Gastric cancer: epidemiology, prevention, and therapy.

Gastric cancer (GC) is still the third leading cause of cancer death in both sexes worldwide. Helicobacter pylori infection is the most important risk factor for GC and, in spite of the consistent trend of a decreasing incidence, in 2015 approximately 4.4 billion individuals-more than half the world's population-were infected with H. pylori. The birth cohort pattern of decreased H. pylori infection reported in a systematic review contributes to explain the declining GC mortality in Japan. Current trends in estimated annual percentage change of GC incidence foreshadow expected reversals in both falling incidence and male predominance among US non-Hispanic whites. Combining serum pepsinogen 1 and H. pylori serology was shown to be useful for GC risk stratification in a Finnish population. Gastritis staging by operative link on gastritis assessment was confirmed to be reliable in predicting GC risk in a large prospective study. In a randomized trial from South Korea, H. pylori eradication therapy significantly reduced the rates of metachronous GC in patients who received curative endoscopic resection for early GC. A study based on a territory-wide health care database of the Hong Kong Hospital Authority showed that aspirin use is associated with a reduced GC risk. Another study based on the same database showed that proton pump inhibitors increase GC risk, but methodological biases have most likely acted as confounders. Confirmatory data on the role of endoscopic submucosal dissection in patients with early GC have been published. The phase III FLOT4 trial has shown that the FLOT triplet regimen (docetaxel, oxaliplatin, leucovorin, and 5-fluorouracil) improves the outcome of patients with GC and locoregional disease as compared to the ECF triplet (epirubicin, cisplatin, and 5-fluorouracil). In the phase III ATTRACTION-2 trial, nivolumab was shown to be an effective treatment option with a relative safe profile for heavily pretreated patients with advanced GC.