I'm just wondering, if you had a stomache tumor how would you know?

Pain or bleeding: The initial onset of gastric malignancies were in the prepyloric or lesser curvature region. We now recognize the major cause as due to H.pylori. This bug causes ulceration of the mucosa more near the upper part of the stomach. The ulcer is healed by bone stem cells migrating into the site and transformed to tumor by the H.pylori toxin. One finds bleeding of an unhealed ulcer or performation