Global burden of gastric cancer: epidemiological trends, risk factors, screening and prevention.

Gastric cancer remains a major cause of cancer-related mortality worldwide. The temporal trends for this malignancy, however, are dynamic, and reports from the past decade indicate important declines in some regions and demographic groups, as well as a few notable exceptions in which gastric cancer rates are either stable or increasing. Two main anatomical subtypes of gastric cancer exist, non-cardia and cardia, with different temporal trends and risk factors (such as obesity and reflux for cardia gastric cancer and Helicobacter pylori infection for non-cardia gastric cancer). Shifts in the distribution of anatomical locations have been detected in several high-incidence regions. H. pylori is an important aetiological factor for gastric cancer; importantly, the anticipated long-term findings from studies examining the effect of H. pylori eradication on the risk of (re)developing gastric cancer have emerged in the past few years. In this Review, we highlight the latest trends in incidence and mortality using an evidence-based approach. We make the best possible inferences, including clinical and public health inference, on the basis of the quality of the evidence available, and highlight burning questions as well as gaps in knowledge and public health practice that need to be addressed to reduce gastric cancer burden worldwide.

Prior Diagnosis of Barrett's Esophagus Is Infrequent, but Associated with Improved Esophageal Adenocarcinoma Survival.

BACKGROUND: Efforts to reduce mortality from esophageal adenocarcinoma (EA) have focused on screening and surveillance of Barrett's esophagus (BE). AIMS: We sought to determine the frequency of prior diagnosis of BE in patients with EA and to evaluate the impact of a prior BE diagnosis on mortality in EA patients. METHODS: This was a retrospective cohort study of patients diagnosed with EA in the VA during 2002-2016. We compared the distributions of EA stage and receipt of treatment between EA patients with and without a prior BE diagnosis and used Cox proportional hazards models to compare mortality risk (all-cause and cancer specific) unadjusted and adjusted for stage and treatment to assess their impact on any survival differences. RESULTS: Among 8564 EA patients, only 4.9% had a prior BE diagnosis. The proportion with prior BE diagnosis increased from 3.2% in EA patients diagnosed during 2005-2007 to 7.0% in those diagnosed during 2014-2016. EA patients with a prior BE diagnosis were more likely to have stage 1 disease and receive any treatment. A prior BE diagnosis was associated with lower all-cause mortality risk (hazard ratio [HR] unadjusted for stage, 0.69; 95% CI, 0.61-0.80), which was largely explained by the earlier stage of EA at the time of diagnosis (HR adjusted for stage, 0.87; 95% CI, 0.75-0.99). There was no evidence of lead time bias or length time bias. CONCLUSIONS: Prior diagnosis of BE was associated with better survival, largely due to earlier EA stage at diagnosis.