尸检意外发现的结直肠癌（CRC）和息肉代表了在一生中实际上并未引起问题的病变，因此在筛查过程中可能不需要切除。本研究旨在调查不同人群尸检中意外发现的CRC（iCRC）和息肉的患病率。于2022年8月19日进行了系统检索，以查找提供iCRC、腺瘤性息肉、增生性息肉和/或所有息肉患病率数据的尸检研究。采用随机效应模型对患病率进行汇总。进行亚组和多变量荟萃分析来研究异质性。共筛选出43项符合条件的研究，包括59,656例尸检，其中94%的研究是在1990年之前进行的，当时CRC筛查较为罕见或不可行。iCRC的汇总患病率为0.7%（95% CI，0.3-1.2%），腺瘤性息肉的汇总患病率为18.4%（95% CI，13.3-24.1%），增生性息肉的汇总患病率为16.4%（95% CI，8.7-25.9%），所有息肉的汇总患病率为26.3%（95% CI，15.4-38.8%），iCRC加上息肉的汇总患病率为29.9%（95% CI，14.8-47.6%）。白人为主的人群iCRC的患病率较高（1.2%），但排除低质量研究后较低（0.4%）。多变量分析显示，息肉的患病率在白人为主的人群和高质量的研究中较高，随年龄增长而增加，并在“1975年之前”至“1985年之后”的时间段呈下降趋势。总之，尸检中iCRC的患病率并不低，考虑到结直肠癌的平均寿命风险，而意外息肉则较为常见。不同人群间患病率存在很大差异。这些发现在权衡筛查的益处和危害时可能具有意义。© 2023 Springer Nature B.V.

The colorectal cancer (CRC) and polyps incidentally found in autopsies represent the lesions that have not actually caused problems throughout the lifetime and thus may not need to be removed during screening. This study aimed to investigate the prevalence of incidental CRC (iCRC) and polyps in autopsies of different populations. A systematic search was performed on 19 August 2022 to identify autopsy studies that provided data on prevalence of iCRC, adenomatous polyps, hyperplastic polyps, and/or all polyps combined. The prevalence was pooled with the random-effects model. Subgroup and multivariable meta-regression analyses were conducted to investigate the heterogeneity. Forty-three eligible studies including 59,656 autopsies were identified, with 94% conducted before 1990 when CRC screening was uncommon or not available. The pooled prevalence was 0.7% (95% confidence interval [CI], 0.3-1.2%) for iCRC, 18.4% (95% CI, 13.3-24.1%) for adenomatous polyps, 16.4% (95% CI, 8.7-25.9%) for hyperplastic polyps, 26.3% (95% CI, 15.4-38.8%) for all polyps combined, and 29.9% (95% CI, 14.8-47.6%) for iCRC plus polyps. The prevalence of iCRC was higher (1.2%) in white-predominant populations but lower (0.4%) after excluding low-quality studies. Multivariable analyses showed that the prevalence of polyps was higher in white-predominant populations and higher-quality studies, increased with age, and showed a downward trend from "before 1975" through "after 1985". In conclusion, the prevalence of iCRC in autopsies was not low, considering the average lifetime risk of CRC, while incidental polyps were common. Both varied greatly in different populations. These findings may have implications when weighing the benefits and harms of screening.© 2023. Springer Nature B.V.