BACKGROUND AND AIMS The clinical significance of a family history (FH) of colorectal cancer (CRC) in first-degree relatives (FDRs) in CRC screening stratified by different age groups of screened individuals is not fully understood. We investigated the relationship between FH and the presence of advanced colorectal neoplasia (ACN) in screened individuals in different age groups. METHODS Data from screened individuals aged 40 to 54 years (n = 2263) and 55 to 69 years (n = 2621) who underwent their first-ever screening colonoscopy were analyzed. The relationship between FH and ACN was examined, and a multivariate logistic regression analysis incorporating other baseline characteristics was performed. RESULTS Among individuals aged 40 to 54 years, the prevalence of ACN was significantly higher in 249 individuals with affected FDRs than in those without (5.6% vs 1.6%; P < .01), with an adjusted odds ratio of 3.7 (95% confidence interval, 1.9-7.0; P < .01); the prevalence was particularly high in those having FDRs with CRC mortality (7.3%). Among individuals aged 55 to 69 years, the prevalence of ACN was not significantly different between 291 individuals with affected FDRs and those without (5.8% vs 5.8%; P = .95); however, individuals with 2 FDRs with CRC and mortality showed a high prevalence of ACN (17.4% and 42.9%, respectively). CONCLUSIONS An FH of CRC in FDRs was associated with a higher prevalence of ACN in younger individuals, with a particularly high impact of FH of CRC mortality. In contrast, the impact of FH was weaker in older individuals except those having 2 FDRs with CRC or mortality.

中文翻译：

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在不同年龄段的无症状筛查人群中，大肠癌的家族史和晚期大肠癌的患病率。

背景和目的在按筛查个体不同年龄组分层的CRC筛查中，一级亲属（FDR）的大肠癌（CRC）家族史（FH）的临床意义尚不完全清楚。我们调查了不同年龄组筛查的个体中FH与晚期结直肠肿瘤（ACN）的存在之间的关系。方法分析了首次接受结肠镜检查的年龄在40至54岁（n = 2263）和55至69岁（n = 2621）的个体的数据。检查了FH和ACN之间的关系，并进行了包含其他基线特征的多元逻辑回归分析。结果在40至54岁的人群中，249名受FDR影响的个体中ACN的患病率显着高于未受FDR影响的个体（5.6％vs 1.6％； P <.01），调整后的优势比为3.7（95％置信区间为1.9-7.0； P <。 01）; 在患有CRC死亡率的FDR患者中，患病率特别高（7.3％）。在55岁至69岁之间的人群中，ACN的患病率在291名FDR受感染者与无FDR者之间无显着差异（5.8％比5.8％； P = 0.95）；但是，具有2个CRC和死亡率的FDR的个体显示出较高的ACN患病率（分别为17.4％和42.9％）。结论FDR中CRC的FH与年轻个体中ACN的患病率较高有关，而FH对CRC死亡率的影响特别高。相反，