Objective The risk associated with a family history of non-advanced adenoma (non-AA) is unknown. We determined the prevalence of colorectal neoplasms in subjects who have a first-degree relative (FDR) with non-AA compared with subjects who do not have an FDR with adenomas. Design In a blinded, cross-sectional study, consecutive subjects with newly diagnosed non-AA were identified from our colonoscopy database. 414 FDRs of subjects with non-AA (known as exposed FDRs; mean age 55.0±8.1 years) and 414 age and sex-matched FDRs of subjects with normal findings from colonoscopy (known as unexposed FDRs; mean age 55.2±7.8 years) underwent a colonoscopy from November 2015 to June 2018. One FDR per family was recruited. FDRs with a family history of colorectal cancer were excluded. The primary outcome was prevalence of advanced adenoma (AA). Secondary outcomes included prevalence of all adenomas and cancer. Results The prevalence of AA was 3.9% in exposed FDRs and 2.4% in unexposed FDRs (matched OR (mOR)=1.67; 95% CI 0.72 to 3.91; p=0.238 adjusted for proband sex and proband age). Exposed FDRs had a higher prevalence of any adenomas (29.2% vs 18.6%; mOR=1.87; 95% CI 1.32 to 2.66; p<0.001) and non-AA (25.4% vs 16.2%; mOR=1.91; 95% CI 1.32 to 2.76; p=0.001). A higher proportion of exposed FDRs than unexposed FDRs (4.3% vs 2.2%; adjusted mOR=2.44; 95% CI 1.01 to 5.86; p=0.047) had multiple adenomas. No cancer was detected in both groups. Conclusion A positive family history of non-AA does not significantly increase the risk of clinically important colorectal neoplasia. The data support current guidelines which do not advocate earlier screening in individuals with a family history of non-AA. Trial registration number NCT0252172.

中文翻译：

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前瞻性结肠镜研究以调查非晚期腺瘤患者的一级亲属患结直肠肿瘤的风险

目的与非晚期腺瘤 (non-AA) 家族史相关的风险未知。我们确定了一级亲属 (FDR) 患有非 AA 的受试者与没有 FDR 的腺瘤受试者相比的结直肠肿瘤患病率。设计 在一项盲法横断面研究中，从我们的结肠镜检查数据库中确定了新诊断为非 AA 的连续受试者。414 名非 AA 受试者的 FDR（称为暴露 FDR；平均年龄 55.0±8.1 岁）和 414 名具有结肠镜检查结果正常的受试者（称为未暴露 FDR；平均年龄 55.2±7.8 岁）的年龄和性别匹配的 FDR 2015 年 11 月至 2018 年 6 月进行结肠镜检查。每个家庭招募一名 FDR。有结直肠癌家族史的 FDR 被排除在外。主要结果是晚期腺瘤 (AA) 的患病率。次要结果包括所有腺瘤和癌症的患病率。结果 暴露的 FDR 中 AA 的患病率为 3.9%，未暴露 FDR 中的 AA 患病率为 2.4%（匹配 OR (mOR)=1.67；95% CI 0.72 至 3.91；p=0.238，根据先证者性别和先证者年龄调整）。暴露的 FDR 具有更高的腺瘤患病率（29.2% 对 18.6%；mOR=1.87；95% CI 1.32 至 2.66；p<0.001）和非 AA（25.4% 对 16.2%；mOR=1.91；95% CI 1.3）到 2.76；p=0.001）。暴露的 FDR 的比例高于未暴露的 FDR（4.3% 对 2.2%；调整后的 mOR=2.44；95% CI 1.01 至 5.86；p=0.047）有多个腺瘤。两组均未检测到癌症。结论 非 AA 阳性家族史不会显着增加临床上重要的结直肠肿瘤的风险。数据支持当前的指南，该指南不提倡对具有非 AA 家族史的个体进行早期筛查。试验注册号 NCT0252172。