The incidence of early onset colorectal cancer, or colorectal cancer (CRC) diagnosed before age 50, is increasing.1 In response, multiple societal guidelines in the United States now recommend initiating CRC screening at age 45 in average-risk individuals (ie, those without high-risk clinical characteristics, such as bleeding, or iron deficiency anemia), inflammatory bowel disease, or family history of colorectal neoplasia.2 The Veterans Health Administration (VHA) is the largest integrated health system in the United States and is contending with how best to expand CRC screening access to this younger population in the setting of limited colonoscopy resources. Understanding the rate and anatomic location of colorectal neoplasia in Veterans younger than age 50 can inform the expected yield of different screening modalities. Prior work has shown that individuals undergoing colonoscopy for low-risk diagnostic indications have equivalent risk of colorectal neoplasia as those undergoing average-risk screening.3 This study and a recent meta-analysis4 reported that 3.6% (95% confidence interval, 1.9%-6.7%) to 3.7% (95% confidence interval, 3.0%-4.7%) of average-risk individuals age 45-49 have advanced colorectal neoplasia (ACN), defined as an advanced polyp or carcinoma; however, data specific to the VHA population are lacking.

中文翻译：

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50 岁以下退伍军人的晚期结直肠肿瘤谱和平均风险筛查的预期产量。

50 岁之前诊断出的早发性结直肠癌或结直肠癌 (CRC) 的发病率正在增加。 1 作为回应，美国的多项社会指南现在建议在 45 岁时对平均风险人群（即那些无高危临床特征，如出血或缺铁性贫血）、炎症性肠病或结直肠肿瘤家族史。 2 退伍军人健康管理局 (VHA) 是美国最大的综合卫生系统，正在与在结肠镜检查资源有限的情况下，如何最好地将 CRC 筛查范围扩大到这一年轻人群。了解 50 岁以下退伍军人结直肠肿瘤的发生率和解剖位置，可以告知不同筛​​查方式的预期产量。先前的工作表明，因低风险诊断适应症而接受结肠镜检查的个体患结直肠肿瘤的风险与接受平均风险筛查的个体相同。 3 这项研究和最近的一项荟萃​​分析 4 报告称，3.6%（95% 置信区间，1.9%- 6.7% 至 3.7%（95% 置信区间，3.0%-4.7%）的 45-49 岁平均风险人群患有晚期结直肠肿瘤 (ACN)，定义为晚期息肉或癌；然而，缺乏针对 VHA 人群的数据。7% 的 45-49 岁平均风险人群患有晚期结直肠肿瘤 (ACN)，定义为晚期息肉或癌；然而，缺乏针对 VHA 人群的数据。7% 的 45-49 岁平均风险人群患有晚期结直肠肿瘤 (ACN)，定义为晚期息肉或癌；然而，缺乏针对 VHA 人群的数据。