It is impossible to estimate the possibility that chronic indigestion is cancer. Chronic indigestion is not necessarily caused by cancer, but may be caused by functional dyspepsia, gastritis, gastric ulcer or gastric cancer. 1. Functional dyspepsia: it is mostly caused by improper diet, such as eating too much greasy food or overeating, or it may be caused by the decline of digestive ability of the elderly. 2. Gastritis and gastric ulcer: due to different degrees of decline in gastric function, it may lead to gastric indigestion. 3. Gastric cancer: early symptoms are not obvious, with the gradual increase of tumor, it may lead to non-specific indigestion symptoms such as epigastric discomfort, acid reflux, belching (hiccup), early satiety and so on. If you have long-term indigestion, you should go to the hospital in time and cooperate with doctors to take examination and treatment.