 1) specific, less common vitamin, mineral, botanical, and other supplements (e.g., folate, beta carotene, selenium, fish oil/omega-3 fatty acids, fiber, and garlic supplements) and 2) non-steroidal anti-inflammatory drugs (NSAIDs) and lifestyle factors (e.g., diet, physical activity) with incidence of the lung and colorectal cancers and their interactions with supplements. Between 2000-2002, 77,738 men and women, aged 50-76 from western Washington State completed a baseline questionnaire that captured detailed information on use of 38 supplements over the previous 10 years, diet, physical activity, health history, and cancer risk factors. Supplement users were targeted in recruitment, therefore supplement use by cohort members is both high and of long duration: 79% were ever users of a supplement, and 66% used multivitamins, 46% used individual vitamin C, 47% used individual vitamin E, and 46% used calcium, typically for 5-8 of the previous 10 years. The cohort is being followed for lung and colorectal cancers by linkage to the western Washington SEER cancer registry, deaths by linkage to the Washington State death file, and out-migration from the SEER catchment area by linkage to the National Change of Address system. This proposal seeks funds to conduct analyses addressing the specific aims. We expect to identify 540 lung cancer cases after a mean follow-up of 4.3 years and 450 colorectal cancer cases after 5.3 years mean follow-up. The primary exposure would be average intake per day over the previous 10 years of the nutrient of interest (single supplements plus multivitamins) categorized as nonuse and tertiles among users, and all analyses will be adjusted for diet and other potential confounders and effect modifiers. The results of this study will augment the current body of scientific knowledge regarding associations of dietary supplements with lung and colorectal cancer risk and provide information to help guide the 100,000,000 adult Americans who take supplements, regardless of whether protective effects, no effects, or increased risks for specific supplements are found.