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.
Keywords: Dysplasia; Gastric cancer; Intestinal metaplasia; Meta-analysis; Subtypes.