Interval for colon cancer screening by sigmoidoscopy

描述(由申请人提供)： 乙状结肠镜筛查结直肠癌 识别和切除癌前病变(腺瘤性息肉)，从而 预防癌症发病病例。目前的指南建议进行筛查 对于50岁及以上的中等风险成年人，每3至5年。几乎没有什么 然而，支持这种间隔的证据，实际上有一些 有证据表明这段时间不必要地频繁。 拟议研究的目标是确定适当的 乙状结肠镜检查结直肠癌的间隔时间。结直肠癌 北加州凯撒永久居民的预防(CoCaP)计划 (KPNC)定期输入乙状结肠镜检查结果 输入到计算机数据库中。使用来自这一独特资源的数据，一群 大约100,000名年龄在50岁及以上的人患上 结直肠癌，以及基线筛查腺瘤性息肉呈阴性的世卫组织 将确定在1994年至1996年期间进行检查。有关以下信息： 可以使用筛查程序、病史和人口统计变量 在电子文件中，CRC的事故案例将使用 人口登记处。届时，该人群中结直肠癌的发病率将为 按筛查后连续一年的间隔计算；所有费率 将通过直接标准化根据年龄进行调整。CRC的相对风险为 筛查之后的时间段(与第一年相比 筛查后)然后将用于确定筛查间隔 最大限度地降低风险，同时最大限度地提高 连续筛查检查之间的间隔时间。 类似的方法将被用来建议一秒钟的筛查间隔 CoCaP计划中约15,000名患有腺瘤的患者的队列 基线诊断和治疗息肉。这将提供有用的信息 关于筛查阳性个体的筛查间隔。 这项研究将为解决这一问题提供合理的依据 乙状结肠镜检查结直肠癌的适宜筛查间隔。这样的信息将 考虑到减少CRC的发病率和死亡率，同时最大限度地减少 乙状结肠镜检查项目的相关费用。

DESCRIPTION (provided by applicant): Screening for colorectal cancer (CRC) by sigmoidoscopy results in the identification and removal of pre-cancerous lesions (adenomatous polyps), thus preventing incident cases of cancer. Current guidelines recommend screening for average-risk adults aged 50 and above every 3 to 5 years. There is little evidence supporting such an interval, however, and in fact there is some evidence suggesting that this interval is unnecessarily frequent. The objective of the proposed research is to determine an appropriate interval for screening for CRC by sigmoidoscopy. The Colorectal Cancer Prevention (CoCaP) program of Kaiser Permanente of Northern California (KPNC) has routinely entered results of their sigmoidoscopy screening program into a computer database. Using data from this unique resource, a cohort of approximately 100,000 individuals aged 50 and older who are at low risk for CRC, and who screened negative for adenomatous polyps at a baseline examination between 1994 and 1996, will be identified. Information regarding screening procedures, medical history, and demographic variables is available in electronic files, and incident cases of CRC will be identified using a population registry. Incidence rates of CRC in this population will then be calculated for successive one-year intervals following screening; all rates will be adjusted for age by direct standardization. Relative risks of CRC for later time periods following screening (as compared to the first year post-screen) will then be used to determine the screening interval that is associated with the greatest risk reduction, while maximizing the amount of time between successive screening examinations. Similar methods will be used to suggest a screening interval for a second cohort of about 15,000 individuals in the CoCaP program who had adenomatous polyps diagnosed and treated at baseline. This will provide useful information regarding screening interval in screen-positive individuals. This study will provide a rational basis to address the question of appropriate screening interval for CRC by sigmoidoscopy. Such information will allow for the reduction in CRC incidence and mortality, while minimizing the costs associated with a sigmoidoscopy screening program.