Who benefits from Colorectal Cancer Screening? A subgroup Analysis of the Minnes

1.为了确定粪便潜血试验（FOBT）筛查对结直肠癌死亡率的影响， 明尼苏达州结肠癌控制研究中的结肠癌死亡率和全因死亡率， （军事协调和控制系统）更新至2006年 2.确定FOBT筛查对结直肠癌死亡率和非结直肠癌的影响 按年龄（按5岁和10岁年龄组）和性别分列的2006年最新《儿童死亡情况调查》死亡率 3.确定基线特征对结直肠癌死亡率的独立影响， MCCCS中的非结直肠癌死亡率。 意义：大多数指南建议在50岁时开始筛查结直肠癌， 平均风险的人。其中最早和最受考验的战略是FOBT，由四个大型 建立结直肠癌筛查有效性的随机临床试验。明尼苏达 结肠癌控制研究在美国明尼苏达州进行。该试验招募了健康志愿者， 年龄在50到80岁之间这些试验没有报告按年龄和性别分层的结果。另夕h 其他基线变量（如合并症和阿司匹林摄入量）对结局的影响尚未被证实。 报道最近对这些试验的荟萃分析证实了结直肠癌死亡率的降低（RR 0.87; 95% CI 0.8-0.95），但也报告了非结直肠癌死亡率增加约等于 绝对幅度（RR 1.02; 95% CI 1.00-1.04），因此总体死亡率几乎相同（RR 1.002， 95% CI 0.989-1.015）。为什么非CRC死亡率会增加尚不清楚，但一种可能性是， FOBT试验包括一些从CRC筛查中受益的个体，以及 经历了净伤害。因此，对FOBT试验数据进行详细的亚组分析， 从那些可能受到伤害的人中筛选出受益的群体将是重要的。为 例如，70岁或75岁以上的患者可能从筛查中获得较少的益处和更多的伤害，在这种情况下， 对这一人群的筛查可能需要重新考虑。这项研究的目的是评估是否影响 随机分组后18年（1999年报告）， 明尼苏达州结肠癌控制研究持续存在，或在随机化后28-30年不同（当 （更新至2006年），以及大肠癌普查的成效是否因年龄及性别而异， 组我们还希望评估基线特征的影响，如饮食，阿司匹林的使用和身体状况。 这些结果的质量指数 项目设计和方法：该项目涉及更新所有人的生命状态和死亡原因 参与者来自明尼苏达州结肠癌控制研究，直到2006年，计算CRC，非CRC和 全因死亡率估计。我们计划比较结直肠癌（CRC）死亡率和非结直肠癌死亡率。 按年龄类别分列的筛查组和未筛查组之间的癌症死亡率， 5年（50-54、55-59、60-64、65-69、70-74、75-80）和10年（50-59、60-69、70-80）随机化 的间隔我们还将按性别亚组对上述分析进行分层。无患者基线数据， 年龄和性别已经从明尼苏达州结肠癌控制研究中分析或报告。四页的， 56-项目基线问卷由参与者完成。我们将对产品进行质量检查， 现有数据文件，以确定是否需要重新输入基线上的所有问题或部分问题 问卷我们感兴趣的是探索非甾体抗炎药，高纤维， 饮食和BMI作为筛选有效性的影响因素。

1. To determine the effect of fecal occult blood testing (FOBT) screening on colorectal cancer mortality, non- colorectal cancer mortality and all-cause mortality in the Minnesota Colon Cancer Control Study, (MCCCS) updated to 2006 2. To determine the effect of FOBT screening on colorectal cancer mortality and non-colorectal cancer mortality by age (by 5 and 10 year age groups) and gender in the MCCCS updated to 2006 3. To determine the independent influence of baseline characteristics on colorectal cancer mortality and non-colorectal cancer mortality in the MCCCS. Significance: Most guidelines recommend starting screening for colorectal cancer at age 50 years for average risk individuals. The earliest and most tested strategy among these is FOBT, supported by four large randomized clinical trials that established the effectiveness of colorectal cancer screening. The Minnesota Colon Cancer Control Study was conducted in Minnesota, US. The trial recruited healthy volunteers between the ages of 50 to 80. The trials have not reported results stratified by age and gender. Additionally, the effects of other baseline variables, such as co-morbidities and intake of aspirin on outcomes have not been reported. A recent meta-analysis of these trials confirmed a reduction in colorectal cancer mortality (RR 0.87; 95% CI 0.8-0.95), but also reported an increase in non-colorectal cancer mortality of approximately equal absolute magnitude (RR 1.02; 95% CI 1.00-1.04) so that overall mortality was nearly identical (RR 1.002, 95% CI 0.989-1.015). Why non-CRC mortality would be increased is unclear, but one possibility is that the FOBT trials included some individuals that benefited from CRC screening, and other individuals who experienced net harm. Therefore, detailed sub-group analyses of the FOBT trial data, to separate out sub- groups that benefit from screening from those who may potentially be harmed would be important. For example, patients over age 70 or 75 might derive less benefit and more harm from screening, in which case screening this population may need to be re-considered. The goals of this research are to evaluate if effects of screening on colorectal cancer mortality seen 18 years after randomization (reported in 1999) in the Minnesota Colon Cancer Control Study persist, or are different 28-30 years after randomization (when updated to year 2006), and whether effect of screening for colorectal cancer varies in age and gender sub- groups. We also wish to evaluate the influence of baseline characteristics, such as diet, aspirin use and body mass index on these outcomes. Project Design and methods: This project involves updating the vital status and cause of death of all participants from the Minnesota Colon Cancer Control Study up to 2006 and calculating CRC, non-CRC and all-cause mortality estimates. We plan to compare colorectal cancer (CRC) mortality and non-colorectal cancer mortality rates between the screened and unscreened groups, by age categories at time of randomization of 5 year (50-54, 55-59, 60-64, 65-69, 70-74, 75-80) and 10 year (50-59, 60-69, 70-80) intervals. We will also stratify the above analyses by gender subgroups. No patient baseline data other than age and gender has been analyzed or reported from the Minnesota Colon Cancer Control Study. A 4-page, 56-item baseline questionnaire was completed by participants. We will perform a quality check on the existing data files to determine if re-entry is required for all or a subset of the questions on the baseline questionnaire. We are interested in exploring the relationship between consumption of NSAIDs, high fiber diet and BMI as effect modifiers of effectiveness of screening.