Background & Aims

The rate of postcolonoscopy colorectal cancer (PCCRC) is a measure of colonoscopy quality, but there are conflicting results from studies of survival times of patients with PCCRC. We assessed survival times of patients with PCCRC and characterized the microscopic and macroscopic features of postcolonoscopy colorectal tumors.

Methods

We performed a population-based cohort study using data from a database in Sweden, on 458,937 colonoscopies (54.0% women) performed from 2003 through 2012. Rates of colorectal cancer within 3 years of a colonoscopy were calculated based on the World Endoscopy Organization guidelines. Risk factors were evaluated using Poisson regression analysis. We used Cox regression models and Kaplan–Meier analyses, stratified by sex, to assess conditional survival. Logistic regression models were used to evaluate features of postcolonoscopy colorectal tumors, including stage location (right, left, or rectum) differentiation grade (high or low), synchronous tumors, perineural growth, resection margins, and mucinous and vessel characteristics.

Results

Within 36 months after a colonoscopy, there were 19,184 individuals who had received a diagnosis of CRC; 1384 of these were PCCRCs (7.2%). The proportion of individuals with PCCRC decreased from 9.4% in 2003 to 6.1% in 2012. The largest risk factors for PCCRC were a prior diagnosis of CRC (relative risk [RR], 3.31; 95% CI, 2.71–4.04), ulcerative colitis (RR, 5.44; 95% CI, 4.75–6.23), Crohn’s disease (RR, 3.81; 95% CI, 2.98–4.87), and prior polypectomy (RR, 2.32; 95% CI, 1.97–2.72). Individuals with PCCRCs had shorter survival times than individuals with CRCs detected during the index colonoscopy. Multivariate hazard ratios for PCCRC were 2.75 for men (95% CI, 2.21–3.42) and 2.00 for women (95% CI, 1.59–2.52), respectively. Individuals with left-side PCCRC had shorter survival times than patients with CRC detected during the index colonoscopy. Postcolonoscopy colorectal tumors had increased odds of low differentiation grade (odds ratio, 1.27; 95% CI, 1.09–1.49) compared with colorectal tumors detected during the index colonoscopy.

Conclusions

In an analysis of colonoscopies in Sweden, the rate of PCCRCs decreased from 9.4% in 2003 to 6.1% in 2012. Diseases that require surveillance (such as prior colorectal neoplasms and inflammatory bowel diseases) are the largest risk factors for PCCRC. Patients with PCCRC have shorter survival times than patients with CRC detected during their initial colonoscopy—especially women and patients with left-side tumors.

中文翻译：

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2003 年至 2012 年瑞典结肠镜检查后结直肠癌：存活率、肿瘤特征和危险因素。

背景与目标

结肠镜检查后结直肠癌 (PCCRC) 的发生率是衡量结肠镜检查质量的指标，但对 PCCRC 患者生存时间的研究结果存在矛盾。我们评估了 PCCRC 患者的生存时间，并表征了结肠镜检查后结直肠肿瘤的微观和宏观特征。

方法

我们使用瑞典数据库中的数据对 2003 年至 2012 年进行的 458,937 次结肠镜检查（54.0% 为女性）进行了一项基于人群的队列研究。根据世界内窥镜组织指南计算结肠镜检查后 3 年内的结直肠癌发生率。使用泊松回归分析评估风险因素。我们使用按性别分层的 Cox 回归模型和 Kaplan-Meier 分析来评估有条件生存。Logistic 回归模型用于评估结肠镜检查后结直肠肿瘤的特征，包括分期位置（右、左或直肠）分化等级（高或低）、同步肿瘤、神经周围生长、切除边缘以及粘液和血管特征。

结果

在结肠镜检查后的 36 个月内，有 19,184 人被诊断为 CRC；其中 1384 个是 PCCRC (7.2%)。PCCRC 患者的比例从 2003 年的 9.4% 下降到 2012 年的 6.1%。 PCCRC 的最大风险因素是先前诊断出的 CRC（相对风险 [RR]，3.31；95% CI，2.71-4.04）、溃疡性结肠炎（RR，5.44；95% CI，4.75-6.23），克罗恩病（RR，3.81；95% CI，2.98-4.87）和先前的息肉切除术（RR，2.32；95% CI，1.97-2.72）。PCCRC 患者的生存时间比结肠镜检查中检测到的 CRC 患者的生存时间短。PCCRC 的多变量风险比，男性为 2.75（95% CI，2.21-3.42），女性为 2.00（95% CI，1.59-2.52）。左侧 PCCRC 患者的生存时间比索引结肠镜检查中检测到的 CRC 患者短。

结论

在瑞典结肠镜检查的分析中，PCCRC 的发生率从 2003 年的 9.4% 下降到 2012 年的 6.1%。需要监测的疾病（如既往结直肠肿瘤和炎症性肠病）是 PCCRC 的最大危险因素。PCCRC 患者的生存时间比在初次结肠镜检查中检测到的 CRC 患者短，尤其是女性和左侧肿瘤患者。