本研究旨在调查肠癌幸存者中二次原发恶性肿瘤（SPMs）发生率及其危险因素。进行了大规模人群队列研究。从1990年1月至2017年12月，从Surveillance、Epidemiology和End Results数据库的8个癌症登记处识别和提取了诊断为肠癌的患者数据。感兴趣的结果是一次发生肠癌之后SPM发病的百分比和常见部位。也报告了累计发病率和标准化发病率（SIRs）。然后，我们使用多变量竞争风险和Poisson回归模型估计了SPM发生的亚分布危险比（SHRs）和相对风险（RRs）。分析了152,402例肠癌患者。总体而言，23,816例肠癌幸存者（15.6％）报告了SPM发生。所有幸存者中，一次肠癌后SPMs发展的最高比例是第二个CRC，其次是肺和支气管癌。此外，CRC幸存者更容易发生第二个胃肠癌（GICs）。此外，与没有RT治疗的组相比，接受RT的患者中盆腔癌的比例相对较高。所有SPMs发病的累计发病率在近30年的随访中为22.16％（95％ CI：21.82-22.49％）。一些因素，包括年龄较大，男性，已婚状态和CRC的局部分期与SPMs发生的高风险相关。在治疗特异性分析中，RT与SPMs发生率较高相关联（所有SPMs：14.08％vs. 8.72％；GICs：2.67％vs. 2.04％；CRC：1.01％vs. 1.57％；所有p＜0.01）。此外，接受RT的患者中发生SPMs的风险高于NRT组内的患者（SHR：1.50，95％ CI：1.32-1.71，p＜0.01；RR：1.61，95％ CI：1.45-1.79，p＜0.01）。本研究描述了CRC幸存者中SPM的发病模式，并确定了SPM发生的危险因素。对于这些患者，肠癌诊断后的RT治疗可能会增加SPMs发生的风险。这些发现表明这些患者需要长期的随访监测。©2023年。作者（们）以Springer-Verlag GmbH德国的独家许可证，隶属于Springer Nature。

This study aimed to investigate the incidence and the risk factors of incidence for second primary malignancies (SPMs) onset among survivors diagnosed with colorectal cancer (CRC).A large population-based cohort study was performed. Data of patients diagnosed with CRC was identified and extracted from 8 cancer registries of Surveillance, Epidemiology, and End Results database from January 1990 to December 2017. The outcome of interest was percentage and common sites of SPM onset after primary CRC diagnosis. The cumulative incidence and standardize incidence rates (SIRs) were also reported. Afterwards, we estimated sub-distribution hazards ratios (SHRs) and relative risks (RRs) for SPM occurrence using multivariable competing-risk and Poisson regression models, respectively.A total of 152,402 patients with CRC were included to analyze. Overall, 23,816 patients of all CRC survivors (15.6%) were reported SPM occurrence. The highest proportion of SPMs development after primary CRC diagnosis was second CRC, followed by lung and bronchus cancer among all survivors. Also, CRC survivors were more susceptible to develop second gastrointestinal cancers (GICs). Besides, pelvic cancers were analyzed with a relative high proportion among patients who received RT in comparison to those without RT. The cumulative incidence of all SPMs onset was 22.16% (95% CI: 21.82-22.49%) after near 30-year follow-up. Several factors including older age, male, married status, and localized stage of CRC were related to the high risk of SPMs onset. In treatment-specific analyses, RT was related to a higher cumulative incidence of SPMs occurrence (all SPMs: 14.08% vs. 8.72%; GICs: 2.67% vs. 2.04%; CRC: 1.01% vs. 1.57%; all p < 0.01). Furthermore, the increased risk of SPMs onset was found among patients who received RT than patients within the NRT group (SHR: 1.50, 95% CI: 1.32-1.71), p < 0.01; RR: 1.61, 95% CI: 1.45-1.79, p < 0.01).The present study described the incidence pattern of SPM among CRC survivors and identified the risk factors of the SPM onset. RT treatment for patients diagnosed with CRC may increase the risk of SPMs occurrence. The findings suggest the need for long-term follow-up surveillance for these patients.© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.