Gastric cancer- clinical and effect of H pylori Flashcards
What are the symptoms?
Dyspepsia + alarm symptoms: Weight loss Anaemia Mass Recurrent vomiting
Is family history common in gastric cancer?
Yes, in first degree relatives
What has been noticed about patients with H pylori infection who develop peptic ulcer disease in relation to gastric cancer?
They are somehow protected from gastric cancer
How does H pylori inhibit gastric acid secretion?
The effect of body inflammation induced by H pylori
IL-1B production is stimulated in H pylori gastritis
This is a powerful inhibitor of acid secretion
It acts on the ECL cell to inhibit histamine release and on the parietal cell to inhibit HCl release
What is a potential host genetic factor predisposing to hypochlorhydric response to H pylori?
Il-1 beta gene- there is IL-1 beta in H pylori gastritis. IL-1B is a powerful acid inhibitor.
There are recognised polymorphisms of the IL-1B gene with differing pro-inflammatory activities.
What is the effect of differing IL-1B pro inflammatory activities on the development of gastric cancer, caused by H pylori?
H pylori infection –> mucosal inflammation –> IL-1B inflammatory response Host genotype :
1 of two results: If there is a pro inflammatory response, there can be acid hyposecretion and body predominant gastritis, which becomes atrophic gastritis, and can become cancer.
If the host does not have a proinflammatory IL-1B phenotype, there is normal or high acid secretion. The gastritis is antral predominant and there is no cancer (or duodenal cancer).
