Prevalence of Gastric Precursor Lesions in Countries With Differential Gastric Cancer Burden: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: The prevalence of precursor lesions for gastric cancer (GC) and the differential burden between countries of varying GC risk is not well-understood. We conducted a systematic review and meta-analysis to estimate the global prevalence of precursor lesions. METHODS: We estimated the prevalence of atrophic gastritis (AG), gastric intestinal metaplasia (IM), and dysplasia in regions with low, medium, and high GC incidence. Because IM is an advanced manifestation of AG, we assessed the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. Prevalence was sub-stratified by Helicobacter pylori infection, symptomatology, and period (<2000, 2000-2010, and >2010). RESULTS: Among the 582 articles that underwent full-text review, 166 studies met inclusion criteria. The global prevalence estimates of AG, IM, and dysplasia were 25.4%, 16.2%, and 2.0%, respectively, on the basis of 126 studies that reported the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. The prevalence of all precursor lesions was higher in high and medium compared with low GC incidence countries (P < .01). Prevalence of AG and IM was significantly higher among H pylori-infected individuals (P < .01) but not statistically different between symptomatic and asymptomatic individuals (P > .17). All precursors demonstrated a secular decrease in prevalence over time. CONCLUSIONS: Gastric precursor lesions have differences in prevalence in regions with differential GC incidence and are associated with H pylori infection. Because of the substantial prevalence of precursor lesions in both symptomatic and asymptomatic individuals, symptomatic evaluation may not be sufficient to identify individuals at risk. These estimates provide important insights for tailoring GC prevention strategies.

Global Progression Rates of Precursor Lesions for Gastric Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Whether gastric cancer (GC) precursor lesions progress to invasive cancer at similar rates globally remains unknown. We conducted a systematic review and meta-analysis to determine the progression of precursor lesions to GC in countries with low versus medium/high incidence. METHODS: We searched relevant databases for studies reporting the progression of endoscopically confirmed precursor lesions to GC. Studies were stratified by low (<6 per 100,000) or medium/high (≥6 per 100,000) GC incidence countries. Random-effects models were used to estimate the progression rates of atrophic gastritis (AG), intestinal metaplasia (IM), and dysplasia to GC per 1,000 person-years. RESULTS: Among the 5,829 studies identified, 44 met our inclusion criteria. The global pooled estimates of the progression rate per 1,000 person-years were 2.09 (95% CI 1.46-2.99), 2.89 (2.03-4.11) and 10.09 (5.23-19.49) for AG, IM, and dysplasia respectively. The estimated progression rates per 1,000 person-years for low versus medium/high GC incidence countries, respectively, were 0.97 (0.86-1.10) vs. 2.47 (1.70-2.99) for AG (p<0.01); 2.37 (1.43-3.92) vs. 3.47 (2.13-5.65) for IM (p=0.29); and 5.51 (2.92-10.39) vs. 14.80 (5.87-37.28) for dysplasia (p=0.08). There were no differences for progression of AG between groups when high quality studies were compared. CONCLUSION: Similar progression rates of IM and dysplasia were observed among low and medium/high GC incidence countries. This suggests that the potential benefits of surveillance for these lesions in low-risk regions may be comparable to those of population-wide interventions in high-risk regions. Further prospective studies are needed to confirm these findings and inform global screening and surveillance guidelines.

Changes in Mean Corpuscular Volume and RBC Distribution Width Predict Erythrocyte Engraftment Following ABO-Incompatible Hematopoietic Stem Cell Transplantation.

OBJECTIVES: The purpose of this study was to identify laboratory parameters representing erythrocyte engraftment to be used as an indicator to change the recipient to donor ABO group and Rh type following an ABO-incompatible hematopoietic stem cell transplant (HSCT). Studies have shown that ABO incompatibility does not have an effect on outcome of HSCT; however, the serologic consequences of these ABO-incompatible transplants can make it difficult to decide when to begin support with donor ABO/Rh-type blood products. METHODS: This study explored the use of RBC distribution width (RDW), mean corpuscular volume, and hemoglobin as regularly tested laboratory parameters that could be used as surrogate markers for RBC engraftment in 65 patients who received ABO/Rh-incompatible HSCT. RESULTS: The appearance of engrafted donor RBCs correlated with a peak in RDW (P = .002). In addition, our findings suggest that serologic changes in ABO/Rh appear to correspond with a peak in RDW (P = .002). CONCLUSIONS: High values of RDW likely result from a substantial proportion of large, young erythrocytes from recent engraftment with smaller, older pretransplant erythrocytes from the recipient. Our findings suggest that peak RDW may be an indicator of erythrocyte engraftment, following an ABO/Rh-incompatible HSCT.