GAST and gastric neuroendocrine tumor G1: The above results, with a rapidly increasing and prolonged use of PPIs coupled with their ability to cause chronic hypergastrinemia with proliferative gastric ECL cell changes in man; their ability to cause gastric carcinoid tumors in rodents, but not humans with chronic PPI use over <5 years; and the experimental result of gastrin’s effect on a number of other cancer’s growth have led to debate over their safety during prolonged, life-time usage.