Impact of Family History of Colon Cancer on Adenomas in 40-49 Year Olds

描述（由申请人提供）： CRC家族史对40-49岁奥尔兹腺瘤的影响背景：CRC筛查的目标是通过识别和去除晚期癌前息肉（即，晚期腺瘤定义为> 10 mm的腺瘤、绒毛状腺瘤、具有高度异型增生的腺瘤）。来自学术团体和VA指令的当前指南提供了关于在40-49岁的一级亲属（FDR）中有CRC家族史的患者中进行结肠镜检查的需要的不同建议。我们假设，40-49岁的个体与年龄匹配的对照组相比，有CRC家族史的个体发生晚期腺瘤的风险增加。目的：（A）估计具有CRC家族史的40 - 49岁个体中晚期腺瘤的绝对患病率，并将该绝对患病率与具有少量便血、腹部不适或改变的排便习惯（即，便秘或腹泻）作为其结肠镜检查的适应症;（B）使用多元逻辑回归分析鉴定与具有CRC家族史的40-49岁个体中的晚期腺瘤或腺瘤（任何大小）相关的风险因素。方法：这是一项多中心、前瞻性队列研究，在4个研究中心（安阿伯VAHS，达勒姆VAHS，美国）进行。和马里兰州贝塞斯达的国家海军医疗中心）。入选标准：40-49岁的无症状个体由于CRC家族史而被转诊进行结肠镜检查，以及40-49岁的没有CRC或结肠息肉家族史的个体被转诊进行结肠镜检查以评估便血不足、腹部不适或排便习惯改变。[Note虽然结肠镜检查是评估这些症状的“标准治疗”，但这些症状的存在与40-49奥尔兹中晚期腺瘤的风险增加无关。因此，结肠镜检查可以在这些患者中进行，并且这些患者代表了晚期腺瘤的“平均风险”人群。 在获得研究患者的知情同意后，我们将从结肠镜检查报告表和息肉病理报告中收集关于息肉大小、形态和位置的数据。研究患者还将完成一项腺瘤风险因素调查，该调查改编自美国国家癌症研究所的调查。将使用CRC家族史的患者自我报告，因为已发表的文献证明该家族史自我报告的敏感性为86-93%，特异性为92-100%。本研究的样本量设定为1940例患者，如果晚期腺瘤的绝对患病率至少为4.0%，则足以量化具有CRC家族史的40-49岁个体中晚期腺瘤的相对风险为2.0。已获得试点资金，并已在两个地点开始招募患者。2009年8月31日，入组了160例患者，招募人数增加到每周7-8例患者。 公共卫生相关性： 7.9百万退伍军人在VA接受医疗保健。大约10%或790，000人有一级亲属（FDR）患有结直肠癌（CRC）。由于晚期腺瘤的发病率增加，这些患者中的任何一个在40岁时都应该接受结肠镜检查吗？在40-49岁有这种家族史的人群中，没有足够的前瞻性数据来回答这个问题。指南对这些患者在40岁或50岁时进行结肠镜检查提供了相互矛盾的建议，但指南强调需要前瞻性数据来阐明建议。2007年VA CRC指令规定，FDR与CRC <60岁的个体在40岁时进行结肠镜检查，但FDR与CRC > 60的个体可以在40岁时进行结肠镜检查。VA内窥镜资源有限。这项研究将确定数十万退伍军人是否应该从40岁或50岁开始接受结肠镜检查。

DESCRIPTION (provided by applicant): IMPACT OF FAMILY HISTORY OF CRC ON ADENOMAS IN 40-49 YEAR OLDS BACKGROUND: The goal of CRC screening is to prevent cancer by identifying and removing advanced pre- cancerous polyps (i.e., advanced adenomas defined as adenomas > 10 mm, villous adenomas, adenomas with high-grade dysplasia) during colonoscopy. Current guidelines from academic societies and VA Directives provide different recommendations about the need to perform colonoscopy in 40-49 year olds with a family history of CRC in a first-degree relative (FDR). We hypothesize that 40-49 year old individuals with a family history of CRC will have an increased risk of advanced adenoma compared to age-matched controls. OBJECTIVES: (A) To estimate the absolute prevalence of advanced adenomas among 40-49 year old individuals with a family history of CRC and to compare this absolute prevalence versus the absolute prevalence of advanced adenomas in 40-49 year old "average-risk" individuals with scant hematochezia, abdominal discomfort, or altered bowel habits (i.e., constipation or diarrhea) as their indication for colonoscopy; (B) Identify risk factors associated with advanced adenomas or adenomas (any size) among 40-49 year old individuals with a family history of CRC using multiple logistic regression analysis. METHODS: This is a multi-center, prospective cohort study conducted at four sites (Ann Arbor VAHS, Durham VAHS, U. of Michigan Health System, and the National Naval Medical Center, Bethesda, MD). Inclusion criteria: 40-49 year old asymptomatic individuals referred for colonoscopy due to a family history of CRC AND 40-49 year old individuals without a family history of CRC or colon polyps who are referred for colonoscopy to evaluate scant hematochezia, abdominal discomfort or altered bowel habits. [Note: Although performance of colonoscopy is the "standard of care" to evaluate these symptoms, the presence of these symptoms is NOT associated with an increased risk of advanced adenomas in 40-49 year olds. Therefore, colonoscopy can be justified in these patients AND these patients represent an "average-risk" population for advanced adenomas.] After obtaining informed consent from study patients, we will gather data on the size, morphology, and location of polyps from colonoscopy report forms and polyp pathology reports. Study patients will also complete a risk factor survey for adenomas which has been adapted from a National Cancer Institute survey. Patient self-report of family history of CRC will be used since published literature demonstrates 86-93% sensitivity and 92-100% specificity for self-report of this family history. Sample size for this study has been set at 1940 patients which will be sufficient to quantify a relative risk of 2.0 for advanced adenomas in 40-49 year old individuals with a family history of CRC if the absolute prevalence of advanced adenomas is at least 4.0%. Pilot funding has been obtained, and patient recruitment has already been initiated at two sites. On August 31, 2009, 160 patients had been enrolled and recruitment has increased to 7-8 patients per week. PUBLIC HEALTH RELEVANCE: 7.9 million Veterans receive health care in the VA. Approximately 10% or 790,000 have a first-degree relative (FDR) with colorectal cancer (CRC). Should any of these patients undergo colonoscopy at age 40 due to an increased prevalence of advanced adenomas? There is not adequate prospective data in 40-49 year olds with this family history to answer this question. Guidelines provide conflicting recommendations about performing colonoscopy at age 40 or 50 in these patients, but guidelines emphasize that prospective data are needed to clarify recommendations. The 2007 VA CRC Directive states that individuals with a FDR with CRC <60 years old are to get colonoscopy at age 40, but individuals with a FDR with CRC > 60 may get colonoscopy at age 40. VA endoscopic resources are limited. This study will determine if hundreds of thousands of Veterans should get colonoscopy starting at age 40 or age 50.