Wu Xinhui, Wang Jingxi, Ye Zhen, Wang Jin, Liao Xibei, Liv Mengsi, Svn Zhen
Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China.
Stomatological Hospital of Chongqing Medical University, Chongqing Medical University, Chongqing, China.
Front Med (Lausanne). 2022 Mar 2;9:819122. doi: 10.3389/fmed.2022.819122. eCollection 2022.
Evidence on the association between irritable bowel syndrome (IBS) and colorectal cancer (CRC) risk is inconsistent. Therefore, we aimed to examine whether IBS leads to an increased risk for CRC using a systematic review and meta-analysis approach.
PubMed, Embase, and Web of Science were systematically searched to identify all relevant literature published through July 30, 2021. The pooled risk ratios (RRs) and corresponding 95% confidence intervals (CIs) for CRC after diagnosis of IBS were computed using random-and fixed-effects models and stratified by age, follow-up time, gender, and study design. The quality of included studies was assessed by the Newcastle-Ottawa scale.
We included six studies consisting of 1,085,024 participants. Overall, the risk of detecting CRC after the initial IBS diagnosis was significantly higher than non-IBS controls (RR = 1.52, 95% CI: 1.04-2.22, = 0.032). The peak of elevated risk occurred within the first year of IBS diagnosis (RR = 6.84, 95% CI: 3.70-12.65, < 0.001), and after 1 year, the risk of CRC was similar to that of the general population (RR = 1.02, 95% CI: 0.88-1.18, = 0.813). Notably, we found that the RR of CRC was more significant in IBS patients younger than 50 years compared to those older than 50 years (RR = 2.03, 95% CI: 1.17-3.53, = 0.012 vs. 1.28, 95%CI: 0.94-1.75, = 0.118, respectively). Gender and study design did not affect the results.
The risk of CRC within one year of the initial IBS diagnosis was increased approximately six-fold, whereas the long-term risk was not increased. However, current evidence does not support that IBS leads to an increased incidence of CRC, and the early excess risk is more likely attributable to misclassification resulting from overlapping symptoms rather than causation. Clinicians must remain vigilant for the CRC risk in patients younger than 50 years with IBS-like symptoms to avoid delaying necessary screening.
肠易激综合征（IBS）与结直肠癌（CRC）风险之间关联的证据并不一致。因此，我们旨在采用系统评价和荟萃分析方法，研究IBS是否会导致CRC风险增加。
系统检索了PubMed、Embase和Web of Science，以识别截至2021年7月30日发表的所有相关文献。使用随机效应模型和固定效应模型计算IBS诊断后CRC的合并风险比（RRs）及相应的95%置信区间（CIs），并按年龄、随访时间、性别和研究设计进行分层。纳入研究的质量采用纽卡斯尔-渥太华量表进行评估。
我们纳入了6项研究，共1,085,024名参与者。总体而言，IBS初始诊断后检测到CRC的风险显著高于非IBS对照（RR = 1.52，95% CI：1.04 - 2.22，P = 0.032）。风险升高的峰值出现在IBS诊断后的第一年内（RR = 6.84，95% CI：3.70 - 12.65，P < 0.001），1年后，CRC风险与普通人群相似（RR = 1.02，95% CI：0.88 - 1.18，P = 0.813）。值得注意的是，我们发现年龄小于50岁的IBS患者CRC的RR比年龄大于50岁的患者更显著（分别为RR = 2.03，95% CI：1.17 - 3.53，P = 0.012与RR = 1.28，95% CI：0.94 - 1.75，P = 0.118）。性别和研究设计不影响结果。
IBS初始诊断后一年内CRC风险增加约6倍，而长期风险未增加。然而，目前的证据不支持IBS会导致CRC发病率增加，早期额外风险更可能归因于症状重叠导致的错误分类而非因果关系。临床医生必须对有IBS样症状的50岁以下患者的CRC风险保持警惕，以避免延误必要的筛查。
