Prevalence and Progression of Subtypes of Gastric Premalignant Lesions: A Systematic Review & Meta-Analysis.

BACKGROUND AND AIMS: Gastric intestinal metaplasia (IM) and dysplasia are precursor lesions for gastric cancer (GC). This systematic review and meta-analysis examined the global prevalence and progression rates of subtypes of these understudied lesions. METHODS: We searched databases for publications reporting prevalence and progression of subtypes of IM and dysplasia among individuals undergoing endoscopy, including incomplete/complete IM, limited (antrum-restricted)/extensive (corpus-involving) IM, and low-grade dysplasia (LGD)/high-grade dysplasia (HGD). Random-effects models were used to estimate pooled prevalence and progression rates to GC. I2 statistic was used to determine heterogeneity. RESULTS: 83 studies were included for prevalence and 23 for progression. The prevalence of complete IM was 11% (95% confidence interval (CI) 8-15%) and incomplete IM was 10% (6-14%), with corresponding progression rates of 1.73 (1.08-2.79) vs. 12.15 (5.28-27.94) per 1000 person-years, respectively (p <0.01). The prevalence of limited vs. extensive IM was 12% (8-17%) vs. 5% (4-8%), respectively, and corresponding progression rates were 3.31 (1.18-9.32) vs. 4.19 (0.95-18.41) per 1000 person-years (p=0.80). The prevalence of LGD was 2% (1-4%) and HGD was 0.28% (0.14-0.55%), with corresponding progression rates of 11.55 (5.93-22.47) vs. 344.48 (144.88-819.09, p <0.01). Substantial heterogeneity was observed for all estimates. CONCLUSION: While lesion subtypes with high progression risk like incomplete IM account for a large portion of the total burden of precancerous lesions, subtyping remains underutilized in clinical practice. While estimates are limited by heterogeneity, differences in progression rates between lesion subtypes support risk-stratification of these lesions within management guidelines, particularly complete vs. incomplete IM and LGD vs. HGD.