HORMONAL REPLACEMENT THERAPY AND RISK OF COLON CANCER

描述：结直肠癌是最常见的第三种癌症， 西方世界女性癌症死亡的第二个原因。虽然 其发病机制尚未得到证实，流行病学研究和一些 来自动物研究的证据表明，生殖激素， 具体地说，雌激素可以防止结肠的发展 绝经后妇女的癌症。这个历史上以人口为基础的嵌套 病例对照研究将调查过去暴露于 激素替代疗法(HRT)对患结肠癌风险的影响。 方法：研究的来源人群将是动态队列 由萨斯喀彻温省处方药计划(SPDP)的成员定义。 50岁以上的结肠癌病例将由 1981年至1998年的省级癌症登记(n=2400)。四个年龄匹配的人 每个病例的控制将从源总体中选择，使用 发病密度抽样。详细的处方药暴露数据 HRT在确诊前至少5年，最多20年 年数将从社民党获得。还从SPDP获得了这一点 同一时间段将提供口服避孕药的处方信息 和非甾体抗炎药。关于潜在混杂因素的数据将从样本中获得 在一九九四年一月一日至一九九八年十二月三十一日期间， 进行电话采访时对疾病状况视而不见。抽样调查 分数将根据疾病和药物暴露状态的不同而变化，因此 第二阶段的样本将包含大约150个已曝光的病例和对照 对照组150例，总人数500~650人。令人困惑 将受到控制，并将与Logistic一起研究效果修改 回归，使用第二阶段的适当校正--抽样 计划。 意义：申请者处于独特的地位，可以审查 HRT剂量、持续时间和时间对风险的影响 患结肠癌的可能性，最早可以追溯到20年前 在指数数据之前。调查结果将详细说明风险/收益 HRT简介，将帮助妇女和她们的医生 明智的决定。此外，研究结果还将在 为HRT制定全面的实践指南。

DESCRIPTION: Colorectal cancer is the third most frequent cancer and the second cause of cancer mortality in women in the Western World. Although the mechanism has not been confirmed, epidemiological studies and some evidence from animal studies suggest that reproductive hormones, specifically estrogens, may protect against the development of colon cancer in post-menopausal women. This historical population-based nested case-control study will investigate the effect of past exposure to hormonal replacement therapy (HRT) on the risk of developing colon cancer. Methods: The source population for the study will be the dynamic cohort defined by membership in the Saskatchewan Prescription Drug Plan (SPDP). Incident cases of colon cancer over 50 years of age will be accrued by the provincial cancer registry from 1981 to 98 (n=2,400). Four age-matched controls per case will be selected from the source population, using incidence density sampling. Detailed prescription drug exposure data on HRT over a minimum of 5 years before diagnosis and up to a maximum 20 years will be obtained from the SPDP. Also obtained from the SPDP for this same time period will be prescription information on oral contraceptives and NSAIDs. Data on potential confounders will be obtained from a sample of the subjects accrued from January 1, 1994 to December 31, 1998 by means of telephone interviews carried out blind to disease status. The sampling fractions will vary according to disease and drug exposure status, so that the second stage sample will contain about 150 exposed cases and controls and 150 unexposed cases and controls (total=500-650 subjects). Confounding will be controlled and effect modification will be studied with logistic regression, using appropriate correction for the second stage-sampling scheme. Significance: The applicant is in a unique position to examine the respective effect of dose, duration and timing of HRT exposure on the risk of developing colon cancer, for a period of time as far back as 20 years prior to the index data. The findings will elaborate on the risk/benefit profile of HRT, which will assist women and their physicians to make informed decisions. In addition the results will be of value in the development of comprehensive practice guidelines for HRT.