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

1.为确定粪便潜血检测(FOBT)筛查对结直肠癌死亡率的影响，非 明尼苏达州结肠癌控制研究中的结直肠癌死亡率和全因死亡率， (MCCCS)更新至2006年 2.确定FOBT筛查对结直肠癌和非结直肠癌死亡率的影响 2006年更新的MCCCS按年龄(按5岁和10岁年龄组)和性别分列的死亡率 3.确定基线特征对结直肠癌死亡率的独立影响以及 MCCCS中的非结直肠癌死亡率。 意义：大多数指南建议从50岁开始筛查结直肠癌 平均风险个体。其中最早和最受考验的战略是FOBT，得到了四大 确定结直肠癌筛查有效性的随机临床试验。明尼苏达州 结肠癌控制研究在美国明尼苏达州进行。这项试验招募了健康的志愿者， 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。此外， 其他基线变量，如合并症和阿司匹林的摄入量对预后的影响尚未得到证实 据报道。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%可信区间0.8-0.95)，但也报告了非结直肠癌死亡率大致相等的增加 绝对值(RR 1.02；95%CI 1.00-1.04)，因此总体死亡率几乎相同(RR 1.002， 95%可信区间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试验包括一些从结直肠癌筛查中受益的个人，以及其他 经历过净伤害。因此，对FOBT试验数据进行详细的亚组分析，以分离出亚组 从可能受到伤害的人那里进行筛查而受益的群体将是重要的。为 例如，70岁或75岁以上的患者可能会从筛查中获得更少的好处和更多的伤害，在这种情况下 可能需要重新考虑对这一人群进行筛查。这项研究的目的是评估IF的效果 随机化18年后的结直肠癌死亡率筛查(1999年报告) 明尼苏达州结肠癌控制研究持续进行，或在随机分组28-30年后不同(当 更新至2006年)，以及结直肠癌筛查的效果是否因年龄和性别而异。 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 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患者的生命状况和死因 明尼苏达州结肠癌控制研究的参与者，截至2006年，计算结直肠癌、非结直肠癌和 全死因死亡率估计。我们计划比较结直肠癌(CRC)和非结直肠癌的死亡率 筛查和未筛查人群之间的癌症死亡率，按年龄段分列 5年(50-54，55-59，60-，65-69，70-74，75-80)和10年(50-59，60-69，70-80)的随机化 间隔时间。我们还将按性别分组对上述分析进行分层。没有患者基线数据，只有 明尼苏达州结肠癌控制研究对年龄和性别进行了分析或报告。一份4页的报告， 参与者完成了包含56个项目的基线问卷。我们将对这些产品进行质量检查 现有数据文件，以确定基线上的所有问题或部分问题是否需要重新输入 问卷调查。我们有兴趣探索非甾体抗炎药的消费与高纤维 饮食和体重指数作为筛查效果的效应修饰物。

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.