Dairy Products, Calcium, and Risk of Prostate Cancer

描述（由申请人提供）： 前列腺癌是美国男性中最常见的癌症（除了非黑色素瘤皮肤癌），也是导致死亡的主要原因。不幸的是，这种疾病的公认风险因素（例如，年龄）是不可更改的。在寻找可改变的预测因素时，钙摄入量被认为是一个危险因素。高钙摄入量可能会通过下调1，25羟基维生素D3（一种抑制前列腺癌细胞生长和发育的激素）来增加风险。明确钙摄入量与前列腺癌风险之间的关系很重要，因为钙在预防和治疗骨质疏松症中很重要。关于钙摄入量与前列腺癌风险相关性的流行病学数据一直不一致。很少有研究专门调查从乳制品中摄入钙和前列腺癌的风险。关于钙补充剂使用和前列腺癌风险的数据甚至更少。此外，关于钙摄入量与前列腺癌风险之间的关联是否会因年龄而改变的信息很少。这是一个重要的问题，因为老年男性患骨质疏松症的风险更高。最后，有一个建议，钙的摄入量可能与晚期前列腺癌更密切相关，但数据很少。 我们建议分析1988年11,122名男性（平均年龄67岁）从乳制品和补充剂中摄入钙的相关性。1988年，男性报告了他们的饮食情况，包括乳制品和钙补充剂的摄入量。关于非致命性前列腺癌发展的信息可提供至1998年;致命性前列腺癌，1995年。我们建议再收集三年至一九九八年的死亡率资料。我们预计受试者中共发生800例前列腺癌（包括116例致命性癌症），提供了足够的统计功效来解决感兴趣的问题。我们将研究从乳制品和补充剂中摄入钙与所有和致命前列腺癌风险的关系。从乳制品和钙补充剂中看到的钙的一致增加的风险增加了假设的权重，即是钙，而不是乳制品中的其他营养素，是导致风险增加的原因。我们还将检查65岁以下、65-74岁和75岁以上的男性。这一大型数据库为回答具有公共卫生重要性的问题提供了一个独特且具有成本效益的机会。

DESCRIPTION (provided by applicant): Prostate cancer is the most common cancer among men in the U.S. (apart from non-melanoma skin cancer), and is a leading cause of death. Unfortunately, well-established risk factors for this disease (e.g., age) are not modifiable. In the search for modifiable predictors, calcium intake has been proposed to be a risk factor. A high intake of calcium may increase risk by down-regulating 1,25 hydroxyvitamin D3, a hormone that inhibits prostate cancer cell growth and development. It is important to clarify the relation between calcium intake and risk of prostate cancer because calcium is important in the prevention and treatment of osteoporosis. Epidemiologic data on the association of calcium intake and prostate cancer risk have been inconsistent. Few studies have specifically investigated intake of calcium from dairy products and risk of prostate cancer. The data on calcium supplement use and prostate cancer risk are even sparser. Additionally, little information is available on whether the association of calcium intake and prostate cancer risk is modified by age. This is an important question since older men are at higher risk of osteoporosis. Finally, there is a suggestion that calcium intake may be more strongly related to advanced prostate cancer, but few data are available. We propose to analyze the associations of calcium intake from dairy products and supplements among 11,122 men (mean age, 67 years) who were free of cancer in 1988. Men reported on their diet, including intake of dairy products and calcium supplements, in 1988. Information on the development of nonfatal prostate cancer is available through 1998; fatal prostate cancer, 1995. We propose to collect another 3 years of mortality data through 1998. We anticipate a total of 800 prostate cancers (including 116 fatal cancers) to occur among subjects, providing sufficient statistical power to address the questions of interest. We will examine the associations of calcium intake from dairy products and supplements with risk of all and fatal prostate cancer. A consistent increased risk seen with both calcium from dairy products and calcium supplements lends weight to the hypothesis that it is calcium, rather than other nutrients in the dairy products, that is responsible for the increased risk. We also will examine men aged <65, 65-74, and 75+ years. This large database provides a unique and cost-effective opportunity to answer questions of public health importance.