“…Table 2 presents the characteristics of the studies included in the meta-analysis. The studies were conducted using either population or hospital controls in various countries and investigated gastrointestinal cancers, including esophageal,13, 14 gastric,13, 15, 16, 17, 18, 19, 20, 21, 22, 23 colorectal,24, 25, 26, 27, 28, 29, 30, 31, 32 hepatocellular,33, 34 and pancreatic cancer 35, 36, 37…”