Colorectal cancer risk after colonoscopy in elderly diabetes patient and men

描述(申请人提供)：结直肠癌(CRC)是美国第二大癌症死亡原因。结肠镜检查被广泛用于筛查CRC。目前的指南建议对结肠镜检查未发现息肉的50岁以上的平均风险患者每10年筛查一次结肠镜检查(即阴性结肠镜检查)。然而，结直肠癌和息肉的患病率随着年龄的增长而增加。此外，近四分之一的美国60岁以上人口患有糖尿病(DM)。最近的数据表明，糖尿病(DM)患者患CRC的风险增加。此外，基于人群的癌症发病率数据一直表明男性的结直肠癌发病率高于女性，这种差异在65岁的人群中最为显著。因此，在65岁男性或糖尿病患者中，结肠镜检查阴性的阴性预测值可能较低。因此，还不确定推荐的结肠镜检查间隔10年是否适用于老年男性或老年糖尿病患者。我们假设，在65岁以上的患者中，男性结肠镜检查阴性后发生结直肠癌的风险高于女性，糖尿病患者比非糖尿病患者更高。为了验证这一假设，我们设计了一项基于人群的队列研究，使用的是关联的SEERMedicare 数据。这项研究将确定在SEER-Medicare人群中，1)有 接受阴性结肠镜检查的女性比接受结肠镜检查的女性有更高的结直肠癌后续发病率 研究目的：1)研究结肠镜检查阴性的糖尿病患者的CRC发病率是否高于结肠镜检查阴性的非糖尿病患者；3)结肠镜检查阴性的男性或DM患者的CRC发病率是否低于未接受结肠镜检查的普通SEER-Medicare人群，以及低发病率是否持续长达10年；4)确定男性、女性、所有糖尿病患者、男性糖尿病患者及女性糖尿病患者在接受结肠镜检查后发生CRC的绝对发病率。在后续期间，将对相对风险和绝对风险进行审查。亚组分析将检查近端结肠癌的风险以及男性和糖尿病的联合影响。 与公共卫生的相关性：CRC是老年人口的常见死亡原因。结直肠癌筛查可以降低癌症风险和癌症相关死亡率。鉴于老年男性患者或老年糖尿病患者结直肠癌发病率的增加，重要的是确定建议的结肠镜检查之间没有息肉的10年间隔是否为这些高危人群提供了足够的保护。我们的研究将有助于确定老年男性和老年糖尿病患者在结肠镜检查阴性后进行第二次结肠镜检查的适当时间间隔，以便他们不会面临不可接受的高发病率和可预防的结直肠癌死亡率。

DESCRIPTION (Provided by Applicant): Colorectal cancer (CRC) is the second leading cause of cancer death in the U.S. Colonoscopy is widely used to screen for CRC. Current guidelines recommend screening colonoscopy once every 10 years in average risk patients over >50 year who have no polyps identified at colonoscopy (i.e., negative colonoscopy). However, the prevalence of CRC and polyps increase with age. In addition, nearly 1/4 of the U.S. population over 60 years of age have diabetes mellitus (DM). Recent data suggest patients with diabetes mellitus (DM) have an increased risk of CRC. Furthermore, population-based cancer incidence data have consistently suggested a higher incidence of CRC among men vs. women, and the disparity is most striking among those >65 years. Hence, the negative predictive value of a negative colonoscopy may be lower in patients >65 years who are male or have DM. As a result, there is uncertainty whether the recommended 10-year interval between screening colonoscopies in whom no polyps were identified should apply to elderly men or elderly DM patients. We hypothesize that among patients over the age of 65, the risk of CRC following a negative colonoscopy is higher in men vs. women, and in DM patients vs. non-DM patients. To test this hypothesis, we have designed a population-based cohort study using the linked SEERMedicare data. The study will determine among the SEER-Medicare population, 1) whether men who have undergone a negative colonoscopy have a higher subsequent incidence of CRC than women with a negative colonoscopy; 2) whether DM patients who have undergone a negative colonoscopy have a higher subsequent incidence of CRC than non-DM patients with a negative colonoscopy; 3) whether men or DM patients who have undergone a negative colonoscopy have a lower incidence of CRC than the general SEER-Medicare population who have not undergone colonoscopy and whether the lower incidence persists for up to 10 years; 4) determine the absolute incidence by time of CRC following a colonoscopy without polyps for men, women, all patients with diabetes, men with diabetes, and women with diabetes. Both relative and absolute risks will be examined during the follow-up period. Subgroup analysis will examine the risk for proximal colon cancer and the combined effect of male sex and DM. Relevance to Public Health: CRC is a common cause of death among the elderly population. Screening for colorectal cancer can reduce the risk of cancer and cancer-related mortality. Given the increased incidence of CRC in elderly male patients or elderly DM patients, it is important to determine whether the recommended 10-year interval between colonoscopies without polyps offers adequate protection to these high risk groups. Our study will help establish the appropriate time interval for elderly men and elderly DM patients to undergo a second colonoscopy following a negative colonoscopy so that they will not be facing an unacceptably high rate of preventable CRC morbidity and mortality.