早发性结直肠癌 (EOCRC)（定义为年龄小于 50 岁）的诊断人数正在增加，而这些人中所谓的危险信号体征和症状经常被遗漏，导致诊断延误。提高对 EOCRC 相关体征和症状的认识可以促进更及时的诊断并影响临床结果。报告 EOCRC 个体出现危险信号体征和症状的频率，检查其与 EOCRC 风险的关联，并测量时间变化从数据库建立到 2023 年 5 月，对 PubMed/MEDLINE、Embase、CINAHL 和 Web of Science 进行了检索。报告了 20 岁以下患者的体征和症状表现或从体征和症状表现到诊断的时间的研究年龄 50 岁诊断出非遗传性 CRC 被纳入。使用系统评价和荟萃分析报告指南的首选报告项目，对所有纳入的研究独立进行数据提取和质量评估，一式两份。乔安娜·布里格斯研究所的批判性评估工具用于衡量偏差风险。使用随机效应模型汇总体征和症状频率的数据。感兴趣的结果是 EOCRC 患者体征和症状的汇总比例、体征和症状与 EOCRC 风险关联的估计，以及从体征或症状出现到出现症状的时间。 EOCRC 诊断。在最初检索到的 12859 篇独特文章中，纳入了 81 项研究，涉及 24908126 名 50 岁以下患者。 78 项纳入研究报告的最常见的体征和症状是便血（汇总患病率，45% [95% CI，40%-50%]）、腹痛（汇总患病率，40% [95% CI，35%] -45%]），以及排便习惯改变（汇总患病率为 27% [95% CI, 22%-33%]）。便血（估计范围，5.2-54.0）、腹痛（估计范围，1.3-6.0）和贫血（估计范围，2.1-10.8）与较高的 EOCRC 可能性相关。从体征和症状出现到 EOCRC 诊断的时间平均（范围）为 6.4（1.8-13.7）个月（23 项研究），中位数（范围）为 4（2.0-8.7）个月（16 项研究）。对 EOCRC 患者的荟萃分析显示，近一半的患者出现便血和腹痛，四分之一的患者排便习惯改变。便血与 EOCRC 风险增加至少 5 倍相关。诊断延迟 4 至 6 个月的情况很常见。这些发现强调需要识别有关 EOCRC 体征和症状并及时完成诊断检查，特别是对于没有其他诊断或体征或症状解决的个体。

Early-onset colorectal cancer (EOCRC), defined as a diagnosis at younger than age 50 years, is increasing, and so-called red flag signs and symptoms among these individuals are often missed, leading to diagnostic delays. Improved recognition of presenting signs and symptoms associated with EOCRC could facilitate more timely diagnosis and impact clinical outcomes.To report the frequency of presenting red flag signs and symptoms among individuals with EOCRC, to examine their association with EOCRC risk, and to measure variation in time to diagnosis from sign or symptom presentation.PubMed/MEDLINE, Embase, CINAHL, and Web of Science were searched from database inception through May 2023.Studies that reported on sign and symptom presentation or time from sign and symptom presentation to diagnosis for patients younger than age 50 years diagnosed with nonhereditary CRC were included.Data extraction and quality assessment were performed independently in duplicate for all included studies using Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines. Joanna Briggs Institute Critical Appraisal tools were used to measure risk of bias. Data on frequency of signs and symptoms were pooled using a random-effects model.Outcomes of interest were pooled proportions of signs and symptoms in patients with EOCRC, estimates for association of signs and symptoms with EOCRC risk, and time from sign or symptom presentation to EOCRC diagnosis.Of the 12 859 unique articles initially retrieved, 81 studies with 24 908 126 patients younger than 50 years were included. The most common presenting signs and symptoms, reported by 78 included studies, were hematochezia (pooled prevalence, 45% [95% CI, 40%-50%]), abdominal pain (pooled prevalence, 40% [95% CI, 35%-45%]), and altered bowel habits (pooled prevalence, 27% [95% CI, 22%-33%]). Hematochezia (estimate range, 5.2-54.0), abdominal pain (estimate range, 1.3-6.0), and anemia (estimate range, 2.1-10.8) were associated with higher EOCRC likelihood. Time from signs and symptoms presentation to EOCRC diagnosis was a mean (range) of 6.4 (1.8-13.7) months (23 studies) and a median (range) of 4 (2.0-8.7) months (16 studies).In this systematic review and meta-analysis of patients with EOCRC, nearly half of individuals presented with hematochezia and abdominal pain and one-quarter with altered bowel habits. Hematochezia was associated with at least 5-fold increased EOCRC risk. Delays in diagnosis of 4 to 6 months were common. These findings highlight the need to identify concerning EOCRC signs and symptoms and complete timely diagnostic workup, particularly for individuals without an alternative diagnosis or sign or symptom resolution.