早发性结直肠癌的增加令人担忧，导致美国癌症协会在 2018 年修改了指南，将首次结直肠癌筛查的年龄从 50 岁降低至 45 岁。尽管这预计将导致筛查率提高以及随后结直肠癌的早期检测，但这一指南变更在国家层面的影响尚未完全了解。利用国家癌症数据库，我们确定了新的筛查目标患者（年龄45-49 岁）在 2017 年（早期队列）或 2019 年（晚期队列）被诊断患有结肠癌。通过单变量分析和多变量逻辑回归模型检查了发病时间段和疾病阶段之间的关系。总共有 5,479 名患者符合纳入标准。晚期和早期队列患者的诊断中位年龄没有差异（两个队列均为 47 岁，P = 0.41）。晚期和早期队列中的患者患有 III-IV 期疾病的几率相同（晚期队列与早期队列的比值比为 1.05，95% 置信区间为 0.94-1.17），晚期队列中的患者出现 III-IV 期疾病的几率略有增加。患有较高 T 分期（pT3 或 pT4）疾病（比值比，1.20，95% 置信区间，1.05-1.35）。尽管建议早期进行结直肠癌初始筛查，但在患者中并未观察到具有临床意义的结肠癌分期早期转变新的筛选目标。需要进一步研究来评估提供者和患者对这些建议的采纳情况，并确定需要改进的领域。版权所有 © 2024 Elsevier Inc. 保留所有权利。

A concerning increase in early-onset colorectal cancer led to guideline changes in 2018 by the American Cancer Society to lower the age for initial colorectal cancer screening from 50 to 45 years of age. Although this would be expected to result in increased screening rates and subsequent earlier detection of colorectal cancer, the effect of this guideline change at a national level is not yet fully understood.Using the National Cancer Database, we identified patients newly targeted for screening (age 45-49 years) diagnosed with colon cancer in either 2017 (early cohort) or 2019 (late cohort). The relationship between time period and stage of disease at presentation was examined by univariate analysis and in a multivariable logistic regression model.In total, 5,479 patients met inclusion criteria. The median age at diagnosis did not differ between patients in the late and early cohorts (47 years for both cohorts, P = .41). Patients in the late and early cohorts had equal odds of having stage III-IV disease (odds ratio for late cohort to early cohort, 1.05, 95% confidence interval, 0.94-1.17), and patients in the late cohort showed slightly increased odds of having higher T-stage (pT3 or pT4) disease (odds ratio, 1.20, 95% confidence interval, 1.05-1.35).Despite recommendations of earlier initial colorectal cancer screening, a clinically meaningful earlier shift in colon cancer stage was not observed in patients newly targeted for screening. Further studies will be needed to assess uptake of these recommendations by providers and patients and identify areas of improvement.Copyright © 2024 Elsevier Inc. All rights reserved.