A meta-analysis and systematic review on subtypes of gastric intestinal metaplasia and neoplasia risk

Background Gastric intestinal metaplasia (GIM) is a significant risk factor for gastric cancer. Risk of gastric cancer/dysplasia between complete intestinal metaplasia (CIM) and incomplete intestinal metaplasia (IIM) was controversial. Our study aimed to pool relative risk (RR) of cancer/dysplasia of IIM compared with CIM in GIM patients. Methods PubMed, EMBASE, Cochrane Library and Web of Science were searched for studies concerning cancer/dysplasia in GIM patients. Random-effects or fixed-effects model was utilized for pooling RR. Sensitivity and publication bias analyses were conducted. Stability of results would be evaluated in case of publication bias. Results 12 studies were included. Compared with CIM, pooled RR of cancer/dysplasia in IIM patients was 4.48 (95% CI 2.50–8.03), and the RR was 4.96 (95% CI 2.72–9.04) for cancer, and 4.82 (95% CI 1.45–16.0) for dysplasia. The pooled RR for cancer/dysplasia in type III IM was 6.27 (95% CI 1.89–20.77) compared with type II + I IM, while it was 5.55 (95% CI 2.07–14.92) compared with type II IM. Pooled RR between type II IM and type I IM was 1.62 (95% CI 1.16–2.27). Subgroup analyses showed that IIM was associated with a higher risk of gastric cancer/dysplasia in Western population (pooled RR = 4.65 95% CI 2.30–9.42), but not in East Asian population (pooled RR = 4.01 95% CI 0.82–19.61). Conclusions IIM was related to a higher risk of cancer/dysplasia compared with CIM. Risk of developing cancer/dysplasia from type I, II, and III intestinal metaplasia increased gradually.