“Heartburn is a burning feeling in the chest caused by stomach acid travelling up towards the throat (acid reflux),” the health body added.
As well as a sour taste in the mouth, there may also be a burning sensation in the middle of the chest.
Other possible indications of stomach cancer include difficulties with swallowing, feeling nauseous, and feeling full very quickly when eating.
Stomach cancer may also lead to a loss of appetite, pain at the top of the belly, and feeling tired as if you have no energy.
READ MORE: High cholesterol: The recurrent sensation warning of extremely dangerous levels