What is the quantitative risk of gastric cancer in the first-degree relatives of patients? A meta-analysis

AIM To quantify the risk of gastric cancer in first-degree relatives of patients with the cancer. METHODS A comprehensive literature search was performed. Case-control trials comparing the frequency of a positive family history of gastric cancer in patients with gastric cancer, vs non-gastric cancer controls were retrieved. Studies with missed or non-extractable data, studies in children, abstracts, and duplicate publications were excluded. A meta-analysis of pooled odd ratios was performed using Review Manager 5.0.25. We performed subgroup analysis on Asian studies and a sensitivity analysis based on the quality of the studies, type of the outcome, sample size, and whether studies considered only first-degree relatives. RESULTS Thirty-two relevant studies out of 612 potential abstracts(n = 80690 individuals) were included. 19.0% of the patients and 10.9% of the controls had at least one relative with gastric cancer(P < 0.00001). The pooled relative risk for the development of gastric cancer in association with a positive family history was 2.35(95%CI: 1.96-2.81). The Cochran Q test for heterogeneity was positive(P < 0.00001, I 2 = 92%). After excluding the three outlier studies with the highest relative risks, heterogeneity remained significant(P < 0.00001, I 2 = 90%). The result was not different among Asian studies as compared to others and remained robust in several sensitivity analyses. In the 26 studies which exclusively analysed the history of gastric cancer in first-degree relatives, the relative risk was 2.71(95%CI: 2.08-3.53; P < 0.00001). CONCLUSION Individuals with a first-degree relative affected with gastric cancer have a risk of about 2.5-fold for the development of gastric cancer. This could be due to genetic or environmental factors. Screening and preventive strategies should be developed for this highrisk population.

Quantitative risk of positive family history in developing colorectal cancer: A meta-analysis

BACKGROUND Positive family history is a risk factor for development of colorectal cancer.Despite numerous studies on the topic,the absolute risk in patients with a positive family history remains unclear and therefore studies are lacking to validate non-invasive screening methods in individuals with positive family history.AIM To quantify the risk of colorectal cancer in individuals with a positive family history.METHODS A comprehensive electronic literature search was performed using PubMed from January 1955 until November 2017,EMBASE from 1947 until 2018,and Cochrane Library without date restrictions.Two independent reviewers conducted study selection,data extraction and quality assessment.A meta-analysis of Mantel-Haenzel relative risks was performed using the random effects model.Newcastle-Ottawa scale was used to score the quality of selected papers.Funnel plot and Egger’s regression test was performed to detect publication bias.Subgroup analysis was performed comparing Asian and non-Asian studies.Sensitivity analyses were performed to rule out the effect of the timing of the study,overall quality,the main outcome and the effect of each individual study in overall result.RESULTS Forty-six out of 3390 studies,including 906981 patients were included in the final analysis.41 of the included studies were case-control and 5 were cohort.A positive family history of colorectal cancer in first-degree relatives was associated with significantly increased risk of colorectal cancer with a relative risk of 1.87(95%CI:1.68-2.09;P<0.00001).Cochrane Q test was significant(P<0.00001,I2=90%).Egger’s regression test showed asymmetry in the funnel plot and therefore the Trim and Fill method was used which confirmed the validity of the results.There was no difference between Asian versus non-Asian studies.Results remained robust in sensitivity analyses.CONCLUSION Individuals with a positive family history of colorectal cancer are 1.87 times more likely to develop colorectal cancer.Screening guidelines should pay specific attention to individuals with positive family history and further studies need to be done on validating current screening methods or developing new modalities in this high-risk population.

内镜在炎症性肠病中的作用

克罗恩病(CD)和溃疡性结肠炎(UC)是炎症性肠病(IBD)两种最常见的类型。回结肠镜加活检被认为是IBD诊断的金标准。CD与UC的鉴别诊断是非常重要的,因为它们的治疗策略及预后是有所不同的。然而,约有15%的IBD患者由于未能明确诊断为CD或UC而错误地归入了不定型肠炎。内镜在IBD中的作用受到了越来越多的关注。例如,一些新的影像技术有助于CD与UC的内镜下鉴别诊断。内镜球囊扩张和内镜下支架放置已经CD狭窄治疗的重要组成部分。在CD患者的肛瘘检查中,内镜超声也被认为较磁共振更加准确。此外,色素内镜较普通白光肠镜能更早期发现不典型增生。因此,内镜已经成为IBD诊断、治疗以及并发症处理的基石。近年来,内镜在IBD中的作用不断提升,从小肠成像到内镜球囊扩张以及色素内镜对不典型增生的监测。本文我们讨论了内镜用于IBD诊断、治疗和并发症处理的最新证据。